Browsing by Subject "Adipocytes"

Now showing 1 - 5 of 5
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    Conjugated linoleic acids CLAs and white adipose tissue: how both in vitro and in vivo studies tell the story of a relationship
    (Murcia : F. Hernández, 2006) Domeneghini, C.; Di Giancamillo, A.; Corino, C.
    The distribution of adipose tissue in mammals is dependent on genetic and environmental factors, and in health the fundamental role of adipocytes is to store triacylglycerol during energetic excess and to mobilize this reserve during energy expenditure or reduced food intake. This requires an accurate balance, which is maintained through the interactions of several regulatory factors, as well as dietary manipulations. Dietary supplementation with CLAs (conjugated linoleic acids) is regarded as promising in many mammalian species for obtaining good body mass repartition and diminution of fat depots. CLAs are a group of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid, naturally present in foods originating from ruminant species, and normally present in human adipose tissue. CLAs can, however, also be obtained as commercial supplements, usually containing synthetically prepared isomeric mixtures, and as dietary supplements CLAs are widely used by obese people, above all in the USA and Europe. CLAs are claimed to have protective effects against human degenerative pathologies, such as cancer, atherosclerosis, and diabetes, as well as showing beneficial effects on immune functions and food and energy intakes. The mechanisms of action of CLAs are not fully clarified at present, because in vitro and in vivo studies are not always in agreement, and possibly because CLAs act in different ways and with different consequences when administered in the diet to different species. The present review summarizes the ascertained mechanisms of action of CLAs, the mammalian species of major interest in which important studies have been conducted, and the future prospects for the use of CLAs in both humans and food animal species.
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    Emerging role of fatty acid binding proteins in cancer pathogenesis
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Gurung, Shilpa; Po Sin Chung, Katherine; Lee, Terence Kin Wah
    Fatty acid binding proteins (FABPs) are 15- kDa proteins responsible for the transport of fatty acids both intracellularly and extracellularly. Consisting of 12 different isoforms, some of the proteins have been found to be released in the serum and to be correlated with various diseases including cancer. Differential expression of these proteins has been reported to result in cancer pathogenesis by modulating various cancer signaling pathways; hence, in this review, we present the recent studies that have investigated the roles of different kinds of FABPs in different types of cancer and any possible underlying mechanisms to better understand the role of FABPs in cancer progression.
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    Histological assessment for femora of ovariectomized obesity (db/db) mice carrying mutated leptin receptor
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Tanaka, Yusuke; Hasegawa, Tomoka; Yamada, Tamaki; Yamamoto, Tomomaya; Sasaki, Muneteru; Hongo, Hiromi; Tsuboi, Kanako; Haraguchi, Mai; Luiz de Freitas, Paulo Henrique; Li, Minqi; Oda, Kimimitsu; Totsuka, Yasunori; Tei, Kanchu; Amizuka, Norio
    In order to provide a clue to understand the interplay between leptin and estrogen, we have examined femoral metaphyses of ovariectomized db/db mice carrying a mutated leptin receptor. We performed ovariectomy (OVX) or sham-operation (sham) on 12- week old female wild-type and db/db mice, and then, after 8 weeks, divided the animals into four groups: wild-type sham, wild-type OVX, db/db sham and db/db OVX. Samples from all groups were prepared for histochemical and ultrastructural examinations. As a result, db/db sham mice showed a reduced number and thickness of metaphyseal trabeculae and excessive adipose tissue when compared to wild-type sham mice. The wild-type OVX group exhibited markedly diminished trabecular number, as well as lower populations of osteoblasts and osteoclasts in comparison to wild-type sham group. On the other hand, trabecular numbers were similar for the two db/db groups, suggesting that the effect of the ovariectomy, i.e., estrogen deficiency may be lessened in this animal model. Leptin receptor was mainly found in osteoblasts and in bone marrow stromal cells including adipocytes. In addition, the expression of estrogen receptor did not seem to change after OVX in wild-type mice and in db/db mice. Both db/db sham and OVX mice featured many adipocytes close to the metaphyseal chondroosseous junction, while osteoblasts accumulated glycogen granules and lipid droplets. Therefore, it seems likely that the disruption of leptin signaling in db/db mice shifts the cell differentiation cascade towards the adipocyte lineage, resulting in an osteoporotic bone independently of estrogen deficiency.
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    Plasticity and regulation of human bone marrow stromal osteoprogenitor cells: potential implication in the treatment of age-related bone loss
    (Murcia : F. Hernández, 2004) Ahdjoudj, S.; Fromigué, O.; Marie, P.J.
    Human bone marrow stroma contains pluripotent mesenchymal progenitor cells that can give rise to many mesenchymal lineages, including chondroblasts, adipocytes or osteoblasts. The differentiation of these cells towards a specific lineage is dependent on hormonal and local factors activating specific transcription factors. Attempts have been recently made to identify osteoprogenitor cells in the human bone marrow and to identify the molecular mechanisms responsible for lineage-specific differentiation of human bone marrow stromal cells. Using a clonal pluripotent human bone marrow stromal cell line with tri-potential characteristics, we have provided evidence for a controlled reciprocal regulation of osteoblast/chondroblast and osteoblast/adipocyte differentiation of human bone marrow stromal cells. We have also shown that administration of TGFß that regulates the expression of specific osteoblast and adipocyte transcription factors can promote osteoblast differentiation and inhibit adipocyte conversion of rat marrow stromal cells in vivo. This indicates that the reciprocal relationship between osteoblastogenesis and adipogenesis can be manipulated in vivo in order to improve bone formation. Future studies will have to identify key signals for lineage-specific differentiation of human marrow stromal cells. This may result in the development of therapeutic strategies to promote the differentiation of these cells towards the osteoblast lineage and to inhibit excessive bone marrow adipogenesis associated with aging.
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    PVAT: an important guardian of the cardiovascular system
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Liang, Xiuying; Qi, Yan; Dai, Fan; Gu, Jingya; Yao, Wenjuan
    Perivascular adipose tissue (PVAT) had long been considered to serve only structural, vessel- supporting purposes, but today PVAT is recognized to be an endocrine organ with important physiological and pathological effects. The expansion of PVAT in vascular homeostasis and vascular disease has attracted much interest. PVAT has been shown to release a wide spectrum of molecules, such as PVAT-derived relaxing factors (PVATRFs) and PVAT-derived contracting factors (PVATCFs). PVAT dysfunction may lead to obesity, atherosclerosis, and other cardiovascular diseases. This review describes recent advances in our understanding of PVAT’s important effects on the cardiovascular system