Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model

Advances in Fabrication Technologies for the Development of Next-Generation Cardiovascular Stents

Coronary artery disease is the most prevalent cardiovascular disease, claiming millions of lives annually around the world. The current treatment includes surgically inserting a tubular construct, called a stent, inside arteries to restore blood flow. However, due to lack of patient-specific design, the commercial products cannot be used with different vessel anatomies. In this review, we have summarized the drawbacks in existing commercial metal stents which face problems of restenosis and inflammatory responses, owing to the development of neointimal hyperplasia. Further, we have highlighted the fabrication of stents using biodegradable polymers, which can circumvent most of the existing limitations. In this regard, we elaborated on the utilization of new fabrication methodologies based on additive manufacturing such as three-dimensional printing to design patient-specific stents. Finally, we have discussed the functionalization of these stent surfaces with suitable bioactive molecules which can prove to enhance their properties in preventing thrombosis and better healing of injured blood vessel lining.

Purification and Characterization of the Enzyme Fucoidanase from Cobetia amphilecti Utilizing Fucoidan from Undaria pinnatifida

Fucoidanase is an unstable enzyme with high specificity that requires a large about of time to screen it from microorganisms. In this study, enzymatic hydrolysis was used to produce low-molecular-weight fucoidan from microorganisms via the degradation of high-molecular-weight fucoidan without damage to the sulfate esterification structure of oligosaccharide. The microbial strain HN-25 was isolated from sea mud and was made to undergo mutagenicity under ultraviolet light. Fucoidanase was extracted via ultrasonication and its enzymatic activity was improved via optimization of the ultrasonic conditions. The enzymatic properties and degradation efficiency of fucoidanase were characterized. The microbial strain HN-25 is a Gram-negative aerobic and rod-shaped-cell bacterium, and therefore was identified as Cobetia amphilecti via 16s rDNA. The results proved that fucoidanase is a hydrolytic enzyme with a molecular weight of 35 kDa and with high activity and stability at 30 °C and pH 8.0. The activity of fucoidanase was significantly enhanced by sodium and calcium ions and inhibited by a copper ion and ethylenediaminetetraacetate (EDTA). There was a significant decrease in the molecular weight of fucoidan after enzymatic hydrolysis. The low-molecular-weight fuicodan was divided into four fractions, mainly concentrated at F3 (20~10 kDa) and F4 (≤6 kDa). These consequences suggest that fucoidanase obtained from Cobetia amphilecti is stable and efficient and could be a good tool in the production of bioactive compounds.

Targeting the epigenome in in-stent restenosis: from mechanisms to therapy

Coronary artery disease (CAD) is one of the most common causes of death worldwide. The introduction of percutaneous revascularization has revolutionized the therapy of patients with CAD. Despite the advent of drug-eluting stents, restenosis remains the main challenge in treating patients with CAD. In-stent restenosis (ISR) indicates the reduction in lumen diameter after percutaneous coronary intervention, in which the vessel's lumen re-narrowing is attributed to the aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) and dysregulation of endothelial cells (ECs). Increasing evidence has demonstrated that epigenetics is involved in the occurrence and progression of ISR. In this review, we provide the latest and comprehensive analysis of three separate but related epigenetic mechanisms regulating ISR, namely, DNA methylation, histone modification, and non-coding RNAs. Initially, we discuss the mechanism of restenosis. Furthermore, we discuss the biological mechanism underlying the diverse epigenetic modifications modulating gene expression and functions of VSMCs, as well as ECs in ISR. Finally, we discuss potential therapeutic targets of the small molecule inhibitors of cardiovascular epigenetic factors. A more detailed understanding of epigenetic regulation is essential for elucidating this complex biological process, which will assist in developing and improving ISR therapy.

A low-molecular-weight ascophyllan prepared from Ascophyllum nodosum: Optimization, analysis and biological activities

In this study, a low-molecular-weight saccharide fragment (LMWAs-L) was prepared from alginate lyase (EC 4.2.2.3) hydrolyzed ascophyllan by ultra-filtration separation method. LMWAs-L was a homogeneous saccharide fraction with an average molecular weight of 6.96 kDa. Enzymolysis process optimization experiments revealed that the optimum process parameters for preparing LMWAs-L were the enzyme concentration 0.02 U/mL, initial pH 6.8, and enzymolysis temperature 43 °C. After optimization, the yield of LMWAs-L was increased to 9.74% higher than that without optimization. Interestingly, LMWAs-L exhibited stronger enhancing activities on the proliferation and migration of human skin fibroblasts cells in vitro and better antibacterial activities as compared to native ascophyllan at the same mass concentration. Our study establishes a simple way to prepare low-molecular-weight saccharide with beneficial bioactivities from ascophyllan efficiently. This is the first report to reveal that ascophyllan and its low-molecular-weight saccharide have the potentials to be developed as natural biological dressing and antibacterial agents.

Vascular reconstruction: A major challenge in developing a functional whole solid organ graft from decellularized organs

Bioengineering a functional organ holds great potential to overcome the current gap between the organ need and shortage of available organs. Whole organ decellularization allows the removal of cells from large-scale organs, leaving behind extracellular matrices containing different growth factors, structural proteins, and a vascular network with a bare surface. Successful application of decellularized tissues as transplantable organs is hampered by the inability to completely reline the vasculature by endothelial cells (ECs), leading to blood coagulation, loss of vascular patency, and subsequent death of reseeded cells. Therefore, an intact, continuous layer of endothelium is essential to maintain proper functioning of the vascular system, which includes the transfer of nutrients to surrounding tissues and protecting other types of cells from shear stress. Here, we aimed to summarize the available cell sources that can be used for reendothelialization in addition to different trials performed by researchers to reconstruct vascularization of decellularized solid organs. Additionally, different techniques for enhancing reendothelialization and the methods used for evaluating reendothelialization efficiency along with the future prospective applications of this field are discussed. STATEMENT OF SIGNIFICANCE: Despite the great progress in whole organ decellularization, reconstruction of vasculature within the engineered constructs is still a major roadblock. Reconstructed endothelium acts as a multifunctional barrier of vessels, which can reduce thrombosis and help delivering of oxygen and nutrients throughout the whole organ. Successful reendothelialization can be achieved through reseeding of appropriate cell types on the naked vasculature with or without modification of its surface. Here, we present the current research milestones that so far established to reconstruct the vascular network in addition to the methods used for evaluating the efficiency of reendotheilization. Thus, this review is quite significant and will aid the researchers to know where we stand toward biofabricating a transplantable organ from decellularizd extracellular matrix.

Evidence for the Fucoidan/P-Selectin Axis as a Therapeutic Target in Hypoxia-induced Pulmonary Hypertension

Rationale: Pulmonary arterial hypertension (PAH) is characterized by vascular remodeling and excessive proliferation of pulmonary artery smooth muscle cells (PASMCs). Fucoidan, a polysaccharidic ligand of the adhesion molecule P-selectin, exhibits antiproliferative properties. The effects of the fucoidan/P-selectin axis on vascular remodeling and pulmonary hypertension (PH) after hypoxia remain unexplored. Objectives: We aimed to evaluate the therapeutic potential of targeting the fucoidan/P-selectin axis in PH. Methods: Mice with PH induced by chronic hypoxia (35 d) were given either fucoidan (from Fucus vesiculosus) or anti-P-selectin antibody (Rb40.34) during Days 21-35. Right ventricular (RV) function was determined by echocardiography. Vascular morphometry was assessed by immunohistochemistry. Human and experimental PH lungs and PASMCs were used for assessment of P-selectin expression and function. Measurements and Main Results: Fucoidan attenuated chronic hypoxia-induced PH in mice, reducing pulmonary vascular remodeling and restoring RV function. In vitro, fucoidan inhibited hypoxia and growth factor-stimulated PASMC proliferation and migration. Chronic hypoxia caused an upregulation of P-selectin in the medial layer of the small pulmonary arteries. P-selectin was persistently upregulated in PASMCs of human and hypoxia-induced experimental PH. HIF-1α (hypoxia-inducible factor 1α) directly bound to the P-selectin promoter and transcriptionally activated P-selectin in hypoxia. P-selectin blockage resulted in a marked reduction of PASMC proliferation in vitro. Blockage of P-selectin by administration of anti-P-selectin Rb40.34 antibody and P-selectin-deficient mice improved vascular remodeling and restored RV function. Conclusions: Fucoidan is a potent natural adjuvant that represents a promising therapeutic approach for PH. Our data indicate a previously unrecognized role of P-selectin in the proliferative response of PASMCs associated with PH.

Fucoidan⁻Fucoxanthin Ameliorated Cardiac Function via IRS1/GRB2/ SOS1, GSK3β/CREB Pathways and Metabolic Pathways in Senescent Mice

The effects of low molecular weight fucoidan (LMWF) in combination with high-stability fucoxanthin (HSFUCO) on cardiac function and the metabolic pathways of aging mice (Mus musculus) were investigated. We demonstrated that LMWF and HSFUCO could improve cardiac function in aging mice. Aging mice were treated with LMWF and HSFUCO, either on their own or in combination, on 28 consecutive days. Electrocardiography and whole-cell patch-clamp were used to measure QT interval and action potential duration (APD) of the subjects. Cardiac tissue morphology, reactive oxygen species, and Western blot were also applied. Ultra-high-performance liquid chromatography⁻quadrupole time-of-flight (UPLC-QTOF) mass spectrometry was used for investigating metabolic alterations. The use of LMWF and HSFUCO resulted in improvements in both ventricular rhythms (QT and APD). Treatment with fucoidan and fucoxanthin reduced the expression levels of SOS1 and GRB2 while increasing GSK3β, CREB and IRS1 proteins expression in the aging process. Three main metabolic pathways, namely the TCA cycle, glycolysis, and steroid hormone biosynthesis, were highly enriched in the pathway enrichment analysis. When taken together, the LMWF and HSFUCO treatment improved both the ventricular rhythm and the muscular function of aging subjects by interfering with the metabolism and gene function.

A Nonlinear Mathematical Model of Drug Delivery from Polymeric Matrix

The objective of the present study is to mathematically model the integrated kinetics of drug release in a polymeric matrix and its ensuing drug transport to the encompassing biological tissue. The model embodies drug diffusion, dissolution, solubilization, polymer degradation and dissociation/recrystallization phenomena in the polymeric matrix accompanied by diffusion, advection, reaction, internalization and specific/nonspecific binding in the biological tissue. The model is formulated through a system of nonlinear partial differential equations which are solved numerically in association with pertinent set of initial, interface and boundary conditions using suitable finite difference scheme. After spatial discretization, the system of nonlinear partial differential equations is reduced to a system of nonlinear ordinary differential equations which is subsequently solved by the fourth-order Runge-Kutta method. The model simulations deal with the comparison between a drug delivery from a biodegradable polymeric matrix and that from a biodurable polymeric matrix. Furthermore, simulated results are compared with corresponding existing experimental data to manifest the efficaciousness of the advocated model. A quantitative analysis is performed through numerical computation relied on model parameter values. The numerical results obtained reveal an estimate of the effects of biodegradable and biodurable polymeric matrices on drug release rates. Furthermore, through graphical representations, the sensitized impact of the model parameters on the drug kinetics is illustrated so as to assess the model parameters of significance.

Absorption Study of Mozuku Fucoidan in Japanese Volunteers

We performed an oral administration study of fucoidan in 396 Japanese volunteers and investigated significant factors concerning the absorption of fucoidan. Urine samples were collected at 0, 3, 6, and 9 h after ingestion of 3 g of fucoidan. Fucoidan was detected in urine after ingestion in 385 out of 396 subjects. The maximum value (mean ± standard deviation (SD)) of urinary fucoidan was 332.3 ± 357.6 μg/gCr in subjects living in Okinawa prefecture, compared with 240.1 ± 302.4 μg/gCr in subjects living outside Okinawa. Compared with the estimated urinary excretion of fucoidan by place of residence, those of subjects living in Okinawa prefecture were significantly higher than those living outside Okinawa prefecture (p < 0.01). In addition, subjects living in Okinawa prefecture consumed significantly greater amounts of mozuku compared with those living outside Okinawa prefecture (p < 0.01). Multiple regression analysis showed that having Okinawa prefecture as a place of residence was a significant factor (p < 0.01) contributing to the estimated urinary excretion of fucoidan. Because the habit of eating mozuku was significantly higher (p < 0.01) in subjects living in Okinawa prefecture than in those living outside Okinawa prefecture, the habit of eating mozuku was speculated to be a factor in the absorption of fucoidan.

PM2.5 induced cardiac hypertrophy via CREB/GSK3b/SOS1 pathway and metabolomics alterations

The particle matter with diameter less 2.5μm (PM2.5) easier to adsorb toxic substance, and interfere with pulmonary gas exchange. In this study, cardioprotective effects of low molecular weight (LMW) fucoidan in cardiac hypertrophy subjects induced by PM2.5 exposure was conducted by measuring QT interval, Blood pressure, cardiac structure, metabolites and proteins expression in different organs. After PM2.5 exposure, increase in blood pressure, abnormal cardiac function (Prolongation of Action Potential Duration and QT Interval), and structral remodeling (cardiac hypertrophy and fibrosis) were recorded. Fucoidan supplement in consecutive 28 days can reduce the damage to myocardial injury caused by PM2.5. Clearance effect of fucoidan in serum, heart, kidney, lung and liver was found due to organic and inorganic compounds reduced SOS1, CREB, GSK3b, and GRB2 protein level were changed under PM2.5 exposure. Whereas, only CREB level was reduced after fucoidan treatment. Metabolic alteration was also determined that PM2.5 severely damage cardiac tissue and compromise its function. After treatment with fucoidan, the cardiac function was significantly recovered. Our finding demonstrated that LMW could enhance the cardiac status of mice with PM2.5 exposures by rescued QT interval prolongation, action potential and cardiac hypertrophy, and cardiac fibrosis decline.

Low molecular weight fucoidan attenuates experimental abdominal aortic aneurysm through interfering the leukocyte-endothelial cells interaction

Low molecular weight fucoidan (LMWF) is a sulfated polysaccharide extracted from Saccharina Japonica that presents high affinity for P-selectin and abolish selectin-dependent recruitment of leukocytes. We hypothesized that dietary intake of LMWF, as a competitive binding agent of P-selectin, could limit the inflammatory infiltration and aneurysmal growth in an Angiotensin II-induced abdominal aortic aneurysm (AAA) mouse model. The Gene Expression Omnibus database was used for gene expressions and gene set enrichment analysis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that focal adhesion was involved in the development of AAA. However, dietary intake of LMWF could limit the enlargement of AAA, decreasing maximal aortic diameter and preserving elastin lamellae. Although LMWF did not decrease the circulatory monocytes count and lower the expression of P-selectin in endothelium, it reduced macrophages infiltration in media and adventitia. Furthermore, matrix metalloproteinase expression was markedly downregulated, accompanied with reduced expression of inflammatory mediators, including interleukin 1β, tumor necrosis factor-α and monocyte chemotactic protein-1. The present study revealed a novel target for the treatment of AAA and the anti-inflammatory effects of LMWF.

Promoting Wound Healing Using Low Molecular Weight Fucoidan in a Full-Thickness Dermal Excision Rat Model

Low molecular weight fucoidan (LMF) has been reported to possess anti-inflammatory and antioxidant activities. Thus, we examined the effects of LMF extracted from Undaria pinnatifida on dermal wounds. Five round dermal wounds were created on the dorsal back of rats, and they were then treated topically with distilled water (DW), Madecasol Care™ (MC) or LMF at 200, 100 and 50 mg/mL, twice a day for a week. There were dose-dependent increases in wound contraction in the groups receiving LMF but not in the MC group, compared with the DW. Histopathological examination revealed that LMF treatment accelerated wound healing, which was supported by increases in granular tissue formation on day four post-treatment but a decrease on day seven, accompanied by an evident reduction in inflammatory cells. In the LMF-treated wounds, collagen distribution and angiogenesis were increased in the granular tissue on days four and seven post-treatment. Immunoreactive cells for transforming growth factor-β1, vascular endothelial growth factor receptor-2 or matrix metalloproteinases 9 were also increased, probably due to tissue remodeling. Furthermore, LMF treatment reduced lipid peroxidation and increased antioxidant activities. These suggested that LMF promotes dermal wound healing via complex and coordinated antioxidant, anti-inflammatory and growth factor-dependent activities.

Functional restoration of replicative senescent mesenchymal stem cells by the brown alga Undaria pinnatifida

The brown alga Undaria pinnatifida, which is called Mi-Yoek in Korea, has been traditionally consumed as a health food in East Asian countries. Recent studies have reported that U. pinnatifida has beneficial effects on arteriosclerosis, inflammation, fat metabolism, and tumors. In this study, we examined the anti-senescence effects of ethanol extracts of U. pinnatifida (UP-Ex) in human bone marrow mesenchymal stem cells (hBM-MSCs). UP-Ex protected hBM-MSCs against oxidative injury, as determined by MTT assays. This effect was confirmed by immunoblot analysis of the oxidation-sensitive protein p53 and the apoptotic protein cleaved caspase-3. Excessive intracellular reactive oxygen species (ROS) accumulation induced by oxidative stress was moderated in UP-Ex-treated hBM-MSCs (UP-Ex-MSCs). Similarly, expression of the ROS-scavenging enzymes superoxide dismutase 1 (SOD1), SOD2, and catalase was recovered in UP-Ex-MSCs. Excessive ROS induced by long-term cell expansion (passage 17) was significantly decreased along with restoration of the senescence proteins p53, p21, and p16 in UP-Ex-MSCs. UP-Ex treatment also improved the ability of these replicative, senescent hBM-MSCs (passage 17) to differentiate into osteocytes or adipocytes, suggesting that UP-Ex ameliorates the functional decline of senescent stem cells and may provide better therapeutic efficacy in stem cell therapy.

Abbreviations: hBM-MSCs: human bone marrow mesenchymal stem cells; DCF: 2′,7′-dichlorodihydrofluorescein; DCFH-DA: 2′,7′-dichlorofluorescein diacetate; MTT: 3-(4,5-dimethylthiazol-2-yl-)2,5-diphenyltetrazolium bromide; PBS: phosphate-buffered saline; PFA: paraformaldehyde; RIPA: radioimmunoprecipitation assay; ROS: reactive oxygen species; SOD1: superoxide dismutase 1; SOD2: superoxide dismutase 2.

Recent advances to accelerate re-endothelialization for vascular stents

Cardiovascular diseases are considered as one of the serious diseases that leads to the death of millions of people all over the world. Stent implantation has been approved as an easy and promising way to treat cardiovascular diseases. However, in-stent restenosis and thrombosis remain serious problems after stent implantation. It was demonstrated in a large body of previously published literature that endothelium impairment represents a major factor for restenosis. This discovery became the driving force for many studies trying to achieve an optimized methodology for accelerated re-endothelialization to prevent restenosis. Thus, in this review, we summarize the different methodologies opted to achieve re-endothelialization, such as, but not limited to, manipulation of surface chemistry and surface topography.

Prospects for the therapeutic application of sulfated polysaccharides of brown algae in diseases of the cardiovascular system: review

CONTEXT

Fucoidans are water-soluble, highly sulfated, branched homo- and hetero-polysaccharides derived from the fibrillar cell walls and intercellular spaces of brown seaweeds of the class Phaeophyceae. Fucoidans possess mimetic properties of the natural ligands of protein receptors and regulate functions of biological systems via key signaling molecules.

OBJECTIVES

The aim of this review was to collect and combine all available scientific literature about the potential use of the fucoidans for diseases of cardiovascular system.

MATERIALS AND METHODS

The review has been compiled using references from major databases such as Web of Science, PubMed, Scopus, Elsevier, Springer and Google Scholar (up to September 2015). After obtaining all reports from database (a total number is about 580), the papers were carefully analyzed in order to find data related to the topic of this review (129 references).

RESULTS

An exhaustive survey of literature revealed that fucoidans possess a broad spectrum of biological activity, including anti-coagulant, hypolipidemic, anti-thrombotic, anti-inflammatory, immunomodulatory, anti-tumor, anti-adhesive and anti-hypertensive properties. Numerous investigations of fucoidans in diseases of the cardiovascular system mainly focus on pleiotropic anti-inflammatory effects. Fucoidans also possess pro-angiogenic and pro-vasculogenic properties.

CONCLUSION

A great number of investigations in the past years have demonstrated that fucoidans has great potential for in-depth investigation of their effects on cardiovascular system. Through this review, the authors hope to attract the attention of researchers to use fucoidan as mimetic of natural ligand receptor protein with the view of developing new formulations with an improved therapeutic value.

Identification of a Pro-Angiogenic Potential and Cellular Uptake Mechanism of a LMW Highly Sulfated Fraction of Fucoidan from Ascophyllum nodosum

Herein we investigate the structure/function relationships of fucoidans from Ascophyllum nodosum to analyze their pro-angiogenic effect and cellular uptake in native and glycosaminoglycan-free (GAG-free) human endothelial cells (HUVECs). Fucoidans are marine sulfated polysaccharides, which act as glycosaminoglycans mimetics. We hypothesized that the size and sulfation rate of fucoidans influence their ability to induce pro-angiogenic processes independently of GAGs. We collected two fractions of fucoidans, Low and Medium Molecular Weight Fucoidan (LMWF and MMWF, respectively) by size exclusion chromatography and characterized their composition (sulfate, fucose and uronic acid) by colorimetric measurement and Raman and FT-IR spectroscopy. The high affinities of fractionated fucoidans to heparin binding proteins were confirmed by Surface Plasmon Resonance. We evidenced that LMWF has a higher pro-angiogenic (2D-angiogenesis on Matrigel) and pro-migratory (Boyden chamber) potential on HUVECs, compared to MMWF. Interestingly, in a GAG-free HUVECs model, LMWF kept a pro-angiogenic potential. Finally, to evaluate the association of LMWF-induced biological effects and its cellular uptake, we analyzed by confocal microscopy the GAGs involvement in the internalization of a fluorescent LMWF. The fluorescent LMWF was mainly internalized through HUVEC clathrin-dependent endocytosis in which GAGs were partially involved. In conclusion, a better characterization of the relationships between the fucoidan structure and its pro-angiogenic potential in GAG-free endothelial cells was required to identify an adapted fucoidan to enhance vascular repair in ischemia.

Low molecular weight fucoidan modulates P-selectin and alleviates diabetic nephropathy

Diabetic nephropathy (DN) is a serious microvascular complication that can lead to chronic and end-stage renal failure. It is understood that inflammation is associated with the onset and process of DN. Low molecular weight fucoidan (LMWF) isolated from Saccharina japonica has anti-inflammatory properties. Therefore, this study aimed to explore the mechanism of LMWF in DN model induced by streptozotocin. The biochemical indices levels showed LMWF reduced the DN diagnostic indices to protect renal function. The HE stained sections exhibited LMWF protected normal morphological structures and reduced inflammatory cell infiltration in the kidneys of DN rats. Furthermore, the levels of P-selectin and selectin-dependent inflammatory cytokines resulting from LMWF were obviously decreased at both the transcriptional and protein levels. Thus, our results found that LMWF protected the renal function in DN rats and alleviated inflammation through the modulation of P-selectin and inflammatory cytokines. LMWF may have therapeutic potential against DN.

The sulfated polysaccharide fucoidan rescues senescence of endothelial colony-forming cells for ischemic repair

The efficacy of cell therapy using endothelial colony-forming cells (ECFCs) in the treatment of ischemia is limited by the replicative senescence of isolated ECFCs in vitro. Such senescence must therefore be overcome in order for such cell therapies to be clinically applicable. This study aimed to investigate the potential of sulfated polysaccharide fucoidan to rescue ECFCs from cellular senescence and to improve in vivo vascular repair by ECFCs. Fucoidan-preconditioning of senescent ECFCs was shown by flow cytometry to restore the expression of functional ECFC surface markers (CD34, c-Kit, VEGFR2, and CXCR4) and stimulate the in vitro tube formation capacity of ECFCs. Fucoidan also promoted the expression of cell cycle-associated proteins (cyclin E, Cdk2, cyclin D1, and Cdk4) in senescent ECFCs, significantly reversed cellular senescence, and increased the proliferation of ECFCs via the FAK, Akt, and ERK signaling pathways. Fucoidan was found to enhance the survival, proliferation, incorporation, and endothelial differentiation of senescent ECFCs transplanted in ischemic tissues in a murine hind limb ischemia model. Moreover, ECFC-induced functional recovery and limb salvage were markedly improved by fucoidan pretreatment of ECFCs. To our knowledge, the findings of our study are the first to demonstrate that fucoidan enhances the neovasculogenic potential of ECFCs by rescuing them from replicative cellular senescence. Pretreatment of ECFCs with fucoidan may thus provide a novel strategy for the application of senescent stem cells to therapeutic neovascularization.

Nanostructured ultra-thin patches for ultrasound-modulated delivery of anti-restenotic drug

This work aims to demonstrate the possibility to fabricate ultra-thin polymeric films loaded with an anti-restenotic drug and capable of tunable drug release kinetics for the local treatment of restenosis. Vascular nanopatches are composed of a poly(lactic acid) supporting membrane (thickness: ~250 nm) on which 20 polyelectrolyte bilayers (overall thickness: ~70 nm) are alternatively deposited. The anti-restenotic drug is embedded in the middle of the polyelectrolyte structure, and released by diffusion mechanisms. Nanofilm fabrication procedure and detailed morphological characterization are reported here. Barium titanate nanoparticles (showing piezoelectric properties) are included in the polymeric support and their role is investigated in terms of influence on nanofilm morphology, drug release kinetics, and cell response. Results show an efficient drug release from the polyelectrolyte structure in phosphate-buffered saline, and a clear antiproliferative effect on human smooth muscle cells, which are responsible for restenosis. In addition, preliminary evidences of ultrasound-mediated modulation of drug release kinetics are reported, thus evaluating the influence of barium titanate nanoparticles on the release mechanism. Such data were integrated with quantitative piezoelectric and thermal measurements. These results open new avenues for a fine control of local therapies based on smart responsive materials.

Low-Molecular-Weight Fucoidan Induces Endothelial Cell Migration via the PI3K/AKT Pathway and Modulates the Transcription of Genes Involved in Angiogenesis

Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed that presents antithrombotic and pro-angiogenic properties. However, its mechanism of action is not well-characterized. Here, we studied the effects of LMWF on cell signaling and whole genome expression in human umbilical vein endothelial cells and endothelial colony forming cells. We observed that LMWF and vascular endothelial growth factor had synergistic effects on cell signaling, and more interestingly that LMWF by itself, in the absence of other growth factors, was able to trigger the activation of the PI3K/AKT pathway, which plays a crucial role in angiogenesis and vasculogenesis. We also observed that the effects of LMWF on cell migration were PI3K/AKT-dependent and that LMWF modulated the expression of genes involved at different levels of the neovessel formation process, such as cell migration and cytoskeleton organization, cell mobilization and homing. This provides a better understanding of LMWF’s mechanism of action and confirms that it could be an interesting therapeutic approach for vascular repair.

Heparanase and Syndecan-4 Are Involved in Low Molecular Weight Fucoidan-Induced Angiogenesis

Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases.

Fucoidan protects mesenchymal stem cells against oxidative stress and enhances vascular regeneration in a murine hindlimb ischemia model

BACKGROUND

Mesenchymal stem cells (MSCs) have the potential to differentiate into multiple cell lineages. Given this potential for tissue regeneration, MSC-based therapeutic applications have been considered in recent years. However, ischemia-induced apoptosis has been reported to be one of the main causes of MSC death following transplantation. The primary objective of this study was to determine whether a natural antioxidant, fucoidan, could protect MSCs from ischemia-induced apoptosis in vitro and in vivo. Furthermore, we investigated the mechanism of action of fucoidan's anti-ischemic effect in MSCs.

METHODS AND RESULT

Pre-treatment with fucoidan (10 μg/mL) suppressed the increase in H2O2-induced reactive oxygen species (ROS) levels and drastically reduced apoptotic cell death in MSCs. Fucoidan inhibited the activation of the pro-apoptotic proteins p38-mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK), and caspase-3, and augmented the expression of the anti-apoptosis protein cellular inhibitor of apoptosis (cIAP). Moreover, fucoidan significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the Akt pathway, resulting in enhanced cell survival. In a murine hindlimb ischemia model, transplanted fucoidan-treated MSCs showed significantly enhanced cell survival and proliferation in ischemic tissues. Functional recovery and limb salvage also remarkably improved in mice injected with fucoidan-stimulated MSCs compared with mice injected with non-stimulated MSCs.

CONCLUSION

Taken together, these results show that fucoidan protects MSCs from ischemia-induced cell death by modulation of apoptosis-associated proteins and cellular ROS levels through regulation of the MnSOD and Akt pathways, suggesting that fucoidan could be powerful therapeutic adjuvant for MSC-based therapy in ischemic diseases.

Modeling and analysis of drug-eluting stents with biodegradable PLGA coating: consequences on intravascular drug delivery

Increasing interests have been raised toward the potential applications of biodegradable poly(lactic-co-glycolic acid) (PLGA) coatings for drug-eluting stents in order to improve the drug delivery and reduce adverse outcomes in stented arteries in patients. This article presents a mathematical model to describe the integrated processes of drug release in a stent with PLGA coating and subsequent drug delivery, distribution, and drug pharmacokinetics in the arterial wall. The integrated model takes into account the PLGA degradation and erosion, anisotropic drug diffusion in the arterial wall, and reversible drug binding. The model simulations first compare the drug delivery from a biodegradable PLGA coating with that from a biodurable coating, including the drug release profiles in the coating, average arterial drug levels, and arterial drug distribution. Using the model for the PLGA stent coating, the simulations further investigate drug internalization, interstitial fluid flow in the arterial wall, and stent embedment for their impact on drug delivery. Simulation results show that these three factors, while imposing little change in the drug release profiles, can greatly change the average drug concentrations in the arterial wall. In particular, each of the factors leads to significant and yet distinguished alterations in the arterial drug distribution that can potentially influence the treatment outcomes. The detailed integrated model provides insights into the design and evaluation of biodegradable PLGA-coated drug-eluting stents for improved intravascular drug delivery.

Fucoidan and cancer: a multifunctional molecule with anti-tumor potential

There is a wide variety of cancer types yet, all share some common cellular and molecular behaviors. Most of the chemotherapeutic agents used in cancer treatment are designed to target common deregulated mechanisms within cancer cells. Many healthy tissues are also affected by the cytotoxic effects of these chemical agents. Fucoidan, a natural component of brown seaweed, has anti-cancer activity against various cancer types by targeting key apoptotic molecules. It also has beneficial effects as it can protect against toxicity associated with chemotherapeutic agents and radiation. Thus the synergistic effect of fucoidan with current anti-cancer agents is of considerable interest. This review discusses the mechanisms by which fucoidan retards tumor development, eradicates tumor cells and synergizes with anti-cancer chemotherapeutic agents. Challenges to the development of fucoidan as an anti-cancer agent will also be discussed.

Degradation of fucoidans from Sargassum fulvellum and their biological activities

A fucoidan extracted from Sargassum fulvellum, was degraded by ultrasound (US) or electron beam (EB) irradiation in the presence of hydrogen peroxide aqueous solution. From the energetic point of view, the most effective method for the fucoidan degradation was found to be EB radiation method in H2O2 with a yield of scission Gs 3.310 × 10(-8)mol/J at the reaction condition of 1.5% hydrogen peroxide and irradiation 2.5 kGy. The degradation took place by the formation of a reactive hydroxyl radical due to the dissociation of H2O2 in the presence of US or EB. The low molecular weight fucoidans (LMWFs) prevented P-selectin binding to Sialyl Lewis X with an IC50 (inhibitory concentration 50) of 20 nM as compared to 400 nM for heparin and 25,000 nM for dextran sulfate. The LMWFs showed no hemolytic activity at concentrations up to 950 μg/ml.

Ultrasmall superparamagnetic iron oxide nanoparticles coated with fucoidan for molecular MRI of intraluminal thrombus

AIM

We have designed ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles associated with fucoidan (USPOI-FUCO), a natural sulfated polysaccharide with high affinity for activated platelets, to visualize by MRI arterial thrombi.

MATERIALS & METHODS

USPIOs were prepared and sizes, zeta-potentials and relaxivities were measured. Elastase perfusion in the infrarenal aorta of Wistar rats induced intraluminal thrombus. They were scanned on 4.7 T MRI before and after injection of USPIO-FUCO or USPIO coated with anionic dextran.

RESULTS

Surface plasmon resonance evidenced that fucoidan and USPIO-FUCO bind in vitro to immobilized P-selectin. All intraluminal hyposignals detected by MRI after injection of USPIO-FUCO on animals (13 out of 13) were correlated by histology with thrombi, whereas none could be identified with control USPIOs (0 out of 7). No signal was seen in absence of thrombus. Thrombi by MRI were correlated with P-selectin immunostaining and USPIO detection by electron microscopy.

CONCLUSION

In vivo thrombi can thus be evidenced by MRI with USPIO-FUCO.

Low-molecular-weight fucoidan protects endothelial function and ameliorates basal hypertension in diabetic Goto-Kakizaki rats

Endothelial dysfunction, characterized by impairment of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) bioavailability, has been implicated in diabetic cardiovascular pathogenesis. In this study, low-molecular-weight fucoidan (LMWF), which has multiple biological activities including anti-inflammatory and anti-oxidative properties, was investigated for its protective effect against endothelial dysfunction in Goto-Kakizaki type 2 diabetic rats. LMWF (50, 100, or 200 mg/kg/day) or probucol (100 mg/kg/day) were given to diabetic rats for 12 weeks. Basal blood pressure, acetylcholine- or flow-mediated relaxation of mesenteric and paw arteries, endothelium-dependent dilation of aorta, eNOS phosphorylation, and NO production were measured using laser Doppler flowmetry, force myograph, hematoxylin and eosin staining, western blot analysis, and an NO assay. We found that LMWF robustly ameliorated the basal hypertension and impairment of endothelium-dependent relaxation in the aorta, as well as mesenteric and paw arteries in diabetic rats. In addition, the reduction in eNOS phosphorylation at Ser1177, eNOS expression, and NO production because of diabetes were partially reversed by LMWF treatment. However, probucol, a lipid-modifying drug with antioxidant properties, displayed only mild effects. Moreover, LMWF induced, in a dose-dependent manner, endothelium-dependent vasodilation and eNOS phosphorylation at Ser1177 in normal aorta, and also promoted Ser1177 phosphorylation and NO synthesis in primary cultured vasoendothelial cells. Thus, these data demonstrate for the first time that fucoidan protects vasoendothelial function and reduces basal blood pressure in type 2 diabetes rats via, at least in part, preservation of eNOS function. Fucoidan is therefore a potential candidate drug for protection of endothelium in diabetic cardiovascular complications.

Fucoidan promotes early step of cardiac differentiation from human embryonic stem cells and long-term maintenance of beating areas

Somatic stem cells require specific niches and three-dimensional scaffolds provide ways to mimic this microenvironment. Here, we studied a scaffold based on Fucoidan, a sulfated polysaccharide known to influence morphogen gradients during embryonic development, to support human embryonic stem cells (hESCs) differentiation toward the cardiac lineage. A macroporous (pore 200 μm) Fucoidan scaffold was selected to support hESCs attachment and proliferation. Using a protocol based on the cardiogenic morphogen bone morphogenic protein 2 (BMP2) and transforming growth factor (TGFβ) followed by tumor necrosis factor (TNFα), an effector of cardiopoietic priming, we examined the cardiac differentiation in the scaffold compared to culture dishes and embryoid bodies (EBs). At day 8, Fucoidan scaffolds supported a significantly higher expression of the 3 genes encoding for transcription factors marking the early step of embryonic cardiac differentiation NKX2.5 (p<0.05), MEF2C (p<0.01), and GATA4 (p<0.01), confirmed by flow cytometry analysis for MEF2C and NKX2.5. The ability of Fucoidan scaffolds to locally concentrate and slowly release TGFβ and TNFα was confirmed by Luminex technology. We also found that Fucoidan scaffolds supported the late stage of embryonic cardiac differentiation marked by a significantly higher atrial natriuretic factor (ANF) expression (p<0.001), although only rare beating areas were observed. We postulated that absence of mechanical stress in the soft hydrogel impaired sarcomere formation, as confirmed by molecular analysis of the cardiac muscle myosin MYH6 and immunohistological staining of sarcomeric α-actinin. Nevertheless, Fucoidan scaffolds contributed to the development of thin filaments connecting beating areas through promotion of smooth muscle cells, thus enabling maintenance of beating areas for up to 6 months. In conclusion, Fucoidan scaffolds appear as a very promising biomaterial to control cardiac differentiation from hESCs that could be further combined with mechanical stress to promote sarcomere formation at terminal stages of differentiation.

Fucoidan as a marine anticancer agent in preclinical development

Fucoidan is a fucose-containing sulfated polysaccharide derived from brown seaweeds, crude extracts of which are commercially available as nutritional supplements. Recent studies have demonstrated antiproliferative, antiangiogenic, and anticancer properties of fucoidan in vitro. Accordingly, the anticancer effects of fucoidan have been shown to vary depending on its structure, while it can target multiple receptors or signaling molecules in various cell types, including tumor cells and immune cells. Low toxicity and the in vitro effects of fucoidan mentioned above make it a suitable agent for cancer prevention or treatment. However, preclinical development of natural marine products requires in vivo examination of purified compounds in animal tumor models. This review discusses the effects of systemic and local administration of fucoidan on tumor growth, angiogenesis, and immune reaction and whether in vivo and in vitro results are likely applicable to the development of fucoidan as a marine anticancer drug.

Healthy aging diets other than the Mediterranean: a focus on the Okinawan diet

The traditional diet in Okinawa is anchored by root vegetables (principally sweet potatoes), green and yellow vegetables, soybean-based foods, and medicinal plants. Marine foods, lean meats, fruit, medicinal garnishes and spices, tea, alcohol are also moderately consumed. Many characteristics of the traditional Okinawan diet are shared with other healthy dietary patterns, including the traditional Mediterranean diet, DASH diet, and Portfolio diet. All these dietary patterns are associated with reduced risk for cardiovascular disease, among other age-associated diseases. Overall, the important shared features of these healthy dietary patterns include: high intake of unrefined carbohydrates, moderate protein intake with emphasis on vegetables/legumes, fish, and lean meats as sources, and a healthy fat profile (higher in mono/polyunsaturated fats, lower in saturated fat; rich in omega-3). The healthy fat intake is likely one mechanism for reducing inflammation, optimizing cholesterol, and other risk factors. Additionally, the lower caloric density of plant-rich diets results in lower caloric intake with concomitant high intake of phytonutrients and antioxidants. Other shared features include low glycemic load, less inflammation and oxidative stress, and potential modulation of aging-related biological pathways. This may reduce risk for chronic age-associated diseases and promote healthy aging and longevity.

Low molecular weight fucoidan against renal ischemia-reperfusion injury via inhibition of the MAPK signaling pathway

BACKGROUND

Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI) in both native and transplanted kidneys. The objective of the present study was to evaluate whether low-molecular-weight fucoidan (LMWF) could attenuate renal IRI in an animal model and in vitro cell models and study the mechanisms in which LMWF protected from IRI.

METHODOLOGY/PRINCIPAL FINDINGS

Male mice were subjected to right renal ischemia for 30 min and reperfusion for 24 h, or to a sham operation with left kidney removed. Kidneys undergone IR showed characteristic morphological changes, such as tubular dilatation, and brush border loss. However, LMWF significantly corrected the renal dysfunction and the abnormal levels of MPO, MDA and SOD induced by IR. LMWF also inhibited the activation of MAPK pathways, which consequently resulted in a significant decrease in the release of cytochrome c from mitochondria, ratios of Bax/Bcl-2 and cleaved caspase-3/caspase-3, and phosphorylation of p53. LMWF alleviated hypoxia-reoxygenation or CoCl(2) induced cell viability loss and ΔΨm dissipation in HK2 renal tubular epithelial cells, which indicates LMWF may result in an inhibition of the apoptosis pathway through reducing activity of MAPK pathways in a dose-dependent manner.

CONCLUSIONS/SIGNIFICANCE

Our in vivo and in vitro studies show that LMWF ameliorates acute renal IRI via inhibiting MAPK signaling pathways. The data provide evidence that LMWF may serve as a potential therapeutic agent for acute renal IRI.

Therapeutic potential of fucoidan in myocardial ischemia

Fucoidan, a sulfated polysaccharide extracted from brown seaweed, is a candidate for the treatment of ischemic diseases. The aim of this study was to measure the therapeutic potential of fucoidan in a rat model of myocardial ischemia-reperfusion injury. Forty rats were submitted to myocardial ischemia-reperfusion injury by transient occlusion of the left coronary artery. Rats were then randomized into 2 groups: fucoidan (5 mg/kg, intramuscularly; n = 20) or control (saline intramuscularly; n = 20) was administered 1 hour before injury and daily thereafter for 1 month. At 1 month, plasma levels of stromal cell-derived factor-1α (SDF-1α) were assessed by enzyme-linked immunosorbent assay kit. Hearts were evaluated by histoimmunochemistry. Fucoidan induced significant antifibrotic effects, reducing the infarct scar size by almost 30% on Sirius red-stained sections (9.45% ± 4.27% vs. 13% ± 5.67% in controls; P = 0.03). Vascular density in the fucoidan group (α-actin, RECA-1, or lectin BS1 stained) was increased by 40% (2.18 ± 0.79 mm vs. 1.49 ± 0.42 mm in controls ×200; P = 0.001). Plasma SDF-1α at 1 month was not significantly different between the 2 groups. However, increased immunostaining density of SDF-1α and vascular endothelial growth factor in fibrotic ischemic tissues was observed in fucoidan-treated animals versus controls. In conclusion, fucoidan enhanced tissue repair in myocardial ischemia-reperfusion by promoting revascularization (in situ vascular endothelial growth factor and SDF-1α overexpression) and limiting fibrosis. Consequently, fucoidan may be useful for myocardial ischemic patients.

Heparin-like entities from marine organisms

Polysaccharides are ubiquitous in animals and plant cells where they play a significant role in a number of physiological situations e.g. hydration, mechanical properties of cell walls and ionic regulation. This review concentrates on heparin-like entities from marine procaryotes and eukaryotes. Carbohydrates from marine prokaryotes offer a significant structural chemodiversity with novel material and biological properties. Cyanobacteria are Gram-negative photosynthetic prokaryotes considered as a rich source of novel molecules, and marine bacteria are a rich source of polysaccharides with novel structures, which may be a good starting point from which to synthesise heparinoid molecules. For example, some sulphated polysaccharides have been isolated from gamma-proteobacteria such as Alteromonas and Pseudoalteromonas sp. In contrast to marine bacteria, all marine algae contain sulphated wall polysaccharides, whereas such polymers are not found in terrestrial plants. In their native form, or after chemical modifications, a range of polysaccharides isolated from marine organisms have been described that have anticoagulant, anti-thrombotic, anti-tumour, anti-proliferative, anti-viral or anti-inflammatory activities.In spite of the enormous potential of sulphated oligosaccharides from marine sources, their technical and pharmaceutical usage is still limited because of the high complexity of these molecules. Thus, the production of tailor-made oligo- and polysaccharidic structures by biocatalysis is also a growing field of interest in biotechnology.

Algal fucoidan: structural and size-dependent bioactivities and their perspectives

Fucoidan is a complex-sulfated polysaccharide distributed in various marine organisms, and the brown algae are reported as the major producer. The fucoidan is important for their high bioactive properties, like antibacterial, anticoagulant, antiviral, anti-tumor, etc., and many more to be explored. There is a strong archival support for the bioactivity and promising properties of this molecule, which creates a hope for this molecule as future drug against thrombosis and some kind of cancers. Reports other than the above bioactive properties have also been a matter of interest for the design of signal or enzyme-arrested new class of drugs. In the past three decades, the research on isolation, molecular characterization, and screening of biological applications has significantly increased. One major issue associated with this molecule is the higher size and seasonal variation in their chemical composition; to resolve the issue and maintain its bioactivity, a prioritized and literal hydrolysis process is required to be developed. Here, in this mini-review, we have tried to summarize the algal fucoidan research and the bioactivities influenced by their molecular size.

Therapies from fucoidan; multifunctional marine polymers

Published research on fucoidans increased three fold between 2000 and 2010. These algal derived marine carbohydrate polymers present numerous valuable bioactivities. This review discusses the role for fucoidan in the control of acute and chronic inflammation via selectin blockade, enzyme inhibition and inhibiting the complement cascade. The recent data on toxicology and uptake of fucoidan is detailed together with a discussion on the comparative activities of fractions of fucoidan from different sources. Recent in vivo, in vitro and clinical research related to diverse clinical needs is discussed. Targets include osteoarthritis, kidney and liver disease, neglected infectious diseases, hemopoietic stem cell modulation, protection from radiation damage and treatments for snake envenomation. In recent years, the production of well characterized reproducible fucoidan fractions on a commercial scale has become possible making therapies from fucoidan a realizable goal.

Cardioprotective activity of Cladosiphon okamuranus fucoidan against isoproterenol induced myocardial infarction in rats

Fucoidans, sulfated polysaccharides of brown algae, have attracted steady attention in the last few years as readily accessible biopolymers possessing a wide spectrum of biological activities. In this study, cardioprotective activity of fucoidan extracted from Cladosiphon okamuranus was evaluated in isoproterenol induced myocardial infarction in rats. Male Wistar albino rats (180±25 g) were divided in to four groups of six animals each as follows: Group (1) control, Group (2) isoproterenol alone, Group (3) fucoidan alone and Group (4) fucoidan+isoproterenol. To evaluate the efficacy of fucoidan treatment against isoproterenol induced myocardial damage, biochemical parameters and histopathological studies were carried out. Isoproterenol administration produced severe myocardial damage and high lipid peroxidation level. On the contrary, fucoidan treatment reduced myocardial damage, which has been reflected by improvement in parameters such as creatinine phosphokinase (CPK), lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate transaminase (AST). In addition, fucoidan improved the antioxidant defence system in treated animals and considerably reduced the oxidative stress exerted by isoproterenol. The reduction in oxidative stress in Group (4) was evident from the lipid peroxidation and antioxidant activities. Furthermore, the increase in the levels of total cholesterol, triglycerides and low density lipoprotein (LDL) and decrease in the levels of high density lipoprotein (HDL) was significantly reversed in Group (4), when compared with Group (2). The histopathological studies also showed that fucoidan treatment significantly minimized the damage induced by isoproterenol. Thus, fucoidan provide cardioprotection against isoproterenol induced myocardial infarction in rats.

Biomimetic MRI contrast agent for imaging of inflammation in atherosclerotic plaque of ApoE-/- mice: a pilot study

OBJECTIVE

Atherosclerosis involves an inflammatory process characterized by cellular and molecular responses. A slow-clearance blood-pool paramagnetic agent (CMD-A2-Gd-DOTA: P717) chemically modified to create a functionalized product (F-P717) for targeting inflammation in vessel walls was evaluated in vivo in mice.

METHODS AND RESULTS

Carboxylate and sulfate groups were grafted onto the macromolecular paramagnetic Gd-DOTA-dextran backbone. Products were also fluorescently labeled with rhodamine isothiocyanate. Pre- and postcontrast MRI was performed on a 2-Tesla magnet in ApoE-/- and control C57BL/6 mice after P717 or F-P717 injection at a dose of 60 micromol Gd/kg. Axial T1-weighted images of the abdominal aorta were obtained using a 2D multislice spin-echo sequence. F-P717 significantly enhanced the magnetic resonance imaging (MRI) signal in the abdominal aortic wall of ApoE-/- mice (>50% signal-to-noise ratio increase between 10 and 30 minutes), but not of control mice. P717 produced only moderate (<20%) MRI signal enhancement within the same time frame. The MRI data were correlated to histopathology. Immunofluorescence in ApoE-/- mice colocalized F-P717 but not P717 with the inflammatory area revealed by P-selectin labeling.

CONCLUSION

This study demonstrates the efficacy of F-P717 as a new molecular imaging agent for noninvasive in vivo MRI location of inflammatory vascular tree lesions in ApoE-/- mice.

The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load

Residents of Okinawa, the southernmost prefecture of Japan, are known for their long average life expectancy, high numbers of centenarians, and accompanying low risk of age-associated diseases. Much of the longevity advantage in Okinawa is thought to be related to a healthy lifestyle, particularly the traditional diet, which is low in calories yet nutritionally dense, especially with regard to phytonutrients in the form of antioxidants and flavonoids. Research suggests that diets associated with a reduced risk of chronic diseases are similar to the traditional Okinawan diet, that is, vegetable and fruit heavy (therefore phytonutrient and antioxidant rich) but reduced in meat, refined grains, saturated fat, sugar, salt, and full-fat dairy products. Many of the characteristics of the diet in Okinawa are shared with other healthy dietary patterns, such as the traditional Mediterranean diet or the modern DASH (Dietary Approaches to Stop Hypertension) diet. Features such as the low levels of saturated fat, high antioxidant intake, and low glycemic load in these diets are likely contributing to a decreased risk for cardiovascular disease, some cancers, and other chronic diseases through multiple mechanisms, including reduced oxidative stress. A comparison of the nutrient profiles of the three dietary patterns shows that the traditional Okinawan diet is the lowest in fat intake, particularly in terms of saturated fat, and highest in carbohydrate intake, in keeping with the very high intake of antioxidant-rich yet calorie-poor orange-yellow root vegetables, such as sweet potatoes, and green leafy vegetables. Deeper analyses of the individual components of the Okinawan diet reveal that many of the traditional foods, herbs, or spices consumed on a regular basis could be labeled "functional foods" and, indeed, are currently being explored for their potential health-enhancing properties.

Higher specificity of the activity of low molecular weight fucoidan for thrombin-induced platelet aggregation

Algal fucoidans possess a wide variety of biological activities, including anticoagulation and antithrombosis, making them potential candidates for clinical use. We assessed the antiaggregant, anticoagulant and antithrombotic activities and the underlying mechanism of the low- and high-molecular weight fucoidans from the seaweed Laminaria japonica of Qingdao, China (F-Q and HMWF-Q). In the platelets of rats and humans, HMWF-Q demonstrated a pro-aggregation response, whereas F-Q (like the commercially purchased fucoidan (F-S) and heparin), showed an inhibitory effect on thrombin-induced aggregation with an IC(50) of 8 microg/mL, approximately five times lower than those of F-S and heparin. In the activated partial thromboplastin time test, F-Q (40 microg/mL) demonstrated less potent effect than F-S (40 microg/mL) and heparin (7mug/mL); 162+/-2.4s vs. 250+/-13.2s and >300s, p<0.01, respectively. It was also less effective than F-S on inhibiting thrombin catalyzed fibrinogen cleavage (IC(50) 10 microg/mL vs. 2.8 microg/mL) in vitro and rat thrombosis in vivo at 3mg/kg (i.v.). The inhibitory effects of F-Q and heparin on thrombin activity were strikingly enhanced by either antithrombin (AT) or heparin cofactor II (HCII). A direct interaction of F-S with thrombin, and F-Q or heparin with AT was demonstrated in both fluorescence quenching and PAGE analysis. Additionally, a pro-aggregation effect and an enhancement of thrombin activity were also observed with F-S, but not with F-Q or heparin, treatment. These results indicate that F-Q inhibits thrombin via activation of AT and HCII, whereas F-S mainly interacts directly with thrombin. Importantly, F-Q shows a higher specificity for hypoaggregation and a weaker effect for anticoagulant profiles than heparin and F-S. Therefore, F-Q could be a promising candidate for the treatment of thrombosis-related cardiovascular diseases.

A novel mouse model of in-stent restenosis

BACKGROUND AND AIMS

In-stent restenosis (ISR) is the major complication that occurs after percutaneous coronary interventions to facilitate coronary revascularization. Herein we described a simple and cost-effective model, which reproduces important features of ISR in the mouse.

METHODS AND RESULTS

Microvascular bare metal stents were successfully implanted in the abdominal aorta of atherosclerotic ApoE-null mice. Patency of implanted stents was interrogated using ultrasound biomicroscopy. Aortas were harvested at different time points after implantation and processed for histopathological analysis. Thrombus formation was histologically detected after 1 day. Leukocyte adherence and infiltration were evident after 7 days and decreased thereafter. Neointimal formation, neointimal thickness and luminal stenosis simultaneously increased up to 28 days after stent implantation. Using multichannel fluorescence molecular tomography (FMT) for spatiotemporal resolution of MMP activities, we observed that MMP activity in the stented aorta of Apo-E null mice was 2-fold higher than that of wild-type mice. Finally, we compared neointimal formation in response to stenting in two genetically different mouse strains. In-stent neointimas in FVB/NJ mice were 2-fold thicker than in C57BL/6J mice (p=0.002).

CONCLUSION

We have developed a model that can take advantage of the multiple genetic resources available for the mouse to study the mechanisms of in-stent restenosis.

Fucoidans and fucoidanases--focus on techniques for molecular structure elucidation and modification of marine polysaccharides

The research field of fucoidans (sulphated polysaccharides from algae) and fucoidanases was strongly developing in recent years. Several different fucoidans and a few fucoidan-degrading enzymes were isolated and characterised. A high potential is seen in the medical exploitation of the fucoidans and its degradation products. This review gives an overview about the research of the last 5 years concerning fucoidan characterisation and application as well as enzyme detection, characterisation and production.

Structure, biology, evolution, and medical importance of sulfated fucans and galactans

Sulfated fucans and galactans are strongly anionic polysaccharides found in marine organisms. Their structures vary among species, but their major features are conserved among phyla. Sulfated fucans are found in marine brown algae and echinoderms, whereas sulfated galactans occur in red and green algae, marine angiosperms, tunicates (ascidians), and sea urchins. Polysaccharides with 3-linked, beta-galactose units are highly conserved in some taxonomic groups of marine organisms and show a strong tendency toward 4-sulfation in algae and marine angiosperms, and 2-sulfation in invertebrates. Marine algae mainly express sulfated polysaccharides with complex, heterogeneous structures, whereas marine invertebrates synthesize sulfated fucans and sulfated galactans with regular repetitive structures. These polysaccharides are structural components of the extracellular matrix. Sulfated fucans and galactans are involved in sea urchin fertilization acting as species-specific inducers of the sperm acrosome reaction. Because of this function the structural evolution of sulfated fucans could be a component in the speciation process. The algal and invertebrate polysaccharides are also potent anticoagulant agents of mammalian blood and represent a potential source of compounds for antithrombotic therapies.

Affinity of low molecular weight fucoidan for P-selectin triggers its binding to activated human platelets

BACKGROUND

P-selectin is an adhesion receptor expressed on activated platelets and endothelial cells. Its natural ligand, P-selectin glycoprotein ligand-1, is expressed on leucocytes and the P-selectin/PSGL-1 interaction is involved in leukocyte rolling. We have compared the interaction of P-selectin with several low molecular weight polysaccharides: fucoidan, heparin and dextran sulfate.

METHODS

Binding assays were obtained from the interaction of the polysaccharides with Sialyl Lewis X and PSGL-1 based constructs onto microtiter plates coated with P-selectin. SELDI TOF mass spectrometry was performed with anionic chips arrays coated with P-selectin in the absence or in the presence of polysaccharides. Kd were obtained from surface plasmon resonance experiments with immobilized P-selectin constructs, polysaccharides being injected in the mobile phase. Human whole blood flow cytometry experiments were performed with fluorescein isothiocyanate labelled polysaccharides with or without platelets activators.

RESULTS

The fucoidan prevented P-selectin binding to Sialyl Lewis X with an IC(50) of 20 nM as compared to 400 nM for heparin and <25000 nM for dextran sulfate. It exhibited the highest affinity for immobilized P-selectin with a KD of 1.2 nM, two orders of magnitude greater than the K(D) of the other polysaccharides. Mass spectrometry evidenced the formation of a complex between P-selectin and fucoidan. The intensity of the fucoidan binding to platelets was dependent on the level of platelet activation. Competition between fucoidan and an anti P-selectin antibody demonstrated the specificity of the interaction.

GENERAL SIGNIFICANCE

Low molecular weight fucoidan is a promising therapeutic agent of natural origin for biomedical applications.

Synthesis and characterization of a new polysaccharide-graft-polymethacrylate copolymer for three-dimensional hybrid hydrogels

Hybrid materials constituted by hydrophobic and hydrophilic biocompatible macromolecules are useful for biomedical applications. In this context, a well-known acrylic monomer (methyl methacrylate) was polymerized and grafted onto the polysaccharide dextran by the use of ceric ammonium nitrate as a redox initiator in aqueous nitric acid medium. The effects of concentrations of dextran, acrylic monomer, and ceric ions on the copolymerization yields were investigated in detail. The obtained polymers were studied by solubility measurements, Fourier transform infrared spectrometry, (13)C nuclear magnetic resonance spectroscopy, and viscosimetric analysis. Interestingly, we found conditions to form transparent and homogeneous thin films or 3D structures with hybrid properties. Indeed, the copolymer, but not dextran or PMMA, could be dissolved in water/THF (20/80 v/v). The thermomechanical properties of the resulting copolymer analyzed by differential scanning calorimetry and dynamic mechanical analysis showed the occurrence of a single glass-transition temperature and a marked difference with the two homopolymers. The cytocompatibility of the copolymer with human endothelial cells was evidenced by the normal cell adhesion, proliferation, and morphology after 5 days in culture on these gels. In conclusion, this type of copolymer with hybrid properties of two biocompatible macromolecules could be of great interest as a 3D scaffold or for coating in biomedical applications.

Fucoidan: structure and bioactivity

Fucoidan refers to a type of polysaccharide which contains substantial percentages of L-fucose and sulfate ester groups, mainly derived from brown seaweed. For the past decade fucoidan has been extensively studied due to its numerous interesting biological activities. Recently the search for new drugs has raised interest in fucoidans. In the past few years, several fucoidans' structures have been solved, and many aspects of their biological activity have been elucidated. This review summarizes the research progress on the structure and bioactivity of fucoidan and the relationships between structure and bioactivity.