Extracellular Nucleotides Regulate Arterial Calcification by Activating Both Independent and Dependent Purinergic Receptor Signaling Pathways

Arterial calcification, the deposition of calcium-phosphate crystals in the extracellular matrix, resembles physiological bone mineralization. It is well-known that extracellular nucleotides regulate bone homeostasis raising an emerging interest in the role of these molecules on arterial calcification. The purinergic independent pathway involves the enzymes ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs), ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), 5′-nucleotidase and alkaline phosphatase. These regulate the production and breakdown of the calcification inhibitor—pyrophosphate and the calcification stimulator—inorganic phosphate, from extracellular nucleotides. Maintaining ecto-nucleotidase activities in a well-defined range is indispensable as enzymatic hyper- and hypo-expression has been linked to arterial calcification. The purinergic signaling dependent pathway focusses on the activation of purinergic receptors (P1, P2X and P2Y) by extracellular nucleotides. These receptors influence arterial calcification by interfering with the key molecular mechanisms underlying this pathology, including the osteogenic switch and apoptosis of vascular cells and possibly, by favoring the phenotypic switch of vascular cells towards an adipogenic phenotype, a recent, novel hypothesis explaining the systemic prevention of arterial calcification. Selective compounds influencing the activity of ecto-nucleotidases and purinergic receptors, have recently been developed to treat arterial calcification. However, adverse side-effects on bone mineralization are possible as these compounds reasonably could interfere with physiological bone mineralization

Coxsackie-adenovirus receptor expression is enhanced in pancreas from patients with type 1 diabetes

Objectives: One of the theories connecting enterovirus (EV) infection of human islets with type 1 diabetes (T1D) is the development of a fertile field in the islets. This implies induction of appropriate proteins for the viral replication such as the coxsackie–adenovirus receptor (CAR). The aim of this study was to investigate to what extent CAR is expressed in human islets of Langerhans, and what conditions that would change the expression. Design: Immunohistochemistry for CAR was performed on paraffin-embedded pancreatic tissue from patients with T1D (n=9 recent onset T1D, n=4 long-standing T1D), islet autoantibody-positive individuals (n=14) and non-diabetic controls (n=24) individuals. The expression of CAR was also examined by reverse transcription PCR on microdissected islets (n=5), exocrine tissue (n=5) and on explanted islets infected with EV or exposed to chemokines produced by EV-infected islet cells. Results: An increased frequency of patients with T1D and autoantibody-positive individuals expressed CAR in the pancreas (p<0.039). CAR staining was detected more frequently in pancreatic islets from patients with T1D and autoantibody-positive subjects (15/27) compared with (6/24) non-diabetic controls (p<0.033). Also in explanted islets cultured in UV-treated culture medium from coxsackievirus B (CBV)-1-infected islets, the expression of the CAR gene was increased compared with controls. Laser microdissection of pancreatic tissue revealed that CAR expression was 10-fold higher in endocrine compared with exocrine cells of the pancreas. CAR was also expressed in explanted islets and the expression level decreased with time in culture. CBV-1 infection of explanted islets clearly decreased the expression of CAR (p<0.05). In contrast, infection with echovirus 6 did not affect the expression of CAR. Conclusions: CAR is expressed in pancreatic islets of patients with T1D and the expression level of CAR is increased in explanted islets exposed to proinflammatory cytokines/chemokines produced by infected islets. T1D is associated with increased levels of certain chemokines/cytokines in the islets and this might be the mechanism behind the increased expression of CAR in TID islets

Extracellular Nucleotides Regulate Arterial Calcification by Activating Both Independent and Dependent Purinergic Receptor Signaling Pathways

Arterial calcification, the deposition of calcium-phosphate crystals in the extracellular matrix, resembles physiological bone mineralization. It is well-known that extracellular nucleotides regulate bone homeostasis raising an emerging interest in the role of these molecules on arterial calcification. The purinergic independent pathway involves the enzymes ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs), ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), 5′-nucleotidase and alkaline phosphatase. These regulate the production and breakdown of the calcification inhibitor—pyrophosphate and the calcification stimulator—inorganic phosphate, from extracellular nucleotides. Maintaining ecto-nucleotidase activities in a well-defined range is indispensable as enzymatic hyper- and hypo-expression has been linked to arterial calcification. The purinergic signaling dependent pathway focusses on the activation of purinergic receptors (P1, P2X and P2Y) by extracellular nucleotides. These receptors influence arterial calcification by interfering with the key molecular mechanisms underlying this pathology, including the osteogenic switch and apoptosis of vascular cells and possibly, by favoring the phenotypic switch of vascular cells towards an adipogenic phenotype, a recent, novel hypothesis explaining the systemic prevention of arterial calcification. Selective compounds influencing the activity of ecto-nucleotidases and purinergic receptors, have recently been developed to treat arterial calcification. However, adverse side-effects on bone mineralization are possible as these compounds reasonably could interfere with physiological bone mineralization

Is cognitive lifestyle associated with depressive thoughts and self-reported depressive symptoms in later life?

© 2015, The Author(s). Key components of cognitive lifestyle are educational attainment, occupational complexity and engagement in cognitively stimulating leisure activities. Each of these factors is associated with experiencing fewer depressive symptoms in later life, but no study to date has examined the relationship between overall cognitive lifestyle and depressive symptoms. This task is made more complex because relatively few older participants in cross-sectional studies will be currently experiencing depression. However, many more will show evidence of a depressive thinking style that predisposes them towards depression. This study aimed to investigate the extent to which cognitive lifestyle and its individual components are associated with depressive thoughts and symptoms. Two hundred and six community-dwelling participants aged 65+ completed the depressive cognitions scale, the geriatric depression scale and the lifetime of experiences questionnaire, which assesses cognitive lifestyle. Correlational analysis indicated that each of the individual lifestyle factors—education, occupational complexity and activities in young adulthood, mid-life and later life—and the combined cognitive lifestyle score was positively associated with each other and negatively with depressive symptoms, while all except education were negatively associated with depressive thoughts. Depressive thoughts and symptoms were strongly correlated. Cognitive lifestyle score explained 4.6 % of the variance in depressive thoughts and 10.2 % of the variance in depressive symptoms. The association of greater participation in cognitive activities, especially in later life, with fewer depressive symptoms and thoughts suggests that preventive interventions aimed at increasing participation in cognitively stimulating leisure activity could be beneficial in decreasing the risk of experiencing depressive thoughts and symptoms in later life

Imunidade celular em caninos neonatos - do nascimento ao 45° dia de idade

The aim of this study was to evaluate the immune development of newborn canines, evaluating the cellular immunity by analysis of leukocyte and lymphocyte totals and sub-population of T lymphocytes (CD4+ and CD8+) by the flow cytometry technique. Thirty neonatal mongrel dogs of both sexes were used, at 3, 10, 17, 24, 31, 38 and 45 days of age. The total leukocyte count to 45 days (11639±3574/µL) was significantly greater than on the third day of age (8740±1812) (p<0.05); There were no differences between the total count of lymphocytes at 45 days in relation to the third day of age. As for the subpopulations of CD4+ and CD8+, CD4+ cell percentages, at three days of age (24.9±16.8) they were inferior when compared to the average between the 10th, 24th and 31st day (35.5), and CD8+ cells, on the third day, were lower compared with averages from the 10th and 31st day of age. It can be concluded that the subpopulations of CD4+ and CD8+ cells undergo oscillations during development, with growing postnatal levels obtained at three days old. The CD4:CD8 ratio showed superiority to the first cell type, and the largest relationship between CD4+ and CD8+ occurred on the third day of age. Based on the results obtained in this study, the differences noted in lymphocyte populations weekly showed the dynamics of these cells during the neonatal period.O objetivo do presente trabalho foi acompanhar o desenvolvimento imunológico dos neonatos caninos, a fim de avaliar a imunidade celular pela análise dos leucócitos e linfócitos totais e das subpopulações de linfócitos T (CD4+ e CD8+) pela técnica de citometria de fluxo. Foram utilizados 30 cães neonatos de ambos os sexos, sem raça definida, aos três, 10, 17, 24, 31, 38 e 45 dias de idade. A contagem de leucócitos totais aos 45 dias (11.639±3.574) foi significativamente maior que no terceiro dia de idade (8.740±1.812) (P<0,05); não houve diferença entre a contagem total de linfócitos aos 45 dias em relação ao terceiro dia de idade. Quanto às subpopulações de LT CD4+ e LT CD8+, os percentuais de LT CD4+, aos três dias de idade (24,9±16,8%), foram inferiores quando comparados à média entre o 10°, o 24° e o 31°dia (35,5%), e os de CD8+, ao terceiro dia, menores em relação às médias do 10° e do 31° dia de idade. Pode-se concluir que as subpopulações de LT CD4+ e CD8+ sofrem oscilações durante o desenvolvimento pós-natal, sendo estas crescentes em relação aos níveis obtidos aos três dias de idade. A relação CD4+:CD8+ mostrou superioridade para o primeiro tipo celular, sendo que a maior relação entre CD4+ e CD8+ ocorreu no terceiro dia de idade. Com base nos resultados obtidos neste estudo, notaram-se as diferenças semanais nas populações linfocitárias, o que demonstra a dinâmica dessas células durante o período neonatal.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UFPI Faculdade de Medicina VeterináriaUNESP Faculdade de Medicina Veterinária e ZootecniaUEM Faculdade de Medicina VeterináriaUFRB Faculdade de Medicina VeterináriaUNESP Faculdade de Medicina Veterinária e Zootecni

An attempt to protect cats against infestation with Ctenocephalides felis felis using gut membrane antigens as a vaccine

Cats (n = 5) were vaccinated with membrane antigens extracted from the gut of unfed fleas (Ctenocephalides felis felis) together with Quil A and RIBI as adjuvants. Five unvaccinated cats were retained as controls. All the cats were infested on 6 separate occasions with fleas (46-250 per challenge). Protection was assessed from the number of fleas retrieved and the fecundity of the female fleas, measured as the number of developed oocytes contained in the reproductive tract. Cats injected with gut membrane antigens had significantly elevated levels of anti-flea antibodies in their sera, but they were neither protected significantly against infestation with fleas nor was the apparent fecundity of fleas which had fed on vaccinated cats decreased. The possible reason why gut membrane antigens failed to protect cats against fleas are discussed

Chronic Kidney Disease-Induced Arterial Media Calcification in Rats Prevented by Tissue Non-Specific Alkaline Phosphatase Substrate Supplementation Rather Than Inhibition of the Enzyme

Patients with chronic kidney disease (CKD) suffer from arterial media calcification and a disturbed bone metabolism. Tissue-nonspecific alkaline phosphatase (TNAP) hydrolyzes the calcification inhibitor pyrophosphate (PPi) into inorganic phosphate (Pi) and thereby stimulates arterial media calcification as well as physiological bone mineralization. This study investigates whether the TNAP inhibitor SBI-425, PPi or the combination of both inhibit arterial media calcification in an 0.75% adenine rat model of CKD. Treatments started with the induction of CKD, including (i) rats with normal renal function (control diet) treated with vehicle and CKD rats treated with either (ii) vehicle, (iii) 10 mg/kg/day SBI-425, (iv) 120 µmol/kg/day PPi and (v) 120 µmol/kg/day PPi and 10 mg/kg/day SBI-425. All CKD groups developed a stable chronic renal failure reflected by hyperphosphatemia, hypocalcemia and high serum creatinine levels. CKD induced arterial media calcification and bone metabolic defects. All treatments, except for SBI-425 alone, blocked CKD-related arterial media calcification. More important, SBI-425 alone and in combination with PPi increased osteoid area pointing to a less efficient bone mineralization. Clearly, potential side effects on bone mineralization will need to be assessed in any clinical trial aimed at modifying the Pi/PPi ratio in CKD patients who already suffer from a compromised bone status.</jats:p