Autologous transplantation of adult adipose derived stem cells into rabbit urethral wall

A study was carried out to evaluate the feasibility of autologous adipose derived stem cells (ADSC) transplantation into female rabbits` urethra walls as an alternative to intrinsic urethral regeneration. Inguinal fat pad of 12 New Zealand adult female rabbits were harvested and processed to obtain stromal vascular fraction (SVF). The SVF were platted to isolate ADSC. Before urethral injection, cells were labeled with DiI marker. The urethra wall was injected with 1 x 10(7) autologous cells or saline (sham). The urethra was harvested at 2, 4, and 8 weeks to identify DiI-labeled cells. At 2 and 4 weeks, the ADSCs create a nodule localized in the urethral sub-mucosa. At 8 weeks, the ADSCs spread and integrated with the urethra wall from the initial injection site. This is the first study to demonstrate a successful autologous ADSCs transplantation. It confirms that ADSCs can survive and integrate within the urethral wall.

Lipofilling : rôle de la centrifugation

Introduction : Le lipofilling s'est développé au cours du 20ème siècle, mais nécessite encore d'être amélioré, notamment à cause de sa grande variabilité. Dans cette revue de littérature, nous tenterons de déterminer les caractéristiques et les rôles de la centrifugation dans le transfert graisseux autologue. Méthodes : La discussion est fondée sur les 14 articles (Pubmed) qui traitent directement ou non de la centrifugation et ses implications. Discussion : Quelques auteurs s'accordent à penser que la centrifugation crée un gradient de cellules stromales le long du tube centrifugé et statuent que cette sous-couche dense de la phase graisseuse est la plus viable. La centrifugation apparaît donc délétère pour la partie peu dense du tissu prélevé, mais semble, pour certains, améliorer la survie de la sous-couche dense, puisqu'elle est enrichie en ADSC's/MSC's. Conclusion : Dans la mesure où le prélèvement est traumatique pour le tissu graisseux, son taux de survie est relativement faible. Mais si toutes les mesures sont prises en influant sur les déterminants de la prise de greffe, la survie s'optimise et les résultats sont meilleurs.

Selective Oxidations of Organoboron Compounds Catalyzed by Baeyer-Villiger Monooxygenases

The applicability of Baeyer-Villiger monooxygenases (BVMOs) in organoboron chemistry has been explored through testing chemo-and enantioselective oxidations of a variety of boron-containing aromatic and vinylic compounds. Several BVMOs, namely: phenylacetone monooxygenase (PAMO), M446G PAMO mutant, 4-hydroxyacetophenone monooxygenase (HAPMO) and cyclohexanone monooxygenase (CHMO) were used in this study. The degree of chemoselectivity depends on the type of BVMO employed, in which the biocatalysts prefer boron-carbon oxidation over Baeyer-Villiger oxidation or epoxidation. Interestingly, it was discovered that PAMO can be used to perform kinetic resolution of boron-containing compounds with good enantioselectivities. These findings extend the known biocatalytic repertoire of BVMOs by showing a new family of compounds that can be oxidized by these enzymes.

Autologous transplantation of adult adipose derived stem cells into rabbit urethral wall

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chitosan-collagen scaffolds can regulate the biological activities of adipose mesenchymal stem cells for tissue engineering

Scaffolds of chitosan and collagen can offer a biological niche for the growth of adipose derived stem cells (ADSC). The objective of this work was to characterize the physico-chemical properties of the scaffolds and the ADSC, as well as their interactions to direct influences of the scaffolds on the behavior of ADSC. The methodology included an enzymatic treatment of fat obtained by liposuction by collagenase, ASDC immunophenotyping, cell growth kinetics, biocompatibility studies of the scaffolds analyzed by the activity of alkaline phosphatase (AP), nitric oxide (NO) determination by the Griess-Saltzman reaction, and images of both optical and scanning electron microscopy of the matrices. The extent of the crosslinking of genipin and glutaraldehyde was evaluated by ninhydrin assays, solubility tests and degradation of the matrices. The results showed that the matrices are biocompatible, exhibit physical and chemical properties needed to house cells in vivo and are strong stimulators of signaling proteins (AP) and other molecules (NO) which are important in tissue healing. Therefore, the matrices provide a biological niche for ADSC adhesion, proliferation and cells activities.

Matrizes de quitosina-colágeno podem regular as atividades biológicas de células tronco mensenquimais adiposas para a engenharia de tecidos

Pós-graduação em Biofísica Molecular - IBILCE

Molecular determinants of caste differentiation in the highly eusocial honeybee Apis mellifera

Abstract Background In honeybees, differential feeding of female larvae promotes the occurrence of two different phenotypes, a queen and a worker, from identical genotypes, through incremental alterations, which affect general growth, and character state alterations that result in the presence or absence of specific structures. Although previous studies revealed a link between incremental alterations and differential expression of physiometabolic genes, the molecular changes accompanying character state alterations remain unknown. Results By using cDNA microarray analyses of >6,000 Apis mellifera ESTs, we found 240 differentially expressed genes (DEGs) between developing queens and workers. Many genes recorded as up-regulated in prospective workers appear to be unique to A. mellifera, suggesting that the workers' developmental pathway involves the participation of novel genes. Workers up-regulate more developmental genes than queens, whereas queens up-regulate a greater proportion of physiometabolic genes, including genes coding for metabolic enzymes and genes whose products are known to regulate the rate of mass-transforming processes and the general growth of the organism (e.g., tor). Many DEGs are likely to be involved in processes favoring the development of caste-biased structures, like brain, legs and ovaries, as well as genes that code for cytoskeleton constituents. Treatment of developing worker larvae with juvenile hormone (JH) revealed 52 JH responsive genes, specifically during the critical period of caste development. Using Gibbs sampling and Expectation Maximization algorithms, we discovered eight overrepresented cis-elements from four gene groups. Graph theory and complex networks concepts were adopted to attain powerful graphical representations of the interrelation between cis-elements and genes and objectively quantify the degree of relationship between these entities. Conclusion We suggest that clusters of functionally related DEGs are co-regulated during caste development in honeybees. This network of interactions is activated by nutrition-driven stimuli in early larval stages. Our data are consistent with the hypothesis that JH is a key component of the developmental determination of queen-like characters. Finally, we propose a conceptual model of caste differentiation in A. mellifera based on gene-regulatory networks.

Engraftment of human adipose derived stem cells delivered in a hyaluronic acid preparation in mice

PURPOSE: To evaluate the implant of human adipose derived stem cells (ADSC) delivered in hyaluronic acid gel (HA), injected in the subcutaneous of athymic mice. METHODS: Control implants -HA plus culture media was injected in the subcutaneous of the left sub scapular area of 12 athymic mice. ADSC implants: HA plus ADSC suspended in culture media was injected in the subcutaneous, at the contra lateral area, of the same animals. With eight weeks, animals were sacrificed and the recovered implants were processed for extraction of genomic DNA, and histological study by hematoxilin-eosin staining and immunufluorescence using anti human vimentin and anti von Willebrand factor antibodies. RESULTS: Controls: Not visualized at the injection site. An amorphous substance was observed in hematoxilin-eosin stained sections. Human vimentin and anti von Willebrand factor were not detected. No human DNA was detected. ADSC implants - A plug was visible at the site of injection. Fusiform cells were observed in sections stained by hematoxilin- eosin and both human vimentin and anti von Willebrand factor were detected by immunofluorescence. The presence of human DNA was confirmed. CONCLUSION: The delivery of human adipose derived stem cells in preparations of hyaluronic acid assured cells engraftment at the site of injection.

Adipose tissue-derived mesenchymal stem cells increase skin allograft survival and inhibit Th-17 immune response

Adipose tissue-derived mesenchymal stem cells (ADSC) exhibit immunosuppressive capabilities both in vitro and in vivo. Their use for therapy in the transplant field is attractive as they could render the use of immunosuppressive drugs unnecessary. The aim of this study was to investigate the effect of ADSC therapy on prolonging skin allograft survival. Animals that were treated with a single injection of donor allogeneic ADSC one day after transplantation showed an increase in donor skin graft survival by approximately one week. This improvement was associated with preserved histological morphology, an expansion of CD4(+) regulatory T cells (Treg) in draining lymph nodes, as well as heightened IL-10 expression and down-regulated IL-17 expression. In vitro, ADSC inhibit naïve CD4(+) T cell proliferation and constrain Th-1 and Th-17 polarization. In summary, infusion of ADSC one day post-transplantation dramatically increases skin allograft survival by inhibiting the Th-17 pathogenic immune response and enhancing the protective Treg immune response. Finally, these data suggest that ADSC therapy will open new opportunities for promoting drug-free allograft survival in clinical transplantation.

Valoración del tratamiento con sellantes biológicos y terapia celular en la prevención de la fístula broncopleural en un modelo experimental in vivo

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Remote Effects Modulating the Spin Equilibrium of the Resting State of Cytochrome P450cam –An Investigation Using Active Site Analogues

The crystal structure of the resting state of cytochrome P450cam (CYP101), a heme thiolate protein, shows a cluster of six water molecules in the substrate binding pocket, one of which is coordinating to iron(III) as sixth ligand. The resting state is low-spin and changes to high-spin when substrate camphor binds and H2O is removed. In contrast to the protein, previously synthesised enzyme models such as H2O[BOND]FeIII(porph)(ArS−) were shown to be purely high-spin. Iron(S−)porphyrins with different distal sites mimicking proposed remote effects have been prepared and studied by cw-EPR. The results indicate that the low-spin of the resting state of P450cam is due to the fact that the water molecule coordinating to iron has an OH−-like character because of hydrogen bonding and polarisation of the water cluster, respectively.