Navegando por Palavras-chave "Cell biology"

Agora exibindo 1 - 2 de 2
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Decoherence in yeast cell populations and its implications for genome-wide expression noise
    (Funpec-editora, 2009-01-01) Briones, Marcelo Ribeiro da Silva [UNIFESP]; Bosco, Francisco [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Gene expression noise is commonly defined as the stochastic variation of gene expression levels in different cells of the same population under identical growth conditions. Here, we tested whether this noise is amplified with time, as a consequence of decoherence in global gene expression profiles (genome-wide microarrays) of synchronized cells. The stochastic component of transcription causes fluctuations that tend to be amplified as time progresses, leading to a decay of correlations of expression profiles, in perfect analogy with elementary relaxation processes. Measuring decoherence, defined here as a decay in the auto-correlation function of yeast genome-wide expression profiles, we found a slowdown in the decay of correlations, opposite to what would be expected if, as in mixing systems, correlations decay exponentially as the equilibrium state is reached. Our results indicate that the populational variation in gene expression (noise) is a consequence of temporal decoherence, in which the slow decay of correlations is a signature of strong interdependence of the transcription dynamics of different genes.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Extracellular vesicles: structure, function, and potential clinical uses in renal diseases
    (Assoc Bras Divulg Cientifica, 2013-10-01) Borges, Fernanda Teixeira [UNIFESP]; Reis, L. A. [UNIFESP]; Schor, Nestor [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Cruzeiro Sul
    Interest in the role of extracellular vesicles in various diseases including cancer has been increasing. Extracellular vesicles include microvesicles, exosomes, apoptotic bodies, and argosomes, and are classified by size, content, synthesis, and function. Currently, the best characterized are exosomes and microvesicles. Exosomes are small vesicles (40- 100 nm) involved in intercellular communication regardless of the distance between them. They are found in various biological fluids such as plasma, serum, and breast milk, and are formed from multivesicular bodies through the inward budding of the endosome membrane. Microvesicles are 100-1000 nm vesicles released from the cell by the outward budding of the plasma membrane. the therapeutic potential of extracellular vesicles is very broad, with applications including a route of drug delivery and as biomarkers for diagnosis. Extracellular vesicles extracted from stem cells may be used for treatment of many diseases including kidney diseases. This review highlights mechanisms of synthesis and function, and the potential uses of wellcharacterized extracellular vesicles, mainly exosomes, with a special focus on renal functions and diseases.