Qualitative mucin disorders in patients with primary Sjögren's syndrome: a literature review

Background

It is a common opinion that Primary Sjögren Syndrome (pSS) damages the exocrine glands and determines the reduction of secreted saliva, some studies show that there are qualitative anomalies of the mucins produced in saliva, including MUC7, MUC5B, MUC1. The purpose of this study is to trace all the information useful to establish whether there is a qualitative or quantitative defect of the mucins in the pSS.

Material and Methods

We reviewed the literature by looking for publications relevant to the topic in electronic databases. Sixteen articles met the search criteria. The studies were divided into two categories, those that studied the rheological characteristics of the saliva and those that studied the structural and / or metabolism modifications of the muciparous cells in the salivary glands.

Results

in Patients with pSS, xerostomia and the reduction of salivary spinnbarkeit are only partially related to the reduction of the unstimulated salivary flow. In pSS, pathological alterations of mucins’ chemical-physical properties prevail as a cause of the clinical characteristics. Moreover, in pSS there are structural and metabolism changes in salivary glands’ muciparous cells.

Conclusions

There is much evidence that supports the presence of qualitative alterations in the saliva’s rheological properties in Patients with pSS, and these are the main cause, more than the reduction of the unstimulated salivary flow, of the disease clinical characteristics - dry mouth and complications in the oral cavity. Therefore we propose to add to the classification criteria of pSS also a qualitative test of salivary glycoproteins.

Key words:Primary Sjögren's syndrome, mucin, MUC7, MUC5B, MUC1, sulphate oligosaccharides.

Relationship between proinflammatory cytokines (Il-1beta, Il-18) and leukocyte telomere length in mild cognitive impairment and Alzheimer's disease

Inflammation plays a crucial role in Alzheimer's disease (AD). AD neurodegeneration and concurrent involvement of the peripheral immune system may promote leukocyte division and telomere shortening. We examined genotypes and plasma levels of two proinflammatory cytokines, IL-1beta and IL-18, and leukocyte telomere length (LTL) in patients with mild cognitive impairment (MCI) and AD. We wanted to determine whether changes in plasma IL-1beta and IL-18 levels, together with LTL shortening, could be diagnostic for disease progression from MCI to AD. Median plasma IL-1beta levels were in the order MCI patients (2.2 pg/ml) < AD patients (4.0 pg/ml), both of which differed significantly from the controls (0.0 pg/ml). In the AD patients, the lowest IL-1beta levels were associated with the presence of the C allele of IL-1beta rs16944 SNP. Median plasma IL-18 levels were in the order MCI patients (116.3 pg/ml) > AD patients (85.8 pg/ml), both of which were significantly higher than in the controls (17.6 pg/ml). Analysis of LTL showed a progressive reduction in the order controls > MCI > AD patients (p < 0.0001). Overall LTL reduction was correlated with increased plasma IL-1beta levels, substantiating the hypothesis that inflammatory processes secondary to neuroinflammation may trigger telomere attrition. Changes in plasma IL-1beta and Il-18 levels, and LTL seem to reflect shifts in AD stage; they may have potential use as blood biomarkers to monitor disease onset and progression from MCI to AD.

Modulation of Inflammation as a Way of Delaying Alzheimer's Disease Progression: The Diet's Role

Background:

Most of the recent reports suggest that inflammatory mediators play a central role in the etiopathogenesis of Alzheimer's disease (AD) and that the conditions leading to a chronic low-grade inflammation, such as stress, depression, obesity and metabolic syndrome, increase the odds of developing Mild Cognitive Impairment (MCI) and AD. Microglia cells are the main actors in the AD process: stimuli from the microenvironment may induce microglia cells to switch to a classically activated inflammatory phenotype M1, or, on the contrary to an alternatively activated M2 phenotype characterized by the secretion of different types of cytokines. Many attempts are currently being made in order to delay the progression of AD by reducing inflammatory mechanisms underlying the disease. Several studies support a relationship among neuroinflammation and nutrients, foods or dietary patterns, taking into account the synergistic or antagonistic biochemical interactions among nutrients as well as the different food sources of the same nutrient. Natural antioxidant and anti-inflammatory compounds found in plant foods, such as fruits, particularly berries (such as strawberry, blueberry, blackcurrant, blackberry, blueberry and mulberry) have been shown to exert neuroprotective activity. It is still unclear whether the dietary bioactive compounds enter the Blood Brain Barrier (BBB) playing a direct antiinflammatory or pro-inflammatory effect on microglia and/or other Central Nervous System (CNS) cells. Another hypothesis is that they may trigger a peripheral reaction that induce indirectly a CNS' response. The subsequent synthesis of cytokines may drive microglia polarization by different ways. So, via an indirect route microglia detects and responds to immune-to-brain signaling.

Conclusion:

This review summarizes current evidence about the potential mechanisms of the interaction among diet, neuroinflammation and AD.

Cognitive disability in alzheimer's disease and its management

Cognitive disability linked to neurodegenerative diseases and in particular to Alzheimer's disease, remains an increasing cause for concern through a dramatic prevalence increment and associated socio-economic burdens. Initially Alzheimer's disease develops asymptomatically with primary clinical signs, such as memory impairment, decline of spatial and perceptual abilities, occurring at a later stage. This delay implies the possibility of promoting early interventions during the pre-symptomatic stage of the disease. Different strategies have been applied in order to prevent/delay onset of Alzheimer's disease or at least to improve quality of life and health conditions of Alzheimer's disease patients and their caregivers, especially in the absence of current viable therapies. Multidomain interventions, aimed at affecting several risk factors simultaneously, offer a versatility that may attain improved outcomes in comparison with single-domain prevention trials. These multidomain interventions involve diet, physical exercise, cognitive training and social activities, while music therapy, improving self-consciousness and reducing neurofibrils, may contribute to deceleration/delay onset of Alzheimer's disease progression. Information and Communication Technology (ICT) provides broad applications to improve quality of life and well-being of Alzheimer's disease patients and caregivers, suffering from psychological distress, as well as reducing additional public health costs.

Neuropeptide Y reduces the expression of PLCB2, PLCD1 and selected PLC genes in cultured human endothelial cells

Endothelial cells (EC) are the first elements exposed to mediators circulating in the bloodstream, and react to stimulation with finely tuned responses mediated by different signal transduction pathways, leading the endothelium to adapt. Neuropeptide Y (NPY), the most abundant peptide in heart and brain, is mainly involved in the neuroendocrine regulation of the stress response. The regulatory roles of NPY depend on many factors, including its enzymatic processing, receptor subtypes and related signal transduction systems, including the phosphoinositide (PI) pathway and related phospholipase C (PI-PLC) family of enzymes. The panel of expression of PI-PLC enzymes differs comparing quiescent versus differently stimulated human EC. Growing evidences indicate that the regulation of the expression of PLC genes, which codify for PI-PLC enzymes, might act as an additional mechanism of control of the PI signal transduction pathway. NPY was described to potentiate the activation of PI-PLC enzymes in different cell types, including EC. In the present experiments, we stimulated human umbilical vein EC using different doses of NPY in order to investigate a possible role upon the expression PLC genes. NPY reduced the overall transcription of PLC genes, excepting for PLCE. The most significant effects were observed for PLCB2 and PLCD1, both isoforms recruited by means of G-proteins and G-protein-coupled receptors. NPY behavior was comparable with other PI-PLC interacting molecules that, beside the stimulation of phospholipase activity, also affect the upcoming enzymes' production acting upon gene expression. That might represent a mode to regulate the activity of PI-PLC enzymes after activation.

Plaque-infiltrating T lymphocytes in patients with carotid atherosclerosis: an insight into the cellular mechanisms associated to plaque destabilization

AIM

Inflammation plays a crucial role in the progression of atherosclerotic plaques. The aim of the present study was to investigate phenotypic and functional characteristics of plaque-infiltrating T lymphocytes associated with a complicated phenotype of carotid atherosclerotic lesions.

METHODS

Atherosclerotic plaques were obtained from 17 patients undergoing carotid endarterectomy and cultured to isolate infiltrating T lymphocytes. Blood samples were obtained from patients and from 20 sex- and age-matched healthy subjects. The presence of lymphocytes (CD3+ cells) within atherosclerotic plaques was determined by immunohistochemistry. Phenotypic characteristics and intracellular cytokine expression of plaque-infiltrating and circulating T lymphocytes were determined by flow cytometry. Cytokine levels in supernatants from infiltrating T cell cultures were evaluated by enzyme-linked immunosorbent assay.

RESULTS

A higher number of CD3+ cells was detected in complicated than in uncomplicated plaques. Complicated plaques had higher percentages of tumor necrosis factor (TNF)-α- and interferon (IFN)-γ- positive cells than uncomplicated ones, especially in CD4+ subpopulation. In patients the percentages of TNF-α-positive cells were higher in infiltrating than in circulating lymphocyte samples. Intracellular TNF-α, IFN-γ, interleukin (IL)-4 and IL-10 expression resulted higher in circulating lymphocyte samples from patients than in those from healthy subjects. Supernatants of infiltrating T cell cultures from complicated plaques showed higher levels of TNF-α and lower levels of IL-4 than those from uncomplicated plaques.

CONCLUSION

Our data provide new information on the presence of increased percentages of pro-inflammatory T lymphocytes in complicated plaques with respect to uncomplicated ones and support the concept of the key role played by activated T cells in the progression of atherosclerotic lesions.

[Investigation on a group of autistic children: risk factors and medical social considerations]

AIMS

The aim of this work is to study the association between autism in a group of autistic children and risk factors for specific familiar diseases and developmental disease in the early years of life, through a medical social investigation.

MATERIALS AND METHODS

For this study, we have submitted an anamnestic questionnaire to 29 autistic children and their families in a South Italy region (Basilicata), collecting data about children and their parents.

RESULTS

The results show that many children have a family history of autoimmune diseases (psoriasis, rheumatoid arthritis, celiac disease, Takayasu's arteritis), allergies and food intolerances, suggesting a putative involvement of the immune system in autism etiopathogenesis. Analyzing residences areas of patients, Potenza and Matera, with their environmental factors (radioactive waste repositories, incinerators, intensive farming), we demonstrate that the particular territorial characteristics don't affect autism.

CONCLUSIONS

Autistic disorder is a spectrum of neurologic disorders complex both in etiopathogenesis and healthcare. So we aim to continue the study already undertaken on cytokines of autistic subjects serum and to extend it through biomolecular approaches assessing the presence of specific genetic polymorphisms in order to identify the physiopathogenetic mechanisms underlying the disease and to evaluate the predictive risk with the aim to improve care interventions.

Expression of phosphoinositide-specific phospholipase C isoforms in human umbilical vein endothelial cells

Aims

The signalling system of phosphoinositides (PIs) is involved in a number of cell and tissue functions including membrane trafficking, ion channel activity, cell cycle, apoptosis, differentiation and cell and tissue polarity. Recently, a role in cell migration was hypothesised for PI and related molecules including the phosphoinositide-specific phospholipases C (PI-PLCs), main players in PI signalling. The expression of PI-PLCs is tissue-specific and evidence suggests that it varies under different conditions such as tumour progression or cell activation. In order to obtain a complete picture, the expression of all PI-PLC isoforms was analysed in human endothelial cells (EC).

Methods

Using molecular biology methods (RT-PCR), the expression of PI-PLC isoforms was analysed in human umbilical vein endothelial cells (HUVEC), a widely used experimental model for human EC.

Results

All the PI-PLC isoforms except PI-PLC β1, PI-PLC ɛ and PI-PLC ζ were expressed in HUVEC.

Conclusions

The growing interest in the complex cascade of events occurring in angiogenesis will provide useful insights for therapeutic strategies. The expression of PI-PLC isoforms in HUVEC is a useful tool for further studies directed to understanding their role in angiogenesis. However, although HUVEC represent a widely used experimental model for human macrovascular EC, limitations remain in that they cannot fully represent the metabolic properties and interactions of the EC distributed in the entire organism.

Transcritpional effects of S100B on neuroblastoma cells: perturbation of cholesterol homeostasis and interference on the cell cycle

S100B is a Ca2+ binding protein mainly secreted by astrocytes in the vertebrate brain that is considered a multifunctional cytokine and/or a damage-associated molecular pattern (DAMP) protein and a marker of brain injury and neurodegeneration when measured in different body fluids. It has been widely shown that this protein can exert diverse effects in neural cultures depending on its concentration, having detrimental effects at micromolar concentrations. The molecular mechanisms underlying this effect are still largely unknown. This study attempts to delineate the genome-wide gene expression analysis of the events associated with exposure to micromolar concentration of S100B in a human neuroblastoma cell line. In this experimental condition cells undergo a severe perturbation of lipid homeostasis along with cell cycle arrest. These mechanisms might reasonably mediate some aspects of the S100B-related detrimental effects of S100B, although obvious differences between mature neurons and neuroblastoma cells have to be considered.

S100B protects LAN-5 neuroblastoma cells against Abeta amyloid-induced neurotoxicity via RAGE engagement at low doses but increases Abeta amyloid neurotoxicity at high doses

At the concentrations normally found in the brain extracellular space the glial-derived protein, S100B, protects neurons against neurotoxic agents by interacting with the receptor for advanced glycation end products (RAGE). It is known that at relatively high concentrations S100B is neurotoxic causing neuronal death via excessive stimulation of RAGE. S100B is detected within senile plaques in Alzheimer's disease, where its role is unknown. The present study was undertaken to evaluate a putative neuroprotective role of S100B against Abeta amyloid-induced neurotoxicity. We treated LAN-5 neuroblastoma cultures with toxic amounts of Abeta25-35 amyloid peptide. Our results show that at nanomolar concentrations S100B protects cells against Abeta-mediated cytotoxicity, as assessed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein isothiocyanate nick end-labeling (TUNEL) experiments, by countering the Abeta-mediated decrease in the expression of the anti-apoptotic factor Bcl-2. This effect depends on S100B binding to RAGE because S100B is unable to contrast Abeta-mediated neurotoxicity in neurons overexpressing a signaling-deficient RAGE mutant lacking the cytosolic and transducing domain. Our data suggest that at nanomolar doses S100B counteracts Abeta peptide neurotoxicity in a RAGE-mediated manner. However, at micromolar doses S100B is toxic to LAN-5 cells and its toxicity adds to that of the Abeta peptide, suggesting that additional molecular mechanisms may be involved in the neurotoxic process.

Morphological analysis of cell subpopulations within carotid atherosclerotic plaques

Atherosclerosis is considered a chronic inflammatory process, prompted by lipid accumulation and propagated by cell-mediated mechanisms. The present work was undertaken to clarify this process by characterizing cellular components of inflammatory infiltrate localized within atheroma. Cryostat sections of atherosclerotic lesions obtained from human carotid endarterectomy were analysed immunohistochemically by using monoclonal and polyclonal antibody directed against T cell subpopulations (CD3, CD4, CD8), B cells (CD20), plasma cells (CD138), macrophages (CD14), mast cells (anti-tryptase). Our results assess that T cells are the predominant cell type among plaque infiltrating inflammatory cells. B cells were detected near the lipid core of atheroma and clusters of plasma cells were observed within cellular infiltrates in most plaques. Numerous tryptase positive mast cells were noticed in many areas of complicated lesions. Our results indicate the presence of many inflammatory cells within type V and VI atherosclerotic plaques, suggesting the involvement of those cells in plaque progression. In fact it was previously shown that stability of atherosclerotic lesions is influenced by mast cell-released matrix metalloproteinases which induce plaque rupture and by cytokines and chemokines which increase local inflammatory response and are produced by lymphocytes and macrophages.

Altered balance of proteinase inhibitors in atrophic muscle after denervation

Skeletal muscle denervation leads to an increase of proteolytic activity, which is also favoured by reduced levels of alpha1 antichymotrypsin and nexin II, two serine-proteinase inhibitors normally acting at the neuromuscular junction. In the present experiments we extended our investigation to other muscular proteinase inhibitors after denervation. In all muscles examined (soleus, plantaris, extensor digitorum longus) specific immunoreactivity for alpha2macroglobulin (alpha2M) and alpha1proteinase inhibitor (alpha-1-antitrypsin, ATI) was distributed in peri-endomysial structures as well as in small patches inside the fibres. By contrast, inter-alpha-trypsin inhibitor (ITI) was mainly localized in the extracellular matrix. These localization patterns did not change substantially in 15-days denervated muscles. Dot-blot analysis revealed a small decrease (about 15%) of alpha2M in 15-days denervated muscles, while ATI and ITI specific activities were substantially unchanged. RT-PCR allowed us to detect the above protease inhibitor mRNAs in normal muscle homogenates. Denervation atrophy induced by section of the sciatic nerve resulted in a remarkable reduction of (2macroglobulin mRNA (60%) and ITI (30%), but not ATI, as measured by computer-assisted semiquantitative densitometry of electrophoresed RT-PCR bands. The marked decrease of alpha2M we have detected in denervated muscle may be responsible, at least in part, for the proteolytic increase which is known to occur in skeletal muscle during denervation atrophy.

Role of alpha2-macroglobulin in regulating amyloid beta-protein neurotoxicity: protective or detrimental factor?

alpha2-Macroglobulin (alpha2M) has been identified as a carrier protein for beta-amyloid (Abeta) decreasing fibril formation and affecting the neurotoxicity of this peptide. The alpha2-macroglobulin receptor/low density lipoprotein receptor related protein (LRP) is involved in the internalization and degradation of the alpha2M/Abeta complexes and its impairment has been reported to occur in Alzheimer's disease. Previous studies have shown alpha2M to determine an enhancement or a reduction of Abeta toxicity in different culture systems. In order to clarify the role of alpha2M in Abeta neurotoxicity, we challenged human neuroblastoma cell lines with activated alpha2M in combination with Abeta. Our results show that in neuroblastoma cells expressing high levels of LRP, the administration of activated alpha2M protects the cells from Abeta neurotoxicity. Conversely, when this receptor is not present alpha2M determines an increase in Abeta toxicity as evaluated by MTT and TUNEL assays. In LRP-negative cells transfected with the full-length human LRP, the addition of activated alpha2M resulted to be protective against Abeta-induced neurotoxicity. By means of recombinant proteins we ascribed the neurotoxic activity of alpha2M to its FP3 fragment which has been previously shown to bind and neutralize transforming growth factor-beta. These studies provide evidence for both a neuroprotective and neurotoxic role of alpha2M regulated by the expression of its receptor LRP.

Immunohistochemical detection of three serum protease inhibitors in mouse skeletal muscle by confocal laser scanning microscopy

The tissue-associated counterpart of some plasmatic protease inhibitors has been studied in mouse skeletal muscle by combining immunoperoxidase confocal microscopy and Western blot analysis. To remove serum contamination all experiments were performed on C57 BL/10 adult mice perfused extensively with physiological solution under deep anesthesia. The following serum inhibitors were investigated in skeletal muscle by immunoperoxidase staining: alpha-2-macroglobulin (alpha2M), antithrombin III (ATIII) and inter-alpha-trypsin inhibitor (ITI). The resulting localization patterns were analysed by laser transmittance scanning at 488 nm using a confocal microscope. Images obtained from a series of optical sections were then digitally intensified by a computerized program, allowing detection of even negligible amounts of immunoreaction product. In all muscles examined (soleus and extensor digitorum longus mm.) an extracellular (endomysial) localization was apparent for all inhibitors. By contrast remarkable differences were observed for the intracellular component: in fact alpha2M was present in about a half of the muscle fibers; ATIII was present inside all fibers; intracellular ITI was completely absent. Western blotting analysis of muscle homogenate was performed to biochemically characterize the above immunoreactivities. In preliminary experiments alpha2M-related immunoreactivity could not be found in the soluble fraction of perfused muscle, confirming an absence of serum contamination after in vivo perfusion. By contrast experiments on detergent-solubilized extracts (0.3% Triton X-100) revealed that tissue-bound alpha2M consisted of two main bands (168-166 KDa) and a minor component (35 KDa); ATIII of a single band (50 KDA); ITI of four bands (180, 50, 45, 40 KDa). These results confirmed that the specific immunoreactivities visualized by morphological techniques corresponded to muscle-associated plasmatic inhibitors. The present data suggest that in mouse skeletal muscle i) numerous tissue-associated plasmatic inhibitors may protect the extracellular matrix from an excess of proteolysis; ii) a more restricted set of inhibitors may be also involved in the down-regulation of intracellular proteolytic processes.

Activated alpha2macroglobulin increases beta-amyloid (25-35)-induced toxicity in LAN5 human neuroblastoma cells

The presence of the alpha2macroglobulin receptor/low density lipoprotein receptor-related protein (alpha2Mr/LRP) and its ligands alpha2macroglobulin (alpha2M), apoliprotein E, and plasminogen activators was detected in senile plaques of Alzheimer's disease (AD). To explore a possible role of alpha2M in neurodegenerative processes occurring in AD, we analyzed the effect of alpha2M on Abeta 25-35-induced neurotoxicity. Treatment of LAN5 human neuroblastoma cells with 10 microM beta-amyloid peptide fragment 25-35 (Abeta 25-35) for 72 h resulted in a 50% decrease in cell viability as determined by MTT incorporation and cell counts. The addition of alpha2M to the culture medium of these cells did not determine any effect, but when the activated form alpha2M* was used a dose-dependent decrease in cell viability was observed, the maximum effect being reached at 140 and 280 nM. Moreover, treatment of LAN5 cells with alpha2M* in combination with Abeta 25-35 increased the neurotoxicity of the amyloid peptide by 25%. This neurotoxic effect of alpha2M* seems to be related to its capability to bind and inactivate TGFbeta in the culture medium, since it was mimicked by a TGFbeta neutralizing antibody. A possible involvement of receptor-mediated endocytosis was ruled out, since alpha2M receptor is not present on LAN5, as revealed by RT-PCR and Western blotting experiments. The presence of alpha2M* in amyloid deposits of Alzheimer's disease has been recently reported and a possible impairment of LRP internalization processes has been hypothesized. Our data suggest that the local accumulation of alpha2M* in AD plaques may increase Abeta 25-35-induced neurotoxicity by neutralizing TGFbeta-mediated neuroprotective mechanisms.

The expression of the LDL receptor-related protein (LRP) correlates with the differentiation of human neuroblastoma cells

The low density lipoprotein receptor-related protein (LRP) has been localized in human brain at the level of neurons, astrocytes and along capillary membranes. It is a multifunctional receptor responsible for binding and internalization of lipoproteins enriched with apoliprotein E, lipoprotein lipase, protease-alpha 2 macroglobulin complexes and plasminogen activator-inhibitor complexes. LRP expression is observed in cells involved in Alzheimer's disease, neoplastic transformation and tissue repair. Moreover, its synthesis is modulated during brain development. In this study we used the SK-N-AS human neuroblastoma cell line as a model system to study LRP expression during cellular differentiation induced by phorbol esters, retinoic acid and interferon gamma. Since LRP plays a major role in the regulation of lipid metabolism, the decreased levels of LRP measured by immunofluorescence, western blot and PCR on differentiated neuroblastoma cells may be the consequence of the lower requirements of cholesterol and lipids of differentiated cells in relation to their reduced mitotic index.

Modulation of the alpha 2 macroglobulin receptor/low density lipoprotein receptor related protein by interferon-gamma in human astroglial cells

Alpha 2 macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2 Mr/LRP) is a multi-functional cell surface receptor that has been implicated in important processes, such as atherogenesis, cellular migration, immune response and degenerative diseases. Its expression increases in human brain during Alzheimer's disease, tissue injury and neoplastic transformation. In the present paper we studied the regulation of alpha 2 Mr expression by interferon-gamma (IFN gamma) in human astrocytoma cell lines and in fetal astrocytes. Western blots demonstrated an increase of the alpha 2 Mr expression after 24 h of IFN gamma treatment. This effect paralleled the up-regulation of alpha 2 Mr mRNA, as detected by PCR. By prolonging incubation with IFN gamma, we observed a decrement of alpha 2 Mr in IFN gamma treated cells, both by western blot and cytometric analysis. Since in the same cells IFN gamma also up-regulates alpha 2 macroglobulin, this effect may be due to an augmented degradation of the receptor during its recycling.

Protease inhibitors in mouse skeletal muscle: tissue-associated components of serum inhibitors and calpastatin

The proteinase inhibitor set in skeletal muscle is poorly characterized at present. This study was aimed to investigate in mouse skeletal muscle 1) the tissue-associated counterpart, if any, of serum protease inhibitors (which may also play antiproteolytic functions in tissues) and 2) calpastatin, a tissue inhibitor of calcium-activated neutral proteases (calpains). Triton-extracts were prepared from muscle homogenates of mice, which had been perfused extensively with phosphate buffered saline (PBS) (under deep anesthesia) to remove blood inhibitors. Among various inhibitors tested, the following muscle-associated inhibitors were identified by western-blotting: alpha-2-macroglobulin (185, 165, 35 kDa), alpha-1-antitrypsin (52 kDa), inter-alpha-trypsin inhibitor (220, 180 kDa) and calpastatin (70 kDa). Combined light microscope and confocal immunohistochemical experiments revealed that, in all muscles examined (soleus, plantaris, extensor digitorum longus) the above specific immunoreactivities were localized outside the muscle fibers (in periendomysium, blood vessel wall) as well as within them. Inter-alpha-trypsin inhibitor, however, completely lacked the intracellular localization. This wide distribution of proteinase inhibitors suggests that numerous muscular structures may be normally protected from unwanted proteolysis, thus providing an essential background for further studies on pathological models with altered proteolysis (m. dystrophy, denervation atrophy, etc.).

Prevalence and clinical correlates of microalbuminuria in stage I hypertension. Results from the Hypertension and Ambulatory Recording Venetia Study (HARVEST Study)

The objective of the present study was to examine the association between albumin excretion rate (AER) and office and ambulatory blood pressures (BP), and other recognized cardiovascular risk factors in stage I hypertension. The study was carried out in 870 never-treated 18- to 45-year-old hypertensives (628 men, 242 women). Office and ambulatory BP, 24-h urinary collection for AER assessment, and echocardiographic left ventricular mass (n = 587) were obtained. AER was similar in men and women (12.3 v 12.5 mg/24 h) and was unrelated to age and body mass index. In 85.2% of the subjects, AER was < 16 mg/24 h, in 8.3% it was between 16 and 29 mg/24 h (borderline microalbuminuria), and in 6.1% it was >or= 30 mg/24 h (overt microalbuminuria). Office systolic BP was not different in the three groups, whereas 24-h systolic BP was higher in the subjects with microalbuminuria than in those with normal AER (P < .0001) and was similar in the two microalbuminuric groups. Office and 24-h diastolic BPs were higher in the subjects with overt microalbuminuria than in those with normal AER. Left ventricular mass was correlated to systolic (P < .0001) and diastolic (P = .01) 24-h BP, but was unrelated to AER. Family history for hypertension, smoking, coffee and alcohol intake, and physical activity habits did not influence AER. In a logistic regression analysis, 24-h systolic BP emerged as the only determinant of microalbuminuria (P < .0001). In conclusion, these results indicate that borderline levels of microalbuminuria may also be clinically relevant in stage I hypertension. Overweight and lifestyle factors do not appear to influence AER in these patients. Finally, the lack of correlation between AER and left ventricular mass suggests that renal and cardiac involvement do not occur in a parallel fashion in the initial phase of hypertension.

Evidence for tissue-associated alpha(2) macroglobulin in mouse skeletal muscle

Alpha(2)-Macroglobulin (alpha(2)M), a major serum protease inhibitor, was localized in mouse skeletal muscle by immunoperoxidase histochemistry. In all muscles examined (mm. soleus, plantaris, and extensor digitorum longus) specific immunoreactivity occurred diffusely in extracellular structures (periendomysium, blood vessel wall) as well as inside about a half of the muscle fibers. This localization pattern did not change substantially by extensively perfusing deeply anesthetized mice with phosphate buffered saline (PBS) to remove serum alpha(2)M. In release experiments on fresh (nonfixed) cryostat sections, specific immunoreactivity persisted after an extensive prewash with PBS (up to 5-6 h), but a new specific staining appeared inside those fibers that were originally negative. Western blotting experiments were negative on the soluble fraction of muscle homogenate, thus confirming that the perfusion procedure was effective in removing serum alpha(2)M. By contrast, three specific bands (185, 165, and 35 kDa) appeared in detergent-solubilized extracts (0.3% Triton X-100), indicating the occurrence of tissue-associated alpha(2)M. Confocal immunofluorescence microscopy revealed that the intracellular specific staining was associated to a longitudinal network, probably corresponding to the sarcoplasmic reticulum. A multifunctional role of alpha(2)M in skeletal muscle was hypothesized.

Response to orthostatic stress predicts office-daytime blood pressure difference, but not nocturnal blood pressure fall in mild essential hypertensives: results of the harvest trial

1. The aim of the present study was to evaluate whether postural blood pressure (BP) change could predict office-day-time BP disparity and the nocturnal BP fall in young, mild essential hypertensives. We investigated 411 males aged between 18 and 45 years with never treated borderline to mild hypertension. BP was measured three times after a 5 min rest in the supine position and thereafter three times after 2 min of standing. The mean of six BP measurements obtained during two visits in the lying position was defined as office BP. 2. Twenty-four hour ambulatory BP monitoring was performed with either the A&D TM-2420 model 7 or the ICR Spacelabs 90207. BP values were averaged for day- and night-time periods. The nocturnal BP fall was defined as the difference between the average day- and night-time BP. 3. The standing-lying difference was significantly inversely correlated with the office-daytime difference for both systolic blood pressure (SBP) (r = -0.34, P < 0.001) and diastolic blood pressure (DBP) (r = -0.24, P < 0.001). These correlations did not change when the obese subjects (body mass index > 30 kg/m2) were excluded from the analysis. No significant correlation between standing-lying difference and nocturnal BP fall was found. 4. Our results indicate that white coat hypertension assessed as the office-daytime BP disparity is partially related (in a negative fashion) to the BP reaction to standing. The postural BP change does not predict nocturnal BP fall in young, mild essential hypertensives.

Interferon gamma up-regulates alpha 2 macroglobulin expression in human astrocytoma cells

An established human astrocytoma cell line (T67) was shown to constitutively produce the proteinase inhibitor alpha 2 macroglobulin (alpha 2M). Interferon gamma (IFN gamma), a potent immunoregulatory lymphokine, was able to increase the synthesis of alpha 2M by these cells, as measured by ELISA on cell supernatants. The alpha 2M induction was also observed in other human glioma cell lines (T70 and ADF) and in human fetal astrocyte cultures following IFN gamma treatment. In T67 cells this effect was dose-dependent and the maximum (2.7-fold increase) was obtained with 2000 U/ml of IFN gamma. A corresponding enhanced alpha 2M mRNA accumulation was demonstrated by PCR and Northern blot techniques. Our results suggest an important role of alpha 2M during inflammatory and immune processes in the CNS. An increased release of alpha 2M following IFN gamma stimulation may allow the removal of the bulk of proteases released at the site of inflammation, strengthening at the same time the antigen presentation processes.

Receptor-mediated endocytosis of alpha 2 macroglobulin by a glioma cell line

Previous experiments have shown that human neoplastic and embryonic glial cell lines synthesize and secrete in culture, alpha 2 macroglobulin (alpha 2M), a broad spectrum proteinase inhibitor present in serum and extracellular fluids. The present study was aimed to investigate the presence of alpha 2M receptors on glial cell membrane, since several non-neural cell types producing alpha 2M also express alpha 2M receptors. By flow cytometric analysis, immunofluorescence and immunoelectronmicroscopy techniques we demonstrate an alpha 2M receptor-related immunoreactivity on the plasma membrane of a human glioma cell line. Ultrastructural experiments reveal a close colocalization of immunoreactivities for alpha 2M and its receptor in clathrin-coated pits and vesicles, structures typically involved in receptor-mediated endocytic pathways.

Human astroglial but not microglial cells synthesize alpha 2-macroglobulin in vitro

Alpha 2-macroglobulin (alpha 2M) is a serum proteinase inhibitor with a broad specificity. At present its role in human brain is unknown, but recent data report its presence in the CNS, particularly at glial level. Previous studies from our group demonstrated the synthesis and secretion of alpha 2M in different glial cultures derived from an astrocytoma and a glioblastoma. In the present study a human fetal astroglial cell line and two microglial established cell lines are examined for the presence of alpha 2M by using polyclonal antibodies in ELISA and immunofluorescence assays. While we observed a strong specific positivity in the cytoplasm and in the culture medium of the GFAP, vimentine positive cells, no positivity was detected in FcR, lysozyme positive microglial cells. Since interaction of proteinases and proteinase inhibitors appear to play a crucial role in the development of neuroimmunological competence, these data suggest a dissociation of macro and micro-glia immune functions.

Inter-alpha-trypsin inhibitor-related immunoreactivity in human tissues and body fluids

The distribution of inter-alpha-trypsin inhibitor (ITI) and related inhibitors was investigated in normal human tissues and body fluids by using an enzyme-linked immunosorbent assay (ELISA) and a streptavidin-biotin-peroxidase immunohistochemical technique. ITI-related immunoreactivity was localized in different cell types of various organs, such as liver, kidney, testis, gross intestine, cutis and brain. Specific immunoreactivity was also detected in serum, urine and bronchial mucus. This widespread, but not ubiquitous pattern of localization suggests that, in addition to the well known plasmatic role, ITI and/or ITI-related inhibitors may play a number of different physiological roles in various human tissues.

Synthesis and secretion of α2-macroglobulin by human glioma established cell lines

Human alpha 2-macroglobulin (alpha 2M) is a high molecular weight plasma proteinase inhibitor exhibiting a broad specificity; in fact it is capable of binding endopeptidases from all known classes of proteases (Barret 1981). Two human glioma cell lines, namely an astrocytoma and a glioblastoma, were found to synthesize and secrete in the culture medium a protein which resembles the serum alpha 2M for immunological, biochemical and biological features. Using polyclonal antibodies to serum alpha 2M, an alpha 2M-like factor could be detected in the cytoplasm and in the culture medium of the tumor cells. Furthermore this factor accumulated in cytoplasmic granules if cells were incubated with monensin and its production was dramatically reduced following a treatment with cycloheximide. This protein behaved like the serum alpha 2M in immunoblotting analysis and exhibited the same antiproteolytic activity. Its role in human brain is unknown at present. Since interactions of proteinases and proteinase-inhibitors appear to influence the host-tumor immune response and to play a crucial role during the migration of metastasizing tumor cells, alpha 2M expression observed in these glioma cells could be involved in tumor cell proliferation and invasion.

[The normal limits of arterial pressure registered with portable methods: an approach to the problem]

In the present paper the problem of the normalcy limits of whole-day ambulatory blood pressure has been faced by evaluating the difference between casual and ambulatory blood pressure in a population of 522 subjects with blood pressure values covering the whole blood pressure range. On the basis of the casual blood pressure levels, 60 subjects were normotensives, 110 borderline hypertensives, 214 mild, 103 moderate and 35 severe hypertensives. The differences between casual and median 24-hour blood pressure averaged 18.4/9.6 mmHg. The difference between casual and median day-time was 14.2/6.7 mmHg. This difference was independent from the ambulatory blood pressure values and unrelated to the sex or age of subjects. The upper normal limits of ambulatory blood pressure were established by subtracting the above differences from the normal limits established by the WHO for casual blood pressure (140/90 mmHg). For 24-hour blood pressure the upper limits were 121.6/80.4 mmHg and for day-time blood pressure these were 125.8/83.3 mmHg. Contrary to previous studies conducted on normotensive populations with this approach the selection of patients based on casual blood pressure is avoided and the WHO normalcy limits are taken into account.

[Clinical significance of nocturnal blood pressure and blood pressure variability: analysis of 522 cases]

Purpose of the study was to investigate whether and to what extent blood pressure variability and average night-time blood pressure are related to cardiovascular complications in hypertension. To this aim 60 normotensive and 462 hypertensive subjects were studied by means of non-invasive 24 hour blood pressure monitoring, using either the Avionics, or the ICR Spacelabs, or the Takeda system. Each subject was attributed a target organ damage score on the basis of 12-lead electrocardiogram, chest X-ray and fundoscopy, starting from 0 (no damage) up to 5 (maximum degree of damage). The 522 subjects were subsequently subdivided into 5 classes of increasing average daytime diastolic blood pressure. In each class a higher degree of cardiovascular complications was present in the subjects with the higher blood pressure variability and the higher average night-time blood pressure. From these results it may be inferred that both blood pressure variability and night-time blood pressure are related to the degree of target organ damage in hypertension. This stresses the importance of recording blood pressure throughout the 24 hours.

Identification and immunohistochemical localization of various bovine pancreatic trypsin inhibitor-isoforms in bovine pituitary gland

Three isoinhibitors of bovine pancreatic trypsin inhibitor (BPTI) have been identified and isolated from bovine pituitary gland. The results of the purification process by affinity chromatography on immobilized trypsin, the electrophoretic mobility in non-denaturing conditions, the antiproteolytic activity and the immunochemical reactions indicate that these inhibitors correspond to those previously isolated from bovine spleen and lung. In addition, immunohistochemical experiments show that the isoinhibitors and BPTI are exclusively localized in the mast cells, and not in the endocrine cells, of the pars intermedia and posterior lobe (neurohypophysis) of the pituitary gland. The physiological implications of these findings are discussed.

Bovine pancreatic trypsin inhibitor and related isoinhibitors in bovine liver. A biochemical and histochemical study

A Kunitz-type inhibitor family has been biochemically and histochemically characterized in bovine liver. This family includes the well-known pancreatic trypsin inhibitor (BPTI) and three BPTI-related molecular forms (isoinhibitors I, II and III). The purification of the inhibitors was performed by affinity chromatography on immobilized trypsin followed by fast protein liquid chromatography. The inhibitors were identical to those identified previously in bovine spleen and lung. Light immunohistochemical experiments were done by a streptavidin-biotin-peroxidase method using two different immunoglobulin preparations, which selectively discriminated between BPTI and the other isoinhibitors. BPTI-related immunoreactivity was found exclusively at the level of isolated cells, of which many were identified as mast cells by toluidine blue staining. By contrast, isoinhibitor-related immunoreactivity showed a more widespread distribution, including hepatocytes, mast cells and biliary duct epithelial cells. Finally, specific immunoreactivity was also present in plasma. These results suggest that: i) BPTI and related isoinhibitors may be involved in the regulation of the activity of some mast cell proteases, as it happens in other bovine organs (Businaro et al. 1987, 1988); ii) BPTI isoinhibitors, but not BPTI itself, may also control proteolytic activities in hepatic specific structures (hepatocytes and biliary duct epithelial cells).

[Changes in arterial pressure and adrenergic activity during a holiday at a mountain at low altitude]

To answer the question often asked by hypertensive patients whether it is advisable for them to spend a holiday in the mountains for fear of a rise in blood pressure, 12 untreated mild hypertensive and 12 normotensive subjects underwent 24-hour non-invasive blood pressure monitoring, plasma catecholamines assay (HPLC) and plasma renin activity determination at home (sea level) and in a mountain resort (1210 m). The 2 evaluations (at home and in the mountains) were performed in a cross-over fashion. The ICR Spacelabs Pressuromaster and the Del Mar Avionics Pressurometer IV were used: blood pressure was measured every 8 minutes during daytime and every 15 minutes during sleep. Blood pressure was also recorded during a 1.5 to 3 hour excursion by cable-car to a height of 3006 m. Average 24-hour blood pressure at sea level was 134/86.7 mmHg in the hypertensive subjects and 115.8/73.6 mmHg in the normotensive ones. At 1210 m, it rose to 140.6/90.2 mmHg (n.s.) and to 120.8/74.9 mmHg (n.s.) respectively. Twenty-four-hour profiles showed that the blood pressure difference was present only during waking hours, while during sleep blood pressure levels were similar at sea level and in the mountains.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of physical exercise training on the arterial pressure in normotensive subjects]

To determine the effect of exercise training on blood pressure at rest and during maximal exercise 15 adolescent and 15 adult normotensive cyclists were studied after a period of detraining and of physical activity. In the lying position resting blood pressure did not change with training, while a slight but significant decrease in blood pressure (p less than 0.05) was observed on standing up. At the same absolute work rate, after training exertional blood pressure was lower than before training, but at peak exercise the same blood pressure levels were achieved before and after training. These results indicate that, contrary to what has been reported in the sedentary subject, resuming exercise training after a period of detraining brings about in the normotensive athlete only minor changes in blood pressure.

[Reproducibility of ambulatory blood pressure monitoring]

Short-term blood pressure variability has been studied extensively with monitoring techniques. To assess whether or not and to what extent average 24-hour blood pressure varies when repeatedly recorded, 12 mild to moderate hypertensive subjects underwent 3 non-invasive blood pressure monitorings at monthly intervals. When the average 24-hour blood pressure of the whole group was evaluated no substantial differences were found between the 3 recordings, even though slightly lower blood pressure values were recorded at the first monitoring. However, when the within-period comparison was studied in the single patients, remarkable discrepancies of up to 20.9/15.8 mmHg were detected. Systolic and diastolic blood pressure variations greater than or equal to 5 mmHg were recorded in 58% of the subjects. These differences were unrelated to the number of faulty readings. Casual blood pressure varied even to a greater extent between the first and the subsequent visits; no correlation was found between casual and 24-hour blood pressure variations. The results of the present study indicate that ambulatory blood pressure may vary even to a great extent when repeatedly recorded. This finding entails important clinical implications, as the evaluation of the hypertensive patient is usually made with a single blood pressure monitoring.

Cellular localization of bovine pancreatic trypsin inhibitor and related molecular forms in bovine lung

In addition to bovine pancreatic trypsin inhibitor (BPTI), three BPTI-related molecular forms (isoinhibitors I, II and III) were isolated from bovine lung by affinity chromatography on immobilized trypsin and subsequently purified by Fast Protein Liquid Chromatography. These inhibitors are identical to the isoinhibitors previously isolated from bovine spleen. Their localization in bovine lung was studied by immunohistochemical techniques, using two different immunoglobulin preparations, selectively recognizing BPTI or the other molecular forms. BPTI-related immunoreactivity was found to be restricted to isolated cells, often identified as mast cells by Toluidine Blue staining. In contrast, isoinhibitor-related immunoreactivity, which also occurs in the mast cells, is present in a number of other cell types. These types include: (i) the smooth muscle cells of different calibre vessels, (ii) the ciliated cells of the bronchial epithelium and the related mucus, and (iii) many cells at alveolar level. Comparison of these data with previous results obtained for bovine spleen suggest multiple physiological roles for these inhibitors.

Vascular localization of bovine pancreatic trypsin-inhibitor-related molecular forms in bovine spleen

Bovine spleen proteic inhibitors of serine proteases, belonging to the bovine pancreatic trypsin inhibitor (BPTI or aprotinin) family, have been localized, using immunocytochemical techniques, in the smooth muscle cells of some bovine spleen blood vessels. This vascular localization also occurs in a variety of bovine organs and differs from that of BPTI itself which is found exclusively in bovine mast cells, in agreement with previous reports. These data would be in favour of a possible involvement of one or more BPTI-type inhibitors in vascular processes by acting at the level of the smooth muscle cells, the tissue responsible for vasodilation/vasoconstriction events.

Inverse relationship between spontaneous interleukin-1 production and mitogen-driven proliferation in patients with pulmonary tuberculosis

The blastogenic response to mitogens of peripheral blood mononuclear cells (PBMC) obtained from healthy volunteers and patients with chronic or acute tuberculosis (TB) was evaluated. Cells derived from TB patients showed a reduced proliferative capacity compared to that of healthy individuals. Three possible causes of such an impairment were investigated, namely: 1) a change in the proportion of lymphocyte subpopulations; 2) an altered ratio between monocytes and lymphocytes and 3) a reduction in the state of monocyte-macrophage activation, with an impaired production of interleukin-1 (IL-1). We observed no significant modification of lymphocyte subsets from TB patients and normal individuals. However, the relative number of monocytes in the patients was always higher than the controls. Furthermore, circulating monocytes from the patients with TB exhibited a decreased phagocytosis of latex beads, a normal expression of DR antigens, and an increased spontaneous production of IL-1. The possibility that the hyperactivation of macrophages may be responsible for the observed low blastogenic response is discussed.

Monoclonal antibodies against mouse nerve growth factor produced by somatic cell hybrids

Spleen leukocytes from rats and mice immunized against mouse 2.5S nerve growth factor (NGF) and peripheral blood leukocytes from rabbits hyper-immunized against the same antigen were fused with the mouse plasmacytoma P3X63Ag8. Hybridomas were screened by immunological assays (micro-complement fixation test and solid phase radioimmunoassay) for production of antibodies that reacted with NGF. Significant variations were seen between culture fluids from different hybrid cells. In addition, most but not all hybridoma antibodies that reacted immunologically with NGF prevented neurite outgrowth from 8-day chick embryo sensory ganglia explants after binding to NGF. These results suggest that the hybridoma antibodies produced by the different clones react with different antigenic sites on the NGF molecule.

Protection of mice against syngeneic C1300 neuroblastoma challenge by immunization with membranes of C1300 neuroblastoma cells

Male A/J mice 2-3 months old were inoculated sc with membranes from syngeneic C1300 neuroblastoma cells (clone NB6R) in complete Freund's adjuvant. Significant immunoprophylaxis was noted in the sensitized mice upon sc challenge with viable NB6R cells. During the experiment (60 days from viable cell challenge), each control mouse developed a palpable tumor and died within 50 days. Complete protection was obtained with a program of 4 inoculations of NB6R cell membranes. Each mouse given only 1 inoculation of NB6R cell membranes developed a palpable tumor, but afer 60 days only 1 mouse in 7 had died, which indicated a significant degree of protection. With in vitro tests of lymphocyte proliferation, rosette formation, and complement fixation, it was shown that these mice had mounted both cellular and humoral immune response against the tumor cells.

Fluctuation of serum complement levels in children with neuroblastoma

Serum samples from eleven children with neuroblastoma were drawn at diagnosis and again every 15 days or a month after the beginning of treatment over the course of 17 months observation. Twenty healthy children of the same age with no appreciable clinical manifestation were also studied as controls. Investigations included quantitative serum complement levels (total complement hemolytic activity, C3 and C4), anticomplementary serum activity and urine catecholamine levels (VMA and HVA). Complement levels of tumor patients were significantly higher than those of healthy subjects, but fluctuations were seen at different stages of the disease; patients at admission with active tumors or tumor recurrence had higher complement levels than those of patients in remission. Temporary recurrences of the disease were usually accompanied by fluctuations of urinary catecholamines, serum complement levels (mainly C3) and anticomplementary serum activity. At the terminal phase of the disease a drop in complement levels was usually seen, while urinary catecholamines were progressively increasing.