Fucoidan promotes osteoblast differentiation via JNK- and ERK-dependent BMP2-Smad 1/5/8 signaling in human mesenchymal stem cells

Chitosan as a vehicle for growth factor delivery: Various preparations and their applications in bone tissue regeneration

The replacement of conventional autografts and allografts by bone fragments constructed from alternate materials, cells, and molecules (growth factors, drugs, etc.) is an exciting prospect in the field of bone tissue engineering. Bone morphogenetic protein-2 (BMP-2) is a growth factor that has been extensively studied from this point of view. This review analyzes the relevance of chitosan and its derivatives and composites with various materials such as ceramics, heparin, silica, stem cells, titanium implants, etc., in terms of delivering BMP-2 for the purpose of bone regeneration. Chitosan offers the versatility to be modified into any shapes or sizes including conversion to nanoparticles, microspheres, nanofibers, porous scaffolds, and films. The results presented in this review clearly demonstrate that chitosan-based materials are biocompatible and have the potential to systematically and sustainably release BMP-2 where required. This release results in enhanced cell proliferation levels, enhancement of alkaline phosphatase activity, increased differentiation as well as increased mineralization under in vitro and in vivo conditions. This review also shines a spotlight on the currently developed chitosan-based products that are being used for BMP-2 delivery.

The mechanism of a chitosan-collagen composite film used as biomaterial support for MC3T3-E1 cell differentiation

Natural composite biomaterials are good structural supports for bone cells to regenerate lost bone. Here, we report that a chitosan-collagen composite film accelerated osteoblast proliferation, differentiation and matrix mineralization in MC3T3-E1 cells. Intriguingly, we observed that the film enhanced the phosphorylation of Erk1/2. We showed that the chitosan-collagen composite film increased the transcriptional activity of Runx2, which is an important factor regulating osteoblast differentiation downstream of phosphorylated Erk1/2. Consistent with this observation, we found that the chitosan-collagen composite film increased the expression of osteoblastic marker genes, including Type I Collagen and Runx2 in MC3T3-E1 cells. We conclude that this film promoted osteoblast differentiation and matrix mineralization through an Erk1/2-activated Runx2 pathway. Our findings provide new evidence that chitosan-collagen composites are promising biomaterials for bone tissue engineering in bone defect-related diseases.

RETRACTED: Potential role of andrographolide in the proliferation of osteoblasts mediated by the ERK signaling pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The authors contacted the journal to request a retraction: "We found some errors in reviewing the original data, the current results could not fully support the conclusions". Concern was also raised about the reliability of the Western blot results in Figure 8A+E, which appear to have a similar phenotype as contained within other publications, as detailed here: https://pubpeer.com/publications/CC36842602D94EB300623ED982FBFA; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. Concerns were also raised about suspected image duplications within Figure 1C. The journal requested the corresponding author comment on these concerns and provide the raw data. The author did not fulfil this request and the Editor-in-Chief decided to retract the article.

Fucoidan Induces ROS-Dependent Apoptosis in 5637 Human Bladder Cancer Cells by Downregulating Telomerase Activity via Inactivation of the PI3K/Akt Signaling Pathway

Preclinical Research Fucoidan, a sulfated polysaccharide, is a compound found in various species of seaweed that has anti-viral, anti-bacterial, anti-oxidant, anti-inflammatory, and immunomodulatory activities; however, the underlying relationship between apoptosis and anti-telomerase activity has not been investigated. Here, we report that fucoidan-induced apoptosis in 5637 human bladder cancer cells was associated with an increase in the Bax/Bcl-2 ratio, the dissipation of the mitochondrial membrane potential (MMP, Δψm), and cytosolic release of cytochrome c from the mitochondria. Under the same experimental conditions, fucoidan-treatment decreased hTERT (human telomerase reverse transcriptase) expression and the transcription factors, c-myc and Sp1. This was accompanied by decreased telomerase activity. Fucoidan-treatment also suppressed activation of the PI3K/Akt signaling pathway. Inhibition of PI3K/Akt signaling enhanced fucoidan-induced apoptosis and anti-telomerase activity. Meanwhile, fucoidan treatment increased the generation of intracellular ROS, whereas the over-elimination of ROS by N-acetylcysteine, an anti-oxidant, attenuated fucoidan-induced apoptosis, inhibition of hTERT, c-myc, and Sp1 expression, and reversed fucoidan-induced inactivation of the PI3K/Akt signaling pathway. Collectively, these data indicate that the induction of apoptosis and the inhibition of telomerase activity by fucoidan are mediated via ROS-dependent inactivation of the PI3K/Akt pathway. Drug Dev Res 78 : 37-48, 2017.   © 2016 Wiley Periodicals, Inc.

Glycitin regulates osteoblasts through TGF-β or AKT signaling pathways in bone marrow stem cells

The aim of the present study was to examine the effect of glycitin on the regulation of osteoblasts from bone marrow stem cells (BMSCs) through transforming growth factor (TGF)-β or protein kinase B (AKT) signaling pathways. BMSCs were extracted from New Zealand white rabbits and used to analyze the effect of glycitin on BMSCs. BMSCs were cleared using xylene and observed via light microscopy. BMSCs were subsequently induced with glycitin (0.01, 0.5, 1, 5 and 10 µM) for 7 days, and stained with Oil Red O. The mechanism of action of glycitin on BMSCs was investigated, in which contact with collagen type I (Col I), alkaline phosphatase (ALP), TGF-β and AKT was studied. Firstly, BMSCs appeared homogeneously mazarine blue, and which showed that BMSCs were successful extracted. Administration of glycitin increased cell proliferation and promoted osteoblast formation from BMSCs. Furthermore, glycitin activated the gene expression of Col I and ALP in BMSCs. Notably, glycitin suppressed protein expression of TGF-β and AKT in BMSCs. These results indicated that glycitin may regulate osteoblasts through TGF-β or AKT signaling pathways in BMSCs.

Highly scalable, closed-loop synthesis of drug-loaded, layer-by-layer nanoparticles

Layer-by-layer (LbL) self-assembly is a versatile technique from which multicomponent and stimuli-responsive nanoscale drug carriers can be constructed. Despite the benefits of LbL assembly, the conventional synthetic approach for fabricating LbL nanoparticles requires numerous purification steps that limit scale, yield, efficiency, and potential for clinical translation. In this report, we describe a generalizable method for increasing throughput with LbL assembly by using highly scalable, closed-loop diafiltration to manage intermediate purification steps. This method facilitates highly controlled fabrication of diverse nanoscale LbL formulations smaller than 150 nm composed from solid-polymer, mesoporous silica, and liposomal vesicles. The technique allows for the deposition of a broad range of polyelectrolytes that included native polysaccharides, linear polypeptides, and synthetic polymers. We also explore the cytotoxicity, shelf life and long-term storage of LbL nanoparticles produced using this approach. We find that LbL coated systems can be reliably and rapidly produced: specifically, LbL-modified liposomes could be lyophilized, stored at room temperature, and reconstituted without compromising drug encapsulation or particle stability, thereby facilitating large scale applications. Overall, this report describes an accessible approach that significantly improves the throughput of nanoscale LbL drug-carriers that show low toxicity and are amenable to clinically relevant storage conditions.

A review of the components of brown seaweeds as potential candidates in cancer therapy

Brown seaweeds have opened new opportunities for the development of novel anticancer agents due to their diverse structural composition and mode of action.

Osteoblastogenic activity of ark shell protein hydrolysates with low molecular weight in mouse mesenchymal stem cells

Ark shell protein promotes bone formation through regulating osteoblast differentiation.

Role of P2 × 7 receptor in the differentiation of bone marrow stromal cells into osteoblasts and adipocytes

Imbalance in osteogenesis and adipogenesis of bone marrow stromal cells is a crucial pathological process of osteoporosis. P2 × 7-deficient mice were previously shown to exhibit an osteopenic phenotype and abnormal fat distribution, leading us to hypothesize that P2 × 7R activation was involved in the differentiation of BMSCs. Consequently, we investigated the effect of P2 × 7R activation on osteogenic and adipogenic differentiation of BMSCs in vitro, and established an ovariectomized (OVX) osteoporosis model to test P2 × 7R activation on adipocytes formation, trabecular and cortical bone parameters in vivo. Our results showed that activation of P2 × 7R by BzATP resulted in increase in the gene expression of osteoblastic markers, the activity of alkaline phosphatase and bone mineralization, and decrease in the gene expression of adipogenic markers and the number of adipocytes generated by BMSCs. MicroCT analysis showed that BzATP treatment ameliorated the micro-architecture of trabecular bones in OVX mice, while cortical bone parameters were unaffected. H&E staining analysis showed that was increase in the volume of trabecular bone and number of trabecular bone, and decrease in bone marrow adipocytes in BzATP-treated OVX mice compared with OVX mice. Also, activation of P2 × 7R transduced to ERK1/2 and JNK signaling pathways. This transduction was prevented by BBG, U0126, and SP600125. U0126 and SP600125 prevented BzATP-induced up-regulation of osteogenic-related genes expression and down-regulation of adipogenic-related genes expression. These data suggest that BzATP activates the differentiation of BMSCs into osteoblasts but not adipocytes by stimulating ERK1/2 and JNK signaling pathways in a P2 × 7R-dependent way.

The Effects of the Endocannabinoids Anandamide and 2-Arachidonoylglycerol on Human Osteoblast Proliferation and Differentiation

The endocannabinoid system is expressed in bone, although its role in the regulation of bone growth is controversial. Many studies have examined the effect of endocannabinoids directly on osteoclast function, but few have examined their role in human osteoblast function, which was the aim of the present study. Human osteoblasts were treated from seeding with increasing concentrations of anandamide or 2-arachidonoylglycerol for between 1 and 21 days. Cell proliferation (DNA content) and differentiation (alkaline phosphatase (ALP), collagen and osteocalcin secretion and calcium deposition) were measured. Anandamide and 2-arachidonoylglycerol significantly decreased osteoblast proliferation after 4 days, associated with a concentration-dependent increase in ALP. Inhibition of endocannabinoid degradation enzymes to increase endocannabinoid tone resulted in similar increases in ALP production. 2-arachidonoylglycerol also decreased osteocalcin secretion. After prolonged (21 day) treatment with 2-arachidonoylglycerol, there was a decrease in collagen content, but no change in calcium deposition. Anandamide did not affect collagen or osteocalcin, but reduced calcium deposition. Anandamide increased levels of phosphorylated CREB, ERK 1/2 and JNK, while 2-arachidonoylglycerol increased phosphorylated CREB and Akt. RT-PCR demonstrated the expression of CB2 and TRPV1, but not CB1 in HOBs. Anandamide-induced changes in HOB differentiation were CB1 and CB2-independent and partially reduced by TRPV1 antagonism, and reduced by inhibition of ERK 1/2 and JNK. Our results have demonstrated a clear involvement of anandamide and 2-arachidonoylglycerol in modulating the activity of human osteoblasts, with anandamide increasing early cell differentiation and 2-AG increasing early, but decreasing late osteoblast-specific markers of differentiation.

TGF-β3 and IGF-1 synergy ameliorates nucleus pulposus mesenchymal stem cell differentiation towards the nucleus pulposus cell type through MAPK/ERK signaling

This study aimed to investigate the synergy between transforming growth factor beta 3 (TGF-β3) and insulin-like growth factor 1 (IGF-1) on nucleus pulposus-derived mesenchymal stem cells (NP-MSCs) and the underlying mechanism using a serum-free culture system. NP-MSC proliferation and viability were measured using a CCK-8 assay and annexin V-FITC/propidium iodide, respectively. NP-MSCs in micromasses were investigated for differentiation towards nucleus pulposus cells (NPCs). SOX-9, collagen-I, collagen-II, aggrecan and decorin expressions were detected by RT-PCR and immunoblotting. Matrix deposition was assessed by sulfated glycosaminoglycan (sGAG) analysis. Novel chondrogenic and nucleus pulposus (NP) genes were detected to distinguish differentiated cell types. MAPK/ERK and TGF/Smad signaling pathways were also examined. As a result, the synergy between TGF-β3 and IGF-1 enhanced NP-MSC viability, extracellular matrix (ECM) biosynthesis and differentiation towards NPCs, partly through the activation of the MAPK/ERK signaling pathway. Therefore, the synergy between TGF-β3 and IGF-1 ameliorates NP-MSC viability, differentiation and promotes intervertebral disc regeneration.

[Breath test using C-13-trioleate in the evaluation of the rate of fatty acid metabolism after parenteral feeding of premature and newborn infants]

Malignant glioma (MG) is a poor prognostic brain tumor with inevitable recurrence after multimodality treatment. Searching for more effective treatment is urgently needed. Differentiation induction via epigenetic modification has been proposed as a potential anticancer strategy. Natural products are known as fruitful sources of epigenetic modifiers with wide safety margins. We thus explored the effects of oligo-fucoidan (OF) from brown seaweed on this notion in MG cells including Grade III U87MG cells and Grade IV glioblastoma multiforme (GBM)8401 cells and compared to the immortalized astrocyte SVGp12 cells. The results showed that OF markedly suppress the proliferation of MG cells and only slightly affected that of SVGp12 cells. OF inhibited the protein expressions of DNA methyltransferases 1, 3A and 3B (DNMT1, 3A and 3B) accompanied with obvious mRNA induction of differentiation markers (MBP, OLIG2, S100β, GFAP, NeuN and MAP2) both in U87MG and GBM8401 cells. Accordingly, the methylation of p21, a DNMT3B target gene, was decreased by OF. In combination with the clinical DNMT inhibitor decitabine, OF could synergize the growth inhibition and MBP induction in U87MG cells. Appropriated clinical trials are warranted to evaluate this potential complementary approach for MG therapy after confirmation of the effects in vivo.