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Noriko Kitanaka

Publications and source records attributed to Noriko Kitanaka.

11 recordsLinked to original sources
PubMed2007

Enhanced expression of adipocyte-type fatty acid binding protein in murine lymphocytes in response to dexamethasone treatment.

Fatty acids have a great influence on the process of lymphocyte apoptosis which is considered as a modulating factor of immune response in both humans and animals. However the mechanism underlying the function of fatty acids in the process of lymphocyte apoptosis is not fully understood. In this study we show that the appearance of adipocyte-type fatty acid binding protein (A-FABP) is induced upon administration of dexamethasone (DEX) in both in vivo and cultured lymphocytes, and its distinct nuclear localization occurs in close relation to the DEX-induced apoptosis process. In immunohistochemistry of mouse spleen, A-FABP-immunoreactivity starts to occur 3 h after DEX stimulation, and it massively localizes in the nucleus 8 h after the treatment, while no A-FABP-immunoreactivity is discerned in the lymphocytes of normal as well as 24 h post-injection spleen. In the murine T-cell leukemia CTLL-2 cells, A-FABP-immunoreactivity is also induced in both of the cytoplasm and nucleus when the apoptosis is induced by IL-2 retrieval together with DEX treatment, while in the presence of IL-2 A-FABP-immunoreactivity is confined to the cytoplasm with DEX treatment. On the other hand, A-FABP-immunoreactivity is not detected by IL-2 retrieval alone. The present findings altogether suggest that A-FABP and its ligands, fatty acids, play an important role in the process of apoptosis and the immune modulation induced by DEX.

Adipocytes↗
PubMed2006

Epidermal-type fatty acid binding protein as a negative regulator of IL-12 production in dendritic cells.

Fatty acids and their metabolites have recently been shown to modulate various functions of dendritic cells (DCs) including their differentiation and cytokine production, although the mechanisms underlying their cellular functions are not fully understood. In view of our previous finding that epidermal-type fatty acid binding protein (E-FABP) was exclusively expressed in splenic DCs among FABP family, we examined the phenotype of E-FABP-null mutant mice in order to elucidate the functional significance of E-FABP expression in DCs. Although E-FABP-null mutant mice showed no apparent abnormalities in the population density and subset distribution of DCs as well as the microscopic morphology in the spleen, DCs isolated from E-FABP-null spleen showed enhanced production of IL-12p70, a key cytokine for innate immune responses, in response to appropriate stimuli as compared with wild-type. In real-time PCR, the expression level of IL-12p35 mRNA after LPS stimuli was much higher in mutant DCs when compared with wild-type, while no apparent change of IL-12p40 mRNA level was detected. Phosphorylated forms of p38 mitogen-activated protein kinase (p38MAPK) and IkappaB-alpha, molecules critical for IL-12 production, were detected at higher levels in E-FABP-null-mutant DCs after LPS stimuli when compared with wild-type counterparts. Collectively, it is suggested that E-FABP may be a novel negative regulator of IL-12 production in DCs, and this regulation may be exerted via its involvement in the p38MAPK-mediated transcription of IL-12p35.

Animals↗
PubMed2006

Occurrence of immunoreactivity for adipocyte-type fatty acid binding protein in degenerating granulosa cells in atretic antral follicles of mouse ovary.

The localization of adipocyte-type fatty acid binding protein (A-FABP) in the mature mouse ovary was examined by immuno-light and electron microscopy. Solitary round cells showing the distinct immunoreactivity for A-FABP were detected in 1-6 antral follicles. In sets of two consecutive sections in a mirror alignment on slide glasses which were treated for immunoreactivity for A-FABP and TUNEL reaction separately, cells immunoreactive for A-FABP appeared in the same antral follicles as containing cells exhibiting TUNEL-reaction. In immunoelectron microscopy, A-FABP-immunopositive cells were found to contain highly electron-dense nuclei of round, irregular or crescent shapes together with cytoplasmic remnants without any features of macrophages or cells of extrinsic origin. Therefore the cells were identified as apoptotic granulosa cells. The apoptotic cells immunoreactive for A-FABP were often seen to be enclosed/engulfed in adjacent cells exhibiting normal ultrastructures without containing numerous lysosomes. The present findings suggest that A-FABP is involved in the apoptosis of ovarian granulosa cells, probably through its interaction with peroxisome proliferator activated receptors.

Adipocytes↗
PubMed2006

Decreased keratinocyte motility in skin wound on mice lacking the epidermal fatty acid binding protein gene.

Fatty acids are shown to be important in various skin functions. Fatty acid binding protein (FABP) is postulated to serve as a lipid shuttle, solubilizing hydrophobic fatty acids and delivering them to the appropriate metabolic system. Among the FABP family proteins, epidermal-type FABP (E-FABP) is solely expressed in keratinocyte but its specific role in skin is not yet fully established. We found an elevated expression of E-FABP in regenerative keratinocytes of healing wounds. However, E-FABP null mice showed no marked differences compared to wild type mice in the process of wound closure, in vivo. On the other hand, in keratinocyte culture, E-FABP gene disruption decreased the cell motility, but did not affect the cell proliferation. E-FABP deletion may be compensated for in vivo by the microenvironment comprised of various cells such as fibroblasts and endothelial cells around the wound. Our analyses suggest that the E-FABP elevation may be necessary for the activation of cell motility within regenerative epidermis during wound healing.

Animals↗
PubMed2006

Localization of epidermal-type fatty acid binding protein in macrophages in advanced atretic follicles of adult mice.

The localization of epidermal-type fatty acid binding protein (E-FABP) in the mature mouse ovary was examined by immuno-light and electron microscopy. Numerous macrophages immunopositive for both anti-E-FABP and F4/80 antibodies, together with immunonegative cells, were found in advanced atretic follicles that had eccentric lumens containing deformed ova. While some E-FABP-immunopositive macrophages were spider in shape and appeared singly, others, especially close to the lumen, were round and voluminous and tended to be aggregated. The voluminous macrophages contained phagosomes of various sizes and they were regarded as those actively involved in the phagocytosis of apoptotic granulosa cells. E-FABP-immunopositive macrophages and their processes were often apposed to adjacent immunonegative cells, and some of them lined the lumen containing deformed ova. On the other hand, E-FABP-immunonegative cells in the atretic follicles were classified into two types: the one, a minority, was characterized by small mitochondria containing non-tubular cristae and presumably represented residual granulosa cells, while the other dominant type was characterized by large mitochondria containing tubular cristae and presumably represented theca cells originally surrounding the follicles to be atretic. The present detection of E-FABP-immunopositivity selectively in macrophages of the atretic follicles suggests possible involvement of E-FABP and/or its ligand fatty acids in the process of follicular atresia, and it makes more reliable the identification of the advanced atretic follicles with the antral spaces obliterated, which could provide further details on the histology of the follicular atresia than before.

Animals↗
PubMed2006

Altered emotional behavioral responses in mice lacking brain-type fatty acid-binding protein gene.

Brain-type fatty acid-binding protein (B-FABP) belongs to a family of intracellular lipid-binding proteins. B-FABP exhibits a binding affinity to long-chain fatty acids (FAs) whose effects on brain functions including development, emotion, learning and memory have been proposed. B-FABP is localized in the ventricular germinal cells in embryonic brain and astrocytes in developing and mature brain of rodents. In the present study we generated the mouse harboring a null mutation in the B-FABP gene and studied its phenotype. B-FABP mutant mice exhibited the enhanced anxiety and increased fear memory as well as the decreased content of docosahexaenoic acid (DHA) in their brain during the neonatal period without detection of any histological changes in the brain. In the adult brain, B-FABP was localized more numerously to the astrocytes in the amygdala and septal area than to those in the hippocampal area. Analysis of FA content in the amygdala of adult brain revealed that arachidonic and palmitic acids increased significantly in the mutant mice compared with wild-type. Furthermore, the response of N-methyl-d-aspartate receptor-mediated current to DHA in isolated neurons from B-FABP mutant brain was significantly decreased compared with that of wild-type, while no significant differences were detected in behavioral responses related to the spatial learning/memory or in the hippocampal long-term potentiation. These data indicate that B-FABP is crucially involved in the fear memory and anxiety through its binding with FAs and/or its own direct effects on pertinent metabolism/signaling of FAs.

Animals↗
PubMed2005

Brain arachidonic acid incorporation is decreased in heart fatty acid binding protein gene-ablated mice.

Heart fatty acid binding protein (H-FABP) is expressed in neurons, but its role in brain fatty acid incorporation and metabolism is poorly defined. We examined the effect of H-FABP gene ablation on brain incorporation of arachidonic ([1-(14)C]20:4n-6) or palmitic ([1-(14)C]16:0) acid in vivo. Analysis of brain mRNA confirmed gene ablation and demonstrated no compensatory changes in the levels of other FABP mRNA in the gene-ablated mice. In brains from H-FABP gene-ablated mice, the incorporation coefficient for [1-(14)C]20:4n-6 was reduced 24%, while that for [1-(14)C]16:0 was unaffected. Within the organic and aqueous fractions, significantly more [1-(14)C]20:4n-6 was distributed into the aqueous fraction, suggesting a disruption in the metabolic targeting of 20:4n-6 in these mice. There was less incorporation of [1-(14)C]20:4n-6 into total phospholipids and a marked reduction (51%) in the level of incorporation into the choline glycerophospholipids (ChoGpl). Because FABP can influence steady-state lipid mass, brain individual lipid masses were measured. The brain total phospholipid mass was reduced 17% by gene ablation, ascribed to a 27% and 32% reduction in the masses of ChoGpl and sphingomyelin, respectively. Plasmalogen subclass masses were also reduced, suggesting that H-FABP may augment brain plasmalogen synthesis. In gene-ablated mice, the phosphatidylinositol 20:4n-6 level was reduced 25%, while the proportion of total n-6 fatty acids was reduced in the major phospholipid classes. Thus, these results demonstrate for the first time that H-FABP expression influences brain 20:4n-6 uptake and trafficking as well as steady-state brain lipid levels.

Animals↗
PubMed2004

Differential localization of brain-type and epidermal-type fatty acid binding proteins in the adrenal gland of mice.

In immuno-light and -electron microscopy, brain-type fatty acid binding protein (B-FABP) is localized in the sustentacular cells enclosing the chromaffin cells in the adrenal medulla. This represents another new feature commonly shared by the sustentacular cells and ganglionic satellite cells, the latter of which has already been reported to localize this molecule, and suggests a common feature in lipid metabolism shared by the two cells enclosing peripheral neurons and paraneurons. On the other hand, epidermal-type fatty acid binding protein (E-FABP) is localized in two discrete cells in the adrenal gland: the one is a subpopulation of intra-adrenal macrophages which are intensely immunoreactive for F4/80, a marker of macrophages, and are rich in pleomorphic lysosomes. Because of their direct apposition to adjacent cortical endocrine cells and medullary chromaffin cells, the macrophages may be involved not only in phagocytosis of degenerating adrenal cells but also in exertion of some yet unknown effects on the endocrine function of the cortical and medullary cells via humoral factors such as cytokines which have recently been known to be secreted by macrophages. The other is a population of cells having scanty perikaryal cytoplasm poor in organneles and several thinny extended processes in the cortex and exhibiting weak immunoreactivity for E-FABP. The possible natures of these cells immunoreactive for E-FABP are discussed in view of a subpopulation of endothelial cells or the dendritic cells of antigen-presenting property.

Adrenal Cortex↗
PubMed2003

Specific localization of epidermal-type fatty acid binding protein in dendritic cells of splenic white pulp.

Dendritic cells in the splenic white pulp of mice were intensely immunoreactive for epidermal-type fatty acid binding protein (E-FABP). This specific immunostaining revealed a clear difference in morphology between the dendritic cells in the periarterial lymphoid sheath (PALS) and follicular dendritic cells in the follicles in terms of cell sizes and process branching. No immunoreactivity was detected in dendritic cells in the marginal zones and the red pulp, although endothelial cells of almost all capillaries in the red pulp were immunoreactive for E-FABP. After peritoneal injection of lipopolysaccharide, the immunoreactive cells in PALS progressively enlarged and became rounded in shape with a peak in size at 24 h postinjection and they eventually resumed the dendritic form at 48 h postinjection. Within each of the enlarged immunoreactive cell perikarya were included small immunonegative apoptotic cells, presumptive lymphocytes. Taken together, E-FABP is useful as a marker for dendritic cells in the splenic white pulp, and may be involved through combination with fatty acids in antigen presentation and retention as well as in cytokine production.

Animals↗
PubMed2003

Localization of brain-type fatty acid-binding protein in Kupffer cells of mice and its transient decrease in response to lipopolysaccharide.

Brain-type fatty acid-binding protein (B-FABP) was localized in Kupffer cells of liver of postnatal day 10 (P10) and older mice in immunolight and electron microscopy as well as by in situ hybridization histochemistry. The immunoreaction products were localized in the cytoplasmic matrix but not within the nucleus. After peritoneal injection of lipopolysaccharide (LPS), the immunoreaction for B-FABP decreased markedly in Kupffer cells at 1 h postinjection and thereafter gradually recovered to the preinjection level by 24 h postinjection, although no decrease in the mRNA expression was detected in Northern blotting throughout the course after the injection. The specific localization of B-FABP, but not the other FABPs, in Kupffer cells, and its rapid decrease after LPS injection suggest the intimate involvement of B-FABP in Kupffer cells in the inflammatory reaction, probably through mediation of n-3 polyunsaturated fatty acids, which are strong binders of B-FABP.

Animals↗