Determining the potent immunostimulation potential arising from the heteropolysaccharide structure of a novel fucoidan, derived from Sargassum Zhangii.

A preliminary study was conducted of the chemical, structural properties and immunomodulatory activities of fucoidan isolated from Sargassum Zhangii (SZ). Sargassum Zhangii fucoidan (SZF) was determined to have a sulfate content of 19.74 ± 0.01% (w/w) and an average molecular weight of 111.28 kDa. SZF possessed a backbone structure of (1,4)-α-d-linked-galactose, (3,4)-α-l-fucose, (1,3)-α-d-linked-xylose, ß-d-linked-mannose and a terminal (1,4)-α-d-linked-glucose. The main monosaccharide composition was determined as (w/w) 36.10% galactose, 20.13% fucose, 8.86% xylose, 7.36% glucose, 5.62% mannose, and 18.07% uronic acids, respectively. An immunostimulatory assay showed that SZF, compared to commercial fucoidans (Undaria pitnnaifida and Fucus vesiculosus sources), significantly elevated nitric oxide production via up-regulation of cyclooxygenase-2 and inducible nitric oxide synthase at both gene and protein levels. These results suggest that SZ has the potential to be a source of fucoidan with enhanced properties that may act as a useful ingredient for functional foods, nutritional supplements, and immune enhancers.

Simple Complexity: Incorporating Bioinspired Delivery Machinery within Self-Assembled Peptide Biogels.

Bioinspired self-assembly is a bottom-up strategy enabling biologically sophisticated nanostructured biogels that can mimic natural tissue. Self-assembling peptides (SAPs), carefully designed, form signal-rich supramolecular nanostructures that intertwine to form a hydrogel material that can be used for a range of cell and tissue engineering scaffolds. Using the tools of nature, they are a versatile framework for the supply and presentation of important biological factors. Recent developments have shown promise for many applications such as therapeutic gene, drug and cell delivery and yet are stable enough for large-scale tissue engineering. This is due to their excellent programmability-features can be incorporated for innate biocompatibility, biodegradability, synthetic feasibility, biological functionality and responsiveness to external stimuli. SAPs can be used independently or combined with other (macro)molecules to recapitulate surprisingly complex biological functions in a simple framework. It is easy to accomplish localized delivery, since they can be injected and can deliver targeted and sustained effects. In this review, we discuss the categories of SAPs, applications for gene and drug delivery, and their inherent design challenges. We highlight selected applications from the literature and make suggestions to advance the field with SAPs as a simple, yet smart delivery platform for emerging BioMedTech applications.

Chemical Characterization and Immunomodulatory Activity of Fucoidan from Sargassum hemiphyllum.

Fucoidan is a sulfated algal polyanionic polysaccharide that possesses many biological activities. In this paper, a fucoidan (SHF) polysaccharide was extracted from Sargassum hemiphyllum collected in the South China Sea. The SHF, with a molecular weight of 1166.48 kDa (44.06%, w/w), consisted of glucose (32.68%, w/w), galactose (24.81%, w/w), fucose (20.75%, w/w), xylose (6.98%, w/w), mannose (2.76%, w/w), other neutral monosaccharides, and three uronic acids, including glucuronic acid (5.39%, w/w), mannuronic acid (1.76%, w/w), and guronuronic acid (1.76%, w/w). The SHF exhibited excellent immunostimulatory activity. An immunostimulating assay showed that SHF could significantly increase NO secretion in macrophage RAW 264.7 cells via upregulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) levels based on both gene expression and protein abundance. These results suggest that SHF isolated from Sargassum hemiphyllum has great potential to act as a health-boosting ingredient in the pharmaceutical and functional-food fields.

FPR1 gene silencing suppresses cardiomyocyte apoptosis and ventricular remodeling in rats with ischemia/reperfusion injury through the inhibition of MAPK signaling pathway.

Ischemia/reperfusion (I/R) injury, one of the leading health problems in the world, is defined as a cause of cardiomyocytes death. In the present study, we investigate the role of formyl peptide receptor 1 (FPR1) in cardiomyocyte apoptosis and ventricular remodeling of I/R injury rats and the underlying mechanism involving mitogen-activated protein kinase (MAPK) signaling pathway. The important differentially expressed genes (DEGs) in I/R injury were screened out and downstream pathways affected by DEGs were predicted. We grouped 90 rats into sham, I/R, NC siRNA, FRP1 siRNA, empty vector, and FRP1 vector groups and established a model of I/R injury in rats. CVF value, myocardial infarct areas and positive expression rate of FPR1 and MAPK were detected. Levels of FPR1 and MAPK pathway-related genes were determined by RT-qPCR and western blot analysis. MTT assay was performed to evaluate cell proliferation and flow cytometry to evaluate cell cycle progression and apoptosis. GSE19804 and GSE27262 were screened from Gene Expression Omnibus database. FPR1 was higher in patients with I/R injury and activate the MAPK signaling pathway. FRP1 gene silencing decreased CVF value, infarct area, apoptotic index, positive expression rates of FPR1 and MAPK, decreased FPR1, p38, ERK, JNK, MMP-2, TIMP-2, NF-kB, Bax, p-p38, p-ERK, and p-JNK levels, increased Bcl-2 level, promoted cell proliferation and cell cycle progression, and inhibited cell apoptosis rate. Overall, our study demonstrates that the silencing of FPR1 gene depresses inflammation, cardiomyocyte apoptosis and ventricular remodeling in rats with I/R injury through the suppressing the activation of the MAPK signaling pathway.

Evaluation of transventricular placement of porcine small intestinal submucosa stent valves in the pulmonary position in juvenile sheep model.

OBJECTIVES: We assessed the transventricular placement of porcine small intestinal submucosa (SIS) stent valves in a juvenile sheep model at the 3-month follow-up evaluation. METHODS: We constructed a pulmonary stent valve by suturing a porcine SIS bicuspid valve into a bell-shaped 'Z' nitinol stent and implanted 7 SIS stent valves transventricularly in the pulmonary position in 7 sheep. The function of the stent valves was assessed using a pulsatile flow simulation system in vitro. Haemodynamic, angiographic, echocardiographic, histologic and radiographic examinations were carried out before, immediately after implantation and 3 months after implantation. RESULTS: All SIS stent valves were successfully implanted in the pulmonary position in 7 sheep. Angiographic, echocardiographic, haemodyamic and macroscopic studies confirmed firm anchoring and good positioning of the stents immediately after implantation and at 3-month follow-up. All stent valves had good function immediately after implantation and at the end of the protocol, with the exception of 1 stent valve with mild stenosis detected at the end of the protocol. All SIS valves were free of calcifications and thrombus formation, and all stents were intact with no fractures and migration based on postmortem examination and X-radiography. CONCLUSIONS: We demonstrated successful implantation of porcine SIS stent valves in the pulmonary position in sheep with excellent valve function at the 3-month follow-up evaluation. Porcine SIS has potential superiority as a pulmonary stent bioprosthetic valve material, and the bell-shaped nitinol stent has potential superiority as a frame for pulmonary stent valves.

Effects of astragalus polysaccharide on apoptosis of myocardial microvascular endothelial cells in rats undergoing hypoxia/reoxygenation by mediation of the PI3K/Akt/eNOS signaling pathway.

The study explores the effect of astragalus polysaccharide (APS) mediating P13K/Akt/eNOS signaling pathway on apoptosis of myocardial microvascular endothelial cells (MMECs) in hypoxia/reoxygenation (H/R). MMECs were classified into blank, H/R, H/R + 25 mg/L APS, H/R + 50 mg/L APS, H/R + 100 mg/L APS, H/R + LY, and HR + 100 mg/L APS + LY groups. Cell viability was detected using MTT assay and apoptotic cell morphological changes by Hoechst staining. NO content, cell cycle and apoptosis, PI3K/Akt/eNOS signaling pathway proteins were detected using nitrate reductase assay, flow cytometry and Western blotting. An increased cell survival rate, NO content and expression of PI3K/Akt/eNOS signaling pathway associated proteins, and a decreased apoptosis rate was observed in the H/R + 50 mg/L APS and H/R + 100 mg/L APS groups compared with the H/R and H/R + 25 mg/L APS groups. Compared with the H/R + 50 mg/L APS group, the apoptosis rate decreased, whereas the cell survival rate, NO content and expression of PI3K/Akt/eNOS signaling pathway associated proteins increased in the H/R + 100 mg/L APS group. The H/R + LY and HR + 100 mg/L APS + LY groups followed opposite trends. In comparison to the HR + 100 mg/L APS group, the apoptosis rate in the H/R + LY and HR + 100 mg/L APS + LY groups increased, and the cell survival rate, NO content and expression of PI3K/Akt/eNOS signaling pathway associated proteins decreased. Collectively, APS improves the damage caused by H/P by mediating PI3K/Akt/eNOS signaling pathway.

Implantation of a modified stented bovine pulmonary valve in a beating heart sheep model.

PURPOSE: The aim of this research was to assess the performance of a modified bovine stent valve implanted transventricularly in the pulmonary position in sheep with a 3-month follow-up period. MATERIALS AND METHODS: Seven modified pulmonary bovine stent valves were transventricularly implanted in the pulmonary position into seven sheep using a delivery system. Stent valve performance was investigated and evaluated hemodynamically, angiographically, and with echocardiograms before, immediately after, and 3 months following implantation. Macroscopic, histologic, and radiographic examinations were performed on the explanted graft at 3 months. RESULTS: The modified stent valves were all deployed and implanted successfully in the pulmonary position in seven sheep. Angiographic, echocardiographic, hemodynamic, and macroscopic analyses confirmed firm anchoring of the stents in the target position in the early and 3-month follow-up period. All modified stent valves showed satisfactory function, except one moderate stenosis (32 mmHg gradient) with mild regurgitation that was discovered at 3 months. All seven valves were free of any calcification and thrombus formation at postmortem macroscopic examination, which was confirmed by histologic and radiographic examination. All stents were intact without any fracture at microscopic or radiographic examination. CONCLUSIONS: Transventricular implantation of a modified nitinol pulmonary valve stent showed good structural and functional outcomes without stent fracture or migration.

Up-Regulation of miRNA-21 Expression Promotes Migration and Proliferation of Sca-1+ Cardiac Stem Cells in Mice.

BACKGROUND This study, by regulating the expression level of microRNA-21 (miRNA-21) in antigen-1+ (Sca-1+) cardiac stem cells (CSCs), examined the role of miRNA-21 in migration, proliferation, and differentiation of Sca-1+ CSCs, and explored the use of miRNA-21 in treatment of heart-related diseases in mice. MATERIAL AND METHODS The CSCs of 20 healthy 2-month-old C57BL/6 mice were collected in our study. Immunomagnetic beads were used to separate and prepare pure Sca-1+ CSCs, which were further examined by flow cytometry. The samples were assigned to 4 groups: the blank group, the miRNA-21 mimic group, the miRNA-21 inhibitor group, and the negative control (NC) group. Quantitative real-time polymerase chain reaction (qRT-PCR), Transwell chamber assay, and the methyl thiazolylte-trazolium (MTT) assay were performed. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the expression levels of GATA-4, MEF2c, TNI, and ß-MHC differentiation-related genes. RESULTS Immunomagnetic separation results indicated that Sca-1+ CSCs accounted for more than 87.4% of CSCs. RT-PCR results also showed that the expression level of miRNA-21 of the miRNA-21 mimic group was higher than those of the other groups (all P<0.05). Compared to the NC and the blank group, the migration of Sca-1+ CSCs was more active in the miRNA-21 mimic group and less active in the miRNA-21 inhibitor group (all P<0.05). Moreover, compared to the blank group, the proliferation of Sca-1+ CSCs was enhanced in the miRNA-21 mimic group and inhibited in the miRNA-21 inhibitor group (all P<0.05). The results of RT-PCR indicated that neither miRNA-21 mimics nor miR-21 inhibitors influenced the gene expression levels of GATA-4, MEF2c, TNI, or ß-MHC. CONCLUSIONS Our study provides evidence that up-regulation of miRNA-21 can promote migration and proliferation of Sca-1+ CSCs to enhance the capacity of Sca-1+ CSCs to repair damaged myocardium, which may pave the way for therapeutic strategies directed toward restoring miRNA-21 function for heart-related diseases.

Heparanase antisense suppression of A-549 lung carcinoma invasion.

OBJECTIVE: Heparanase (HPSE), as the only enzyme which can degrade the extracellular matrix and heparin sulfate in basement membrane, plays an important role in invasion and metastasis of tumor cells. In this study, we evaluated the inhibitory effect of HPSE antisense oligoxydeonucleotide (ASODN) on lung carcinoma cell line A-549 invasion. METHODS: Liposome-mediated ASODN was transfected into A-549 cells and expression of HPSE protein and mRNA were detected by flow cytometry and RT-PCR techniques. Matrigel invasion assays were employed to assess effects on invasiveness. RESULTS: Lower expression of HPSE protein and mRNA and lower invasive ability to recombinate basal membrane were apparent after ASOND treatment (P<0.01). The inhibition rates of cell invasiveness were 55.6%, 82.3% and 91.2% treated by ASODN at final concentrations of 100, 200 and 400nmol/L, respectively. CONCLUSIONS: HPSE ASODN can downregulate the expression of HPSE protein and mRNA in the A-549 cell line and can obviously inhibit its invasive ability in a dose-dependent manner in vitro.