Data di Pubblicazione:
2011
Citazione:
ADIPOSE TISSUE GROWTH AND MAINTENANCE / A. Rigamonti ; coordinatore: Enrico Ferrazzi ; relatore: Irene Cetin ; tutor: Chad Cowan. Universita' degli Studi di Milano, 2011 Feb 03. 23. ciclo, Anno Accademico 2010. [10.13130/rigamonti-alessandra_phd2011-02-03].
Abstract:
Because obesity is fast becoming a global health pandemic, understanding the
molecular and cellular processes that regulate fat mass has acquired new
importance. Characterized by an increase in adipose tissue to the point where it is
associated with adverse health effects, the prevalence of obesity has nearly tripled
over the past fifty years. Though for many years adipose tissue was considered to
be merely a storage depot for fatty acids, it is now regarded as an important
endocrine organ involved in the regulation of energy balance, glucose and lipid
homeostasis, blood pressure control, reproduction, inflammation and immune
response. Obesity has an enormous economic burden and it is the second leading
cause of preventable death. The source of increased fat mass in obesity is currently
attributed to two mechanisms: adipocyte hypertrophy, the process by which preexisting
fat cells increase in size due to an accumulation of lipids, and adipocyte
differentiation from fat precursor cells.
Stem cells are defined by the ability to self-renew and differentiate into a variety of
cell types. While some adult organs, including the intestine (Cheng and Leblond,
1974), skin (Oshima et al., 2001), blood (Spangrude et al., 1988), and parts of the
brain (Doetsch et al., 1999; Reynolds and Weiss, 1992), are maintained by stem
cells, others, such as the pancreas (Dor et al., 2004), are not. Though it was recently
demonstrated that there is a substantial degree of cellular turnover within the human
adipocyte population (Spalding et al., 2008), the source of new adipocytes during
one’s lifetime has been entirely attributed to the differentiation of new adipocytes
from preadipocytes and/or stem cells (Avram et al., 2007; Greenwood and Hirsch,
1974; Hausman et al., 2001; Lemonnier, 1972; Salans et al., 1971; Spalding et al.,
2008; Tang et al., 2008). Adipocytes are thought to represent a terminal stage of
differentiation and are widely believed to lack proliferative ability (Prins and
O'Rahilly, 1997). Through four independent experimental approaches —dilution of
an inducible histone 2B-green fluorescent protein (H2BGFP) through cell division,
incorporation of BrdU, labeling with the cell cycle marker Ki67, and genetic
lineage analysis, we aimed to investigate the adult adipose tissue maintenance and
its behavior in the cell cycle.
Tipologia IRIS:
Tesi di dottorato
Keywords:
fat ; turnover
Elenco autori:
A. Rigamonti
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