Accumulation of Plasma-Derived Lipids in the Lipid Core and Necrotic Core of Human Atheroma: Imaging Mass Spectrometry and Histopathological Analyses.

Objective: To clarify the pathogenesis of human atheroma, the origin of deposited lipids, the developmental mechanism of liponecrotic tissue, and the significance of the oxidation of phospholipids were investigated using mass spectrometry-aided imaging and immunohistochemistry.Atherosclerotic lesions in human coronary arteries were divided into 3 groups: pathologic intimal thickening with lipid pool, atheroma with lipid core, and atheroma with necrotic core. The lipid pool and lipid core were characterized by the deposition of extracellular lipids. The necrotic core comprised extracellular lipids and liponecrotic tissue. The proportion of cholesteryl linoleate in cholesteryl linoleate+cholesteryl oleate fraction in the extracellular lipid and liponecrotic regions differed significantly from that of the macrophage foam cell-dominant region, and the plasma-derived components (apolipoprotein B and fibrinogen) were localized in the regions. The liponecrotic region was devoid of elastic and collagen fibers and accompanied by macrophage infiltration in the surrounding tissue. Non-oxidized phospholipid (Non-OxPL), OxPL, and Mox macrophages were detected in the three lesions. In the atheroma with lipid core and atheroma with necrotic core, non-OxPL tended to localize in the superficial layer, whereas OxPL was distributed evenly. Mox macrophages were colocalized with OxPL epitopes.In human atherosclerosis, plasma-derived lipids accumulate to form the lipid pool of pathologic intimal thickening, lipid core of atheroma with lipid core, and necrotic core of atheroma with necrotic core. The liponecrotic tissue in the necrotic core appears to be developed by the loss of elastic and collagen fibers. Non-OxPL in the accumulated lipids is oxidized to form OxPL, which may contribute to the lesion development through Mox macrophages.

Giant cells lepromatous leprosy. Diffuse dermatitis with exuberant foreign body giant cells in treated lepromatous leprosy / Células gigantes en lepra lepromatosa. Dermatitis difusa con células gigantes tipo cuerpo extraño exuberantes en lepra lepromatosa tratada

Patients with lepromatous leprosy that have received treatment for many years usually get follow up biopsies for persistent skin lesions or positive bacilloscopy even if the values are lower than in the initial bacilloscopy. We report the case of a 48-year old woman with long-standing lepromatous leprosy of 15 years of evolution, with a bacterial index of 4 in the direct smear and the initial skin biopsy. The patient was treated with multidrug therapy for 32 months although the treatment recommended by the World Health Organization (WHO) is only for 12 months. A skin biopsy was taken to determine if there was an active disease. We observed a diffuse dermal inflammation with numerous foreign body giant cells and vacuolated macrophages (Virchow´s cells). These cells contained granular acid-fast material that was also positive with immunohistochemistry for BCG. There were fragmented bacilli and the BI was 2. These cells were also strongly positive for CD68. The biopsy was interpreted as a residual form of lepromatous leprosy that did not require further multidrug therapy. We have observed similar histological profiles in several cases. The lack of clinical data makes it a histological challenge. The accumulation of lipids in these giant cells is due to bacillary destruction and fusion of vacuolated macrophages. We discuss here the role of bacillary and host lipids in the pathogenesis of lepromatous leprosy. We concluded that there was no need to extend the 12-month multidrug therapy recommended by WHO.

Los pacientes con lepra lepromatosa (LL) que han recibido tratamiento durante años, usualmente tienen seguimiento con biopsias de piel para lesiones persistentes o con baciloscopia positiva, con valores menores a los iniciales. Presentamos una mujer de 48 años con LL de 15 años de evolución, con índice bacilar (IB) 4 en el extendido directo y en la biopsia, que recibió terapia multidroga durante 32 meses, aunque el tratamiento recomendado por la Organización mundial de la salud (OMS) es de 12 meses. Se tomó una biopsia de piel para determinar si la enfermedad estaba activa. Se observó inflamación dérmica difusa con numerosas células gigantes tipo cuerpo extraño y macrófagos vacuolados (células de Virchow). Estas células, CD68 positivas, contenían material granular ácido-alcohol resistente, positivo con inmunohistoquímica para BCG. Se encontraron bacilos fragmentados y el IB fue de 2. Se interpretó como una forma residual de LL y que la paciente no requería MDT adicional. Este perfil histológico lo hemos observado en casos similares. Sin datos clínicos estas biopsias son un reto diagnóstico. La acumulación de lípidos en estas células gigantes se debe a la destrucción bacilar y a la fusión de macrófagos vacuolados. Revisamos el papel de los lípidos del bacilo y del huésped en la patogénesis de la LL. En estos casos no es necesario extender los 12 meses de MDT recomendados por la OMS. En el seguimiento de los pacientes se recomienda contar con los hallazgos clínicos, la baciloscopia, la biopsia anual de piel y los títulos IgM anti-glicolípido fenólico.

Células gigantes en lepra lepromatosa: dermatitis difusa con células gigantes exuberantes de tipo cuerpo extraño en lepra lepromatosa tratada / Giant cells lepromatous leprosy: Diffuse dermatitis with exuberant foreign body giant cells in treated lepromatous leprosy

Resumen Los pacientes con lepra lepromatosa que han recibido tratamiento durante años, usualmente requieren seguimiento con biopsias de piel para detectar lesiones persistentes o si la baciloscopia es positiva, incluso si los valores son menores que los iniciales. Se presenta el caso de una mujer de 48 años de edad con lepra lepromatosa de 15 años de evolución, índice bacilar de 4 en el extendido directo y en la biopsia, que recibió tratamiento con múltiples medicamentos durante 32 meses, aunque lo recomendado por la Organización Mundial de la Salud (OMS) es una duración de 12 meses. Se tomó una biopsia de piel para determinar si la enfermedad estaba activa. Se observó inflamación dérmica difusa con numerosas células gigantes de tipo cuerpo extraño y macrófagos vacuolados (células de Virchow). Estas células, CD68 positivas, contenían material granular ácido-alcohol resistente positivo con inmunohistoquímica para BCG. Se encontraron bacilos fragmentados y el índice bacilar fue de 2. Se interpretó como una forma residual de lepra lepromatosa y se concluyó que la paciente no requería prolongar el tratamiento con múltiples medicamentos. Este perfil histológico se ha observado en casos similares, pero sin datos clínicos estas biopsias representan un reto diagnóstico. La acumulación de lípidos en estas células gigantes se debe a la destrucción bacilar y a la fusión de macrófagos vacuolados. Se revisó el papel de los lípidos del bacilo y del huésped en la patogenia de la lepra lepromatosa. En estos casos, no es necesario extender los 12 meses de tratamiento con múltiples medicamentos recomendados por la OMS. En el seguimiento de los pacientes, se recomienda contar con los hallazgos clínicos, la baciloscopia, la biopsia anual de piel y los títulos IgM antiglucolípido fenólico.

Abstract Patients with lepromatous leprosy that have received treatment for many years usually get follow up biopsies for persistent skin lesions or positive bacilloscopy even if the values are lower than in the initial bacilloscopy. We report the case of a 48-year old woman with long-standing lepromatous leprosy of 15 years of evolution, with a bacterial index of 4 in the direct smear and the initial skin biopsy. The patient was treated with multidrug therapy for 32 months although the treatment recommended by the World Health Organization (WHO) is only for 12 months. A skin biopsy was taken to determine if there was an active disease. We observed a diffuse dermal inflammation with numerous foreign body giant cells and vacuolated macrophages (Virchow´s cells). These cells contained granular acid-fast material that was also positive with immunohistochemistry for BCG. There were fragmented bacilli and the BI was 2. These cells were also strongly positive for CD68. The biopsy was interpreted as a residual form of lepromatous leprosy that did not require further multidrug therapy. We have observed similar histological profiles in several cases. The lack of clinical data makes it a histological challenge. The accumulation of lipids in these giant cells is due to bacillary destruction and fusion of vacuolated macrophages. We discuss here the role of bacillary and host lipids in the pathogenesis of lepromatous leprosy. We concluded that there was no need to extend the 12-month multidrug therapy recommended by WHO. Clinical findings, bacilloscopy, annual skin biopsy, and anti-phenolic glycolipid-I IgM titers are recommended procedures for the follow-up of these patients.

α- and ß-d-Glucans from the edible mushroom Pleurotus albidus differentially regulate lipid-induced inflammation and foam cell formation in human macrophage-like THP-1 cells.

Macrophages play an essential role in lipid metabolism; however, the excessive uptake of modified lipids and cholesterol crystals (CC) leads to the formation of pro-inflammatory lipid-laden macrophages called foam cells. Since the α-1,6- and ß-1,3-d-glucans from the basidiome and the mycelium of the edible mushroom Pleurotus albidus have previously been shown to regulate macrophage function, these glucans were tested in macrophage-like THP-1 cells previously exposed to acetylated low-density lipoproteins (acLDL) or CC. The glucans inhibited lipid-induced inflammation, but only the ß-1,3-d-glucan regulated both the NLRP3 inflammasome activation and the expression of genes involved on lipid efflux in acLDL- or CC-pretreated cells, thereby reducing foam cell formation. In contrast, the two α-1,6-glucans tested inhibited foam cell formation only in acLDL-pretreated cells and had no effect on the expression of the peroxisome proliferator-activated receptor gamma and liver X receptor alpha genes, suggesting that these glucans regulate lipid influx rather than lipid efflux. Thus, α- and ß-d-glucans differentially regulate lipid-induced inflammation and foam cell formation in macrophage-like cells. Furthermore, results emphasize that P. albidus has potential to be used as a functional food or as a source for the extraction of biologically-active glucans.

Monitoring lipid peroxidation within foam cells by lysosome-targetable and ratiometric probe.

Lipid peroxidation (LPO) in lysosomes is a valuable analyte because it is close associated with the evolutions of some major diseases. As a typical example, in the start-up phase of atherosclerosis, lysosomes get as swollen as foams, by accumulating a large amount of lipoproteins, which facilitates the free-radical chain propagation of LPO. Despite the existences of several fluorescent LPO probes, they are not appropriate for reporting the local extents of lysosomal LPO, for their unspecific intracellular localizations. Here, Foam-LPO, the first fluorescent LPO probe specifically targeting lysosomes, has been developed through straightforward synthesis using low-cost reagents. A basic tertiary amine group enables it to selectively localize in acidic lysosomes; and the conjugated diene moiety within the BODIPY fluorophore will degrade in response to lipid peroxidation, which results in fluorescence maximum shifting from 586 to 512 nm. Thus, under a confocal fluorescence microscope, Foam-LPO is able not only to visualize dynamic morphological changes of lysosomes during the evolution of foam cells, but also to relatively quantify local LPO extents in single lysosomes through ratiometric imaging. In addition, Foam-LPO proves applicable for two-color flow cytometry (FCM) analysis to make quantitative and high-throughput evaluation of LPO levels in large quantity of cells at different stages during the induction to form foam cells. Also importantly, with the aid of this new probe, the different roles played by low-density lipoprotein (LDL) and its oxidized form (ox-LDL) for the LPO processes of foam cells are distinguished and clarified, which benefits the understanding in the initiation and control factors of atherosclerosis.

[Effect of serum from patients with chronic renal insufficiency and indoxyl sulfate on lipid accumulation in macrophages in vitro].

OBJECTIVE: To investigate the pathologies of aortic root atherosclerotic lesion in uremic apoE-/- mice and explore the effect of serum from patients with chronic renal insufficiency (CRI) and the uremic toxin, indoxyl sulfate (IS), on the expression of cholesterol transporting receptors and lipid accumulation in macrophages in vitro. METHODS: The uremic apoE-/- mouse model was established by surgical operation. Frozen sections of the aortic root were collected from uremic apoE-/- mice, sham-operated apoE-/- mice and C57BL/6J mice and stained with oil red O to calculate the relative area of atherosclerotic plaque. Murine macrophage RAW264.7 cell line was treated for 12 h with different concentrations of IS or serum samples from CRI patients and healthy individuals, and the mRNA expressions of cholesterol transporting receptors (SR-A1, CD36, ABCA1, ABCG1 and SR-B1) were detected. After treatment for 24 h, the cells were induced into foam cells to determine lipid contents using oil red O staining. RESULTS: The relative area of the atherosclerotic plaques in the aortic root increased significantly in uremic apoE-/- mice compared with that in sham-operated apoE-/- mice. CRI serum (5%) and IS (250 µmol/L) obviously increased the mRNA expression of CD36 and lipid accumulation in the macrophages, but did not affect the mRNA expression of other cholesterol transporting receptors. CONCLUSION: CRI can accelerate the progression of atherosclerosis through the mechanism that IS in CRI serum promotes lipid accumulation in macrophages by enhancing the mRNA expression of CD36, which contributes to the formation of foam cells.

Low-density lipoprotein apheresis for proteinuria in lupus nephritis with intraglomerular foam cells containing cholesterol crystals.

A 28-year-old woman with systemic lupus erythematosus was referred to our hospital due to nephrotic-level proteinuria despite approximately 1 year of treatment with 50 to 60 mg/d of prednisolone and 100 to 150 mg/d of cyclosporine with methylprednisolone pulse therapy. Kidney biopsy showed diffuse global lupus nephritis (World Health Organization class 4-G A/C) with many intraglomerular foam cells containing cholesterol crystals. Surprisingly, proteinuria diminished after only 5 low-density lipoprotein (LDL) cholesterol apheresis sessions. This case demonstrated the potential of LDL apheresis to exhibit a remarkable effect on not only focal segmental glomerulosclerosis, but also other types of nephritis, particularly nephritis with intraglomerular foam cells.

Jellyfish skin polysaccharides: extraction and inhibitory activity on macrophage-derived foam cell formation.

In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from jellyfish skin (JSP). The optimum parameters were found to be raw material to water ratio 1:7.5 (w/v), extraction temperature 100°C and extraction time 4h. Under these conditions, the JSP yield reached 1.007 mg/g. Papain (15 U/mL) in combination with Sevag reagent was beneficial in removing proteins from JSP. After precipitation with ethanol at final concentration of 40%, 60% and 80% in turn, three polysaccharide fractions of JSP1, JSP2 and JSP3 were obtained from JSP, respectively. The three fractions exhibited different physicochemical properties with respect to molecular weight distribution, monosaccharide composition, infrared absorption spectra, and glycosyl bond composition. In addition, JSP3 showed strong inhibitory effects on oxidized low-density lipoprotein (oxLDL) induced conversion of macrophages into foam cells, which possibly attributed to the down-regulation of some atherogenesis-related gene expressions.

Endomorphin-1 prevents lipid accumulation via CD36 down-regulation and modulates cytokines release from human lipid-laden macrophages.

CD36 is a scavenger receptor known to play a critical role in the development of atherosclerosis by mediating the uptake of oxidized low-density lipoproteins (oxLDL) by macrophages, thus leading to foam cell formation. It is now generally recognized that the immune system has a pivotal role in the pathogenesis of atherosclerosis, whose progression is determined by ongoing inflammatory reactions. Recently, several studies pointed out that opioid peptides exert anti-inflammatory activities. Therefore the aim of the present study was to evaluate a possible endomorphin-1 (EM-1) immunomodulatory activity on human foam cells. Our results showed that EM-1 reduced Nile Red-stained lipid droplets content, decreased the expression of CD36 receptor and modulated tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) release from lipid-laden macrophages. Furthermore, Naloxone, an opioid receptors antagonist, reverted the anti-atherogenic and anti-inflammatory observed effects of EM-1. These data demonstrated, for the first time, an unprecedented ability of EM-1 to act as a novel modulator for macrophage-to-foam cell transformation, and for inflammatory cytokines profile, suggesting possible novel endomorphin-based anti-atherosclerotic approaches for the prevention and treatment of atherosclerosis.

Phenotypic commitment of monocytes towards a protective hemoglobin scavenging phenotype (CD14(pos)CD163(high)HLA-DR(low))following cardiopulmonary bypass.

BACKGROUND: Intravascular hemolysis may cause tissue injury directly or via a systemic inflammatory response. Under physiological conditions, extracorpuscular hemoglobin (Hb) is bound by haptoglobin(Hp) and the complex internalized via the hemoglobin scavenger receptor CD163 on monocytes, prior to catabolism via heme-oxygenase-1 (HO-1). Recently, a novel subset of CD68(pos)CD163(high)HLA-DR(low) macrophages with high expression of HO-1 was recognized in hemorrhagic areas of atherosclerotic plaques, distinct from CD68(pos)CD163(low)HLA-DR(high) foam cell macrophages with low- HO-1 content. Considering the hemolytic insult during CPB, we hypothesized that an equivalent compensatory CD163(high)HLA-DR(low) phenotype will evolve in circulating CD14(pos) monocytes post surgery. METHODS: Twelve patients undergoing elective surgery with CPB were enrolled with informed consent.Whole-blood samples were collected in EDTA at predetermined time-points, pre- intra-, and postoperatively. Whole-blood was evaluated by three-color flow cytometry for expression of CD14, CD163, and HLA-DR; CD14(pos) cells were also permeabilized to detect intracellular HO-1 protein. Plasma [Hp-Hb] concentration was determined by ELISA. RESULTS: A striking phenotypic switch from CD163(low)HLA-DR(high) preoperatively to CD163(high)HLA-DR(low) postoperatively at 24 h was observed on circulating CD14(pos) monocytes. Intracellular HO-1 protein was also significantly up-regulated at 24 h after declamping. These phenotypic changes were preceded by peak Hb-Hp levels observed at 2 h. CONCLUSION: We have shown for the first time, a phenotypic commitment of monocytes towards a protective CD14(pos)CD163(high)HLA-DR(low) population with increased intracellular HO-1 occurring in the circulation during the recovery phase of CPB. These findings have implications for monitoring of anti-inflammatory interventions and linkage to clinical outcomes.

Ubiquitin-positive foam cells are identified in the aortic and mitral valves with atherosclerotic involvement.

AIM: Our aim was to determine the roles of the ubiquitin (Ub)-proteasome system (UPS) in valvular diseases by immunohistochemically identifying Ub-positive cells in aortic and mitral valves and determining if Ub+cells were associated with the severity of valvular diseases. METHODS: We evaluated surgically removed aortic and mitral valves from 60 patients (mean age, 64.5 years) for thickening, fibrosis, foam cell infiltration, thrombus, and atheromatous plaques by using grading scores. U+cells were detected immunohistochemically. RESULTS: We found Ub+cells in 16 (26.7%) of the 60 patients. Eleven (28.2%) of the 39 aortic valves and 5 (23.8%) of the 21 mitral valves were Ub-positive. Ub was found with granular depositions in the cytoplasm of monocyte-derived foam cells that were CD68+. The aortic valvular thickness of the Ub+group was significantly greater than that of the Ub- group (3.9+/-1.6mm vs. 3.2+/-1.6mm, p<0.05). Foam cells and fibrosis were greater in the Ub+group (p<0.05), and calcifications were prominent in aortic valves. There was no difference in the number of apoptotic cells in Ub+ and Ub- groups. Ub+cells were present in the affected valves and ubiquitinated proteins were accumulated in macrophage-derived foam cells. CONCLUSIONS: Ub+ foam cells are present in valves that are vulnerable to valvular disease, and UPS may contribute to the development of atherosclerosis through the inflammatory process.

Lipid metabolism mediated by adipocyte lipid binding protein (ALBP/aP2) gene expression in human THP-1 macrophages.

The critical initiating event in atherogenesis involves the invasion of monocytes through the endothelial wall of arteries, and their transformation from macrophages into foam cells. Human THP-1 monocytic cells can be induced to differentiate into macrophages by phorbol myristate acetate (PMA) treatment, and can then be converted into foam cells by exposure to oxidized low-density lipoprotein (oxLDL). We previously reported that adipocyte lipid binding protein (ALBP/aP2) is a gene that is highly up-regulated in foam cells in response to oxLDL. Here, we showed that overexpression of the ALBP gene using a lentiviral construct in macrophage foam cells enhanced the accumulations of cholesterol and triglyceride, probably due to an increased expression of the scavenger receptor type AI (SR-AI), which plays an important role in cell lipid metabolism. Moreover, we determined that the expression of acyl-coenzyme A: cholesterol-acyltransferase 1 (ACAT1) gene was up-regulated by the overexpression of ALBP gene, and on the other hand, the ATP-binding cassette A1 (ABCA1) gene and hormone sensitive lipase (HSL) gene, which mediate separately cholesterol efflux and cholesterol ester hydrolysis in the macrophage cells, were down-regulated by the overexpression of ALBP gene in these cells. Finally, our data indicated that oxLDL regulates expression of ALBP related to two peroxisome proliferator-responsive elements (PPREs) which are located in ALBP promoter region. These results have determined that ALBP gene expression accelerates cholesterol and triglyceride accumulation in macrophage foam cells and affects some key gene expression for lipid metabolism, suggesting some pivotal roles of ALBP in lipid metabolism for macrophage foam cell formation.

Foamy macrophages within lung granulomas of mice infected with Mycobacterium tuberculosis express molecules characteristic of dendritic cells and antiapoptotic markers of the TNF receptor-associated factor family.

Highly vacuolated or foamy macrophages are a distinct characteristic of granulomas in the lungs of animals infected with Mycobacterium tuberculosis. To date these have usually been considered to represent activated macrophages derived from monocytes entering the lesions from the blood. However, we demonstrate in this study that foamy macrophages express high levels of DEC-205, a marker characteristic of dendritic cells (DCs). In addition to high expression of the DEC-205 marker, these cells were characterized as CD11b(+)CD11c(high)MHC class II(high), and CD40(high), which are additional markers typically expressed by DCs. Up-regulation of CD40 was seen only during the early chronic stage of the lung disease, and both the expression of CD40 and MHC class II markers were down-regulated as the disease progressed into the late chronic phase. Foamy cells positive for the DEC-205 marker also expressed high levels of TNFR-associated factor-1 (TRAF-1), TRAF-2, and TRAF-3, markers associated with resistance to apoptosis. These data indicate that in addition to the central role of DCs in initiating the acquired immune response against M. tuberculosis infection, they also participate in the granulomatous response.

Tendon xanthomas in familial hypercholesterolemia are associated with a differential inflammatory response of macrophages to oxidized LDL.

Tendon xanthomas (TX) are pathognomonic lipid deposits commonly found in familial hypercholesterolemia (FH) patients. The aim of this study was to determine whether macrophages from FH patients with TX (TX+) have higher predisposition to foam cells formation after oxidized LDL (oxLDL) overload than those from FH patients without TX (TX-), and if their differential gene expression profile could explain these different phenotypes. Total RNA pools from macrophages from FH patients TX+ and TX- were analyzed using Affymetrix oligonucleotide arrays to evaluate the gene expression profile in presence and absence of oxLDL. Also, the intracellular lipid content was measured by fluorescence flow cytometry. Results of these studies suggest that macrophages from FH subjects TX+ compared to those TX- have a differential response to oxLDL, since they show higher intracellular cholesterol ester accumulation and a differential gene expression profile. The gene array data were validated by relative quantitative real-time RT-PCR and quantitative ELISA in culture media and plasma samples. FH subjects TX+ showed increased plasma tryptase, TNF-alpha, IL-8 and IL-6 concentrations. We propose that TX formation are associated with higher intracellular lipid content, and higher inflammatory response of macrophages in response to oxLDL.

Human scavenger receptor class B type I is expressed with cell-specific fashion in both initial and terminal site of reverse cholesterol transport.

The reverse cholesterol transport (RCT) is one of the major protective systems against atherosclerosis, in which high-density lipoprotein (HDL) removes cholesterol from lipid-laden cells and delivers it to the liver. Scavenger receptor class B type I (SR-BI) is a HDL receptor in the liver and adrenal glands and is involved in the selective uptake of cholesteryl ester from HDL, which has been extensively, analyzed using rodent models. However, the expression and regulation of the human homologue of this receptor are not known yet. We previously reported that this receptor is expressed in in vitro differentiated macrophages and its expression is up-regulated by the addition of modified lipoproteins into the medium [Hirano K, Yamashita S, Nakagawa Y, et al. Expression of human scavenger receptor class B type I in cultured human monocyte-derived macrophages and atherosclerotic lesions. Circ Res 1999;85:108-16]. In order to further investigate the physiological significance of this receptor in humans, we have performed extensive immunohistochemical analyses with specimens of the liver and adrenal glands as well as arteries with different stages of atherosclerotic lesions. In human liver and adrenal glands, a positive SR-BI immunoreactivity was detected in both hepatic and adrenal parenchymal cells as well as Kupffer cells. These parenchymal cells had a strong signal on the cell surface, whereas Kupffer cells showed a heterogeneous and punctate pattern. In human aorta and coronary arteries, SR-BI was highly expressed in atherosclerotic plaques, but not in non-atherosclerotic lesions. Double immunostaining revealed that SR-BI was expressed in a subpopulation of macrophages, of which staining pattern was similar to that observed in Kupffer cells. These data clearly demonstrated that SR-BI was expressed with cell-specific fashions in both the initial and terminal step of RCT in humans. Thus, SR-BI might be physiologically relevant and have distinct tissue-specific functions.

Interferon-gamma impedes reverse cholesterol transport and promotes foam cell transformation in THP-1 human monocytes/macrophages.

BACKGROUND: Cholesterol 27-hydroxylase, an enzyme expressed at high levels by human monocytes/macrophages, provides a first line of defense against the development of atherosclerosis. Prior studies have suggested that the cytokine interferon-gamma (IFN-gamma) promotes atherosclerosis. We therefore examined the effect of IFN-g on macrophage foam cell formation and on expression of the anti-atherogenic 27-hydroxylase in THP-1 human monocytes/macrophages. MATERIAL/METHODS: THP-1 monocytes and acetylated LDL-treated THP-1 macrophages were incubated in the presence or absence of IFN-gamma (500 U/ml) with or without the addition of IFN- gamma receptor blocking or neutralizing antibody. Foam cell formation was quantified based on percentage of macrophages harboring oil red O-stained globules. Cellular mRNA and protein were isolated. 27-Hydroxylase message was measured by RT-PCR and 27-hydroxylase protein by immunoblot. RESULTS: IFN-gamma -treated THP-1 macrophages exhibit increased foam cell transformation compared to untreated cells under cholesterol loading conditions. IFN-gamma-promoted foam cell formation is abolished by pre-treatment with either IFN-gamma neutralizing or IFN-gamma receptor blocking antibody. IFN-gamma diminishes cholesterol 27-hydroxylase expression in THP-1, and this IFN-gamma -induced downregulation is prevented by pre-treating the cultured cells with either IFN-gamma neutralizing or IFN-gamma receptor blocking antibody. CONCLUSIONS: Imbalances in cellular cholesterol flux within macrophages lead to formation of lipid-laden foam cells, a critical step in the pathogenesis of atherosclerosis. We have demonstrated that IFN-gamma, acting through the IFN-gamma receptor, decreases expression of 27-hydroxylase and increases propensity to foam cell formation in the cell line THP-1. These observations suggest that one mechanism by which IFN-g promotes atherosclerosis may involve affecting expression of cholesterol 27-hydroxylase, a cholesterol homeostatic protein.

[Diagnosis of adult type of Niemann-Pick disease (type C) in two brothers by filipin staining of bone marrow smears].

Niemann-Pick disease, type C (NPC) is a neurometabolic genetic disorder that is distinguished from other types of Niemann-Pick disease by its later onset, more insidious progression, variable visceromegaly, and abnormalities of intracellular cholesterol metabolism. We report cases in 18-year-old and 20-year-old brothers who presented with disinhibition and involuntary movement of their hands. Both brothers presented various signs such as dementia, vertical supranuclear ophthalmoplegia (VSO), dysarthria, axial and limb dystonia, hyperreflexia, pathologic reflex, cerebellar ataxia, as reported. They also presented startle response. Brain MRI showed diffuse cerebral atrophy and abdominal CT reveals hepato-splenomegaly in both patients. These cases were suspected to be NPC based on dementia, VSO, cerebellar ataxia, hepato-splenomegaly and foam cells in the bone marrow. Generally, the diagnosis of NPC is based on deficient cholesterol esterification and excessive lysosomal filipin staining in cultured skin fibroblasts. However, culture of fibroblasts obtained from a biopsied skin samples is slow. We have rapidly made the diagnosis of NPC in our patients by filipin staining of foam cells from bone marrow. This diagnostic process using a bone marrow smear is more convenient and rapid than previous methods using cultured skin fibroblasts.

Müllerian tumor (atypical polypoid adenomyoma) with sex-cord differentiation arising from the oviduct in an adolescent cynomolgus monkey (Macaca fascicularis).

In a 6.5-year-old cynomolgus monkey (Macaca fascicularis), a tumor mass was macroscopically located near the right ovary, connected to the oviduct, and completely separated from the uterus. The mass was an elongated spherical shape with a smooth surface and milky-white color. It was approximately 3.5 cm across its major axis, and the sagittal section was composed of cystic walls and a multi-lobular luminal nodule. Light-microscopically, the polypoid mass consisted of admixtures of neoplastic mesenchymal and epithelial elements. Lipid-rich foamy cells scattered within the tumor mass formed nest-like/aggregated populations. Immunohistochemically, mesenchymal tumor cells stained diffusely positive for vimentin, desmin, and alpha (alpha)-smooth muscle actin, demonstrating a smooth muscle origin. Mesenchymal tumor cells contained mitotic figures, and tumor elements including mesenchymal, epithelial, and lipid-rich foamy cells stained strongly positive for proliferating cell nuclear antigen (PCNA). Moreover, lipid-rich foamy cells elicited positive reactions for testosterone, suggesting sex-cord element differentiation. Electron-microscopically, actin filaments, basement membranes, and electron-dense cytoplasmic bodies were noted in the spindle cells, and invaginated nuclei were observed in adenomatous cells. In contrast, foamy cells contained numerous lipid vacuoles in the cytoplasm. From these findings, the tumor was diagnosed as an atypical polypoid adenomyoma (benign mixed müllerian tumor) with sex-cord differentiation arising from the oviduct. This tumor was considered to be an exceedingly rare finding in the adolescent cynomolgus monkey.