P38 Kinase, SGK1 and NF-κB Dependent Up-Regulation of Na+/Ca2+ Exchanger Expression and Activity Following TGFß1 Treatment of Megakaryocytes

Background: TGFβ1, a decisive regulator of megakaryocyte maturation and platelet formation, has previously been shown to up-regulate both, store operated Ca2+ entry (SOCE) and Ca2+ extrusion by Na+/Ca2+ exchange. The growth factor thus augments the increase of cytosolic Ca2+ activity ([Ca2+]i) following release of Ca2+ from intracellular stores and accelerates the subsequent decline of [Ca2+]i. The effect on SOCE is dependent on a signaling cascade including p38 kinase, serum & glucocorticoid inducible kinase SGK1, and nuclear factor NFκB. The specific Na+/Ca2+ exchanger isoforms involved and the signalling regulating the Na+/Ca2+ exchangers remained, however elusive. The present study explored, whether TGFβ1 influences the expression and function of K+ insensitive (NCX) and K+ sensitive (NCKX) Na+/Ca2+ exchangers, and aimed to shed light on the signalling involved. Methods: In human megakaryocytic cells (MEG01) RT-PCR was performed to quantify NCX/NCKX isoform transcript levels, [Ca2+]i was determined by Fura-2 fluorescence, and Na+/Ca2+ exchanger activity was estimated from the increase of [Ca2+]i following switch from an extracellular solution with 130 or 90 mM Na+ and 0 mM Ca2+ to an extracellular solution with 0 Na+ and 2 mM Ca2+. K+ concentration was 0 mM for analysis of NCX and 40 mM for analysis of NCKX. Results: TGFβ1 (60 ng/ml, 24 h) significantly increased the transcript levels of NCX1, NCKX1, NCKX2 and NCKX5. Moreover, TGFβ1 (60 ng/ml, 24 h) significantly increased the activity of both, NCX and NCKX. The effect of TGFβ1 on NCX and NCKX transcript levels and activity was significantly blunted by p38 kinase inhibitor Skepinone-L (1 µM), the effect on NCX and NCKX activity further by SGK1 inhibitor GSK-650394 (10 µM) and NFκB inhibitor Wogonin (100 µM). Conclusions: TGFβ1 markedly up- regulates transcription of NCX1, NCKX1, NCKX2, and NCKX5 and thus Na+/Ca2+ exchanger activity, an effect requiring p38 kinase, SGK1 and NFκB

Potential for yield and soil fertility improvement with integration of organics in nutrient management for finger millet under rainfed Alfisols of Southern India

Finger millet (Eluesine coracana L.) is gaining importance as a food crop with the increasing emphasis on nutritional aspects and drought resilience. However, the average productivity of the crop has stagnated at around 2,000 kg ha−1 in India. Recently released nutrient responsive high yielding varieties are reported to respond better to application of fertilizers/manures. Further, substitution of chemical fertilizers with organic manures to maintain sustainable yields and improve soil health is gaining attention in recent years. Therefore, identifying the appropriate rate and source of nutrition is important to enhance the productivity of finger millet while improving the soil health. A field experiment was conducted during two rainy seasons (July–November, 2018 and 2019) to study the response of finger millet varieties to chemical fertilizers and farmyard manure (FYM) on growth, yields, N use efficiency, N uptake and on soil properties. Two varieties MR-1 and MR-6 were tested with four nutrient management practices viz., unamended control, 100% recommended dose of fertilizers (RDF; 40–20-20 kg NPK ha−1), 50% RDF + 50% recommended dose of nitrogen (RDN) as FYM and 100% RDN as FYM. Among the varieties, MR-6 outperformed MR-1 in terms of growth, yield, N use efficiency and N uptake. The yield enhancement was up to 22.6% in MR-6 compared to MR-1 across the nutrient management practices. Substituting FYM completely or half of the fertilizer dose increased the growth and yield of finger millet compared to application of chemical fertilizers alone. Similarly, the average biomass yield, ears m−2, grain yield, total N uptake and N use efficiency in response to nutrient management practices followed the order of 100% RDN as FYM > 50% RDF + 50% RDN as FYM > 100% RDF. The soil organic carbon, available N, P, K, and S improved by 25.0, 12.9, 5.7, 6.1, and 22.6%, respectively in the plots under higher rate of FYM application (8 Mg ha−1) compared to plots under chemical fertilizers alone. We conclude that substituting chemical fertilizers either completely or by up to 50% with organic manures supplies adequate amounts of nutrients, improves the yield of finger millet, economic returns, and soil properties

MicroRNAs as Haematopoiesis Regulators

The production of different types of blood cells including their formation, development, and differentiation is collectively known as haematopoiesis. Blood cells are divided into three lineages erythriod (erythrocytes), lymphoid (B and T cells), and myeloid (granulocytes, megakaryocytes, and macrophages). Haematopoiesis is a complex process regulated by several mechanisms including microRNAs (miRNAs). miRNAs are small RNAs which regulate the expression of a number of genes involved in commitment and differentiation of hematopoietic stem cells. Evidence shows that miRNAs play an important role in haematopoiesis; for example, myeloid and erythroid differentiation is blocked by the overexpression of miR-15a. miR-221, miR-222, and miR-24 inhibit the erythropoiesis, whereas miR-150 plays a role in B and T cell differentiation. miR-146 and miR-10a are downregulated in megakaryopoiesis. Aberrant expression of miRNAs was observed in hematological malignancies including chronic myelogenous leukemia, chronic lymphocytic leukemia, multiple myelomas, and B cell lymphomas. In this review we have focused on discussing the role of miRNA in haematopoiesis

Role of Gonadotropin Regulated Testicular RNA Helicase (GRTH/DDX25) on Polysomal Associated mRNAs in Mouse Testis

Gonadotropin Regulated Testicular RNA Helicase (GRTH/Ddx25) is a testis-specific multifunctional RNA helicase and an essential post-transcriptional regulator of spermatogenesis. GRTH transports relevant mRNAs from nucleus to cytoplasmic sites of meiotic and haploid germ cells and associates with actively translating polyribosomes. It is also a negative regulator of steroidogenesis in Leydig cells. To obtain a genome-wide perspective of GRTH regulated genes, in particularly those associated with polyribosomes, microarray differential gene expression analysis was performed using polysome-bound RNA isolated from testes of wild type (WT) and GRTH KO mice. 792 genes among the entire mouse genome were found to be polysomal GRTH-linked in WT. Among these 186 were down-regulated and 7 up-regulated genes in GRTH null mice. A similar analysis was performed using total RNA extracted from purified germ cell populations to address GRTH action in individual target cells. The down-regulation of known genes concerned with spermatogenesis at polysomal sites in GRTH KO and their association with GRTH in WT coupled with early findings of minor or unchanged total mRNAs and abolition of their protein expression in KO underscore the relevance of GRTH in translation. Ingenuity pathway analysis predicted association of GRTH bound polysome genes with the ubiquitin-proteasome-heat shock protein signaling network pathway and NFkB/TP53/TGFB1 signaling networks were derived from the differentially expressed gene analysis. This study has revealed known and unexplored factors in the genome and regulatory pathways underlying GRTH action in mal

MicroRNA function in megakaryocytes

Megakaryocytes (MKs), the largest cells in the bone marrow, are generated from hematopoietic stem cells (HSCs) in a sequential process called megakaryocytopoiesis in which HSCs undergo MK-progenitor (MP) commitment and maturation to terminally differentiated MK. Megakaryocytopoiesis is controlled by a complex network of bone marrow niche factors. Traditionally, the studies on megakaryocytopoiesis were focused on different cytokines, growth factors and transcription factors as the regulators of megakaryocytopoiesis. Over the past two decades many research groups have uncovered the key role of microRNAs (miRNAs) in megakaryocytopoiesis. miRNAs are a class of small length non-coding RNAs which play key regulatory role in cellular processes such as proliferation, differentiation and development and are also known to be involved in disease development. This review summarizes the current state of knowledge of miRNAs which have changed expression during megakaryocytopoiesis, also focuses on miRNAs which are differentially regulated during developmental maturation of MKs. Further, we aimed to discuss potential mechanisms of miRNAs-mediated regulation underlying megakaryocytopoiesis and developmental maturation of MKs

IPA analysis of differentially expressed genes in Leydig cells of GRTH^−/− compared to WT mice.

<p><b>(A) and (B). Left panel-</b>Venn diagram analysis of the overlap among differentially regulated genes in Leydig cells (144 down - and 155 up-regulated genes), in total testicular polysomes (307 down - or 53 up-regulated genes) and polysomal GRTH IP genes noted in WT mice (792 genes). Tpoly3fd or Tpoly3fu: >3 fold (f) down (d) or up (u)- regulated genes found in testicular polysomes (tpoly); lc3fd or lc3fu: >3 fold down- or up-regulated genes found in Leydig cells (lc); GRTHIP: mRNA messages were immunoprecipitated (IP) by GRTH antibody in testicular polysomal fraction of wild type mouse testis. <b>Right panel.</b> IPA predicts one network (nt) function in (<b>A</b>) 18 down- and (<b>B</b>) 3 up- regulated genes (A, in red) associated with GRTH protein in polysomes of Leydig cells. ltp: Leydig cells (l), testicular polysomes (t) and GRTH IP (p). Genes in color green (down-regulated), red (up-regulated) and uncolored (relevant biological genes to the network with no change in expression between WT and GRTH^−/−).</p

Background of the validated differentially expressed testicular polysomal genes in GRTH^−/− compared to WT mice.

<p>IP: immunoprecipitation by GRTH antibody., SP: spermatocytes., RS: round spermatids., LC: Leydig cells. IP: Testicular polysomal mRNA immunoprecipitated by GRTH antibody.</p

qRT-PCR validation of representative differentially expressed genes in testicular polysomes of GRTH^−/− versus WT mice.

<p>Expression of a panel of candidate genes in <b>GRTH^−/−</b> (KO) and wild type (WT) was chosen for further validation by RT-PCR. Gene expression level from three independent experiments were quantified and normalized by β-actin (means ± se). The KO values are presented as percentages of WT. The overall trends of expression by real time PCR were in agreement with the array data. <b>Top and middle panels:</b> down-regulated genes. <b>Bottom panel:</b> up-regulated genes.</p

Network function of validated differentially expressed genes in testicular polysomes of GRTH^−/− versus WT mice.

<p>Three top score of the associated network pathways from validated genes (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032470#pone-0032470-g007" target="_blank">Fig. 7</a>) were presented by ingenuity pathway analysis (IPA). Genes in color green (down-regulated), red (up-regulated) and uncolored (relevant biological genes to the network with no change in expression between WT and GRTH KO).</p

IPA analysis of differentially expressed genes in spermatocytes of GRTH^−/− compared to WT mice.

<p>(<b>A</b>). Venn diagram analysis of the overlap among differentially regulated genes in spermatocytes (<b>left panel</b>,139 down or <b>right panel</b>, 51 up-regulated genes), in testicular polysomes (<b>left panel</b>, 307 down - or <b>right panel</b>, 53 up-regulated genes) and polysomal GRTH IP genes noted in WT mice (792 genes). Tpoly3fd or Tpoly3fu: >3 fold (f) down (d) or up (u)- regulated genes found in testicular polysomes (Tpoly); sp2fd or sp2fu: >2 fold down- or up-regulated genes found in spermatocytes (sp); GRTHIP: mRNA messages were immunoprecipitated (IP) by GRTH antibody in testicular polysomal fraction of wild type mouse testis. (<b>B</b>). IPA predicts one top score of network (nt) function in 51 down regulated genes (A, in red) associated with GRTH protein in polysomes of spermatocytes. stp: spermatocytes (s), testicular polysome (t) and GRTH IP (p). Genes in color green (down-regulated) and uncolored (relevant biological genes to the network with no change in expression between WT and GRTH^−/−).</p