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.

Label-Free Tomographic Imaging of Lipid Droplets in Foam Cells for Machine-Learning-Assisted Therapeutic Evaluation of Targeted Nanodrugs.

Lipid droplet (LD) accumulation, a key feature of foam cells, constitutes an attractive target for therapeutic intervention in atherosclerosis. However, despite advances in cellular imaging techniques, current noninvasive and quantitative methods have limited application in living foam cells. Here, using optical diffraction tomography (ODT), we performed quantitative morphological and biophysical analysis of living foam cells in a label-free manner. We identified LDs in foam cells by verifying the specific refractive index using correlative imaging comprising ODT integrated with three-dimensional fluorescence imaging. Through time-lapse monitoring of three-dimensional dynamics of label-free living foam cells, we precisely and quantitatively evaluated the therapeutic effects of a nanodrug (mannose-polyethylene glycol-glycol chitosan-fluorescein isothiocyanate-lobeglitazone; MMR-Lobe) designed to affect the targeted delivery of lobeglitazone to foam cells based on high mannose receptor specificity. Furthermore, by exploiting machine-learning-based image analysis, we further demonstrated therapeutic evaluation at the single-cell level. These findings suggest that refractive index measurement is a promising tool to explore new drugs against LD-related metabolic diseases.

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.

Oxygen levels during negative pressure wound therapy.

AIM OF THE STUDY: Negative pressure wound therapy (NPWT) has become an established treatment modality when dealing with chronic and infected wounds. The underlying mechanism of action is still under discussion and remains controversial. Evidence exists showing rather hypoxic conditions as the main reason for the positive results and bacterial clearance. In an attempt to further explain the mechanism of action, we investigated oxygen levels within the foam interface of a NPWT device. MATERIALS AND METHODS: We used an optical sensor based on the principle of dynamic fluorescence quenching and tested five different commonly available NPWT systems used during our daily clinical routine. All measurements were done in an in vitro experimental design for at least 24 h and multiple vacuum intensities were investigated. RESULTS: Oxygen levels decreased as much as 22.8% and the amount of vacuum applied inversely correlated with the oxygen reduction. A stepwise increase in vacuum of 25 mmHg showed a linear mean drop of 2.75% per setting. All devices were able to maintain a constant level of negative pressure, and no significant difference between the various dressings was found (p > 0.05). CONCLUSION: Therefore, oxygen levels are decreased within the foam of NPWT dressings, likely leading to oxygen deprivation effects in the underlying wound tissue.

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.

[Trimetazidine reduces cholesterol content of foam cells by up-regulating autophagy and macrophage extracellular traps, and inhibiting inflammasome].

Objective To explore the effects of trimetazidine (TMZ) on the foam cell formation and its underlying mechanism in oxidized low-density lipoprotein (ox-LDL)-induced macrophages. Methods RAW264.7 cells were stimulated with ox-LDL to establish a foam cell model derived from macrophages. In the experiment, the foam cells were divided into control group (medium), model group (ox-LDL 60 µg/mL), chloroquine (CQ) group (ox-LDL 60 µg/mL combined with CQ 10 mmol/L) and TMZ group (ox-LDL 60 µg/mL combined with TMZ 80 µmol/L, CQ 10 mmol/L). The formation of foam cells was measured by oil red O staining. The levels of total cholesterol (TC) and free cholesterol (FC) in the foam cells were detected using ELISA. Autophagy was observed using MDC staining. Picogreen staining and quantitative fluorescence were performed to detect the formation of macrophage extracellular traps (MET). Then, the mRNA expression of LC3B, P62, inflammasome (NLRP3, ASC, caspase-1) and cholesterol efflux-related genes (ABCA1, ABCG1) were examined by real-time quantitative PCR. Results Compared with the model group, the expression of LC3B mRNA increased significantly, and P62 expression decreased in TMZ combined with CQ group. Meanwhile, the levels of TC, FC, CE/TC, and the expression of NLRP3, ASC, caspase-1 in TMZ combined with CQ group were reduced obviously. Furthermore, the formation of MET in TMZ combined with CQ group was promoted. However, the CQ group showed the opposite results. Conclusion Trimetazidine promotes cholesterol efflux in foam cells via activating autophagy and increasing the formation of MET, as well as inhibiting NLRP3 inflammasome.

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.

Morphometric Characterization of Rat and Human Alveolar Macrophage Cell Models and their Response to Amiodarone using High Content Image Analysis.

PURPOSE: Progress to the clinic may be delayed or prevented when vacuolated or "foamy" alveolar macrophages are observed during non-clinical inhalation toxicology assessment. The first step in developing methods to study this response in vitro is to characterize macrophage cell lines and their response to drug exposures. METHODS: Human (U937) and rat (NR8383) cell lines and primary rat alveolar macrophages obtained by bronchoalveolar lavage were characterized using high content fluorescence imaging analysis quantification of cell viability, morphometry, and phospholipid and neutral lipid accumulation. RESULTS: Cell health, morphology and lipid content were comparable (p < 0.05) for both cell lines and the primary macrophages in terms of vacuole number, size and lipid content. Responses to amiodarone, a known inducer of phospholipidosis, required analysis of shifts in cell population profiles (the proportion of cells with elevated vacuolation or lipid content) rather than average population data which was insensitive to the changes observed. CONCLUSIONS: A high content image analysis assay was developed and used to provide detailed morphological characterization of rat and human alveolar-like macrophages and their response to a phospholipidosis-inducing agent. This provides a basis for development of assays to predict or understand macrophage vacuolation following inhaled drug exposure.

Transcriptional Profiling of Foam Cells Reveals Induction of Guanylate-Binding Proteins Following Western Diet Acceleration of Atherosclerosis in the Absence of Global Changes in Inflammation.

BACKGROUND: Foam cells are central to two major pathogenic processes in atherogenesis: cholesterol buildup in arteries and inflammation. The main underlying cause of cholesterol deposition in arteries is hypercholesterolemia. This study aimed to assess, in vivo, whether elevated plasma cholesterol also alters the inflammatory balance of foam cells. METHODS AND RESULTS: Apolipoprotein E-deficient mice were fed regular mouse chow through the study or were switched to a Western-type diet (WD) 2 or 14 weeks before death. Consecutive sections of the aortic sinus were used for lesion quantification or to isolate RNA from foam cells by laser-capture microdissection (LCM) for microarray and quantitative polymerase chain reaction analyses. WD feeding for 2 or 14 weeks significantly increased plasma cholesterol, but the size of atherosclerotic lesions increased only in the 14-week WD group. Expression of more genes was affected in foam cells of mice under prolonged hypercholesterolemia than in mice fed WD for 2 weeks. However, most transcripts coding for inflammatory mediators remained unchanged in both WD groups. Among the main players in inflammatory or immune responses, chemokine (C-X-C motif) ligand 13 was induced in foam cells of mice under WD for 2 weeks. The interferon-inducible GTPases, guanylate-binding proteins (GBP)3 and GBP6, were induced in the 14-week WD group, and other GBP family members were moderately increased. CONCLUSIONS: Our results indicate that acceleration of atherosclerosis by hypercholesterolemia is not linked to global changes in the inflammatory balance of foam cells. However, induction of GBPs uncovers a novel family of immune modulators with a potential role in atherogenesis.

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.

Chemerin and CMKLR1 expression in human arteries and periadventitial fat: a possible role for local chemerin in atherosclerosis?

BACKGROUND: Depending on their anatomical location, different fat depots have a different capacity to produce bioactive peptides, called adipokines. Adipokines produced by periadventitial fat have been implicated in the pathogenesis of vascular disease, including atherosclerosis. Chemerin is an adipokine with an established role in immunity, adipose tissue function and metabolism, acting in autocrine, paracrine and endocrine manners. We investigated the protein expression of chemerin and its receptor, CMKLR1, in human aortas, coronary vessels and the respective periadventitial adipose tissue and correlated their expression with the presence of atherosclerosis. METHODS: Immunohistochemistry for chemerin and CMKLR1 was performed on human aortic and coronary artery samples including the periadventitial adipose tissue. Aortic and coronary atherosclerotic lesions were assessed using the AHA classification. RESULTS: Chemerin immunopositivity was noticed in both periadventitial fat depots, in vascular smooth muscle cells and foam cells in atherosclerotic lesions. Periadventitial fat and foam cell chemerin immunopositivity was statistically significantly correlated with the severity of atherosclerosis in both locations. CMKLR1 was expressed in vascular smooth muscle cells and foam cells in aortic and coronary vessels with atherosclerotic lesions. CMKLR1 immunostaining in foam cells was statistically significantly correlated with aortic atherosclerosis. CONCLUSIONS: Our results lend some support to a presumable role of locally produced chemerin in the progression of atherosclerotic lesions, possibly acting through its CMKLR1 receptor. Further research will elucidate the role of chemerin signaling in atherosclerosis.

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.

Adiponectin/T-cadherin and apelin/APJ expression in human arteries and periadventitial fat: implication of local adipokine signaling in atherosclerosis?

INTRODUCTION: Adipose tissue is considered an endocrine organ, producing bioactive peptides, called adipokines. Adipokines produced by periadventitial fat have been implicated in the pathogenesis of vascular disease, including atherosclerosis. Adiponectin has established antiatherogenic actions, while the role of T-cadherin as an adiponectin receptor is not fully elucidated. The apelinergic system, consisting of apelin and its APJ receptor, is a mediator of various cardiovascular functions and may also be involved in the atherosclerotic process. We investigated the protein expression of adiponectin, T-cadherin, apelin and APJ in human aortas, coronary vessels, and the respective periadventitial adipose tissue and correlated their expression with the presence of atherosclerosis and clinical parameters. METHODS: Immunohistochemistry for adiponectin, T-cadherin, apelin, and APJ was performed on human aortic and coronary artery samples including the periadventitial adipose tissue. Aortic and coronary atherosclerotic lesions were assessed using the american heart association (AHA) classification. RESULTS: Adiponectin immunostaining, of varied intensity, was detected only in adipocytes, while T-cadherin was localized to vascular smooth muscle cells (VSMCs) and endothelial cells. Apelin immunostaining was detected in adipocytes, VSMCs, endothelial cells, and foam cells in atherosclerotic lesions, while APJ was found in VSMCs and endothelia. Periadventitial adiponectin and VSMC T-cadherin expression were negatively correlated with atherosclerosis in both sites, as was VSMC apelin expression. Several other - depot specific - associations were observed. CONCLUSIONS: Our results suggest a possible role for T-cadherin as a mediator of antiatherogenic adiponectin actions, while they support the putative antiatherogenic profile for apelin and its APJ receptor in human arteries. Further research is absolutely necessary to confirm these notions. SUMMARY: Periadventitial adipose tissue adipokines are implicated in vascular physiology and pathology. Adiponectin/T-cadherin and apelin/APJ immunoreactivity is detected in human aortas and coronary arteries. Adiponectin/T-cadherin and apelin/APJ expression patterns were found to be inversely associated with human aortic and coronary atherosclerosis.

Networklike propagation of cell-level stress in sheared random foams.

Quasistatic simple shearing flow of random monodisperse soap froth is investigated by analyzing surface evolver simulations of spatially periodic foams. Elastic-plastic behavior is caused by irreversible topological rearrangements (T1s) that occur when Plateau's laws are violated; the first T1 determines the elastic limit and frequent T1 avalanches sustain the yield-stress plateau at large strains. The stress and shape anisotropy of individual cells is quantified by Q, a scalar derived from an interface tensor that gauges the cell's contribution to the global stress. During each T1 avalanche, the connected set of cells with decreasing Q, called the stress release domain, is networklike and nonlocal. Geometrically, the networklike nature of the stress release domains is corroborated through morphological analysis using the Euler characteristic. The stress release domain is distinctly different from the set of cells that change topology during a T1 avalanche. Our results highlight the connection between the unique rheological behavior of foams and the complex large-scale cooperative rearrangements of foam cells that accompany distinctly local topological transitions.

Intrinsic versus laser-induced fluorescence spectroscopy for coronary atherosclerosis: a generational comparison model for testing diagnostic accuracy.

Laser-induced fluorescence (LIF) and intrinsic fluorescence spectroscopy (IFS) have been used experimentally for diagnosing coronary atherosclerosis. In this study, we demonstrated the diagnostic superiority of IFS at 342-nm excitation (IFS(342)) versus LIF (LIF(342)) and described a protocol for head-to-head comparison of old (LIF) versus new (IFS) generations of similar diagnostic methods, labeled as "generational comparison model". IFS(342) and LIF(342) were modeled with basis spectra of media, fibrous caps, and superficial foam cells and of their correspondent chemicals (elastin, collagen, and lipoproteins). The average accuracy and receiver operating characteristic area under the curve of IFS(342) in single-, double-, and triple-parameter diagnostic algorithm iterations, geared toward identifying 84 atherosclerotic specimens from a group of 117 coronary segments, was 90% ± 1% and 0.87 ± 0.025, superior to LIF(342) (84% ± 3% and 0.84 ± 0.016; P = 0.0002 and 0.02, respectively) in a generational comparison model.

Detection of coronary atherosclerotic plaques with superficial proteoglycans and foam cells using real-time intrinsic fluorescence spectroscopy.

OBJECTIVES: The protein components of low-density lipoprotein (LDL), oxidized LDL and proteoglycans such as versican contain tryptophan, an amino acid with characteristic fluorescence features at 308 nm excitation wavelength. We hypothesize that intrinsic fluorescence spectroscopy at 308 nm excitation wavelength IFS308, a method suitable for clinical use, can identify coronary artery lesions with superficial foam cells (SFCs) and/or proteoglycans. METHODS: We subjected 119 human coronary artery specimens to in vitro fluorescence and reflectance spectroscopy. We used 5 basis spectra to model IFS308, and extracted their contributions to each individual IFS308 spectrum. A diagnostic algorithm using the contributions of Total Tryptophan and fibrous cap to IFS308 was built to identify specimens with SFCs and/or proteoglycans in their top 50 µm. RESULTS: We detected SFCs and/or proteoglycans, such as versican or the glycosaminoglycan hyaluronan, in 24 fibrous cap atheromas or pathologic intimal thickening (PIT) lesions. An algorithm using the contributions of Total Tryptophan and fibrous cap to IFS308 was able to identify these segments with 92% sensitivity and 80% specificity. CONCLUSION: We were able to establish a set of characteristic LDL, oxidized LDL, versican and hyaluronan fluorescence spectra, ready to be used for real-time diagnosis. The IFS(308) technique detects SFCs and/or proteoglycans in fibrous cap atheromas and PIT lesions. SFCs and proteoglycans are histological markers of vulnerable plaques, and this study is a step further in developing an invasive clinical tool to detect the vulnerable atherosclerotic plaque.

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.