scholarly journals Blastocyst implantation failure relates to impaired translational machinery gene expression

Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Vicki Plaks ◽  
Eran Gershon ◽  
Amit Zeisel ◽  
Jasmine Jacob-Hirsch ◽  
Michal Neeman ◽  
...  

Oocyte quality is a well-established determinant of embryonic fate. However, the molecular participants and biological markers that affect and may predict adequate embryonic development are largely elusive. Our aim was to identify the components of the oocyte molecular machinery that part take in the production of a healthy embryo. For this purpose, we used an animal model, generated by us previously, the oocytes of which do not express Cx43 (Cx43del/del). In these mice, oogenesis appears normal, fertilisation does occur, early embryonic development is successful but implantation fails. We used magnetic resonance imaging analysis combined with histological examination to characterise the embryonic developmental incompetence. Reciprocal embryo transfer confirmed that the blastocyst evolved from the Cx43del/deloocyte is responsible for the implantation disorder. In order to unveil the genes, the impaired expression of which brings about the development of defective embryos, we carried out a genomic screening of both the oocytes and the resulting blastocysts. This microarray analysis revealed a low expression ofEgr1,Rpl21andEif4a1in Cx43del/deloocytes and downregulation ofRpl15andEif4g2in the resulting blastocysts. We propose that global deficiencies in genes related to the expression of ribosomal proteins and translation initiation factors in apparently normal oocytes bring about accumulation of defects, which significantly compromise their developmental capacity. The blastocysts resulting from such oocytes, which grow within a confined space until implantation, may be unable to generate enough biological mass to allow their expansion. This information could be implicated to diagnosis and treatment of infertility, particularly to IVF.

2019 ◽  
Author(s):  
Ethan LaFontaine ◽  
Clare M. Miller ◽  
Natasha Permaul ◽  
Alex G. Johnson ◽  
Elliot T. Martin ◽  
...  

AbstractViruses have evolved various strategies to ensure efficient translation using host cell ribosomes and translation factors. In addition to cleaving translation initiation factors required for host cell translation, poliovirus (PV) uses an internal ribosome entry site (IRES) to bypass the need for these translation initiation factors. Recent studies also suggest that viruses have evolved to exploit specific ribosomal proteins to enhance translation of their viral proteins. The ribosomal protein receptor for activated C kinase 1 (RACK1), a protein of the 40S ribosomal subunit, was previously shown to mediate translation of the 5′ cricket paralysis virus and hepatitis C virus IRESs. Here we found that while translation of a PV dual-luciferase reporter shows only a moderate dependence on RACK1, PV translation in the context of a viral infection is drastically reduced. We observed significantly reduced poliovirus plaque size and a delayed host cell translational shut-off suggesting that loss of RACK1 increases the length of the virus life cycle. Our findings further illustrate the involvement of the cellular translational machinery in PV infection and how viruses usurp the function of specific ribosomal proteins.


2020 ◽  
Vol 21 (4) ◽  
pp. 1254 ◽  
Author(s):  
Tomas Masek ◽  
Edgar del Llano ◽  
Lenka Gahurova ◽  
Michal Kubelka ◽  
Andrej Susor ◽  
...  

Meiotic maturation of oocyte relies on pre-synthesised maternal mRNA, the translation of which is highly coordinated in space and time. Here, we provide a detailed polysome profiling protocol that demonstrates a combination of the sucrose gradient ultracentrifugation in small SW55Ti tubes with the qRT-PCR-based quantification of 18S and 28S rRNAs in fractionated polysome profile. This newly optimised method, named Scarce Sample Polysome Profiling (SSP-profiling), is suitable for both scarce and conventional sample sizes and is compatible with downstream RNA-seq to identify polysome associated transcripts. Utilising SSP-profiling we have assayed the translatome of mouse oocytes at the onset of nuclear envelope breakdown (NEBD)—a developmental point, the study of which is important for furthering our understanding of the molecular mechanisms leading to oocyte aneuploidy. Our analyses identified 1847 transcripts with moderate to strong polysome occupancy, including abundantly represented mRNAs encoding mitochondrial and ribosomal proteins, proteasomal components, glycolytic and amino acids synthetic enzymes, proteins involved in cytoskeleton organization plus RNA-binding and translation initiation factors. In addition to transcripts encoding known players of meiotic progression, we also identified several mRNAs encoding proteins of unknown function. Polysome profiles generated using SSP-profiling were more than comparable to those developed using existing conventional approaches, being demonstrably superior in their resolution, reproducibility, versatility, speed of derivation and downstream protocol applicability.


2004 ◽  
Vol 32 (4) ◽  
pp. 589-591 ◽  
Author(s):  
K.S. Browning

Plants have significant differences in some of the ‘parts’ of the translational machinery. There are two forms of eukaryotic initiation factor (eIF) 4F, eIF3 has two novel subunits, eIF4B is poorly conserved, and eIF2 kinases and eIF4E binding proteins (4E-BP) are yet to be discovered. These differences suggest that plants may regulate their translation in unique ways.


2012 ◽  
Vol 23 (18) ◽  
pp. 3499-3510 ◽  
Author(s):  
Lucas C. Reineke ◽  
Jon D. Dougherty ◽  
Philippe Pierre ◽  
Richard E. Lloyd

Stress granules are large messenger ribonucleoprotein (mRNP) aggregates composed of translation initiation factors and mRNAs that appear when the cell encounters various stressors. Current dogma indicates that stress granules function as inert storage depots for translationally silenced mRNPs until the cell signals for renewed translation and stress granule disassembly. We used RasGAP SH3-binding protein (G3BP) overexpression to induce stress granules and study their assembly process and signaling to the translation apparatus. We found that assembly of large G3BP-induced stress granules, but not small granules, precedes phosphorylation of eIF2α. Using mouse embryonic fibroblasts depleted for individual eukaryotic initiation factor 2α (eIF2α) kinases, we identified protein kinase R as the principal kinase that mediates eIF2α phosphorylation by large G3BP-induced granules. These data indicate that increasing stress granule size is associated with a threshold or switch that must be triggered in order for eIF2α phosphorylation and subsequent translational repression to occur. Furthermore, these data suggest that stress granules are active in signaling to the translational machinery and may be important regulators of the innate immune response.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Dessie Salilew-Wondim ◽  
Dawit Tesfaye ◽  
Franca Rings ◽  
Eva Held-Hoelker ◽  
Dennis Miskel ◽  
...  

Abstract Background Morphological evaluation of embryos has been used to screen embryos for transfer. However, the repeatability and accuracy of this method remains low. Thus, evaluation of an embryo’s gene expression signature with respect to its developmental capacity could provide new opportunities for embryo selection. Since the gene expression outline of an embryo is considered as an aggregate of its intrinsic characteristics and culture conditions, we have compared transcriptome profiles of in vivo and in vitro derived blastocysts in relation to pregnancy outcome to unravel the discrete effects of developmental competence and environmental conditions on bovine embryo gene expression outlines. To understand whether the gene expression patterns could be associated with blastocyst developmental competency, the global transcriptome profile of in vivo (CVO) and in vitro (CVT) derived competent blastocysts that resulted in pregnancy was investigated relative to that of in vivo (NVO) and in vitro (NVT) derived blastocysts which did not establish initial pregnancy, respectively while to unravel the effects of culture condition on the transcriptome profile of embryos, the transcriptional activity of the CVO group was compared to the CVT group and the NVO group was compared to the NVT ones. Results A total of 700 differentially expressed genes (DEGs) were identified between CVO and NVO blastocysts. These gene transcripts represent constitutive regions, indel variants, 3′-UTR sequence variants and novel transcript regions. The majority (82%) of these DEGs, including gene clusters like ATP synthases, eukaryotic translation initiation factors, ribosomal proteins, mitochondrial ribosomal proteins, NADH dehydrogenase and cytochrome c oxidase subunits were enriched in the CVO group. These DEGs were involved in pathways associated with glycolysis/glycogenesis, citrate acid cycle, pyruvate metabolism and oxidative phosphorylation. Similarly, a total of 218 genes were differentially expressed between CVT and NVT groups. Of these, 89%, including TPT1, PDIA6, HSP90AA1 and CALM, were downregulated in the CVT group and those DEGs were overrepresented in pathways related to protein processing, endoplasmic reticulum, spliceasome, ubiquitone mediated proteolysis and steroid biosynthesis. On the other hand, although both the CVT and CVO blastocyst groups resulted in pregnancy, a total of 937 genes were differential expressed between the two groups. Compared to CVO embryos, the CVT ones exhibited downregulation of gene clusters including ribosomal proteins, mitochondrial ribosomal protein, eukaryotic translation initiation factors, ATP synthases, NADH dehydrogenase and cytochrome c oxidases. Nonetheless, downregulation of these genes could be associated with pre and postnatal abnormalities observed after transfer of in vitro embryos. Conclusion The present study provides a detailed inventory of differentially expressed gene signatures and pathways specifically reflective of the developmental environment and future developmental capacities of bovine embryos suggesting that transcriptome activity observed in blastocysts could be indicative of further pregnancy success but also adaptation to culture environment.


2020 ◽  
Vol 19 (4) ◽  
pp. 640-654 ◽  
Author(s):  
Mona Radwan ◽  
Ching-Seng Ang ◽  
Angelique R. Ormsby ◽  
Dezerae Cox ◽  
James C. Daly ◽  
...  

C9ORF72-associated Motor Neuron Disease patients feature abnormal expression of 5 dipeptide repeat (DPR) polymers. Here we used quantitative proteomics in a mouse neuronal-like cell line (Neuro2a) to demonstrate that the Arg residues in the most toxic DPRS, PR and GR, leads to a promiscuous binding to the proteome compared with a relative sparse binding of the more inert AP and GA. Notable targets included ribosomal proteins, translation initiation factors and translation elongation factors. PR and GR comprising more than 10 repeats appeared to robustly stall on ribosomes during translation suggesting Arg-rich peptide domains can electrostatically jam the ribosome exit tunnel during synthesis. Poly-GR also recruited arginine methylases, induced hypomethylation of endogenous proteins, and induced a profound destabilization of the actin cytoskeleton. Our findings point to arginine in GR and PR polymers as multivalent toxins to translation as well as arginine methylation that may explain the dysfunction of biological processes including ribosome biogenesis, mRNA splicing and cytoskeleton assembly.


2021 ◽  
Author(s):  
Ekaterina Borvinskaya ◽  
Albina Kochneva ◽  
Polina Drozdova ◽  
Olga Balan ◽  
Victor Zgoda

The protein composition (proteome) of cestode Schistocephalus solidus was measured in an experiment simulating the transition of the parasite from a cold-blooded to a warm-blooded host. Infective S. solidus plerocercoids obtained from the three-spined stickleback Gasterosteus aculeatus were heated at 40 °C for 1 hour or cultured in vitro at 40 °C and 22 °C for 48 hours. In short-term experiment, the content of only one tegument protein was evidenced to decrease after heating. After long-term heating, which triggered parasite sexual maturation, an increase in the content of ribosomal proteins, translation initiation factors and enzymes of the amino acid biosynthesis pathway was observed. The synthesis of certain gene products for carbohydrate metabolism, including glycolysis/gluconeogenesis, was found to be regulated in parasite by temperature.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Hao ◽  
Yawen Chen ◽  
Xiumin Yan ◽  
Xueliang Zhu

AbstractCilia are microtubule-based hair-like organelles propelling locomotion and extracellular liquid flow or sensing environmental stimuli. As cilia are diffusion barrier-gated subcellular compartments, their protein components are thought to come from the cell body through intraflagellar transport or diffusion. Here we show that cilia locally synthesize proteins to maintain their structure and functions. Multicilia of mouse ependymal cells are abundant in ribosomal proteins, translation initiation factors, and RNA, including 18 S rRNA and tubulin mRNA. The cilia actively generate nascent peptides, including those of tubulin. mRNA-binding protein Fmrp localizes in ciliary central lumen and appears to function in mRNA delivery into the cilia. Its depletion by RNAi impairs ciliary local translation and induces multicilia degeneration. Expression of exogenous Fmrp, but not an isoform tethered to mitochondria, rescues the degeneration defects. Therefore, local translation defects in cilia might contribute to the pathology of ciliopathies and other diseases such as Fragile X syndrome.


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