The binding of glucosylceramidase to glucosylceramide is promoted by its activator protein

AbstractA protein activator of glucosylceramidase (EC 3.2.1.45) has been previously identified by us in human placenta [(1985) Biochim. Biophys. Acta 836, 157–166]. In the present paper we report that its function in vitro is to stimulate the binding of the enzyme to its substrate, glucosylceramide. After the purification step which frees the enzyme of most of its activator protein (octyl-Sepharose 4B chromatography), the capacity of glucosylceramidase to bind to the glucosylceramide micelles is dramatically decreased. The addition of the activator protein to the purified enzyme restores this binding

Micro-Raman mapping of the polymorphs of serpentine

Serpentinites are rocks, often used in buildings, formed in large extent by minerals of the serpentine group: chrysotile, antigorite, lizardite, and polygonal serpentine. The fibrous type (e.g. chrysotile) of serpentine group minerals, along with several amphibole varieties (e.g. actinolite and tremolite), are the major components of asbestos family. The exposure to fine fibrous asbestos powder is linked to diseases such as pleural mesothelioma and asbestosis. The identification of the main varieties of the serpentine group, laminated or fibrous, becomes an issue of great interest for public health. This work introduces an analytical strategy able to distinguish the different serpentine polymorphs directly on the sample, allowing the analysiswithin their textural environment, evidencing at themicrometer scale the mineral reactions of the phases. Samples coming from the Koniambo massif (Grande Terre Island, New Caledonia) were studied by means of optical microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, and Raman spectroscopy. Raman peaks observed in the high wavenumber spectral range of 3550–3850 cm-1, associated with OH stretching vibrations, allow the iscrimination of the all four serpentine varieties. The relationship between the different varieties of serpentine, at a micrometric scale, in complex samples, has been investigated by two-dimensional Raman mapping

Snoring, hypertension and Type 2 diabetes in obesity. Protection by physical activity

Sleep-related breathing disorders are recognized as major health problems in obesity. They are involved in both hypertension and Type 2 diabetes, through mechanisms possibly related to increased sympathetic tone. We studied the association of habitual snoring with diabetes, hypertension, weight cycling and physical activity in a large Italian database of treatment-seeking obese subjects. Clinical and behavioral data were assessed by standardized questionnaires. Consecutive data of 1890 obese patients were analyzed [average body mass index (BMI), 38.2 kg/m(2), median age: 46 yr, 78% females], from 25 obesity Italian centers, with low prevalence of clinical manifestations of cardiovascular disease. Habitual snoring was reported in 56% of the cases, and was associated with day-time sleepiness. The prevalence increased with obesity class and waist circumference, and was positively associated with weight cycling and weight gain since the age of 20, and smoking. Regular physical activity had a protective effect. Snoring was associated with diabetes and hypertension at univariate analysis, but in multivariate analysis an independent effect was only observed for hypertension. After adjustment for age, gender and BMI, physical activity maintained an independent, protective effect on both snoring (odds ratio 0.65, 95% confidence interval 0.49-0.84; p = 0.001), diabetes (0.50, 0.30-0.86; p = 0.011) and hypertension (0.71, 0.53-0.95; p = 0.023). We conclude that in treatment-seeking, obese subjects with low prevalence of cardiovascular disease, snoring independently increases the risk of hypertension, whereas physical activity exerts a protection on both snoring and complications. These data underline the importance of lifestyle interventions to limit the burden of obesity and associated diseases.ABSTRACT. Sleep-related breathing disorders are recognized as major health problems in obesity. They are involved in both hypertension and Type 2 diabetes, through mechanisms possibly related to increased sympathetic tone. We studied the association of habitual snoring with diabetes, hypertension, weight cycling and physical activity in a large Italian database of treatmentseeking obese subjects. Clinical and behavioral data were assessed by standardized questionnaires. Consecutive data of 1890 obese patients were analyzed [average body mass index (BMI), 38.2 kg/m2, median age: 46 yr, 78% females], from 25 obesity Italian centers, with low prevalence of clinical manifestations of cardiovascular disease. Habitual snoring was reported in 56% of the cases, and was associated with day-time sleepiness. The prevalence increased with obesity class and waist circumference, and was positively associated with weight cycling and weight gain since the age of 20, and smoking. Regular physical activity had a protective effect. Snoring was associated with diabetes and hypertension at univariate analysis, but in multivariate analysis an independent effect was only observed for hypertension. After adjustment for age, gender and BMI, physical activity maintained an independent, protective effect on both snoring (odds ratio 0.65, 95% confidence interval 0.49–0.84; p=0.001), diabetes (0.50, 0.30–0.86; p=0.011) and hypertension (0.71, 0.53–0.95; p=0.023). We conclude that in treatment-seeking, obese subjects with low prevalence of cardiovascular disease, snoring independently increases the risk of hypertension, whereas physical activity exerts a protection on both snoring and complications. These data underline the importance of lifestyle interventions to limit the burden of obesity and associated diseases

Human aging and longevity are characterized by high levels of mitokines

Mitochondrial stress elicits the production of stress response molecules indicated as mitokines, including FGF21, GDF15 and Humanin (HN). Many diseases are characterized by progressive mitochondrial dysfunction with alterations of mitokine secretion. It is still controversial whether healthy aging and extreme longevity are accompanied by altered production of mitokines. We analyzed FGF21, HN and GDF15 plasma levels in 693 subjects aged from 21 to 113 years, and the association of these mitokines with parameters of health status. FGF21, HN and GDF15 resulted increased in old age, with the highest levels found in centenarians. These molecules are associated with worsened parameters (such as handgrip strength, insulin sensitivity, total triglycerides), particularly in 70-year-old persons, and their levels are inversely correlated with survival in the oldest subjects. Considering the positive biological effect of these molecules, our results can be interpreted in the framework of the hormetic paradigm as an attempt of the cells/tissues to cope with a stress that can have beneficial or detrimental effects depending on its intensity. Finally, persons with Down Syndrome (characterized by accelerated aging) have higher levels of GDF15 and HN with respect to their siblings, suggesting that these molecules, especially GDF15, could be considered markers of biological age

Immune parameters identify Italian centenarians with a longer five-year survival independent of their health and functional status.

Centenarians are rare and exceptional individuals characterized by a peculiar phenotype. They are the best ex- ample of healthy aging in humans as most of them have escaped or substantially delayed the onset of major age-related diseases. Within this scenario, the purpose of the present work was to understand if immune status is associated with survival and health status in centenarians. To this aim, 116 centenarians were concomitantly characterized for their immunological, health and functional status, and followed-up for five-year survival. On the basis of previous knowledge we focused on a core of fundamental and basic immune parameters (number of leukocytes, monocytes, total lymphocytes, CD3+ T lymphocytes, CD4+ helper T lymphocytes, CD8+ cytotoxic T lymphocytes, CD19+ B lymphocytes and plasma levels of IgM), and the most important findings can be sum- marized as follows: i. a hierarchical cluster analysis was able to define Cluster1 (88 centenarians) and Cluster2 (28 centenarians) characterized by low and high values of all these immune parameters, respectively; ii. cente- narians of Cluster2 showed a statistically longer five-year survival and more favorable values of other important immune (naïve, activated/memory and effector/memory T cells) and metabolic (glycemia, insulin and HOMA-IR) parameters, in accord with previous observations that centenarians have a peculiar immune profile, a preserved insulin pathway and a lower incidence of type 2 diabetes; and iii. unexpectedly, parameters related to frailty, as well as functional and cognitive status, did not show any significant correlation with the immune clustering, de- spite being capable per se of predicting survival. In conclusion, high values of basic immunological parameters and important T cell subsets correlate with five-year survival in centenarians, independent of other phenotypic characteristics. This unexpected biological scenario is compatible with the general hypothesis that in centenarians a progressive disconnection and loss of biological coherence among the different functions of the body occur, where survival/mortality result from the failure of any of these domains which apparently follow an independent age-related trajectory

Successful immunosenescence and the remodelling of immune responses with ageing.

In recent decades, major theoretical and technological advances have been achieved in the field of immunology. These have allowed the scientific community to analyse the immune system in a much more sophisticated manner than was possible even 20 years ago. Moreover, great theoretical changes have also occurred in gerontology - in particular, the hypothesis has been put forward that ageing and diseases are two different phenomena, and that successful ageing, i.e. ageing in good psychophysical conditions, is really possible for most humans and animals. Immunosenescence was then carefully investigated, either in selected healthy people of advanced age or in the oldest old people, such as healthy centenarians. The main results showed that most immune parameters are indeed well preserved even at this far advanced age. This paper deals with some of the most important theoretical problems of immunosenescence. An immunological tenet was that the most important phenomenon of immunosenescence is the involution of the thymus. In most textbooks and papers it is taken for granted that the thymus starts its involution immediately after puberty. When people aged 60-65 were considered old, it was not difficult to think that they could live for the rest of their life with a fully involuted thymus. The findings on centenarians challenge this tenet, as they have only a small reduction of T lymphocytes, and a relatively normal number of virgin and memory T cells, together with a functional T cell repertoire. Other observations reported here on centenarians, concerning the activity of B lymphocytes and the cytokine network, as well as those on the well-preserved innate immunity and the cells' capability of undergoing proliferation after appropriate stimuli, suggest that complex immune changes occur with age, but also indicate that we have to modify our attitude, to grasp the new scenario which is emerging. Immunosenescence can no longer be considered as a unidirectional deterioration, and this complex phenomenon is much better described by terms such as 'remodelling', 'reshaping' or 'retuning'

Evidence for sub-haplogroup h5 of mitochondrial DNA as a risk factor for late onset Alzheimer's disease

BACKGROUND: Alzheimer's Disease (AD) is the most common neurodegenerative disease and the leading cause of dementia among senile subjects. It has been proposed that AD can be caused by defects in mitochondrial oxidative phosphorylation. Given the fundamental contribution of the mitochondrial genome (mtDNA) for the respiratory chain, there have been a number of studies investigating the association between mtDNA inherited variants and multifactorial diseases, however no general consensus has been reached yet on the correlation between mtDNA haplogroups and AD. METHODOLOGY/PRINCIPAL FINDINGS: We applied for the first time a high resolution analysis (sequencing of displacement loop and restriction analysis of specific markers in the coding region of mtDNA) to investigate the possible association between mtDNA-inherited sequence variation and AD in 936 AD patients and 776 cognitively assessed normal controls from central and northern Italy. Among over 40 mtDNA sub-haplogroups analysed, we found that sub-haplogroup H5 is a risk factor for AD (OR=1.85, 95% CI:1.04-3.23) in particular for females (OR=2.19, 95% CI:1.06-4.51) and independently from the APOE genotype. Multivariate logistic regression revealed an interaction between H5 and age. When the whole sample is considered, the H5a subgroup of molecules, harboring the 4336 transition in the tRNAGln gene, already associated to AD in early studies, was about threefold more represented in AD patients than in controls (2.0% vs 0.8%; p=0.031), and it might account for the increased frequency of H5 in AD patients (4.2% vs 2.3%). The complete re-sequencing of the 56 mtDNAs belonging to H5 revealed that AD patients showed a trend towards a higher number (p=0.052) of sporadic mutations in tRNA and rRNA genes when compared with controls. CONCLUSIONS: Our results indicate that high resolution analysis of inherited mtDNA sequence variation can help in identifying both ancient polymorphisms defining sub-haplogroups and the accumulation of sporadic mutations associated with complex traits such as AD