scholarly journals CFM9, a Mitochondrial CRM Protein, Is Crucial for Mitochondrial Intron Splicing, Mitochondria Function and Arabidopsis Growth and Stress Responses

2019 ◽  
Vol 60 (11) ◽  
pp. 2538-2548 ◽  
Author(s):  
Kwanuk Lee ◽  
Su Jung Park ◽  
Youn-Il Park ◽  
Hunseung Kang
Keyword(s):  
Stress Responses ◽  
Rna Splicing ◽  
Growth Defect ◽  
Wild Type ◽  
Respiration Activity ◽  
Abnormal Mitochondria ◽  
Chloroplast Rna ◽  
And Function ◽  
Mitochondrial Introns

Abstract Although the importance of chloroplast RNA splicing and ribosome maturation (CRM) domain-containing proteins has been established for chloroplast RNA metabolism and plant development, the functional role of CRM proteins in mitochondria remains largely unknown. Here, we investigated the role of a mitochondria-targeted CRM protein (At3g27550), named CFM9, in Arabidopsis thaliana. Confocal analysis revealed that CFM9 is localized in mitochondria. The cfm9 mutant exhibited delayed seed germination, retarded growth and shorter height compared with the wild type under normal conditions. The growth-defect phenotypes were more manifested upon high salinity, dehydration or ABA application. Complementation lines expressing CFM9 in the mutant background fully recovered the wild-type phenotypes. Notably, the mutant had abnormal mitochondria, increased hydrogen peroxide and reduced respiration activity, implying that CFM9 is indispensable for normal mitochondrial function. More important, the splicing of many intron-containing genes in mitochondria was defective in the mutant, suggesting that CFM9 plays a crucial role in the splicing of mitochondrial introns. Collectively, our results provide clear evidence emphasizing that CFM9 is an essential factor in the splicing of mitochondrial introns, which is crucial for mitochondrial biogenesis and function and the growth and development of Arabidopsis.

scholarly journals The RNA Splicing Factor U2AF1 Controls Hematopoietic Stem Cell Survival and Function

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Avik Dutta ◽  
Yue Yang ◽  
Bao Le ◽  
Golam Mohi
Keyword(s):  
Dna Damage ◽  
Rna Splicing ◽  
Marked Decrease ◽  
Wild Type ◽  
Hematopoietic Progenitors ◽  
Hematopoietic Stem ◽  
Damage Response ◽  
And Function ◽  
Deficient Mice

Somatic mutations in U2AF1 have been identified in ~11% cases of MDS. U2AF1 is involved in the recognition of the 3' splice site required for the recruitment of the U2 snRNP during pre-mRNA splicing. Most U2AF1 mutations are found in two hotspots (S34 and Q157) within the first and second zinc finger domains. Transgenic and knock-in mice expressing U2AF1 S34F mutant exhibit impaired hematopoiesis. However, the role of wild-type U2AF1 in regulating hematopoietic stem cell (HSC) function and normal hematopoiesis has remained unknown. To determine the role of U2AF1 in normal hematopoiesis, we generated a new conditional U2af1 knockout (floxed) mouse. We crossed U2af1 floxed mouse with Mx1-Cre mouse and the expression of Cre recombinase was induced with polyinosine-polycytosine (pI-pC) injection at 5 to 6 weeks after birth. We observed that deletion of U2af1 significantly reduced white blood cell, neutrophil, red blood cell and platelet counts in their peripheral blood compared with control animals within 10-14 days after pI-pC injection. Histopathologic analysis of the BM sections from U2af1-deficient mice showed severe BM aplasia. Flow cytometric analyses revealed a marked decrease in myeloid, erythroid and megakaryocytic precursors in the BM of U2af1-deficient mice compared with control animals. We also observed a marked decrease in Lin-Sca-1+c-kit+(LSK) and long-term hematopoietic stem cells (LT-HSC), short-term HSC (ST-HSC), and multipotential progenitors (MPP) as well as common myeloid progenitors (CMP), granulocyte-macrophage progenitors (GMP), and megakaryocyte-erythroid progenitors (MEP) in the BM of U2af1-deleted mice. Hematopoietic progenitor colony assays showed a significant decrease in myeloid (CFU-GM), erythroid (BFU-E), and megakaryocytic (CFU-Mk) colonies in the BM of U2af1-deficient mice.Together, these data suggest that loss of U2af1 causes severe defects in hematopoiesis. We performed both non-competitive and competitive BM transplantation assays using U2af1-deficient BM to determine the role of U2af1 in HSC function. There was marked reduction of HSC, progenitors and all types of blood and BM cell precursors upon U2af1 deletion (by pI-pC administration) in the transplanted animals. Also, U2af1-deficient HSCs were unable to compete with WT HSCs and there was rapid loss of hematopoietic progenitors/precursors derived from the U2af1-deficient HSCs. Since U2af1 deletion resulted in rapid decrease of hematopoietic progenitors in the BM, we asked whether deletion of U2af1 insulted the genome and induced apoptosis to hematopoietic cells in the BM. We observed significantly increased apoptosis in the total BM as wells as in c-kit+, Gr1+, Ter119+and CD41+cells suggesting that hematopoietic progenitors and precursors of multiple cell lineages underwent apoptosis upon U2af1 deletion. We also performed gamma-H2AX assay using imaging flow cytometry to evaluate DNA damage in total BM, Gr1+(myeloid) and CD71+(erythroid) cells in control and U2af1-deleted mice. We observed markedly elevated gamma-H2AX in total BM, Gr1+and CD71+cells from U2af1-deficient mice compared with control mice.In addition, we observed increased Chk1 phosphorylation (ser345), a hallmark for activation of the ATR pathway, and increased histone H2A K119 ubiquitination (H2AK119Ub), a marker for DNA damage response, in the BM of U2af1-deficient mice. Thus, depletion of U2af1 causes insult to the genome and induces DNA damage and increased cell death. To gain insights into severe hematopoietic defects observed in U2af1-deficient mice, we performed transcriptome profiling of sorted LSK cells from U2af1 wild type (control) and U2af1-deleted mice. GSEA analysis of RNA sequencing data revealed significant downregulation of genes related to HSC maintenance in U2af1-deficient LSK. GSEA also revealed enrichment for cell cycle and DNA damage response-related genes, consistent with decreased proliferation and increased DNA damage and apoptosis observed in U2af1-deficient hematopoietic progenitors. We also determined the effects of U2af1 deletion on RNA splicing. Interestingly, we observed significant changes in gene expression as well as splicing alterations in several genes important for HSC survival and function. In conclusion, our results suggest a crucial role for U2af1 in the survival and function of HSC. Disclosures Mohi: Tolero Pharmaceuticals Inc.: Research Funding.

Regulation of hair follicle development by the TNF signal ectodysplasin and its receptor Edar

Development ◽  
2002 ◽  
Vol 129 (10) ◽  
pp. 2541-2553 ◽  
Author(s):  
Johanna Laurikkala ◽  
Johanna Pispa ◽  
Han-Sung Jung ◽  
Pekka Nieminen ◽  
Marja Mikkola ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Hair Follicles ◽  
Wild Type ◽  
Mutant Mouse Embryos ◽  
Anhidrotic Ectodermal Dysplasia ◽  
Embryonic Morphogenesis ◽  
Hair Follicle Development ◽  
And Function ◽  
Insight Into

X-linked and autosomal forms of anhidrotic ectodermal dysplasia syndromes (HED) are characterized by deficient development of several ectodermal organs, including hair, teeth and exocrine glands. The recent cloning of the genes that underlie these syndromes, ectodysplasin (ED1) and the ectodysplasin A receptor (EDAR), and their identification as a novel TNF ligand-receptor pair suggested a role for TNF signaling in embryonic morphogenesis. In the mouse, the genes of the spontaneous mutations Tabby (Ta) and downless (dl) were identified as homologs of ED1 and EDAR, respectively. To gain insight into the function of this signaling pathway in development of skin and hair follicles, we analyzed the expression and regulation of Eda and Edar in wild type as well as Tabby and Lef1 mutant mouse embryos. We show that Eda and Edar expression is confined to the ectoderm and occurs in a pattern that suggests a role of ectodysplasin/Edar signaling in the interactions between the ectodermal compartments and the formation and function of hair placodes. By using skin explant cultures, we further show that this signaling pathway is intimately associated with interactions between the epithelial and mesenchymal tissues. We also find that Ta mutants lack completely the placodes of the first developing tylotrich hairs, and that they do not show patterned expression of placodal genes, including Bmp4, Lef1, Shh, Ptch and Edar, and the genes for β-catenin and activin A. Finally, we identified activin as a mesenchymal signal that stimulates Edar expression and WNT as a signal that induces Eda expression, suggesting a hierarchy of distinct signaling pathways in the development of skin and hair follicles. In conclusion, we suggest that Eda and Edar are associated with the onset of ectodermal patterning and that ectodysplasin/edar signaling also regulates the morphogenesis of hair follicles.

scholarly journals TLR7 modulating B-cell immune responses in the spleen of C57BL/6 mice infected with Schistosoma japonicum

2021 ◽  
Vol 15 (11) ◽  
pp. e0009943
Author(s):  
Haixia Wei ◽  
Hongyan Xie ◽  
Jiale Qu ◽  
Anqi Xie ◽  
Shihao Xie ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Gene Knockout ◽  
Innate Immune ◽  
Wild Type ◽  
Cell Responses ◽  
Splenic Cells ◽  
And Function ◽  
Egg Antigen

B cells played an important role in Schistosoma infection-induced diseases. TLR7 is an intracellular member of the innate immune receptor. The role of TLR7 on B cells mediated immune response is still unclear. Here, C57BL/6 mice were percutaneously infected by S. japonicum for 5–6 weeks. The percentages and numbers of B cells increased in the infected mice (p < 0.05), and many activation and function associated molecules were also changed on B cells. More splenic cells of the infected mice expressed TLR7, and B cells were served as the main cell population. Moreover, a lower level of soluble egg antigen (SEA) specific antibody and less activation associated molecules were found on the surface of splenic B cells from S. japonicum infected TLR7 gene knockout (TLR7 KO) mice compared to infected wild type (WT) mice (p < 0.05). Additionally, SEA showed a little higher ability in inducing the activation of B cells from naive WT mice than TLR7 KO mice (p < 0.05). Finally, the effects of TLR7 on B cells are dependent on the activation of NF-κB p65. Altogether, TLR7 was found modulating the splenic B cell responses in S. japonicum infected C57BL/6 mice.

PSGL-1 regulates platelet P-selectin-mediated endothelial activation and shedding of P-selectin from activated platelets

2007 ◽  
Vol 98 (10) ◽  
pp. 806-812 ◽  
Author(s):  
Vandana Dole ◽  
Wolfgang Bergmeier ◽  
Ian Patten ◽  
Junichi Hirahashi ◽  
Tanya Mayadas ◽  
...  
Keyword(s):  
Endothelial Activation ◽  
Leukocyte Rolling ◽  
Wild Type ◽  
Platelet Surface ◽  
Activated Platelets ◽  
And Function ◽  
Body Secretion

SummaryWe have previously shown that activated platelets in circulation stimulate release of endothelial Weibel-Palade bodies thus increasing leukocyte rolling in venules. P-selectin on the activated platelets mediates adhesion to leukocytes via PSGL-1 and is rapidly shed into plasma. We were interested in studying the role of PSGL-1 in regulating expression and function of platelet P-selectin. We show here that PSGL-1 is critical for the activation of endothelial cells in venules of mice infused with activated platelets. The interaction of platelet P-selectin with PSGL-1 is also required for P-selectin shedding, as P-selectin was retained significantly longer on the surface of activated platelets infused into PSGL-1-/- compared to wild-type mice. The leukocyte integrin αMβ2 (Mac-1) was not required for P-selectin shedding. In addition to shedding, P-selectin can be downregulated from the platelet surface through internalization and this is the predominant mechanism in the absence of PSGL-1. We demonstrate that leukocyte- neutrophil elastase,known to cleave P-selectin in vitro, is not the major sheddase for P-selectin in vivo. In conclusion, interaction of platelet P-selectin with PSGL-1 is crucial for activation of the endothelium andWeibel-Palade body secretion. The interaction with PSGL-1 also results in rapid shedding of P-selectin thus downregulating the inflammatory potential of the platelet.

scholarly journals Roles of Autophagy in Oxidative Stress

2020 ◽  
Vol 21 (9) ◽  
pp. 3289 ◽  
Author(s):  
Hyeong Rok Yun ◽  
Yong Hwa Jo ◽  
Jieun Kim ◽  
Yoonhwa Shin ◽  
Sung Soo Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Stress Responses ◽  
Basic Mechanism ◽  
Redox Signalling ◽  
Mitochondrial Ros ◽  
Related Stress ◽  
And Function ◽  
Catabolic Process

Autophagy is a catabolic process for unnecessary or dysfunctional cytoplasmic contents by lysosomal degradation pathways. Autophagy is implicated in various biological processes such as programmed cell death, stress responses, elimination of damaged organelles and development. The role of autophagy as a crucial mediator has been clarified and expanded in the pathological response to redox signalling. Autophagy is a major sensor of the redox signalling. Reactive oxygen species (ROS) are highly reactive molecules that are generated as by-products of cellular metabolism, principally by mitochondria. Mitochondrial ROS (mROS) are beneficial or detrimental to cells depending on their concentration and location. mROS function as redox messengers in intracellular signalling at physiologically low level, whereas excessive production of mROS causes oxidative damage to cellular constituents and thus incurs cell death. Hence, the balance of autophagy-related stress adaptation and cell death is important to comprehend redox signalling-related pathogenesis. In this review, we attempt to provide an overview the basic mechanism and function of autophagy in the context of response to oxidative stress and redox signalling in pathology.

scholarly journals miR-221 and miR-155 regulate human dendritic cell development, apoptosis, and IL-12 production through targeting of p27kip1, KPC1, and SOCS-1

Blood ◽  
2011 ◽  
Vol 117 (16) ◽  
pp. 4293-4303 ◽  
Author(s):  
Changming Lu ◽  
Xin Huang ◽  
Xiaoxiao Zhang ◽  
Kristin Roensch ◽  
Qing Cao ◽  
...  
Keyword(s):  
Cytokine Signaling ◽  
Wild Type ◽  
Suppressor Of Cytokine Signaling ◽  
Hematopoietic Progenitor ◽  
Monocyte Differentiation ◽  
P27kip1 Protein ◽  
And Function ◽  
Antigen Presenting ◽  
Dc Maturation

Abstract Dendritic cells (DCs) are potent antigen-presenting cells derived from hematopoietic progenitor cells and circulating monocytes. To investigate the role of microRNAs (miRNAs) during DC differentiation, maturation, and function, we profiled miRNA expression in human monocytes, immature DCs (imDCs), and mature DCs (mDCs). Stage-specific, differential expression of 27 miRNAs was found during monocyte differentiation into imDCs and mDCs. Among them, decreased miR-221 and increased miR-155 expression correlated with p27kip1 accumulation in DCs. Silencing of miR-221 or overexpressing of miR-155 in DCs resulted in p27kip1 protein increase and DC apoptosis. Moreover, mDCs from miR-155−/− mice were less apoptotic than those from wild-type mice. Silencing of miR-155 expression had little effect on DC maturation but reduced IL-12p70 production, whereas miR-155 overexpression in mDCs enhanced IL-12p70 production. Kip1 ubiquitination-promoting complex 1, suppressor of cytokine signaling 1, and CD115 (M-CSFR) were functional targets of miR-155. Furthermore, we provide evidence that miR-155 indirectly regulated p27kip1 protein level by targeting Kip1 ubiquitination-promoting complex 1. Thus, our study uncovered miRNA signatures during monocyte differentiation into DCs and the new regulatory role of miR-221 and miR-155 in DC apoptosis and IL-12p70 production.

scholarly journals Deficiency in the double-stranded RNA binding protein HYPONASTIC LEAVES1 increases sensitivity to the endoplasmic reticulum stress inducer tunicamycin in Arabidopsis

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Rikako Hirata ◽  
Kei-ichiro Mishiba ◽  
Nozomu Koizumi ◽  
Yuji Iwata
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Stress Responses ◽  
Rna Binding ◽  
Transcriptional Response ◽  
Mirna Biogenesis ◽  
Loss Of Function ◽  
Wild Type ◽  
Protein Coding ◽  
And Function

Abstract Objective microRNA (miRNA) is a small non-coding RNA that regulates gene expression by sequence-dependent binding to protein-coding mRNA in eukaryotic cells. In plants, miRNA plays important roles in a plethora of physiological processes, including abiotic and biotic stress responses. The present study was conducted to investigate whether miRNA-mediated regulation is important for the endoplasmic reticulum (ER) stress response in Arabidopsis. Results We found that hyl1 mutant plants are more sensitive to tunicamycin, an inhibitor of N-linked glycosylation that causes ER stress than wild-type plants. Other miRNA-related mutants, se and ago1, exhibited similar sensitivity to the wild-type, indicating that the hypersensitive phenotype is attributable to the loss-of-function of HYL1, rather than deficiency in general miRNA biogenesis and function. However, the transcriptional response of select ER stress-responsive genes in hyl1 mutant plants was indistinguishable from that of wild-type plants, suggesting that the loss-of-function of HYL1 does not affect the ER stress signaling pathways.

scholarly journals Cerebrovascular Changes and Neurodegeneration Related to Hyperlipidemia: Characteristics of the Human ApoB-100 Transgenic Mice

2020 ◽  
Vol 26 (13) ◽  
pp. 1486-1494 ◽  
Author(s):  
Melinda E. Tóth ◽  
Brigitta Dukay ◽  
Zsófia Hoyk ◽  
Miklós Sántha
Keyword(s):  
Transgenic Mouse ◽  
Serum Lipid ◽  
Lipoprotein Metabolism ◽  
Transgenic Mouse Models ◽  
Wild Type ◽  
Lipid Levels ◽  
Cerebrovascular Lesions ◽  
Wide Range ◽  
And Function

Serum lipid levels are closely related to the structure and function of blood vessels. Chronic hyperlipidemia may lead to damage in both the cardio- and the cerebrovascular systems. Vascular dysfunctions, including impairments of the blood-brain barrier, are known to be associated with neurodegenerative diseases. A growing number of evidence suggests that cardiovascular risk factors, such as hyperlipidemia, may increase the likelihood of developing dementia. Due to differences in lipoprotein metabolism, wild-type mice are protected against dietinduced hypercholesterolemia, and their serum lipid profile is different from that observed in humans. Therefore, several transgenic mouse models have been established to study the role of different apolipoproteins and their receptors in lipid metabolism, as well as the complications related to pathological lipoprotein levels. This minireview focused on a transgenic mouse model overexpressing an apolipoprotein, the human ApoB-100. We discussed literature data and current advancements on the understanding of ApoB-100 induced cardio- and cerebrovascular lesions in order to demonstrate the involvement of this type of apolipoprotein in a wide range of pathologies, and a link between hyperlipidemia and neurodegeneration.

scholarly journals Factor XII in PMM2-CDG patients: role of N-glycosylation in the secretion and function of the first element of the contact pathway

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Raquel López-Gálvez ◽  
María Eugenia de la Morena-Barrio ◽  
Alberto López-Lera ◽  
Monika Pathak ◽  
Antonia Miñano ◽  
...  
Keyword(s):  
Factor Xii ◽  
Clinical Effects ◽  
Wild Type ◽  
Vascular Events ◽  
Contact Phase ◽  
Glycosylation Sites ◽  
Expression Model ◽  
Contact Pathway ◽  
And Function

Abstract Background Congenital disorders of glycosylation (CDG) are rare diseases with impaired glycosylation and multiorgan disfunction, including hemostatic and inflammatory disorders. Factor XII (FXII), the first element of the contact phase, has an emerging role in hemostasia and inflammation. FXII deficiency protects against thrombosis and the p.Thr309Lys variant is involved in hereditary angioedema through the hyperreactivity caused by the associated defective O-glycosylation. We studied FXII in CDG aiming to supply further information of the glycosylation of this molecule, and its functional and clinical effects. Plasma FXII from 46 PMM2-CDG patients was evaluated by coagulometric and by Western Blot in basal conditions, treated with N-glycosydase F or activated by silica or dextran sulfate. A recombinant FXII expression model was used to validate the secretion and glycosylation of wild-type and variants targeting the two described FXII N-glycosylation sites (p.Asn230Lys; p.Asn414Lys) as well as the p.Thr309Lys variant. Results PMM2-CDG patients had normal FXII levels (117%) but high proportions of a form lacking N-glycosylation at Asn414. Recombinant FXII p.Asn230Lys, and p.Asn230Lys&p.Asn414Lys had impaired secretion and increased intracellular retention compared to wild-type, p.Thr309Lys and p.Asn414Lys variants. The hypoglycosylated form of PMM2-CDG activated similarly than FXII fully glycosylated. Accordingly, no PMM2-CDG had angioedema. FXII levels did not associate to vascular events, but hypoglycosylated FXII, like hypoglycosylated transferrin, antithrombin and FXI levels did it. Conclusions N-glycosylation at Asn230 is essential for FXII secretion. PMM2-CDG have high levels of FXII lacking N-glycosylation at Asn414, but this glycoform displays similar activation than fully glycosylated, explaining the absence of angioedema in CDG.

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