Different sources of reactive oxygen species contribute to low potassium-induced apoptosis in cerebellar granule cells

An early increase in ROS production is characteristic of cerebellar granule cells undergoing apoptosis in the presence of 5 mM KCl. However, the sources of this increase have not been investigated in detail. In particular whether there is a single enzymatic source or the increase in ROS production is the consequence of the involvement of different enzymes has not been studied in depth. Different enzymatic pathways may indeed contribute to the up-regulation of intracellular ROS production either directly or via side-chain reactions and a number of candidate enzymes are known to be involved in the apoptotic process in various cell types. The aim of this study was to identify the cellular sources of the ROS generated by CGCs undergoing apoptosis by low K+. A panel of specific inhibitors against phospholipase, cytochromes P450, cyclooxygenase, lipoxygenase, xanthine oxidase, ribonucleotide reductase and NADPH oxidase were used. We provide evidence that no single source of ROS can be identified in apoptotic CGCs, but the ROS generated through the arachidonic acid (AA) pathways, mainly via lipoxygenase activities, seems to be the most prominent.     

Treating Diabetes in Patients with Heart Failure: Moving from Risk to Benefit

Over the past two decades, therapeutics for diabetes have evolved from drugs with known heart failure risk to classes with potential benefit for patients with heart failure. As many as 25 to 35 % of patients with heart failure carry a diagnosis of type 2 diabetes mellitus. Therefore, newer drug classes including dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GIP-1) agonists, and sodium-glucose cotransporter 2 (SGLT-2) inhibitors are being examined for cardiovascular safety as well as their effects on left ventricular function, quality of life, and other measures of disease progression. The purpose of this review is to summarize the existing evidence on these classes of anti-diabetic agents in patients with heart failure.     

Hepatitis in Albanian children: molecular analysis of hepatitis A virus isolates

Hepatitis A is a common disease in developing countries and Albania has a high prevalence of this disease associated to young age. In spite of the occurrence of a unique serotype there are different genotypes classified from I to VII. Genotype characterisation of HAV isolates circulating in Albania has been undertaken, as well as the study of the occurrence of antigenic variants in the proteins VP3 and VP1. To evaluate the genetic variability of the Albanian hepatitis A virus (HAV) isolates, samples were collected from 12 different cities, and the VP1/2A junction amplified and sequenced. These sequences were aligned and a phylogenetic analysis performed. Additionally, the amino half sequence of the protein VP3 and the complete sequence of the VP1 was determined. Anti-HAV IgM were present in 66.2% of all the sera. Fifty HAV isolates were amplified and the analysis revealed that all the isolates were sub-genotype IA with only limited mutations. When the deduced amino acid sequences were obtained, the alignment showed only two amino acids substitutions at positions 22 and 34 of the 2A protein. A higher genomic stability of the VP1/2A region, in contrast with what occurs in other parts of the world could be observed, indicating high endemicity of HAV in Albania. In addition, two potential antigenic variants were detected. The first at position 46 of VP3 in seven isolates and the second at position 23 of VP1 in six isolates.     

Comparison of Completion Rates for SF-36 Compared With SF-12 Quality of Life Surveys at a Tertiary Urban Wound Center

Patient-reported outcome measures derived from quality of life instruments are an important tool in monitoring disease progression and treatment response. Although a number of validated instruments are available, the Short Form-36 (SF-36) quality of life survey is the most widely used. It is imperative that the patients answer all the questions in this instrument for appropriate analysis and interpretation. It has been hypothesized that fewer questions (i.e., the Short Form-12 [SF-12]), will result in greater survey completion rates. The present study was a randomized prospective study comparing the completion rates for the SF-36 and SF-12 quality of life surveys. Patients presenting with a chronic wound were asked to complete the SF-36 or SF-12 survey. After an a priori power analysis was performed, the completion rates, patterns of skipped questions, and demographic information were analyzed using t tests for continuous variables or Fisher's exact test for categorical variables and both multivariate linear regression and logistic regression. A total of 59 subjects (30 completed the SF-12 and 29 completed the SF-36) participated in the present study. The SF-12 group had an 80% (24 of 30) completion rate compared with a 55% (16 of 29) completion rate for the SF-36 group (p < .05). However, the length of the survey did not affect the completion rate nor was a statistically detectable pattern of skipped questions found. College graduates were more likely to complete both surveys compared with high school graduates (p < .07). Although it is unclear why, our study results indicate that the SF-12 yields a higher total survey completion rate. However, completion appears independent of the shorter survey length.     

Pharmaceutical strategies against amyloidosis: old and new drugs in targeting a "protein misfolding disease"

The group of diseases caused by abnormalities of the process of protein folding and unfolding is rapidly growing and includes diseases caused by loss of function as well as diseases caused by gain of function of misfolded proteins. Amyloidoses are caused by gain of function of certain proteins that lose their native structure and self-assemble into toxic insoluble, extracellular fibrils. This process requires the contribution of multiple factors of which only a few are established, namely the conformational modification of the amyloidogenic protein, protein's post-translational modifications and the co-deposition of glycosaminoglicans and of serum amyloid P component. In parallel with the exponential growth of biochemical data regarding the key events of the fibrillogenic process, several reports have shown that small molecules, through the interaction with either the amyloidogenic proteins or with the common constituents, can modify the kinetics of formation of amyloid fibrils or can facilitate amyloid reabsorption. These small molecules can be classified on the basis of their protein target and mechanism of action, according to the following properties. 1) molecules that stabilize the amyloidogenic protein precursor 2) molecules that prevent fibrillogenesis by acting on partially folded intermediates of the folding process as well as on low molecular weight oligomers populating the initial phase of fibril formation 3) molecules that interact with mature amyloid fibrils and weaken their structural stability 4) molecules that displace fundamental co-factors of the amyloid deposits like glycosaminoglycans and serum amyloid P component and favor the dissolution of the fibrillar aggregate.     

Constitutive activation of MAPK/ERK inhibits prostate cancer cell proliferation through upregulation of BRCA2

BRCA2 is central to an utterly diverse biological behavior elicited after integrin-mediated normal and prostate cancer cell adhesion to basement membrane (BM) and extracellular matrix (ECM) proteins. Unlike normal cells, adhesive stimuli in cancer cells activate PI 3-kinase/AKT signaling resulting in BRCA2 degradation and unchecked cancer cell proliferation and metastasis. However, the precise mechanisms involved in normal BRCA2 homeostasis are unknown. We investigated ERK and AKT phosphorylation in normal (PNT1A) and cancer (PC-3) prostate cells after adhesion to ECM and the effects upon BRCA2 and cell proliferation. PNT1A cell adhesion to ECM triggered MAPK/ERK signaling resulting in upregulation of BRCA2 mRNA and protein, with negligible effects upon cell proliferation. Disruption of MAPK/ERK with PD98059 prevented any BRCA2 upregulation inhibiting DNA synthesis below basal levels. PC-3 cells exhibited a defective MAPK/ERK pathway that was unresponsive to adhesion to the ECM, which instead triggered PI 3-kinase/AKT signaling leading to BRCA2 protein depletion and cell proliferation. Reconstitution of MAPK/ERK by recombinant expression of a constitutively active form of MAPK kinase 1 (MEK1) effectively reversed the neoplastic phenotype by increasing BRCA2 expression and preventing any aberrant cell proliferation at rest and upon interaction with ECM proteins. Our results suggest that aberrant loss of MAPK/ERK activity in prostate cancer may play a pivotal role in the malignant phenotype, and provide evidence that interventions aimed at bypassing the signaling block are able to effectively reverse neoplastic unchecked cell proliferation.     

GRK2 at the control shaft of cellular metabolism

G protein receptor kinase 2 (GRK2) has been for years mainly considered the negative regulator of the cardiac β adrenergic signaling. However GRK2 is a ubiquitous molecule and its kinase activity and scaffold properties brought to several investigations which have evidenced its involvement in pathophysiology of extra-cardiac diseases. Later discoveries, moreover, indicated that this molecule is also able to influence other pathways such as insulin signaling by an inhibitory role similar to what described years before on βAR signaling. The importance of this novel function is in particular related to the possibility that this molecule can regulate the cellular metabolism, modifying the ability of cells to utilize different substrates. This hypothesis has been recently investigated in animal model of Heart Failure, evidencing that upregulation of GRK2 leads to alterations of cardiac glucose metabolism in the early stages of the disease. However GRK2 shows increased level also in the early stages of others chronic disease such as Alzheimer's Disease, indicating that these findings could be possibly applied to others cellular system and supporting the emerging idea of GRK2 as master regulator of cellular metabolism.     

Implication of a genetic variant at PICALM in Alzheimer’s disease patients and centenarians

A common polymorphism (rs3851179) in the PICALM (phosphatidylinositol-binding clathrin assembly protein) gene has been recently associated with reduced risk of developing late-onset Alzheimer’s disease (LOAD). We analyzed the genotype and allele distributions of the PICALM polymorphism in 813 Italian subjects, including LOAD patients and centenarians. The segregation of the PICALM rs3851179 showed no statistically significant difference between LOAD cases and controls. The implication of a genetic variant at PICALM is confirmed for the first time, in centenarians, thus suggesting a possible role in longevity.