Stem cells, Notch-1 signaling, and oxidative stress: a hellish trio in cancer development and progression within the airways. Is there a role for natural compounds?

Notch-1 signaling plays a crucial role in stem cell maintenance and in repair mechanisms in various mucosal surfaces, including airway mucosa. Persistent injury can induce an aberrant activation of Notch-1 signaling in stem cells leading to an increased risk of cancer initiation and progression. Chronic inflammatory respiratory disorders, including chronic obstructive pulmonary disease (COPD) is associated with both overactivation of Notch-1 signaling and increased lung cancer risk. Increased oxidative stress, also due to cigarette smoke, can further contribute to promote cancer initiation and progression by amplifying inflammatory responses, by activating the Notch-1 signaling, and by blocking regulatory mechanisms that inhibit the growth capacity of stem cells. This review offers a comprehensive overview of the effects of aberrant Notch-1 signaling activation in stem cells and of increased oxidative stress in lung cancer. The putative role of natural compounds with antioxidant properties is also described.

Oxidative Stress, Environmental Pollution, and Lifestyle as Determinants of Asthma in Children.

Exposure to cigarette smoke, allergens, viruses, and other environmental contaminants, as well as a detrimental lifestyle, are the main factors supporting elevated levels of airway oxidative stress. Elevated oxidative stress results from an imbalance in reactive oxygen species (ROS) production and efficiency in antioxidant defense systems. Uncontrolled increased oxidative stress amplifies inflammatory processes and tissue damage and alters innate and adaptive immunity, thus compromising airway homeostasis. Oxidative stress events reduce responsiveness to corticosteroids. These events can increase risk of asthma into adolescence and prompt evolution of asthma toward its most severe forms. Development of new therapies aimed to restore oxidant/antioxidant balance and active interventions aimed to improve physical activity and quality/quantity of food are all necessary strategies to prevent asthma onset and avoid in asthmatics evolution toward severe forms of the disease.

The estrogenic retina: The potential contribution to healthy aging and age-related neurodegenerative diseases of the retina.

These last two decades have seen an explosion of clinical and epidemiological research, and basic research devoted to envisage the influence of gender and hormonal fluctuations in the retina/ocular diseases. Particular attention has been paid to age-related disorders because of the overlap of endocrine and neuronal dysfunction with aging. Hormonal withdrawal has been considered among risk factors for diseases such as glaucoma, diabetic retinopathy and age-related macular disease (AMD), as well as, for Alzheimer's disease, Parkinson's disease, or other neurodegenerative disorders. Sex hormones and aging have been also suggested to drive the incidence of ocular surface diseases such as dry eye and cataract. Hormone therapy has been approached in several clinical trials. The discovery that the retina is another CNS tissue synthesizing neurosteroids, among which neuroactive steroids, has favored these studies. However, the puzzling data emerged from clinical, epidemiological and experimental studies have added several dimensions of complexity; the current landscape is inherently limited to the weak information on the influence and interdependence of endocrine, paracrine and autocrine regulation in the retina, but also in the brain. Focusing on the estrogenic retina, we here review our knowledge on local 17ß-oestradiol (E2) synthesis from cholesterol-based neurosteroidogenic path and testosterone aromatization, and presence of estrogen receptors (ERα and ERß). The first cholesterol-limiting step and the final aromatase-limiting step are discussed as possible check-points of retinal functional/dysfunctional E2. Possible E2 neuroprotection is commented as a group of experimental evidence on excitotoxic and oxidative retinal paradigms, and models of retinal neurodegenerative diseases, such as glaucoma, diabetic retinopathy and AMD. These findings may provide a framework to support clinical studies, although further basic research is needed.

Identifying protein partners of CLN8, an ER-resident protein involved in neuronal ceroid lipofuscinosis.

Neuronal ceroid lipofuscinoses (NCLs) are a genetically heterogeneous group of neurodegenerative diseases characterized by cognitive and motor decline, epilepsy, visual loss and by lysosomal autofluorescent inclusions. Two distinct clinical phenotypes, the progressive epilepsy with mental retardation (EPMR) and a late-infantile variant of NCLs (CLN8-vLINCL) are associated with mutations in the CLN8 gene that encodes a transmembrane protein predominantly located to the endoplasmic reticulum (ER). To gain insight into the function of CLN8 protein, we employed the split-ubiquitin membrane-based yeast two-hybrid (MYTH) system, which detects protein-protein interactions in a membrane environment, using the full-length human CLN8 as bait and a human brain cDNA library as prey. We identified several potential protein partners of CLN8 and especially referred to VAPA, c14orf1/hERG28, STX8, GATE16, BNIP3 and BNIP3L proteins that are associated with biologically relevant processes such as synthesis and transport of lipids, vesicular/membrane trafficking, autophagy/mitophagy and apoptosis. Interactions of CLN8 with VAPA and GATE16 were further validated by co-immunoprecipitation and co-localization assays in mammalian cells. Using a new C-terminal-oriented CLN8 antibody, CLN8-VAPA interaction was also confirmed by co-staining in close spatial proximity within different CNS tissues. The results of this study shed light on potential interactome networks of CLN8 and provide a powerful starting point for understanding protein function(s) and molecular aspects of diseases associated with CLN8 deficiency.

A retinal proteomics-based study identifies αA-crystallin as a sex steroid-regulated protein.

Sex steroids influence the structural and functional organization of ocular tissues, promote survival in several pathological conditions including retinal neurodegeneration and have a prominent role in age-related eye diseases as well as neurodegenerative diseases. However, their underlying mechanisms are still elusive. We explored proteomic profiling of rat retinas following intravitreal injection of the bioactive 17ß-estradiol or androgen dihydrotestosterone. Using narrow range 2-DE gels and MALDI-TOF-MS analysis, we identified three sex steroid-regulated proteins: the galectin-related-inter-fiber (GRIFIN) which is a galectin family member protein of unknown function, the fatty acid-binding protein epidermal-5 (FABP5) protein responsible for the fatty acid uptake and transport and the small heat shock αA-crystallin (CRYAA) protein involved in preventing aggregation of denatured or unfolded proteins. Changes in the expression of these proteins revealed a predominant estrogenic effect and the multiple CRYAA protein species reflected posttranslational modifications. Sex steroid-mediated modifications of CRYAA were confirmed by Western blotting analysis. This study provides new target proteins for sex steroids with a potential link to age-related diseases associated with proteotoxic stress.

Different early ER-stress responses in the CLN8(mnd) mouse model of neuronal ceroid lipofuscinosis.

Neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders characterized by epilepsy, progressive motor and cognitive decline, blindness, and by the accumulation of autofluorescent lipopigment. Late-infantile onset forms (LINCL) include those linked to mutations in CLN8 gene, encoding a transmembrane protein at the endoplasmic reticulum (ER). In the motor neuron degeneration (mnd) mouse model of the CLN8-LINCL (CLN8(mnd)), we carried out an analysis of ER stress-related molecules in CNS structures that exhibit a variable rate of disease progression (early retinal degeneration and delayed brain and motoneuron dysfunction). At the presymptomatic state of 1-month-old CLN8(mnd) mice, we found an upregulation of GRP78 and activation of the transcription factor-6 (ATF6) in all structures examined, an activation of a CHOP-dependent pathway in the cerebellum, hippocampus and retina, a caspase-12-dependent pathway in the retina and no activation of these two pathways in the cerebral cortex and spinal cord. An increased CHOP expression was detected in the cortex and spinal cord at the early symptomatic state (4 months). Caspase-3 cleavage occurred presymptomatically in the cerebellum, hippocampus and retina, and symptomatically in the cerebral cortex and spinal cord. We also monitored activation of NF-κB, which is engaged in the alarming phase of ER stress, together with increased levels of TRAF2, TNF-α and TNFR1, and no activation of ASK-1/JNK signalling pathway, all over mnd structures. The results suggest that early ER-stress responses distinctly combined and ER-stress pathways integrated with inflammatory responses may contribute to the progression of the CLN8(mnd) disease in CNS structures.

Chronic pharmacological treatment in takotsubo cardiomyopathy.

BACKGROUND: Takotsubo cardiomyopathy is a disorder that has been appreciated only recently. In most of reported cases, this syndrome mimes an acute myocardial infarction. Till this moment no data are available from literature about the treatment in the acute phase of this disease. AIM OF THE STUDY: In our multicentric experience we have retrospectively looked at the benefits of a treatment with ACE-inhibitors, beta-blockers, Aspirin and calcium channels blockers, started until the early phases of the disease and continued for 30 days, in 36 patients affected by Takotsubo cardiomyopathy. We chose as endpoint of the study the efficacy of the used drug in improving left ventricular myocardial function and the rapidity of the effects of the same drug.bethods: from an international registry about the Takotsubo cardiomiopathy, co-ordinate by our research group, we evaluated the long term efficacy of some drugs, administrated like single treatment in some patients. RESULTS: Obtained data did not show any statistically significant difference in the percentages of improvement in the left ventricle ejection fraction evaluated at the admission to the hospital, before the discharge and after 30 days of treatment between each treated group and the control group of non-treated patients. No significant differences were found in hospitalization times between treated patients and controls. None of our patients experienced during the observation period a relapse of the disease. CONCLUSIONS: The results of our survey suggest that a chronic treatment with beta-blockers, ACE-inhibitors, calcium channels blockers and aspirin does not provide any benefit in patients with Takotsubo cardiomyopathy. Thus, it seem to be important an early correct differential diagnosis to avoid any chronic treatment in these patients.

Ventricular tachycardia in non-compaction of left ventricle: is this a frequent complication?

BACKGROUND: Isolated left ventricular non-compaction is the result of incomplete myocardial morphogenesis, leading to persistence of the embryonic myocardium. The condition is recognized by an excessively prominent trabecular meshwork and deep intertrabecular recesses of the left ventricle. Whether these intertrabecular recesses are a favorable substrate for ventricular arrhythmias is unclear. Some reports have found that the fatal ventricular arrhythmias may occur in approximately half of the patients. In this report we investigated about this association. METHODS AND RESULTS: In total we evaluated a continuous series of 238 patients affected by non-compaction. Periodic Holter monitoring was performed every 6 months for 4 years. Only 11 patients had documented ventricular tachycardia, which was sustained in two cases and non-sustained in nine. In no cases we observed ventricular fibrillation. CONCLUSIONS: Non-compaction alone does not seem to be a risk factor for malignant ventricular arrhythmias.

[Heart failure and cardiomyopathies: a case report]. / Insufficienza cardiaca acuta e cardiomiopatie: un caso clinico.

Isolated noncompaction of left ventricular myocardium is a rare congenital heart disease, characterized by an excessive prominence of trabecular meshwork, spaced out by deep intertrabecular recesses, consequent to the arrest of the normal myocardial embryogenesis. Although there are numerous descriptions, the pathophysiological effects of the structural alterations, like the clinical spectrum and the evolution of the disease, are not fully clarified. In this paper we evaluated the natural history of the disease, the family incidence and the alterations of the systolic and diastolic function. An interesting case report is described concerning a patient affected by noncompaction and atrial fibrillation.

[Rupture of the atherosclerotic plaque: is Chlamydia pneumoniae a possible agent?]. / Studio osservazionale la chlamydia pneumoniae è correlabile con la rottura della placca aterosclerotica?

BACKGROUND: The natural history of atherosclerosis has not clearly been elucidated yet. Some works reported that flogosis plays a role in plaque instability. Why does this inflammatory process start? We investigated the correlation between Chlamydia pneumoniae acute infection and plaque rupture. METHODS: We compared blood concentrations of IgM anti-Chlamydia pneumoniae in patients affected by acute myocardial infarction (AMI) and in patients affected by stable angina. RESULTS: Our results showed a minimal statistical difference, with a more positive value in patients with AMI. Subsequently, the group affected by AMI was divided into two subgroups with and without plaque rupture: the subgroup with plaque rupture showed a higher blood concentration of Chlamydia antibodies. This subgroup was also divided into two other subgroups according to blood white cell concentration: the subgroup with normal concentration of white blood cells showed the highest value of Chlamydia antibodies. CONCLUSIONS: Chlamydia pneumoniae could play an important role in atherosclerotic plaque instability

Retinal oxidation, apoptosis and age- and sex-differences in the mnd mutant mouse, a model of neuronal ceroid lipofuscinosis.

Retinal degeneration is an early and progressive event in many forms of neuronal ceroid lipofuscinoses (NCLs), a heterogeneous group of neurodegenerative disorders with unknown pathogenesis. We here used the mutant motor neuron degeneration (mnd) mouse, a late-infantile NCL variant, to investigate the retinal oxidative state and apoptotic cell death as a function of age and sex. Total superoxide dismutase (SOD) activities and thiobarbituric acid-reactive substance (TBARS) levels revealed progressive increases in retinal oxyradicals and lipid peroxides of mnd mice of both sexes. Female mnd retinas showed a higher oxidation rate and consistently exhibited the 4-hydroxy-2-nonenal (4-HNE)-adducts staining and advanced histopathologic profile when compared to male mnd retinas matched for age. In situ DNA fragmentation (TUNEL staining) appeared in the outer nuclear layer (ONL) as early as 1 month of age. At 4 months, there were more intense and numerous TUNEL-positive cells in the same layer and in the inner nuclear (INL) and ganglion cell (GCL) layers; whereas at 8 months TUNEL staining was restricted to a few scattered cells in the INL and GCL, when a severe retinal cell loss had occurred. Caspase-3 activation confirmed apoptotic demise and its processing turned out to be higher in mnd females than males. These results demonstrate the involvement of oxidation and apoptotic processes in mnd mouse retinopathy and highlight sex-related differences in retinal vulnerability to oxidative stress and damage.

Oxidative stress-mediated DHEA formation in Alzheimer's disease pathology.

An alternative pathway for dehydroepiandrosterone (DHEA) synthesis has been suggested by treating rat and human brain cells with ferrous sulfate and beta-amyloid (Abeta). To determine if this pathway exists in human brain, levels of DHEA in hippocampus, hypothalamus and frontal cortex from Alzheimer's disease (AD) patients and age-matched controls were measured. DHEA is significantly higher in AD brain than control, and was highest in AD hippocampi. Cytochrome p450 17alpha-hydroxylase, responsible for peripheral DHEA synthesis, is not present in hippocampus. DHEA levels in AD cerebrospinal fluid (CSF) were significantly higher than age-matched controls. AD serum DHEA levels are lower than CSF, and not significantly different from controls. Treatment of control hippocampus, hypothalamus and serum with FeSO(4) increases DHEA, suggesting that levels of precursor are higher in control that in AD brain. This suggests that (i). an alternative precursor is present in control brain, (ii). AD brain DHEA is formed by oxidative stress metabolism of precursor, and (iii). CSF DHEA levels and serum DHEA formation in response to FeSO(4) may serve as an indicator of AD pathology.