Downregulation Of Runx2 Research Articles

SIRT6-mediated Runx2 downregulation inhibits osteogenic differentiation of human aortic valve interstitial cells in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is a progressive cardiovascular disorder involving multiple pathogenesis. Effective pharmacological therapies are currently unavailable. Sirtuin6 (SIRT6) has been shown to protect against aortic valve calcification in CAVD. The exact regulatory mechanism of SIRT6 in osteoblastic differentiation remains to be determined, although it inhibits osteogenic differentiation of aortic valve interstitial cells. We demonstrated that SIRT6 was markedly downregulated in calcific human aortic valves. Mechanistically, SIRT6 suppressed osteogenic differentiation in human aortic valve interstitial cells (HAVICs), as confirmed by loss- and gain-of-function experiments. SIRT6 directly interacted with Runx2, decreased Runx2 acetylation levels, and facilitated Runx2 nuclear export to inhibit the osteoblastic phenotype transition of HAVICs. In addition, the AKT signaling pathway acted upstream of SIRT6. Together, these findings elucidate that SIRT6-mediated Runx2 downregulation inhibits aortic valve calcification and provide novel insights into therapeutic strategies for CAVD.

Novel in vitro evidence on the beneficial effect of quercetin treatment in vascular calcification.

Vascular calcification is a pathological chronic condition characterized by calcium crystal deposition in the vessel wall and is a recurring event in atherosclerosis, chronic kidney disease, and diabetes. The lack of effective therapeutic treatments opened the research to natural products, which have shown promising potential in inhibiting the pathological process in different experimental models. This study investigated the anti-calcifying effects of Quercetin and Berberine extracts on vascular smooth muscle cells (VSMCs) treated with an inorganic phosphate solution for 7days. Quercetin has shown the highest anti-calcifying activity, as revealed by the intracellular quantitative assay and morphological analysis. Confocal microscopy revealed downregulation of RUNX2, a key marker for calcified phenotype, which was otherwise upregulated in calcified VSMCs. To investigate the anti-inflammatory activity of Quercetin, culture media were subjected to immunometric assays to quantify the levels of IL-6 and TNF-α, and the caspase-1 activity. As expected, calcified VSMCs released a large quantity of inflammatory mediators, significantly decreasing in the presence of Quercetin. In summary, our findings suggest that Quercetin counteracted calcification by attenuating the VSMC pathological phenotypic switch and reducing the inflammatory response. In our opinion, these preliminary in vitro findings could be the starting point for further investigations into the beneficial effects of Quercetin dietary supplementation against vascular calcification.

Delayed Reaction of Radiation on the Central Nervous System and Bone System in C57BL/6J Mice.

The aim of this study was to provide a suitable mouse model of radiation-induced delayed reaction and identify potential targets for drug development related to the prevention and treatment of radiation injury. C57BL/6J mice were subjected to singular (109 cGy/min, 5 Gy*1) and fractional (109 cGy/min, 5 Gy*2) total body irradiation. The behavior and activity of mice were assessed 60 days after ionizing radiation (IR) exposure. After that, the pathological changes and mechanism of the mouse brain and femoral tissues were observed by HE, Nissl, Trap staining micro-CT scanning and RNA sequencing (RNA-Seq), and Western blot. The results show that singular or fractional IR exposure led to a decrease in spatial memory ability and activity in mice, and the cognitive and motor functions gradually recovered after singular 5 Gy IR in a time-dependent manner, while the fractional 10 Gy IR group could not recover. The decrease in bone density due to the increase in osteoclast number may be relative to the down-regulation of RUNX2, sclerostin, and beta-catenin. Meanwhile, the brain injury caused by IR exposure is mainly linked to the down-regulation of BNDF and Tau. IR exposure leads to memory impairment, reduced activity, and self-recovery, which are associated with time and dose. The mechanism of cognitive and activity damage was mainly related to oxidative stress and apoptosis induced by DNA damage. The damage caused by fractional 10 Gy TBI is relatively stable and can be used as a stable multi-organ injury model for radiation mechanism research and anti-radiation medicine screening.

Engineering three-dimensional bone macro-tissues by guided fusion of cell spheroids.

Bioassembly techniques for the application of scaffold-free tissue engineering approaches have evolved in recent years toward producing larger tissue equivalents that structurally and functionally mimic native tissues. This study aims to upscale a 3-dimensional bone in-vitro model through bioassembly of differentiated rat osteoblast (dROb) spheroids with the potential to develop and mature into a bone macrotissue. dROb spheroids in control and mineralization media at different seeding densities (1 × 104, 5 × 104, and 1 × 105 cells) were assessed for cell proliferation and viability by trypan blue staining, for necrotic core by hematoxylin and eosin staining, and for extracellular calcium by Alizarin red and Von Kossa staining. Then, a novel approach was developed to bioassemble dROb spheroids in pillar array supports using a customized bioassembly system. Pillar array supports were custom-designed and printed using Formlabs Clear Resin® by Formlabs Form2 printer. These supports were used as temporary frameworks for spheroid bioassembly until fusion occurred. Supports were then removed to allow scaffold-free growth and maturation of fused spheroids. Morphological and molecular analyses were performed to understand their structural and functional aspects. Spheroids of all seeding densities proliferated till day 14, and mineralization began with the cessation of proliferation. Necrotic core size increased over time with increased spheroid size. After the bioassembly of spheroids, the morphological assessment revealed the fusion of spheroids over time into a single macrotissue of more than 2.5mm in size with mineral formation. Molecular assessment at different time points revealed osteogenic maturation based on the presence of osteocalcin, downregulation of Runx2 (p < 0.001), and upregulated alkaline phosphatase (p < 0.01). With the novel bioassembly approach used here, 3D bone macrotissues were successfully fabricated which mimicked physiological osteogenesis both morphologically and molecularly. This biofabrication approach has potential applications in bone tissue engineering, contributing to research related to osteoporosis and other recurrent bone ailments.

Pharmacological inhibition of protein kinase D suppresses epithelial ovarian cancer via MAPK/ERK1/2/Runx2 signalling axis

Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy with poor prognosis and dismal patient survival. Although protein kinase D (PKD) isoforms, especially PKD2 and PKD3 are critical for many cellular and physiological functions involved in carcinogenesis including cell proliferation and angiogenesis, their role in human EOC remains unknown. Towards the goal to identify novel prognostic biomarker and therapeutic interventions against EOC, this study aimed to elucidate the molecular roles of PKD2, PKD3 and highly selective, pan-PKD inhibitor CRT0066101 in this lethal pathology. Our results indicated that inactivation of PKD2 and PKD3 by 1 μM CRT0066101 suppressed EOC cell proliferation, colony formation, cell migration and invasion. Moreover, CRT0066101 induced apoptosis and inhibited cell cycle at G2-M phase in EOC cells. Genetic knockdown of PKD2 and PKD3 confirmed the anti-carcinogenic effects of CRT0066101 against EOC. The anti-cancer phenotype of EOC cells resulted from CRT0066101-mediated PKD2 and PKD3 inactivation or genetic depletion was, in part, mediated by transcription factor Runx2 as abrogation of PKD2 and PKD3 caused downregulation of Runx2 and its downstream target genes including osteopontin, focal adhesion kinase and ERK1/2. Moreover, overexpression of a constitutively active PKD2 augmented the expression levels of phosphor-ERK1/2T202/Y204, Runx2 and its downstream targets. Mechanistically, PKD2 and PKD3 positively regulated Runx2 via MAPK/ERK1/2 pathway and promoted EOC. Taken together, our results indicated that PKD2/3/ERK1/2/Runx2 signalling axis might be a novel drug target against EOC and CRT0066101 could be developed as a promising therapeutic choice against this lethal pathology.

Investigating the role of ASCC1 in the causation of bone fragility.

Bi-allelic variants in ASCC1 cause the ultrarare bone fragility disorder "spinal muscular atrophy with congenital bone fractures-2" (SMABF2). However, the mechanism by which ASCC1 dysfunction leads to this musculoskeletal condition and the nature of the associated bone defect are poorly understood. By exome sequencing, we identified a novel homozygous deletion in ASCC1 in a female infant. She was born with severe muscular hypotonia, inability to breathe and swallow, and virtual absence of spontaneous movements; showed progressive brain atrophy, gracile long bones, very slender ribs, and a femur fracture; and died from respiratory failure aged 3 months. A transiliac bone sample taken postmortem revealed a distinct microstructural bone phenotype with low trabecular bone volume, low bone remodeling, disordered collagen organization, and an abnormally high bone marrow adiposity. Proteomics, RNA sequencing, and qPCR in patient-derived skin fibroblasts confirmed that ASCC1 was hardly expressed on protein and RNA levels compared with healthy controls. Furthermore, we demonstrate that mutated ASCC1 is associated with a downregulation of RUNX2, the master regulator of osteoblastogenesis, and SERPINF1, which is involved in osteoblast and adipocyte differentiation. It also exerts an inhibitory effect on TGF-β/SMAD signaling, which is important for bone development. Additionally, knockdown of ASCC1 in human mesenchymal stromal cells (hMSCs) suppressed their differentiation capacity into osteoblasts while increasing their differentiation into adipocytes. This resulted in reduced mineralization and elevated formation of lipid droplets. These findings shed light onto the pathophysiologic mechanisms underlying SMABF2 and assign a new biological role to ASCC1 acting as an important pro-osteoblastogenic and anti-adipogenic regulator.

Identification of Moesin (MSN) as a Potential Therapeutic Target for Colorectal Cancer via the β-Catenin-RUNX2 Axis.

CRC is the second leading cause of cancer-related death. The complex mechanisms of metastatic CRC limit available therapeutic choice. Thus, identifying new CRC therapeutic targets is essential. Moesin (MSN), a member of the ezrin-radixin-moesin family, connects the cell membrane to the actin-based cytoskeleton and regulates cell morphology. We investigated the role of MSN in the progression of CRC. GENT2 and oncomine were used to study MSN expression and CRC patient outcomes. MSN-specific shRNAs or MSN-overexpressed plasmid were used to establish MSN-KD and MSN overexpressed cell lines, respectively. SRB, migration, wound healing, and flow cytometry were used to test cell survival and migration. Propidium iodide and annexin V stain were used to analyze the cell cycle and apoptosis. MSN expression was found to be higher in CRC tissues than in normal tissues. Higher MSN expression is associated with poor overall survival, disease-free survival, and relapse-free survival rates in CRC patients. MSN silencing inhibits cell proliferation, adhesion, migration, and invasion in vitro, whereas MSN overexpression accelerates cell proliferation, adhesion, migration, and invasion. RNA sequencing was used to investigate differentially expressed genes, and RUNX2 was discovered as a possible downstream target for MSN. In CRC patients, RUNX2 expression was significantly correlated with MSN expression. We also found that MSN silencing decreased cytoplasmic and nuclear β-catenin levels. Additionally, pharmacological inhibition of β-catenin in MSN-overexpressed cells led to a reduction of RUNX2, and activating β-catenin signaling by inhibiting GSK3β rescued the RUNX2 downregulation in MSN-KD cells. This confirms that MSN regulates RUNX2 expression via activation of β-catenin signaling. Finally, our result further determined that RUNX2 silencing reduced the ability of MSN overexpression cells to proliferate and migrate. MSN accelerated CRC progression via the β-catenin-RUNX2 axis. As a result, MSN holds the potential to become a new target for CRC treatment.

Hu'po Anshen decoction promotes fracture healing in mice with traumatic brain injury through BMP2-COX2-ATF4 signaling pathway.

Hu'po Anshen decoction (HPASD), a traditional Chinese medicine used to treat concussion and fracture, could regulate the expression of bone morphogenetic protein 2 (BMP2). However, whether HPASD affects the fracture healing of traumatic brain injury (TBI) combined with a fracture through BMP2 and its downstream signals remains obscure. The chondrocyte-specific BMP2 conditional knockout mice and chondrocyte-specific cyclooxygenase-2 (COX2) overexpression mice were generated. BMP2 conditional knockout mice were treated with fracture surgery, fracture combined with TBI, or fracture combined with TBI followed by different doses of HPASD (2.4, 4.8, and 9.6 g/kg), respectively. TBI was induced by Feeney's weight-drop technique. The fracture callus formation and fracture sites were determined by X-ray, micro-CT, and histological analyses. The expressions of chondrocyte-, osteoblast-, and BMP2/COX2 signal-related targets were determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot assays. The specific absence of BMP2 in chondrocytes led to the prolonged formation of cartilage callus, a delay in the osteogenesis initiation and the downregulation of RUNX2, Smad1/5/9, EP4, ERK1/2, RSK2, ATF4. Overexpression of COX2 partially reverses the effects of chondrocyte-specific BMP2 knockout mice. HPASD promoted cartilage callus formation and osteogenesis initiation, as accompanied by upregulated expression levels of RUNX2, Smad1/5/9, EP4, ERK1/2, RSK2, and ATF4 in a time-dependent and concentration-dependent manner in chondrocyte-specific BMP2 knockout mice. Overall, our findings demonstrated that HPASD induced COX2 transcription through the BMP2-Smad1/5/9-RUNX2 axis, and then affected fracture healing through the COX2-mediated EP4-ERK1/2-RSK2-ATF4 axis.

Abstract 15322: O-glcnac Modification on Runx2 Promotes Vascular Calcification

Vascular calcification is prevalent in patients with diabetes mellitus and well documented in animal models of diabetes. We have previously reported that vascular calcification in diabetes is associated with elevated vascular protein O -linked GlcNAc modification ( O -GlcNAcylation). The present studies sought to determine a causative link of O -GlcNAcylation with diabetic vascular calcification and the underlying molecular mechanisms. Using coronary arteries from diabetic subjects, we identified increased O -GlcNAcylation in the highly calcified lesions compared to those in the surrounding uncalcified areas. By generating a new mouse model with inducible SMC-specific deletion of the O -GlcNAc transferase (OGT), we demonstrated that smooth muscle cell (SMC)-specific OGT deletion significantly inhibited protein O -GlcNAcylation and calcification, and decreased aortic stiffness in the low-dose streptozotocin-induced diabetic mice. Consistent with the observations in human tissues, inhibition of vascular calcification by OGT ablation was associated with down-regulation of Runx2, the essential osteogenic regulator for vascular calcification. OGT deficiency in VSMC further attenuated Runx2-induced VSMC calcification. Immunoprecipitation analysis uncovered a direct O-GlcNAc modification on Runx2, which was abolished in the OGT-deficient VSMC. With a serial of Runx2 truncation mutants and point mutations on putative O -GlcNAcylation sites, we localized the essential Runx2 osteogenic functional domain between amino acids 391 and 432, and identified Runx2 T412 was responsible for Runx2 O -GlcNAcylation and Runx2-induced VSMC calcification. Inhibition of Runx2 O -GlcNAcylation by T412A mutation decreased Runx2 transcription activity and inhibited Runx2 binding with its key co-factors. Taken together, our studies have provided the first genetic proof demonstrating the causative effects of O -GlcNAcylation on vascular calcification in diabetes, and identified a novel mechanism underlying the essential role of O -GlcNAcylation of Runx2 in Runx2 osteogenic activity and Runx2-induced VSMC calcification. These results may shed lights on novel targets that are amenable to drug discovery for diabetic vascular calcification.

RUNX2 interacts with SCD1 and activates Wnt/β-catenin signaling pathway to promote the progression of clear cell renal cell carcinoma.

Previous studies have demonstrated that Runt-associated transcription factor 2 (RUNX2) serves as the main transcription factor for osteoblast differentiation and chondrocyte maturation. RUNX2 is related to a variety of tumors, particularly tumor invasion and metastasis, while the expression and molecular mechanisms of RUNX2 in clear cell renal cell carcinoma (ccRCC) keep to be determined. Stearyl CoA desaturase 1 (SCD1), an endoplasmic reticulum fatty acid desaturase, transfers saturated fatty acids to monounsaturated fatty acids, is expressed highly in numerous malignancies. The Cancer Genome Atlas (TCGA) datebase and Western blot was used to analyzed the mRNA and protein levels of the target gene in ccRCC tissues and adjacent tissues. The proliferation ability of ccRCC cells was tested by colony forming and EdU assay. The migration ability of cells was detected by transwell assay. Immunoprecipitation was utilized to detect protein-protein interaction. Cycloheximide chase assay was used to measure the half-life of SCD1 protein. In this study, the expressions of RUNX2 and SCD1 are increased in ccRCC tissues as well as ccRCC cell lines. Both RUNX2 and SCD1 could promote proliferation and migration in ccRCC cells. Furthermore, RUNX2 could physically interact with SCD1. In addition, the functional degradation and the inactivation of Wnt/β-catenin signaling pathway triggered by the downregulation of RUNX2 could be partly offset by the overexpression of SCD1. The findings indicate that the RUNX2/SCD1 axis may act as a potential therapeutic target via the Wnt/β-catenin signaling pathway of ccRCC.

Chondrogenic differentiation of mouse CD105+ stem/progenitor cells on amino-group-functionalized biosilica-hydrogel scaffolds

Mesenchymal stem/progenitor cells (MSPCs) are critical for tissue regeneration. Moreover, the CD105 antigen identifies early MSPCs with increased chondrogenic differentiation ability. We hypothesized that amine-(NH2)-functionalized biosilica incorporating hydrogel scaffolds, seeded with mCoSPCs105+ would contribute to creating tissue-engineered scaffolds, capable of de novo cartilage synthesis. Scaffolds were characterized by water uptake, lysozyme degradation, axial compression, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Differentiation stimulus of scaffold functionalization was evaluated using Alcian blue staining. Cartilage-forming abilities of mCoSPCs105+ were evaluated using Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry. Biosilica particle incorporation into scaffolds resulted in increased water uptake capacity and compression force withstanding abilities. Amine-(NH2)-group functionalization of biosilica led to significantly increased stem cell differentiation potential, by Alcian blue staining, in the first 3 weeks. Scaffold attachment and viable cell proliferation were observed for 6 weeks under chondrogenic differentiation. Downregulation of Runx2, an increase of Col10a1, Ihh, and maintenance of Sox9, was seen under these culture conditions. mCoSPCs105+ gene expression pattern was defined by the significant upregulation of Col1a1, Col2a1, Prg4, and Agc-1 over 6 weeks of incubation compared to the unsorted control. Immunostaining of cell-seeded scaffolds revealed significantly higher secretion of proteins relevant to cartilage extracellular matrix. The preselecting of CD105+ phenotype in MSPCs may enhance tissue regeneration of fibrocartilage and biosilica nanoparticles may be a beneficial additive in tissue engineering of scaffolds.

An miRNA derived from amelogenin exon4 regulates expression of transcription factor Runx2 by directly targeting upstream activators Nfia and Prkch

Amel, the gene encoding the amelogenin protein involved in enamel formation, is highly alternatively spliced. When exon4 is excised, it can form a mature miRNA (miR-exon4) that has previously been suggested to indirectly regulate expression of the Runt-related transcription factor 2 (Runx2) involved in bone development in ameloblasts and osteoblasts. However, the precise mechanism of this regulation is unclear. In this study, we aimed to identify direct targets of miR-exon4. The transcription factor family nuclear factor I/A (NFI/A) is known to negatively regulate expression of Runx2 and is among the most highly predicted direct targets of miR-exon4 that link to Runx2. Immunostaining detected NFI/A in osteoblasts and ameloblasts in vivo, and reporter assays confirmed direct interaction of the Nfia 3′-UTR and miR-exon4. In addition, silencing of Nfia in MC3T3-E1-M14 osteoblasts resulted in subsequent downregulation of Runx2. In a monoclonal subclone (mi2) of MC3T3-E1 cells wherein mature miR-exon4 was functionally inhibited, we observed significantly downregulated Runx2 expression. We showed that NFI/A was significantly upregulated in mi2 cells at both mRNA and protein levels. Furthermore, quantitative proteomics and pathway analysis of gene expression in mi2 cells suggested that miR-exon4 could directly target Prkch (protein kinase C-eta), possibly leading to RUNX2 regulation through mechanistic target of rapamycin kinase activation. Reporter assays also confirmed the direct interaction of miR-exon4 and the 3′-UTR of Prkch, and Western blot analysis confirmed significantly upregulated mechanistic target of rapamycin kinase phosphorylation in mi2 cells. Taken together, we conclude that Nfia and Prkch expression negatively correlates with miR-exon4-mediated Runx2 regulation in vivo and in vitro, suggesting miR-exon4 directly targets Nfia and Prkch to regulate Runx2.

Irisin alleviates vascular calcification by inhibiting VSMC osteoblastic transformation and mitochondria dysfunction via AMPK/Drp1 signaling pathway in chronic kidney disease

Background and aimsVascular calcification (VC) is an intricate active process, significantly controlled by vascular smooth muscle cells (VSMCs). Mitochondrial dysfunction plays a pivotal role in VC and VSMCs osteoblastic transformation. We previously reported that decreased levels of Irisin were independently associated with VC in hemodialysis patients. The present study aimed to investigate the role of Irisin in VC, especially in VSMCs osteoblastic transformation and mitochondrial function. MethodsIn vitro, VSMCs calcification was induced by β‐glycerophosphate, while in vivo VC was triggered by adenine and high phosphorus diet. Alizarin red, Von Kossa staining, and calcium and Alp activity were performed to test VC. Western blot and immunohistochemical staining were employed to analyze the expression of proteins associated with VSMCs osteoblastic transformation and AMPK signaling. Mitochondrial membrane potential (MMP) and structures were observed by immunofluorescence staining. ResultsIrisin alleviated VSMCs calcification induced by β‐glycerophosphate. Mechanistically, Irisin activated AMPK and downregulated the expression of Drp1, further alleviating mitochondria fission and VSMCs osteoblastic transformation. In vivo, Irisin decreased serum creatinine, urea and phosphorous levels in chronic kidney disease (CKD) mice. Importantly, Irisin treatment postponed CKD-associated VC with the upregulation of α-Sma and p-AMPK expression, and the downregulation of Runx2 and Drp1 expression. ConclusionsOur results firstly reveal that Irisin inhibits CKD-associated VC. Irisin suppresses VSMCs osteoblastic transformation and mitochondria dysfunction via AMPK/Drp1 signaling.

Therapeutic effect of platelet-rich plasma on glucocorticoid-induced rat bone marrow mesenchymal stem cells in vitro

BackgroundGlucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a progressive and disabling disease caused by long-term or high-dose glucocorticoid use. Decreased osteogenesis and proliferation of bone marrow mesenchymal stem cells (BMSCs) are the main pathogenesis of GIONFH. Platelet-rich plasma (PRP) has been shown to play a promising role in bone regeneration. However, the effects of PRP on glucocorticoid-induced BMSCs inhibition remains elusive. The objective of this study was to explore whether PRP could improve the in vitro biological activities of BMSCs inhibited by high-dose glucocorticoid in vitro.MethodsIn this study, a dexamethasone (Dex)-induced in vitro cell model was established. The effects of PRP on proliferation, migration, cell cycle and apoptosis of rat BMSCs induced with high-dose Dex compared to BMSCCTRL, using CCK-8 assay, transwell, flow cytometry and TUNEL assay, respectively. We further performed the alkaline phosphatase (ALP) and alizarin red (ALR) staining to explore the influence of PRP on osteogenic differentiation. Western Blot was used to detect the expression of Bcl-2, Caspase-3, RUNX2 apoptosis, and osteogenic-related proteins.ResultsWe observed increased apoptosis rate and Caspase-3 expression, and the decreased migration and osteogenic differentiation, and down-regulation of RUNX-2 and Bcl-2 expression in Dex-induced BMSCs. PRP could reverse these inhibitory effects of Dex, and enhance the BMSCs proliferation, migration, and osteogenic ability in vitro.ConclusionOur vitro study showed that PRP significantly protected BMSCs from Dex-induced apoptosis, and further promoted BMSCs proliferation, migration, and osteogenic differentiation. This study provides a scientific basis for the prevention and treatment of GIONFH with PRP. Meanwhile, it also lays the foundation for the application of PRP in other musculoskeletal diseases.

MiR-133a is a potential target for arterial calcification in patients with end-stage renal disease.

Arterial calcification is an important risk factor for patients with end-stage renal disease. Despite substantial research efforts, the detailed mechanisms of the process of arterial calcification in end-stage renal disease remain unclear. miR-133a expression in radial artery samples was detected by FISH and Alizarin Red Staining. The expressions of miR-133a and RUNX2 in A7r5 cells with BMP2 induction were detected by qRT-PCR. In addition, qRT-PCR, Western blot, and ELISA assay were performed to detect changes in miR-133a levels in A7R5 cells after different treatments. Alizarin Red staining showed that red crystal deposition occurred in the tunica media. FISH analysis indicated that miR-133a was upregulated in the tunica media of the radial artery samples without calcificationwhen compared with those with calcification. We also found that expression of RUNX2 in A7r5 cells increased at day 7 and day 14 after BMP2 induction and decreased miR-133a expression decreased at day 14. In addition, RUNX2 protein and OCN expression were upregulated in A7r5 cells during BMP2-induced calcification. When miR-133a expression was suppressed, cell calcification aggravated, which led to upregulation of RUNX2 and OCN. When miR-133a was overexpressed, calcification of cells was inhibited, resulting in downregulation of RUNX2 and OCN. The present study reveals that miR-133a could indirectly regulate cell calcification through the RUNX2 gene expression. Our findings provide insight into the potential use of miR-133a as a molecular target for diagnosing vascular calcification in end-stage renal disease.

P-Nonylphenol Impairment of Osteogenic Differentiation of Mesenchymal Stem Cells was Found to be Due to Oxidative Stress and Down-Regulation of RUNX2 and BMP.

Previously, it was found that the para-nonylphenol (p-NP) impairs the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs); thus the aim of the present study was to evaluate the mechanism of the impairment. rBMSCs after 3rd passage cultured in osteogenic media in the presence of 0, 0.5 and 2.5 μM p-NP for 5, 10, 15 and 20 days. The study investigated the viability of the cells using MTT assays. The mineralization was studied using Alizarin red quantification analysis. Using a flame-photometer, the electrolytes (sodium and potassium) were measured, and the level of calcium as well as ALT, AST, ALP and LDH was determined by commercial kits. The level of total-antioxidant, MDA and the activity of SOD and CAT were estimated with the help of a spectrophotometer. Gene expression was studied using rt-PCR. The p-NP treatment of osteogenic differentiated MSCs showed intracellular electrolyte imbalance and variation of cellular metabolism. In addition, we observed oxidative stress due to the reduction of total antioxidant capacity and the imbalance of antioxidant enzymes activity. Investigating the genes involved in the osteogenic differentiation of MSCs to osteoblast showed that the 2.5 μM of p-NP reduced the expression of the ALP, SMAD, BMP and RUNX2 genes. The study concludes that this pollutant via influencing the genomics and metabolic imbalance, as well as oxidative induction, caused a reduction of mineralization and differentiation of MSCs. This environmental pollutant might cause osteoporosis, which necessitates raising public awareness, especially to those who live in the industrial area to prevent its drastic effect.

The effect of aging on the biological and immunological characteristics of periodontal ligament stem cells

BackgroundPeriodontal ligament stem cells (PDLSCs) have many applications in the field of cytotherapy, tissue engineering, and regenerative medicine. However, the effect of age on the biological and immunological characteristics of PDLSCs remains unclear.MethodsIn this study, we compared PDLSCs isolated from young and adult individuals. PDLSC proliferation was analyzed by Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2′-deoxyuridine (EdU) staining, and apoptosis level was detected by Annexin V-PE/7-ADD staining. PDLSC osteogenic/adipogenic/chondrogenic differentiation potentials were assessed by alkaline phosphatase (ALP), Alizarin Red, Oil Red O, Alcian Blue staining, and related quantitative analysis. PDLSC immunosuppressive capacity was determined by EdU and Annexin V-PE/7-ADD staining. To explore its underlying mechanism, microarray, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), and western blot analyses were performed to detect differentially expressed genes and proteins in PDLSCs.ResultsOur results demonstrated that with aging, the proliferation and osteogenic/adipogenic/chondrogenic differentiation potential of PDLSCs decreased, whereas apoptosis of PDLSCs increased. Moreover, the immunosuppressive ability of PDLSCs decreased with aging. Compared with PDLSCs from young subjects, analysis of mRNA expression revealed an upregulation of CCND3 and RC3H2, and a downregulation of Runx2, ALP, COL1A1, PPARγ2, CXCL12, FKBP1A, FKBP1B, NCSTN, P2RX7, PPP3CB, RIPK2, SLC11A1, and TP53 in those from adult individuals. Furthermore, protein expression levels of Runx2, ALP, COL1A1, and PPARγ2 in the adult group were decreased, whereas that of CCND3 increased.ConclusionsTaken together, aging influences the biological and immunological characteristics of PDLSCs, and thus, it is more appropriate to utilize PDLSCs from young individuals for tissue regeneration, post-aging treatment, and allotransplantation.

The Inhibitory Role of Di-2-ethylhexyl Phthalate on Osteogenic Differentiation of Mesenchymal Stem Cells Via Down-regulation of RUNX2 and Membrane Function Impairment

Background: Blood contamination of di-2-ethyl hexyl phthalate (DEHP) has been reported due to its release following medical procedures such as blood transfusion and vital liquid injection. We investigated the effect of DEHP on osteogenic differentiation of mesenchymal stem cells and their viability. Methods: The rat bone marrow mesenchymal cells (MSCs) were cultured three times, and the third passage kept in the differentiation medium with the presence of DEHP. The viability of differentiated cells, sodium and potassium level, calcium concentration, total protein concentration, and the activity of lactate dehydrogenase, alkaline phosphatase, alanine transaminase, and aspartate transaminase were determined. Also, the concentration of malondialdehyde, total antioxidant capacity, the activity of superoxide dismutase and catalase were estimated. Finally, the level of matrix deposition and expression of alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX2) genes were evaluated.Results: We observed a concentration-dependent and significant reduction of matrix mineralization based on alizarin red and calcium analysis. Besides, the expression of ALP and RUNX2 gene was down-regulated, and alkaline-phosphatase activity reduced significantly. Also, we observed cell viability reduction but the elevation of lactate dehydrogenase activity and malondialdehyde level. Sodium level was elevated too, whereas the activity of transaminases, oxidative stress enzymes, potassium level, and total antioxidants decreased. Conclusion: DEHP contamination reduced matrix mineralization due to the down-regulation of the genes involved in osteogenic differentiation and viability reduction via electrolyte and metabolic imbalance as well as induction of oxidative stress.

Potential role of full-length and nonfull-length progranulin in affecting aortic valve calcification

Inflammation is implicated in the pathogenesis of calcific aortic valve disease (CAVD) which is a major contributor to cardiovascular mortality and lacks non-surgical treatment. The progranulin (PGRN) is an important immunomodulatory factor in a variety of inflammatory diseases, including rheumatoid arthritis, osteoarthritis, inflammatory bowel disease and pneumonia. However, its role in calcification of aortic valve remains unknown.We firstly found that PGRN was increased in calcified human aortic valve (AV) tissues. Interestingly, in addition to full-length PGRN (68KD), a much stronger band of approximately 45 KD was also significantly increased. The band of 45 KD (45-GRN), was present in wild type (WT) mouse MEFs and AV but absent in grn−/−MEFs, indicating that it was a specific degradation product derived from PGRN. 45-GRN was upregulated whereas PGRN was reduced in human valve interstitial cells (hVICs) under calcifying conditions which is induced by osteogenic medium (OM). In primary porcine VICs (pVICs), PGRN downregulated TNF-α and α-SMA which was accompanied by downregulation of RUNX2, OPN, OCN, alkaline phosphatase activity and calcium deposition, effects pointing to reduced inflammation, myofibroblastic and osteoblastic transition under calcifying conditions. We overexpressed a mimic of 45-GRN which contains p-G-F-B-A-C in pVICs. However, 45-GRN overexpression promoted OM-induced calcification through activating the Smad1/5/8, NF-κB and AKT signaling pathways. Inhibition of the three signaling pathways suppressed 45-GRN's effect on VICs phenotype transition. 45-GRN promoted TNF-α and expressed converse pathogenic signatures with PGRN during TNF-α stimulation.Collectively, this study provides new insight into the pathogenesis of CAVD, indicating that PGRN is a stratagem in mitigating valve fibrosis/osteoblastic differentiation, and also presenting 45-GRN as a potential target for the treatment of CAVD.

BEL β-Trefoil Reduces the Migration Ability of RUNX2 Expressing Melanoma Cells in Xenotransplanted Zebrafish.

RUNX2, a master osteogenic transcript ion factor, is overexpressed in several cancer cells; in melanoma it promotes cells migration and invasion as well as neoangiogenesis. The annual mortality rates related to metastatic melanoma are high and novel agents are needed to improve melanoma patients’ survival. It has been shown that lectins specifically target malignant cells since they present the Thomsen–Friedenreich antigen. This disaccharide is hidden in normal cells, while it allows selective lectins binding in transformed cells. Recently, an edible lectin named BEL β-trefoil has been obtained from the wild mushroom Boletus edulis. Our previous study showed BEL β-trefoil effects on transcription factor RUNX2 downregulation as well as on the migration ability in melanoma cells treated in vitro. Therefore, to better understand the role of this lectin, we investigated the BEL β-trefoil effects in a zebrafish in vivo model, transplanted with human melanoma cells expressing RUNX2. Our data showed that BEL β-trefoil is able to spread in the tissues and to reduce the formation of metastases in melanoma xenotransplanted zebrafish. In conclusion, BEL β-trefoil can be considered an effective biomolecule to counteract melanoma disease.