Sperm microRNA content is altered in a mouse model of male obesity, but the same suite of microRNAs are not altered in offspring's sperm

The prevalence of obesity is increasing worldwide and has tripled in men of reproductive age since the 1970s. Concerningly, obesity is not only comorbid with other chronic diseases, but there is mounting evidence that it increases the non-communicable disease load in their children (eg mortality, obesity, autism). Animal studies have demonstrated that paternal obesity increases the risk of metabolic (eg glucose metabolism defects, obesity) and reproductive disorders in offspring. Epigenetic changes within sperm are clear mechanistic candidates that are associated with both changes to the father’s environment and offspring phenotype. Specifically there is emerging evidence that a father’s sperm microRNA content both responds to paternal environmental cues and alters the gene expression profile and subsequent development of the early embryo. We used a mouse model of high fat diet (HFD) induced obesity to investigate whether male obesity could modulate sperm microRNA content. We also investigated whether this alteration to a father’s sperm microRNA content lead to a similar change in the sperm of male offspring. Our investigations were initially guided by a Taqman PCR array, which indicated the differential abundance of 28 sperm borne microRNAs in HFD mice. qPCR confirmation in a much larger cohort of founder males demonstrated that 13 of these microRNAs were differentially abundant (11 up-regulated; 2 down-regulated) due to HFD feeding. Despite metabolic and reproductive phenotypes also being observed in grand-offspring fathered via the male offspring lineage, there was no evidence that any of the 13 microRNAs were also dysregulated in male offspring sperm. This was presumably due to the variation seen within both groups of offspring and suggests other mechanisms might act between offspring and grand-offspring. Thus 13 sperm borne microRNAs are modulated by a father’s HFD and the presumed transfer of this altered microRNA payload to the embryo at fertilisation potentially acts to alter the embryonic molecular makeup post-fertilisation, altering its growth trajectory, ultimately affecting adult offspring phenotype and may contribute to paternal programming.Tod Fullston, E. Maria C. Ohlsson-Teague, Cristin G. Print, Lauren Y. Sandeman, Michelle Lan

Pre-microRNA and Mature microRNA in Human Mitochondria

Chantier qualité GAInternational audienceBACKGROUND: Because of the central functions of the mitochondria in providing metabolic energy and initiating apoptosis on one hand and the role that microRNA (miRNA) play in gene expression, we hypothesized that some miRNA could be present in the mitochondria for post-transcriptomic regulation by RNA interference. We intend to identify miRNA localized in the mitochondria isolated from human skeletal primary muscular cells. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the potential origin of mitochondrial miRNA, we in-silico searched for microRNA candidates in the mtDNA. Twenty five human pre-miRNA and 33 miRNA aligments (E-value35) for the smallest RNA input concentration and 204 miRNA for the maximum RNA input concentration. In silico analysis predicted 80 putative miRNA target sites in the mitochondrial genome (E-value<0.05). CONCLUSIONS/SIGNIFICANCE: The present study experimentally demonstrated for the first time the presence of pre-miRNA and miRNA in the human mitochondria isolated from skeletal muscular cells. A set of miRNA were significantly detected in mitochondria fraction. The origin of these pre-miRNA and miRNA should be further investigate to determine if they are imported from the cytosol and/or if they are partially processed in the mitochondria

MicroRNAs hsa-miR-99b, hsa-miR-330, hsa-miR-126 and hsa-miR-30c: Potential Diagnostic Biomarkers in Natural Killer (NK) Cells of Patients with Chronic Fatigue Syndrome (CFS)/ Myalgic Encephalomyelitis (ME)

Chronic Fatigue Syndrome (CFS/ME) is a complex multisystem disease of unknown aetiology which causes debilitating symptoms in up to 1% of the global population. Although a large cohort of genes have been shown to exhibit altered expression in CFS/ME patients, it is currently unknown whether microRNA (miRNA) molecules which regulate gene translation contribute to disease pathogenesis. We hypothesized that changes in microRNA expression in patient leukocytes contribute to CFS/ME pathology, and may therefore represent useful diagnostic biomarkers that can be detected in the peripheral blood of CFS/ME patients.miRNA expression in peripheral blood mononuclear cells (PBMC) from CFS/ME patients and healthy controls was analysed using the Ambion Bioarray V1. miRNA demonstrating differential expression were validated by qRT-PCR and then replicated in fractionated blood leukocyte subsets from an independent patient cohort. The CFS/ME associated miRNA identified by these experiments were then transfected into primary NK cells and gene expression analyses conducted to identify their gene targets.Microarray analysis identified differential expression of 34 miRNA, all of which were up-regulated. Four of the 34 miRNA had confirmed expression changes by qRT-PCR. Fractionating PBMC samples by cell type from an independent patient cohort identified changes in miRNA expression in NK-cells, B-cells and monocytes with the most significant abnormalities occurring in NK cells. Transfecting primary NK cells with hsa-miR-99b or hsa-miR-330-3p, resulted in gene expression changes consistent with NK cell activation but diminished cytotoxicity, suggesting that defective NK cell function contributes to CFS/ME pathology.This study demonstrates altered microRNA expression in the peripheral blood mononuclear cells of CFS/ME patients, which are potential diagnostic biomarkers. The greatest degree of miRNA deregulation was identified in NK cells with targets consistent with cellular activation and altered effector function

Genomic features and computational identification of human microRNAs under long-range developmental regulation

<p>Abstract</p> <p>Background</p> <p>Recent functional studies have demonstrated that many microRNAs (miRNAs) are expressed by RNA polymerase II in a specific spatiotemporal manner during the development of organisms and play a key role in cell-lineage decisions and morphogenesis. They are therefore functionally related to a number of key protein coding developmental genes, that form genomic regulatory blocks (GRBs) with arrays of highly conserved non-coding elements (HCNEs) functioning as long-range enhancers that collaboratively regulate the expression of their target genes. Given this functional similarity as well as recent zebrafish transgenesis assays showing that the miR-9 family is indeed regulated by HCNEs with enhancer activity, we hypothesized that this type of miRNA regulation is prevalent. In this paper, we therefore systematically investigate the regulatory landscape around conserved self-transcribed miRNAs (ST miRNAs), with their own known or computationally inferred promoters, by analyzing the hallmarks of GRB target genes. These include not only the density of HCNEs in their vicinity but also the presence of large CpG islands (CGIs) and distinct patterns of histone modification marks associated with developmental genes.</p> <p>Results</p> <p>Our results show that a subset of the conserved ST miRNAs we studied shares properties similar to those of protein-coding GRB target genes: they are located in regions of significantly higher HCNE/enhancer binding density and are more likely to be associated with CGIs. Furthermore, their putative promoters have both activating as well as silencing histone modification marks during development and differentiation. Based on these results we used both an elevated HCNE density in the genomic vicinity as well as the presence of a bivalent promoter to identify 29 putative GRB target miRNAs/miRNA clusters, over two-thirds of which are known to play a role during development and differentiation. Furthermore these predictions include miRNAs of the miR-9 family, which are the only experimentally verified GRB target miRNAs.</p> <p>Conclusions</p> <p>A subset of the conserved miRNA loci we investigated exhibits typical characteristics of GRB target genes, which may partially explain their complex expression profiles during development.</p

The Role of MicroRNAs in Regulatory T Cells and in the Immune Response

The discovery of microRNA (miRNA) is one of the major scientific breakthroughs in recent years and has revolutionized current cell biology and medical science. miRNAs are small (19~25nt) noncoding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region (3'UTR) of specific messenger RNAs (mRNAs) for degradation of translation repression. Genetic ablation of the miRNA machinery, as well as loss or degradation of certain individual miRNAs, severely compromises immune development and response, and can lead to immune disorders. Several sophisticated regulatory mechanisms are used to maintain immune homeostasis. Regulatory T (Treg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Recent publications have provided compelling evidence that miRNAs are highly expressed in Treg cells, that the expression of Foxp3 is controlled by miRNAs and that a range of miRNAs are involved in the regulation of immunity. A large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, cardiovascular disease and diabetes, as well as psychiatric and neurological diseases. Although it is still unclear how miRNA controls Treg cell development and function, recent studies certainly indicate that this topic will be the subject of further research. The specific circulating miRNA species may also be useful for the diagnosis, classification, prognosis of diseases and prediction of the therapeutic response. An explosive literature has focussed on the role of miRNA. In this review, I briefly summarize the current studies about the role of miRNAs in Treg cells and in the regulation of the innate and adaptive immune response. I also review the explosive current studies about clinical application of miRNA

The role of microRNAs in endometriosis and associated reproductive conditions

BACKGROUND: microRNAs (miRNAs) are short, single-stranded RNAs that regulate gene expression at the post-transcriptional level. Recent research has shown that miRNAs and their target mRNAs are differentially expressed in endometriosis and other disorders of the female reproductive system. Since miRNAs control a broad spectrum of normal and pathological cellular functions, they may play pivotal roles in the pathogenesis of these disorders. METHODS: A systematic review was undertaken of the published literature on; (i) the expression and functions of miRNAs in mammalian female reproductive tissues with a focus on endometriosis and the malignancies and fertility disorders related to this disease; and (ii) the potential roles played by validated mRNA targets of endometriosis-associated miRNAs. The current understanding of the biology of miRNAs is overviewed and the potential diagnostic and therapeutic potential of miRNAs in endometriosis is highlighted. RESULTS: The differential expression of miRNAs in endometriosis, and the putative molecular pathways constituted by their targets, suggests that miRNAs may play an important role in endometriotic lesion development. Models for miRNA regulatory functions in endometriosis are presented, including those associated with hypoxia, inflammation, tissue repair, TGFβ-regulated pathways, cell growth, cell proliferation, apoptosis, extracellular matrix remodelling and angiogenesis. In addition, specific miRNAs which may be associated with malignant progression and subfertility in endometriosis are discussed. CONCLUSIONS: miRNAs appear to be potent regulators of gene expression in endometriosis and its associated reproductive disorders, raising the prospect of using miRNAs as biomarkers and therapeutic tools in endometriosis.E. Maria C. Ohlsson Teague, Cristin G. Print and M. Louise Hul

Sjogren's syndrome and other inflammatory lesions of the salivary glands

http://www.uib.no/Broegelmann/annualreports_files/ar2000.pdfhttp://www.uib.no/Broegelmann/pub2000.htm

Role of anti-calcium channel and anti-receptor autoantibodies in autonomic dysfunction in Sjogren's syndrome

Auto-antibodies cross-reacting with L-type voltage-gated calcium channels (VGCCs) have been described in primary Sjögren's syndrome (pSS), and may mediate the cardiac defects in neonates born to mothers with pSS. L-type VGCCs are also present in autonomically innervated tissues. Therefore, the aim of this project was to investigate a role for anti-VGCC antibodies and antibodies to 1-adrenoceptors or P2X-purinoceptors in the autonomic dysfunction that occurs in pSS. Contraction of the sympathetically innervated vas deferens in response to stimulation of the muscle by an 1-adrenoceptor agonist (phenylephrine) or a P2X-purinoceptor agonist (,β-methylene ATP) was measured in the absence and presence of 2% serum. Contractions produced by phenylephrine and by ,β-methylene ATP were abolished by nicardipine, demonstrating that they are coupled to calcium influx through L-type VGCCs. Serum from patients with pSS or from healthy controls did not significantly alter the L-type channel-dependent responses of smooth muscle to agonist stimulation. We therefore conclude that pSS serum does not contain autoantibodies that functionally inhibit L-type VGCCs, 1-adrenoceptors or P2X-purinoceptors in smooth muscle and that such autoantibodies cannot explain the autonomic dysfunction in pSS.Maria Ohlsson, Tom P. Gordon and Sally A. Waterma

Attenuated apoptosis of B cell activating factor-expressing cells in primary Sjogren's syndrome

B cell activating factor (BAFF) is known to be a powerful regulator of B-cell differentiation and proliferation. The aim of this study was to assess the incidence of apoptosis among BAFF-expressing cells in Sjögren's syndrome (SS) salivary gland tissue. We performed double stainings of BAFF together with one of the markers, CD21, CD68, CD40, Fas, Bcl-2 or Bax, and monitored apoptosis among BAFF expressing cells by using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling method. A significantly lower level of apoptosis among the BAFF-expressing cells was detected in salivary glands from patients with SS compared with controls (p = 0.03). Furthermore, no difference in the coexpression of Fas or CD40 together with BAFF was detected between patients and controls. Coexpression of the pro apoptotic molecule Bax together with BAFF was nonsignificantly decreased in patients with SS compared with controls. Our results suggest that a reduced level of apoptosis among BAFF-expressing cells might lead to longer-existing BAFF expression within these cells and thereby maintain signaling for tissue-infiltrating B cells to proliferate and mature.Peter Szodoray, Stig Jellestad, Maria Ohlsson Teague and Roland Jonsso

CD40, CD154, Bax and Bcl-2 Expression in Sjogren's Syndrome Salivary Glands: a Putative Anti-Apoptotic Role During its Effector Phases

Published in Scandinavian Journal of Immunology, 2008, 56 (6):561-571 at www.interscience.wiley.comSjögren's syndrome (SS) is an autoimmune rheumatic disorder characterized by chronic lymphocytic infiltration and decreased secretion in the salivary glands (SGs). For some time, apoptosis has been suggested to constitute the major mechanism for acinar epithelial destruction during the effector phases; however, this is still controversial. We have recently demonstrated that despite the expression of Fas and FasL, the incidence of apoptosis is not increased in SS patients compared with control individuals. Our aim was therefore to further evaluate the expression of the pro- and anti-apoptotic Bax and Bcl-2 proteins. CD40 and CD154 expression was also investigated, as CD40 ligation has been suggested to protect cells from Fas-mediated apoptosis. Immunohistochemical staining was performed on SG tissue from primary and secondary SS patients, a group of patients with non-SS-related degenerative changes as well as on healthy control individuals. The frequency of stained cells in the foci of infiltrating mononuclear cells (IMCs) and in the acinar and ductal epithelium was determined. We found the expression of Bcl-2 but rarely Bax in SS SG IMCs. Bcl-2 in epithelial cells was sparse, while Bax expression occurred frequently and with no significant difference between the patient groups. CD40 and CD154 expression was high among SS IMCs, while CD40 levels were slightly decreased in SS epithelium compared with controls. Elevated CD154 expression was found in SS epithelium, being significantly increased in the ducts. In conclusion, our study further supports the hypothesis about apoptosis resistance among SS focal IMCs and suggests a putative protective role of CD40 ligation in SS SG epithelium.M. Ohlsson, P. Szodoray, L. L. Loro, A. C. Johannessen and R. Jonsso