In-vitro Evaluation einer neu entwickelten bio-hybriden tissue-engineerten Aortenklappenprothese zur TAVI-Applikation

During the last few years, transcatheter aortic valve implantation (TAVI) has been established as the initial therapy for patients with aortic valve diseases. The prostheses however, are limited in functionality and durability due to their production and implantation process. In this study, newly developed, tissue engineered aortic valve prostheses were analyzed and evaluated. The functionality and integrity of the decellularized and stented heart valves were evaluated after conditioning and in vitro TAVI simulation. The biohybrid aortic valves (BAV; n=6) were composed of decellularized homograft cusps and polyurethane patches sewed into Co-Cr-stents. The BAVs were colonized and cultivated with fibroblasts (FB) and subsequently with endothelial cells (EC), which were extracted from saphenous vein segments. After cell seeding, the valves were conditioned in a pulsatile bioreactor (500ml/min, 5days). Simulation of the TAVI intervention was performed by crimping and subsequent redilatation of the BAVs. The functionality of the BAVs was tested at increased flow conditions (1100ml/min, 2days). The valve function was visually monitored during this process using video imaging. Samples of the BAVs were taken before and after each step and analyzed using scanning electron microscopy (SEM), immunocytochemistry (ICC), immunohistochemistry (IHC) and Live/Dead® staining methods. After cell seeding, static cultivation and first conditioning confluent cell layers were observed in SEM. Positive IHC-staining with CD-31 (EC-specific antibody) and TE-7 (FB-specific antibody) indicated the presence of EC and FB on the surfaces of the BAVs. The construction of extracellular matrix (ECM) was verified through IHC-staining against Collagen IV and Fibronectin. A strong establishment of ECM was detected, especially after the first conditioning phase. However, a large number of lethal cells were detected by Live/Dead®-staining after crimping. Extensive regions of damaged cell-layers were detected by SEM-analysis. Furthermore, highly expressed ICAM staining was seen after perfusion. During conditioning and perfusion, the proper opening and closing behavior of the BAVs were visually monitored. The biohybrid aortic valve proves as an effective scaffold for tissue engineering. However, it is suggested to reconsider the crimping of tissue engineered aortic valves, since the procedure leads to obvious and severe damage to the tissue engineered cell layers

In-vitro Evaluation einer neu entwickelten bio-hybriden tissue-engineerten Aortenklappenprothese zur TAVI-Applikation

During the last few years, transcatheter aortic valve implantation (TAVI) has been established as the initial therapy for patients with aortic valve diseases. The prostheses however, are limited in functionality and durability due to their production and implantation process. In this study, newly developed, tissue engineered aortic valve prostheses were analyzed and evaluated. The functionality and integrity of the decellularized and stented heart valves were evaluated after conditioning and in vitro TAVI simulation. The biohybrid aortic valves (BAV; n=6) were composed of decellularized homograft cusps and polyurethane patches sewed into Co-Cr-stents. The BAVs were colonized and cultivated with fibroblasts (FB) and subsequently with endothelial cells (EC), which were extracted from saphenous vein segments. After cell seeding, the valves were conditioned in a pulsatile bioreactor (500ml/min, 5days). Simulation of the TAVI intervention was performed by crimping and subsequent redilatation of the BAVs. The functionality of the BAVs was tested at increased flow conditions (1100ml/min, 2days). The valve function was visually monitored during this process using video imaging. Samples of the BAVs were taken before and after each step and analyzed using scanning electron microscopy (SEM), immunocytochemistry (ICC), immunohistochemistry (IHC) and Live/Dead® staining methods. After cell seeding, static cultivation and first conditioning confluent cell layers were observed in SEM. Positive IHC-staining with CD-31 (EC-specific antibody) and TE-7 (FB-specific antibody) indicated the presence of EC and FB on the surfaces of the BAVs. The construction of extracellular matrix (ECM) was verified through IHC-staining against Collagen IV and Fibronectin. A strong establishment of ECM was detected, especially after the first conditioning phase. However, a large number of lethal cells were detected by Live/Dead®-staining after crimping. Extensive regions of damaged cell-layers were detected by SEM-analysis. Furthermore, highly expressed ICAM staining was seen after perfusion. During conditioning and perfusion, the proper opening and closing behavior of the BAVs were visually monitored. The biohybrid aortic valve proves as an effective scaffold for tissue engineering. However, it is suggested to reconsider the crimping of tissue engineered aortic valves, since the procedure leads to obvious and severe damage to the tissue engineered cell layers

Broussonetia papyrifera Root Bark Extract Exhibits Anti-inflammatory Effects on Adipose Tissue and Improves Insulin Sensitivity Potentially Via AMPK Activation

The chronic low-grade inflammation in adipose tissue plays a causal role in obesity-induced insulin resistance and its associated pathophysiological consequences. In this study, we investigated the effects of extracts of Broussonetia papyrifera root bark (PRE) and its bioactive components on inflammation and insulin sensitivity. PRE inhibited TNF-alpha-induced NF-kappa B transcriptional activity in the NF-kappa B luciferase assay and pro-inflammatory genes' expression by blocking phosphorylation of I kappa B and NF-kappa B in 3T3-L1 adipocytes, which were mediated by activating AMPK. Ten-week-high fat diet (HFD)-fed C57BL6 male mice treated with PRE had improved glucose intolerance and decreased inflammation in adipose tissue, as indicated by reductions in NF-kappa B phosphorylation and pro-inflammatory genes' expression. Furthermore, PRE activated AMP-activated protein kinase (AMPK) and reduced lipogenic genes' expression in both adipose tissue and liver. Finally, we identified broussoflavonol B (BF) and kazinol J (KJ) as bioactive constituents to suppress pro-inflammatory responses via activating AMPK in 3T3-L1 adipocytes. Taken together, these results indicate the therapeutic potential of PRE, especially BF or KJ, in metabolic diseases such as obesity and type 2 diabetes

PPM1A Controls Diabetic Gene Programming through Directly Dephosphorylating PPAR?? at Ser273

Peroxisome proliferator-activated receptor gamma (PPAR gamma) is a master regulator of adipose tissue biology. In obesity, phosphorylation of PPAR gamma at Ser273 (pSer273) by cyclin-dependent kinase 5 (CDK5)/extracellular signal-regulated kinase (ERK) orchestrates diabetic gene reprogramming via dysregulation of specific gene expression. Although many recent studies have focused on the development of non-classical agonist drugs that inhibit the phosphorylation of PPAR gamma at Ser273, the molecular mechanism of PPAR gamma dephosphorylation at Ser273 is not well characterized. Here, we report that protein phosphatase Mg2+/Mn2+-dependent 1A (PPM1A) is a novel PPAR gamma phosphatase that directly dephosphorylates Ser273 and restores diabetic gene expression which is dysregulated by pSer273. The expression of PPM1A significantly decreases in two models of insulin resistance: diet-induced obese (DIO) mice and db/db mice, in which it negatively correlates with pSer273. Transcriptomic analysis using microarray and genotype-tissue expression (GTEx) data in humans shows positive correlations between PPM1A and most of the genes that are dysregulated by pSer273. These findings suggest that PPM1A dephosphorylates PPAR gamma at Ser273 and represents a potential target for the treatment of obesity-linked metabolic disorders

COMPARATIVE GENETICS OF APODEMUS AGRARIUS (RODENTIA: MAMMALIA) FROM INSULAR AND CONTINENTAL EURASIAN POPULATIONS: CYTOCHROME B SEQUENCE ANALYSES

To reexamine genetic divergence of Apodemus agrarius in insular Taiwan and the Korean Jeju from other populations in continental Eurasia, we obtained 91 cytochrome b complete sequences of A. agrarius across Eurasia, and these sequences were compared to eight corresponding sequences of A. agrarius, obtained from GenBank. We first found that the two insular populations are two clades, and that each of them is divergent from continental Eurasian populations, clustered into another clade. Each of the two insular clades appeared to be isolated in spite of land connection to nearby continent during the last glacial period, and we considered the two insular forms as A. a. insulaemus and A. a. chejuensis and one continental Eurasian form as A. a. agrarius, although further analyses are needed to confirm our present findings. Additionally, the Taiwan clade seemed to be composed of two subclades (western and eastern), separated by Taiwan’s central mountain range

Vav1 inhibits RANKL-induced osteoclast differentiation and bone resorption

Vav1 is a Rho/Rac guanine nucleotide exchange factor primarily expressed in hematopoietic cells. In this study, we investigated the potential role of Vav1 in osteoclast (OC) differentiation by comparing the ability of bone marrow mononuclear cells (BMMCs) obtained from Vav1-deficient (Vav1−/−) and wild-type (WT) mice to differentiate into mature OCs upon stimulation with macrophage colony stimulating factor and receptor activator of nuclear kappa B ligand in vitro. Our results suggested that Vav1 deficiency promoted the differentiation of BMMCs into OCs, as indicated by the increased expression of tartrate-resistant acid phosphatase, cathepsin K, and calcitonin receptor. Therefore, Vav1 may play a negative role in OC differentiation. This hypothesis was supported by the observation of more OCs in the femurs of Vav1−/− mice than in WT mice. Furthermore, the bone status of Vav1−/− mice was analyzed in situ and the femurs of Vav1−/− mice appeared abnormal, with poor bone density and fewer number of trabeculae. In addition, Vav1-deficient OCs showed stronger adhesion to vitronectin, an αvβ3 integrin ligand important in bone resorption. Thus, Vav1 may inhibit OC differentiation and protect against bone resorption

(E)-4-{[(Pyridin-4-yl­methyl­idene)amino]­meth­yl}benzoic acid

The title mol­ecule, C14H12N2O2, exhibits a V-shaped conformation with a dihedral angle of 59.69 (3)° between the benzene and pyridine rings. In the crystal, O—H⋯N hydrogen bonds link the mol­ecules into zigzag chains along [010]

Fabrication of graphene-based electrode in less than a minute through hybrid microwave annealing

Highly efficient and stable MoS 2 nanocrystals on graphene sheets (MoS 2 /GR) are synthesized via a hybrid microwave annealing process. Through only 45 second-irradiation using a household microwave oven equipped with a graphite susceptor, crystallization of MoS 2 and thermal reduction of graphene oxide into graphene are achieved, indicating that our synthetic method is ultrafast and energy-economic. Graphene plays a crucial role as an excellent microwave absorber as well as an ideal support material that mediates the growth of MoS 2 nanocrystals. The formed MoS 2 /GR electrocatalyst exhibits high activity of hydrogen evolution reaction with small onset overpotential of 0.1 V and Tafel slope of 50mV per decade together with an excellent stability in acid media. Thus our hybrid microwave annealing could be an efficient generic method to fabricate various graphene-based hybrid electric materials for broad applications.open2