Epidemiological studies demonstrate the role of early and intensive glycemic control in the prevention of micro and macrovascular disease in both type 1 and type 2 diabetes mellitus (DM). Hyperglycemia elicits several pathways related to the etiopathogenesis of cardiovascular disease (CVD), including the generation of advanced glycation end products (AGEs). In this review, we revisit the role played by AGEs in CVD based in clinical trials and experimental evidence. Mechanistic aspects concerning the recognition of AGEs by the advanced glycosylation end product-specific receptor (AGER) and its counterpart, the dolichyl-diphosphooligosaccharide-protein glycosyltransferase (DDOST) and soluble AGER are discussed. A special focus is offered to the AGE-elicited pathways that promote cholesterol accumulation in the arterial wall by enhanced oxidative stress, inflammation, endoplasmic reticulum stress and impairment in the reverse cholesterol transport (RCT).
Advanced glycated albumin (AGE-albumin) impairs cholesterol efflux and contributes to inflammation in macrophages. The current study evaluated: (1) the persistence of the deleterious effect of AGE-albumin in cholesterol efflux and in inflammation, and (2) how metabolic control in diabetes mellitus (DM) contributes to attenuate the deleterious role of AGE-albumin in macrophage cholesterol homeostasis. Methods: AGE-albumin was produced in vitro or isolated from uncontrolled DM subjects’ serum before (bGC) and after improved glycemic control (aGC). Albumin samples were incubated with bone marrow-derived macrophages and 14C-cholesterol efflux or LPS- induced cytokine secretion were determined immediately, or after cell resting in culture media alone. The ABCA-1 degradation rate was determined after cell incubation with cycloheximide, and ABCA1 protein level by immunoblot. Oil Red O staining was used to assess intracellular lipid accumulation. Results: A persistent effect of AGE-albumin was observed in macrophages in terms of the secretion of inflammatory cytokines and reduced cholesterol efflux. HDL-mediated 14C-cholesterol efflux was at least two times higher in macrophages treated with aCG-albumin as compared to bGC-albumin, and intracellular lipid content was significantly reduced in aGC-albumin-treated cells. As compared to bGC-albumin, the ABCA-1 protein content in whole cell bulk was 94% higher in aCG-albumin. A 20% increased ABCA-1 decay rate was observed in macrophages treated with albumin from poorly controlled DM. AGE-albumin has a persistent deleterious effect on macrophage lipid homeostasis and inflammation. The reduction of AGEs in albumin ameliorates cholesterol efflux.
Background and aims: Diabetic kidney disease (DKD) is associated with lipid derangements that worsen kidney function and enhance cardiovascular (CVD) risk. The management of dyslipidemia, hypertension and other traditional risk factors does not completely prevent CVD complications, bringing up the participation of nontraditional risk factors such as advanced glycation end products (AGEs), carbamoylation and changes in the HDL proteome and functionality. The HDL composition, proteome, chemical modification and functionality were analyzed in nondialysis subjects with DKD categorized according to the estimated glomerular filtration rate (eGFR) and urinary albumin excretion rate (AER).Methods: Individuals with DKD were divided into eGFR> 60 mL/min/1.73 m2plus AER stages A1 and A2 (n = 10) and eGFR< 60 plus A3 (n = 25) and matched by age with control subjects (eGFR> 60;n = 8).Results: Targeted proteomic analyses quantified 28 proteins associated with HDL in all groups, although only 2 were more highly expressed in the eGFR< 60 + A3 group than in the controls: apolipoprotein D (apoD) and apoA-IV. HDL from the eGFR< 60 + A3 group presented higher levels of total AGEs (20%), pentosidine (6.3%) and carbamoylation (4.2 x) and a reduced ability to remove14C-cholesterol from macrophages (33%) in comparison to HDL from controls. The antioxidant role of HDL (lag time for LDL oxidation) was similar among groups, but HDL from the eGFR< 60 + A3 group presented a greater ability to inhibit the secretion of IL-6 and TNF-alpha (95%) in LPS-elicited macrophages in comparison to the control group.Conclusion: The increase in apoD and apoA-IV could contribute to counteracting the HDL chemical modification by AGEs and carbamoylation, which contributes to HDL loss of function in well-established DKD.
1 September 2021 in Journal of Diabetes and its Complications
FUNDAMENTOS: A coccidioidomicose é micose sistêmica usualmente manifesta como infecção benigna de resolução espontânea; porém, uma pequena proporção dos infectados desenvolve quadros progressivos potencialmente fatais, podendo atingir a pele com lesões pleomórficas disseminadas. OBJETIVOS: Identificar e descrever as manifestações cutâneo-mucosas da coccidioidomicose, as ocupações de risco relacionadas à doença e o quadro clínico associado. MÉTODOS: Estudo realizado entre os anos 2003 e 2006 em 30 pacientes portadores de coccidioidomicose provenientes dos estados do Piauí e Maranhão e diagnosticados por exame microscópico direto, cultivo do escarro ou sorologia de triagem de imunodifusão dupla em gel de ágar, aliados à anamnese e exame físico. RESULTADOS: Identificaram-se lesões extrapulmonares em 13 casos (43,3%), com predomínio de manifestações dermatológicas de hipersensibilidade: eritema nodoso (26,6%), exantema com lesões eritemato-escamosas (26,6%) e eritema multiforme (23,3%), além de úlceras de língua (13,3%) e lábio (6,6%) e abscesso subcutâneo (3,3%). Tais manifestações foram observadas na fase aguda da doença. CONCLUSÕES: As manifestações cutâneas associadas à infecção respiratória aguda fortalecem a hipótese diagnóstica desta doença, especialmente, em caçadores de tatus ou pessoas expostas à escavação do solo.