MiR-133a in Human Circulating Monocytes: A Potential Biomarker Associated with Postmenopausal Osteoporosis

Background: Osteoporosis mainly occurs in postmenopausal women, which is characterized by low bone mineral density (BMD) due to unbalanced bone resorption by osteoclasts and formation by osteoblasts. Circulating monocytes play important roles in osteoclastogenesis by acting as osteoclast precursors and secreting osteoclastogenic factors, such as IL-1, IL-6 and TNF-a. MicroRNAs (miRNAs) have been implicated as important biomarkers in various diseases. The present study aimed to find significant miRNA biomarkers in human circulating monocytes underlying postmenopausal osteoporosis. Methodology/Principal Findings: We used ABI TaqManH miRNA array followed by qRT-PCR validation in circulating monocytes to identify miRNA biomarkers in 10 high and 10 low BMD postmenopausal Caucasian women. MiR-133a was upregulated (P = 0.007) in the low compared with the high BMD groups in the array analyses, which was also validated by qRT-PCR (P = 0.044). We performed bioinformatic target gene analysis and found three potential osteoclast-related target genes, CXCL11, CXCR3 and SLC39A1. In addition, we performed Pearson correlation analyses between the expression levels of miR-133a and the three potential target genes in the 20 postmenopausal women. We did find negative correlations between miR-133a and all the three genes though not significant. Conclusions/Significance: This is the first in vivo miRNA expression analysis in human circulating monocytes to identif

Path to Facilitate the Prediction of Functional Amino Acid Substitutions in Red Blood Cell Disorders – A Computational Approach

A major area of effort in current genomics is to distinguish mutations that are functionally neutral from those that contribute to disease. Single Nucleotide Polymorphisms (SNPs) are amino acid substitutions that currently account for approximately half of the known gene lesions responsible for human inherited diseases. As a result, the prediction of non-synonymous SNPs (nsSNPs) that affect protein functions and relate to disease is an important task.In this study, we performed a comprehensive analysis of deleterious SNPs at both functional and structural level in the respective genes associated with red blood cell metabolism disorders using bioinformatics tools. We analyzed the variants in Glucose-6-phosphate dehydrogenase (G6PD) and isoforms of Pyruvate Kinase (PKLR & PKM2) genes responsible for major red blood cell disorders. Deleterious nsSNPs were categorized based on empirical rule and support vector machine based methods to predict the impact on protein functions. Furthermore, we modeled mutant proteins and compared them with the native protein for evaluation of protein structure stability.We argue here that bioinformatics tools can play an important role in addressing the complexity of the underlying genetic basis of Red Blood Cell disorders. Based on our investigation, we report here the potential candidate SNPs, for future studies in human Red Blood Cell disorders. Current study also demonstrates the presence of other deleterious mutations and also endorses with in vivo experimental studies. Our approach will present the application of computational tools in understanding functional variation from the perspective of structure, expression, evolution and phenotype

Rab32 connects ER stress to mitochondrial defects in multiple sclerosis.

Endoplasmic reticulum (ER) stress is a hallmark of neurodegenerative diseases such as multiple sclerosis (MS). However, this physiological mechanism has multiple manifestations that range from impaired clearance of unfolded proteins to altered mitochondrial dynamics and apoptosis. While connections between the triggering of the unfolded protein response (UPR) and downstream mitochondrial dysfunction are poorly understood, the membranous contacts between the ER and mitochondria, called the mitochondria-associated membrane (MAM), could provide a functional link between these two mechanisms. Therefore, we investigated whether the guanosine triphosphatase (GTPase) Rab32, a known regulator of the MAM, mitochondrial dynamics, and apoptosis, could be associated with ER stress as well as mitochondrial dysfunction.This article is freely available via Open Access. Click on the Additional Link above to access the full-text via the publisher's site

TNF-alpha antibodies and osteoprotegerin decrease systemic bone loss associated with inflammation through distinct mechanisms in collagen-induced arthritis.

Introduction: Rheumatoid arthritis (RA) is associated with focal and systemic bone loss involving cytokines such as RANKL and TNF-a. RANK-L promotes focal and systemic osteoporosis, whereas osteoprotegerin (OPG) inhibits bone resorption. Although anti-TNF-a antibodies (anti-TNF-a Ab) decrease joint inflammation and bone erosions, their effects on bone loss are unknown. The aim of this study was to evaluate the effects of OPG and anti-TNF-a Ab, separately or in combination, on inflammation and bone remodeling in collagen-induced arthritis (CIA), a model of RA. Methods: DBA/1 mice (n = 28) were immunized with bovine type II collagen and treated with OPG-Fc or anti-TNF-a Ab or both, or saline. One group of mice (n = 7) was not immunized (naive group). Urinary deoxypyridinoline (D-pyr) and whole-body bone mineral density (BMD) were measured at baseline and at sacrifice. Histomorphometric parameters were evaluated at the femoral metaphysis. Results: Anti-TNF-a Ab, but not OPG, decreased the clinical arthritis score (P b 0.02 vs. saline) and the histological score of inflammation. The BMD change from baseline to sacrifice (DBMD) was significantly smaller in CIA mice than naive mice. OPG and anti-TNF-a Ab significantly increased DBMD versus saline, and the effect was greater with OPG (P b 0.003). DD-pyr decreased by 65% with OPG and 13% with anti-TNF-a Ab. Compared with saline, OPG increased trabecular bone volume (BV/TV) (P b 0.02), decreased trabecular separation (P b 0.02), and decreased the bone formation rate (BFR) (P b 0.01). Anti-TNF-a Ab produced no significant changes in bone volume or trabecular separation but increased trabecular thickness (P b 0.02 vs. saline) to a value close to that in naive mice, suggesting preservation of bone formation. No additive effects of OPG and anti-TNF-a Ab were found. Conclusions: Systemic OPG and anti-TNF-a Ab therapy prevented bone loss in CIA mice through distinct mechanisms involving decreased bone resorption and preserved bone formation. Combining these two agents might help to prevent bone loss in inflammatory diseases

Mortality and morbidity reduction with Candesartan in patients with chronic heart failure and left ventricular systolic dysfunction: results of the CHARM low-left ventricular ejection fraction trials.

Background-Patients with symptomatic chronic heart failure (CHF) and reduced left ventricular ejection fraction (LVEF) have a high risk of death and hospitalization for CHF deterioration despite therapies with angiotensin-converting enzyme (ACE) inhibitors, {beta}-blockers, and even an aldosterone antagonist. To determine whether the angiotensin-receptor blocker (ARB) candesartan decreases cardiovascular mortality, morbidity, and all-cause mortality in patients with CHF and depressed LVEF, a prespecified analysis of the combined Candesartan in Heart Failure Assessment of Reduction in Mortality and morbidity (CHARM) low LVEF trials was performed. CHARM is a randomized, double-blind, placebo-controlled, multicenter, international trial program. Methods and Results-New York Heart Association (NYHA) class II through IV CHF patients with an LVEF of ≤40% were randomized to candesartan or placebo in 2 complementary parallel trials (CHARM-Alternative, for patients who cannot tolerate ACE inhibitors, and CHARM-Added, for patients who were receiving ACE inhibitors). Mortality and morbidity were determined in 4576 low LVEF patients (2289 candesartan and 2287 placebo), titrated as tolerated to a target dose of 32 mg once daily, and observed for 2 to 4 years (median, 40 months). The primary outcome (time to first event by intention to treat) was cardiovascular death or CHF hospitalization for each trial, with all-cause mortality a secondary end point in the pooled analysis of the low LVEF trials. Of the patients in the candesartan group, 817 (35.7%) experienced cardiovascular death or a CHF hospitalization as compared with 944 (41.3%) in the placebo group (HR 0.82; 95% CI 0.74 to 0.90; P<0.001) with reduced risk for both cardiovascular deaths (521 [22.8%] versus 599 [26.2%]; HR 0.84 [95% CI 0.75 to 0.95]; P=0.005) and CHF hospitalizations (516 [22.5%] versus 642 [28.1%]; HR 0.76 [95% CI 0.68 to 0.85]; P<0.001). It is important to note that all-cause mortality also was significantly reduced by candesartan (642 [28.0%] versus 708 [31.0%]; HR 0.88 [95% CI 0.79 to 0.98]; P=0.018). No significant heterogeneity for the beneficial effects of candesartan was found across prespecified and subsequently identified subgroups including treatment with ACE inhibitors, {beta}-blockers, an aldosterone antagonist, or their combinations. The study drug was discontinued because of adverse effects by 23.1% of patients in the candesartan group and 18.8% in the placebo group; the reasons included increased creatinine (7.1% versus 3.5%), hypotension (4.2% versus 2.1%), and hyperkalemia (2.8% versus 0.5%), respectively (all P<0.001). Conclusion-Candesartan significantly reduces all-cause mortality, cardiovascular death, and heart failure hospitalizations in patients with CHF and LVEF s40% when added to standard therapies including ACE inhibitors, β-blockers, and an aldosterone antagonist. Routine monitoring of blood pressure, serum creatinine, and serum potassium is warranted