156 research outputs found

    Dietary supplements in lymphedema

    Get PDF
    Lymphedema is a chronic inflammatory disorder resulting from ineffective fluid uptake by the lymphatic system, and the effects are principally felt in the lower limbs. The condition is said to be primary when caused by genetic mutations and secondary when caused by injuries, infections, or surgery. Lymphedema, a worldwide pathology, does not have an effective therapy so far. Leukotriene B4 has recently been identified as a key molecule in lymphedema pathogenesis. Surgical, nonsurgical, and pharmacological treatments have been proposed; however, they do not cure the disease and only ameliorate the symptoms. Nutrition and nutritional status are extremely important in lymphedema physiopathology. Obesity is a comorbidity that exacerbates the risk for secondary lymphedema and constitutes a negative prognostic factor. Indeed, anti-inflammatory foods and their effects on the inflammatory state and on oxidative stress are now being investigated for their possible therapeutic role in lymphedema. Although no special diet has so far been proven to be very effective, specific dietary tips could help in alleviating the edematous state of patients with lymphedema. A few supplements have been tested for lymphedema treatment. Among them, GARLIVE® containing hydroxytyrosol, hesperidin, spermidine and vitamin A, exhibited promising effects in the animal model. Hydroxytyrosol, a polyphenol from olives, showed anti-inflammatory effects and reduced leukotriene B4 synthesis, thus holding promise as a potential natural candidate for lymphedema treatment

    Ultrastructural characterization of calcification onset and progression in subdermally implanted aortic valves. Histochemical and spectrometric data

    Get PDF
    Detailed characterization of the subdermal model is a significant tool for better understanding of calcification mechanisms occurring in heart valves. In previous ultrastructural investigation on six-week-implantated aortic valve leaflets, modified pre-embedding glutaraldehyde-cuprolinic-blue reactions (GA-CB) enabled sample decalcification with concurrent retention/staining of lipid-containing polyanionic material, which lined cells and cell-derived matrix-vesicle-like bodies (phthalocyanin-positive layers: PPLs) co-localizing with the earliest apatite nucleation sites. Additional post-embedding silver staining (GA-CB-S) revealed PPLs to contain calcium-binding sites. This investigation concerns valve leaflets subjected to shorter implantation times to shed light on the modifications associated with PPLs generation and calcification onset/progression. Spectrometric estimations revealed time-dependent calcium increase, for unreacted samples, and copper modifications indicating an increase in acidic, non-glycanic material, for GA-CB-reacted samples. Two-day-implant thin sections showed emission and subsequent reabsorption of lamellipodium-like protrusions by cells, originating ECM-containing vacuoles, and/or degeneration stages characterized by the appearance of GA-CB-S-reactive, organule-derived dense bodies and progressive dissolution of all cell membranes. In one-week-implants, the first PPL-lined cells were found to co-exist with cells where GA-CB-S-reactive material accumulated, or exudated towards their edges, or outcropped at the ECM milieu, so acquiring PPL features. PPL-derived material was observed increasingly to affect the ECM on thin sections of one-week- to six-week-implants. These results show an endogenous source for PPLs and reveal that a peculiar cascade of cell degenerative steps is associated with valve mineralization in the subdermal model, providing new useful parameters for more reliable comparison of this experimental calcification process versus the physiological and pathological processes

    Involvement of cytosolic phospholipase A2 alpha in pathological and experimental cardiovascular mineralization

    Get PDF
    Cytosolic phospholipase A2 alpha (cPLA2a) is a calcium-dependent enzyme constitutively expressed by most human cells catalyzing the hydrolysis of membrane glycerophospholipids bearing arachidonic acid at the sn-2 position with production of downstream pro-inflammatory lipid mediators (Murakami and Kudo, 2002). Although cPLA2a seems to facilitate the release of pro-calcific matrix vesicles by hypertrophic chondrocytes during ossification (Wuthier et al., 1977), its involvement in pathological biomineralization has not yet been elucidated. Here, cPLA2a expression was assessed in the context of both pathological and experimentally induced mineralization affecting cardiovascular tissues and cultured aortic valve interstitial cells (AVICs). cPLA2a resulted to be expressed by fibroblasts, smooth muscle cells, macrophages, and activated endothelium populating both calcified aortic valves and atherosclerotic aorta walls. cPLA2a was also expressed by cultured AVICs, with enzyme expression rate correlating with mineralization rate, being enhanced by inflammation and high phosphate concentrations. For all calcific contexts, ultrastructural examination revealed mineralization to depend on progressive accumulation and release of acidic lipids, acting as major hydroxyapatite nucleators, followed by cell disgregation into a multitude of particles having calcium nucleation capability, according to peculiar degenerative patterns as those previously described (Ortolani et al., 2010). In conclusion, enzyme expression and ultrastructural patterns being shared by both pathological and experimental calcific conditions suggests that cPLA2a might be actually involved in the etiopathogenesis of cardiovascular mineralization, besides representing a potential target for novel therapeutic strategies aimed to counteract the progression of cardiovascular calcific diseases

    Involvement of cytosolic phospholipase A2 alpha in pathological and experimental cardiovascular mineralization

    Get PDF
    Cytosolic phospholipase A2 alpha (cPLA2a) is a calcium-dependent enzyme constitutively expressed by most human cells catalyzing the hydrolysis of membrane glycerophospholipids bearing arachidonic acid at the sn-2 position with production of downstream pro-inflammatory lipid mediators (Murakami and Kudo, 2002). Although cPLA2a seems to facilitate the release of pro-calcific matrix vesicles by hypertrophic chondrocytes during ossification (Wuthier et al., 1977), its involvement in pathological biomineralization has not yet been elucidated. Here, cPLA2a expression was assessed in the context of both pathological and experimentally induced mineralization affecting cardiovascular tissues and cultured aortic valve interstitial cells (AVICs). cPLA2a resulted to be expressed by fibroblasts, smooth muscle cells, macrophages, and activated endothelium populating both calcified aortic valves and atherosclerotic aorta walls. cPLA2a was also expressed by cultured AVICs, with enzyme expression rate correlating with mineralization rate, being enhanced by inflammation and high phosphate concentrations. For all calcific contexts, ultrastructural examination revealed mineralization to depend on progressive accumulation and release of acidic lipids, acting as major hydroxyapatite nucleators, followed by cell disgregation into a multitude of particles having calcium nucleation capability, according to peculiar degenerative patterns as those previously described (Ortolani et al., 2010). In conclusion, enzyme expression and ultrastructural patterns being shared by both pathological and experimental calcific conditions suggests that cPLA2a might be actually involved in the etiopathogenesis of cardiovascular mineralization, besides representing a potential target for novel therapeutic strategies aimed to counteract the progression of cardiovascular calcific diseases

    Attenuated polyposis of the large bowel: a morphologic and molecular approach

    Get PDF
    Attenuated polyposis could be defined as a variant of familial adenomatous polyposis (FAP) in which synchronous polyps of the large bowel range between 10 and 99. We analysed all cases of attenuated polyposis observed over the last 30 years with the objectives: (A) to classify the disease according to different type and proportion of polyps; (B) To ascertain the contribution of APC and MutYH genes; (C) to discover features which could arise the suspicion of mutations; (D) To obtain indications for management and follow-up. 84 individuals in 82 families were studied. Polyps were classified into four groups as adenoma, hyperplastic, other serrated lesions or others; APC and MutYH mutations were assessed. Mean age at diagnosis was 54 ± 14 years in men and 48 ± 13 in women (P = 0.005). Polyps were more numerous in women (37 ± 26 vs 29 ± 22). Sixty % of patients underwent bowel resection, mainly for cancer; the remaining were managed through endoscopy. A total of 2586 polyps were detected at diagnostic endoscopy: 2026 (80 %) were removed and analysed. Adenomas were diagnosed in 1445 (70 %), hyperplastic polyps in 541 (26 %), other serrated lesions in 61 (2.9 %). Adenomas and hyperplastic lesions were detected in the majority of patients. In 68 patients (81 %) in whom studies were executed, APC mutations were found in 8 and MutYH mutations in 10. Genetic variants were more frequent in women (12 vs 6, P = 0.039). Taking into consideration the prevalent (>50 %) histology and presence of mutations, patients could be subdivided into four groups: (1) APC mutated polyposis (AFAP), when adenomas were >50 % and APC mutations detected (no. 8, 10 %); (2) MutYH mutated polyposis (MAP), adenomas >50 % and biallelic MutYH mutations (no. 10, 12 %); (1) attenuated polyposis without detectable mutations, prevalence of adenomas, 48 cases (57 %); (1) hyperplastic-serrated polyposis, with prevalence (>50 %) of hyperplastic/other serrated lesions and no constitutional mutation (no. 18, 21 %). Aggregation of tumors, cancer in probands, distribution of polyps and other clinical characteristics showed no difference among the four groups. In conclusions, AFAP and MAP, the polyposis labeled by constitutional mutations, represented about 25 % of all attenuated polyposis. Mutation-associated cases showed an earlier age of onset of polyps and were more frequent in the female sex

    Critical effects of inorganic phosphate at threshold concentrations on cultured aortic valve interstitial cells. Macroautophagocytosis versus procalcific cell degeneration

    Get PDF
    The conventional threshold values ascribed to inorganic phosphate concentration ([Pi]) in diagnosing normophosphatemia range between 0.8mM and 1.45mM to 2.0mM [Pi]. In cultures mimicking metastatic calcification ([Pi]=3.0mM) a major role was found to be played by [Pi] (Pi-cultures) in priming a procalcific cell degeneration of bovine aortic valve interstitial cells (bAVICs), with mineralization enhancing subsequent to superstimulation with bacterial lipopolysaccharide (LPS) plus conditioned medium from cultured LPS-stimulated macrophages (Pi-LPS-CM-cultures) [1]. Here, bAVIC primary cultures were carried out which contained different [Pi] (0.4, 0.6, and 1.3mM in added solutions, i.e. 0.8, 1.3, and 2.0mM in final cultures), so including border concentrations on respect to hypophosphatemic- and hyperphosphatemic-like conditions. At 0.8mM and 1.3 [Pi] and for each incubation time (3, 9, 15, 21, and 28 days), bAVICs from Pi-cultures and Pi-LPS-CMcultures shared common ultrastructural features showing prominent macroautophagocytosis to occur, consistently with the immunohistochemical detection of the specific marker of mature autophagosomes MAP1-LC3A. Neither cell death signs nor appearance of calcific nodules were observed. At 2.0 [Pi], most bAVICs were affected by degenerative fragmentation as described for severe metastatic-like calcifcation, i.e. the appearence of phthalocianin- positive material outcropping at cell surface, acting as hydroxyapatite nucleator and being source of real calcospherulae. Quantitative spectrophotometric estimation of calcium amounts and alkaline phosphatase activity were consistent with the ultrastructural data, with (i) similar values for Pi-LPS-CM-cultures versus Pi-cultures and control cultures, at 0.8 and 1.3mM [Pi], and (ii) significantly higher values for Pi-LPS-CM-cultures versus Picultures and these latter versus controls, at 2.0mM [Pi]. Restriction of immunopositivity to caspase-8 to very few cells and complete immunonegativity to annexin-V suggested apoptosis to be a negligible epiphenomenon. In conclusion, the propensity of bAVICs to undergo procalcific degeneration resulted to correlate with [Pi] in such a manner that a differential discrimination of this parameter within the conventional normophosphatemic range is suggested for a proper evaluation of the risk for dystrophic valve calcification. Moreover, bacterial-derived inflammation seems to be regarded as an effective trigger for the higher normophosphatemic [Pi]

    Pro-calcific responses by aortic valve interstitial cells in a novel in vitro model simulating dystrophic calcification

    Get PDF
    Etiopathogenetic mechanisms in calcific aortic valve stenosis are still poorly understood despite this being the third major cause of heart disease in western world. In prior in vitro cultures simulating metastatic calcification, pro­calcific effects on aortic valve interstitial cells (AVICs) resulted by adding bacterial endotoxin lipopolysaccharide (LPS) at high inorganic phosphate (Pi) levels. Here we accomplished improved in vitro models simulating either metastatic (Pi = 2.6 mM) or dystrophic calcification (Pi = 1.3 mM), in which LPS­stimulated bovine AVICs underwent extra-stimulation with macrophage-cytokine-containing media derived from paral­ lel cultures of allogeneic monocyte/macrophages in turn stimulated with LPS. In dystrophic calcification-like cultures, lower calcium amount was spectrometrically assessed with parallel reduced alkaline phosphatase activity with respect to metastatic calcification­like cultures, with an about three­fold slower progression of mineralization. Hydroxyapatite crystal precipitation was ultrastructurally found to correlate with AVIC degeneration processes culminating with the formation of phthalocyanin-positive lipidic layers (PPLs) at the surface of cells and cell-derived matrix-vesicle-like bodies, acting as calcium nucleators according to a pattern mirroring those we had previously found in in vivo conditions. In conclusion, an in vitro model has been devel­ oped enabling reliable simulations of the effects exerted on AVICs by putatively pro- or anti-calcific agents

    In vitro reproduction and ultrastructural detection of the genesis of calcifying cell-derived structures identical to actual hydroxyapatite nucleators in calcific aortic valve stenosis

    Get PDF
    Unlike fairly good characterization gained for the major hydroxyapatite nucleators involved in physiological mineralization, i.e. matrix vesicles and apoptotic bodies, no details are available about source and genesis of so called “thick walled cell-derived-products” (CDPs) and “concentrically laminated calcospherulae” (CLCs), which are primary calcium deposition foci in ectopic calcification, including calcific aortic valve stenosis. Here, generation of these structures was successfully reproduced in vitro using an original model simulating either metastatic or dystrophic calcification, subsequent to differential inorganic phosphate supplementations to primary cultures of interstitial cells from bovine aortic valve cusps (AVICs). Superimposed bacterial infectious effects were simulated by additional stimulation with bacterial endotoxin lipopolysaccharide (LPS) and superstimulation with conditioned medium derived from cultures of bovine LPS-stimulated native monocytes/macrophages. At reverted microscope monitoring, AVICs were observed to undergo fragmentation giving rise to irregular debris and/or sporulation-like processes resulting in the formation of barely appreciable punctate bodies, concurrently with specific increase in spectrophotometrically assayed calcium amounts and alkaline phosphatase activity. Ultrastructurally, these cell-derived products showed features comparable to those characterizing CDPs and CLCs in ex vivo samples. The thick wall of CDPs was found to depend on a peculiar AVIC degenerative process culminating with outcropping of multilaminated lipid-containing phthalocyanin-positive layers (PPLs), as revealed by histochemical reactions with Cuprolinic blue. PPLs represented major calcium nucleators, as revealed by co-precipitation of hydroxyapatite needle-like crystals and co-localization of metallic silver deposition after von Kossa staining applied to electron microscopy. In addition, multilaminated PPLs of both degenerating AVICs and CDPs underwent sporulation-like budding and pinching off, so generating a lot of spherical CLC-like bodies, with many being superimposed by near radially oriented hydroxyapatite crystals. In conclusion, the way by which CDPs and CLCs form was ascertained. In addition, in-vitro reproduction of pro-calcific structures identical to those characterizing actual samples from calcified aortic valve cusps suggests the developed in vitro models to be a reliable tool for testing pro-calcific effects exterted by putative etiopathologic agents as well as anti-calcific by therapeutic compounds

    Different propensity of cultured aortic valve interstitial cells to uptake native or aggregated low density lipoprotein

    Get PDF
    Atherosclerosis is a progressive disease characterized by modified low density lipoprotein (LDL) accumulation in the large artery walls, with subsequent phagocytosis by macrophages, transforming into foam cells, and vascular smooth muscle cells (VSMCs). In particular, native LDL (nLDL) can modify joining to each other giving rise to aggregated LDL (agLDL), which were reported to be internalized more avidly by VSMCs in in vitro conditions (1). Here, primarily cultured aortic valve interstitial cells (AVICs) were treated for 3 up to 21 days with 50 mg/ml blood-derived nLDL or agLDL, alone or combined with pro-calcific culture media, to ascertain whether (i) agLDL are taken up more rapidly than nLDL also by AVICs and (ii) treatment with LDL at low, normolipidemic-like concentration can influence AVIC mineralization. Ultrastructurally, LDL uptake was observed exclusively for agLDL-treated AVICs, which were characterized by a lot of endocytic vesicles and intracytoplasmic vacuoles entrapping agLDL particles. Consistently, treatment with agLDL resulted in a significant increase in intracellular amounts of both esterified cholesterol and triglycerides, as chromatographically assayed. Ultrastructural analyses also revealed pro-calcific AVIC degenerative process to occur, consisting in intracellular release of lipidic material and its layering at cell edges, there acting as major hydroxyapatite nucleator (2,3). The extent of pro-calcific effects resulted to be LDL-dependent, being mitigated in the presence of nLDL and exacerbated in the presence of agLDL. These findings were consistent with spectrophotometrical analyses showing decreased calcium amounts in AVIC cultures superstimulated with nLDL and increased mineral content in the counterpart superstimulated with agLDL. Since aortic valve stenosis is considered as a valve atherosclerotic lesion, these preliminary data suggest that avid uptake of agLDL by AVICs might strongly contribute to lipid accumulation within aortic valves, with agLDL possibly affecting subsequent valve tissue mineralization even at concentrations comprised within the normolipidemic range
    • …
    corecore