scholarly journals Elavl1 Impacts Osteogenic Differentiation and mRNA Levels of Genes Involved in ECM Organization

Author(s):  
Satya K. Kota ◽  
Zhu Wei Lim ◽  
Savithri B. Kota

Posttranscriptional gene regulation by Adenylate Uridylate (AU) rich element RNA binding protein, Elavl1 has been implicated in embryonic development as well as progenitor cell differentiation. Elavl1 binds to hundreds of cellular messenger RNAs predominantly through interactions with AU-rich elements (AREs) found in the untranslated regions (UTRs) and functions by regulating their stability. Biological functions of Elavl1 during osteogenic differentiation of bone marrow derived mesenchymal stem cells is not well-understood. Here we report that specific knockdown of nuclear localized Elavl1 by RNA interference in multipotent BMSCs led to increased osteogenic differentiation. Differential gene expression analysis following unbiased total RNA sequencing upon Elavl1 depletion during osteogenic differentiation of BMSCs showed increased levels of multiple mRNAs that are involved in extracellular matrix organization. We further show that many of these mRNAs contain Elavl1 binding consensus motifs that are preserved in their 3′ UTRs. RNA stability analyses indicated that depletion of Elavl1 prolongs the steady state RNA levels of several of these mRNAs. Together, our data points to Elavl1 mediated negative regulation of multiple genes involved in ECM organization that play a functional role in MSC osteogenic differentiation.

2010 ◽  
Vol 38 (6) ◽  
pp. 1621-1626 ◽  
Author(s):  
Florencia Cano ◽  
Diego Miranda-Saavedra ◽  
Paul J. Lehner

Non-coding RNAs and their interaction with RNA-binding proteins regulate mRNA levels in key cellular processes. This has intensified interest in post-transcriptional regulation. Recent studies on the turnover of AU-rich cytokine mRNAs have linked mRNA metabolism with ubiquitination. Ubiquitin is well recognized for its role in protein regulation/degradation. In the present paper, we describe a new group of RNA-binding E3 ubiquitin ligases which are predicted to bind and regulate RNA stability. Although much effort has been focused on understanding the role of these proteins as key regulators of mRNA turnover, the requirement for E3 ligase activity in mRNA decay remains unclear. It is remarkable that the ubiquitin system is involved, either directly or indirectly, in both the degradation of nucleic acids as well as proteins. These new RNA-binding E3 ligases are potential candidates which link two important cellular regulatory pathways: the regulation of both protein and mRNA stability.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Rui-Chao Chai ◽  
Yu-Zhou Chang ◽  
Xin Chang ◽  
Bo Pang ◽  
Song Yuan An ◽  
...  

Abstract Background The prognosis for diffuse gliomas is very poor and the mechanism underlying their malignant progression remains unclear. Here, we aimed to elucidate the role and mechanism of the RNA N6,2′-O-dimethyladenosine (m6A) reader, YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), in regulating the malignant progression of gliomas. Methods YTHDF2 mRNA levels and functions were assessed using several independent datasets. Western blotting, quantitative polymerase chain reaction, and immunohistochemistry were used to evaluate the expression levels of YTHDF2 and other molecules in human and mouse tumor tissues and cells. Knockdown and overexpression were used to evaluate the effects of YTHDF2, methyltransferase-like 3 (METTL3), and UBX domain protein 1 (UBXN1) on glioma malignancy in cell and orthotopic xenograft models. RNA immunoprecipitation (RIP), methylated RIP, and RNA stability experiments were performed to study the mechanisms underlying the oncogenic role of YTHDF2. Results YTHDF2 expression was positively associated with a higher malignant grade and molecular subtype of glioma and poorer prognosis. YTHDF2 promoted the malignant progression of gliomas in both in vitro and in vivo models. Mechanistically, YTHDF2 accelerated UBXN1 mRNA degradation via METTL3-mediated m6A, which, in turn, promoted NF-κB activation. We further revealed that UBXN1 overexpression attenuated the oncogenic effect of YTHDF2 overexpression and was associated with better survival in patients with elevated YTHDF2 expression. Conclusions Our findings confirmed that YTHDF2 promotes the malignant progression of gliomas and revealed important insight into the upstream regulatory mechanism of NF-κB activation via UBXN1 with a primary focus on m6A modification.


2021 ◽  
Vol 7 ◽  
Author(s):  
Pilar Menendez-Gil ◽  
Alejandro Toledo-Arana

Bacterial messenger RNAs (mRNAs) are composed of 5′ and 3′ untranslated regions (UTRs) that flank the coding sequences (CDSs). In eukaryotes, 3′UTRs play key roles in post-transcriptional regulatory mechanisms. Shortening or deregulation of these regions is associated with diseases such as cancer and metabolic disorders. Comparatively, little is known about the functions of 3′UTRs in bacteria. Over the past few years, 3′UTRs have emerged as important players in the regulation of relevant bacterial processes such as virulence, iron metabolism, and biofilm formation. This MiniReview is an update for the different 3′UTR-mediated mechanisms that regulate gene expression in bacteria. Some of these include 3′UTRs that interact with the 5′UTR of the same transcript to modulate translation, 3′UTRs that are targeted by specific ribonucleases, RNA-binding proteins and small RNAs (sRNAs), and 3′UTRs that act as reservoirs of trans-acting sRNAs, among others. In addition, recent findings regarding a differential evolution of bacterial 3′UTRs and its impact in the species-specific expression of orthologous genes are also discussed.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aijun Qiao ◽  
Junlan Zhou ◽  
Shiyue Xu ◽  
Wenxia Ma ◽  
Chan Boriboun ◽  
...  

AbstractHepatic gluconeogenesis is essential for glucose homeostasis and also a therapeutic target for type 2 diabetes, but its mechanism is incompletely understood. Here, we report that Sam68, an RNA-binding adaptor protein and Src kinase substrate, is a novel regulator of hepatic gluconeogenesis. Both global and hepatic deletions of Sam68 significantly reduce blood glucose levels and the glucagon-induced expression of gluconeogenic genes. Protein, but not mRNA, levels of CRTC2, a crucial transcriptional regulator of gluconeogenesis, are >50% lower in Sam68-deficient hepatocytes than in wild-type hepatocytes. Sam68 interacts with CRTC2 and reduces CRTC2 ubiquitination. However, truncated mutants of Sam68 that lack the C- (Sam68ΔC) or N-terminal (Sam68ΔN) domains fails to bind CRTC2 or to stabilize CRTC2 protein, respectively, and transgenic Sam68ΔN mice recapitulate the blood-glucose and gluconeogenesis profile of Sam68-deficient mice. Hepatic Sam68 expression is also upregulated in patients with diabetes and in two diabetic mouse models, while hepatocyte-specific Sam68 deficiencies alleviate diabetic hyperglycemia and improves insulin sensitivity in mice. Thus, our results identify a role for Sam68 in hepatic gluconeogenesis, and Sam68 may represent a therapeutic target for diabetes.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vikram Agarwal ◽  
Sereno Lopez-Darwin ◽  
David R. Kelley ◽  
Jay Shendure

Abstract3′ untranslated regions (3′ UTRs) post-transcriptionally regulate mRNA stability, localization, and translation rate. While 3′-UTR isoforms have been globally quantified in limited cell types using bulk measurements, their differential usage among cell types during mammalian development remains poorly characterized. In this study, we examine a dataset comprising ~2 million nuclei spanning E9.5–E13.5 of mouse embryonic development to quantify transcriptome-wide changes in alternative polyadenylation (APA). We observe a global lengthening of 3′ UTRs across embryonic stages in all cell types, although we detect shorter 3′ UTRs in hematopoietic lineages and longer 3′ UTRs in neuronal cell types within each stage. An analysis of RNA-binding protein (RBP) dynamics identifies ELAV-like family members, which are concomitantly induced in neuronal lineages and developmental stages experiencing 3′-UTR lengthening, as putative regulators of APA. By measuring 3′-UTR isoforms in an expansive single cell dataset, our work provides a transcriptome-wide and organism-wide map of the dynamic landscape of alternative polyadenylation during mammalian organogenesis.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lizhen Liu ◽  
Kaimin Hu ◽  
Jingjing Feng ◽  
Huafang Wang ◽  
Shan Fu ◽  
...  

Abstract Background Isocitrate dehydrogenase (IDH1/2) gene mutations are the most frequently observed mutations in cartilaginous tumors. The mutant IDH causes elevation in the levels of R-enantiomer of 2-hydroxylglutarate (R-2HG). Mesenchymal stromal cells (MSCs) are reasonable precursor cell candidates of cartilaginous tumors. This study aimed to investigate the effect of oncometabolite R-2HG on MSCs. Methods Human bone marrow MSCs treated with or without R-2HG at concentrations 0.1 to 1.5 mM were used for experiments. Cell Counting Kit-8 was used to detect the proliferation of MSCs. To determine the effects of R-2HG on MSC differentiation, cells were cultured in osteogenic, chondrogenic and adipogenic medium. Specific staining approaches were performed and differentiation-related genes were quantified. Furthermore, DNA methylation status was explored by Illumina array-based arrays. Real-time PCR was applied to examine the signaling component mRNAs involved in. Results R-2HG showed no influence on the proliferation of human MSCs. R-2HG blocked osteogenic differentiation, whereas promoted adipogenic differentiation of MSCs in a dose-dependent manner. R-2HG inhibited chondrogenic differentiation of MSCs, but increased the expression of genes related to chondrocyte hypertrophy in a lower concentration (1.0 mM). Moreover, R-2HG induced a pronounced DNA hypermethylation state of MSC. R-2HG also improved promotor methylation of lineage-specific genes during osteogenic and chondrogenic differentiation. In addition, R-2HG induced hypermethylation and decreased the mRNA levels of SHH, GLI1and GLI2, indicating Sonic Hedgehog (Shh) signaling inhibition. Conclusions The oncometabolite R-2HG dysregulated the chondrogenic and osteogenic differentiation of MSCs possibly via induction of DNA hypermethylation, improving the role of R-2HG in cartilaginous tumor development.


2021 ◽  
Vol 11 (9) ◽  
pp. 1774-1779
Author(s):  
Feng Sun ◽  
Tianwen Huang ◽  
Jianhui Shi ◽  
Tianli Wei ◽  
Haiwei Zhang

Osteoactivin (OA) plays a key role in osteogenic differentiation. miR-26b is elevated in the bone formation process of BMSCs, but whether it is involved in this process is unclear. Bone formation is regulated by FLT3/AXL signaling pathway, which may be a potential target of miR-26b. qRT-PCR detected miR-26b mRNA levels and bone formation-related genes or FLT3/AXL signaling pathway-related genes. Bone formation was analyzed by staining and FLT3/AXL signaling was evaluated along with analysis of miR-26b’s relation with LT3/AXL. miR-26b was significantly elevated in OA-induced bone formation of BMSCs, which can be promoted by miR-26b mimics. When miR-26b was overexpressed, FLT3/AXL signaling pathway was activated. miR-26b can ameliorate Dex-induced osteo-inhibition. miR-26b promotes bone formation of BMSCs by directly targeting FLT3/AXL signaling pathway, suggesting that miR-26b might be a target for inducing osteogenic differentiation.


2003 ◽  
Vol 23 (19) ◽  
pp. 7055-7067 ◽  
Author(s):  
Shelly A. Waggoner ◽  
Stephen A. Liebhaber

ABSTRACT Posttranscriptional controls in higher eukaryotes are central to cell differentiation and developmental programs. These controls reflect sequence-specific interactions of mRNAs with one or more RNA binding proteins. The α-globin poly(C) binding proteins (αCPs) comprise a highly abundant subset of K homology (KH) domain RNA binding proteins and have a characteristic preference for binding single-stranded C-rich motifs. αCPs have been implicated in translation control and stabilization of multiple cellular and viral mRNAs. To explore the full contribution of αCPs to cell function, we have identified a set of mRNAs that associate in vivo with the major αCP2 isoforms. One hundred sixty mRNA species were consistently identified in three independent analyses of αCP2-RNP complexes immunopurified from a human hematopoietic cell line (K562). These mRNAs could be grouped into subsets encoding cytoskeletal components, transcription factors, proto-oncogenes, and cell signaling factors. Two mRNAs were linked to ceroid lipofuscinosis, indicating a potential role for αCP2 in this infantile neurodegenerative disease. Surprisingly, αCP2 mRNA itself was represented in αCP2-RNP complexes, suggesting autoregulatory control of αCP2 expression. In vitro analyses of representative target mRNAs confirmed direct binding of αCP2 within their 3′ untranslated regions. These data expand the list of mRNAs that associate with αCP2 in vivo and establish a foundation for modeling its role in coordinating pathways of posttranscriptional gene regulation.


2009 ◽  
Vol 132 (2) ◽  
Author(s):  
Ricarda Hess ◽  
Timothy Douglas ◽  
Kenneth A. Myers ◽  
Barbe Rentsch ◽  
Claudia Rentsch ◽  
...  

Human mesenchymal stem cells (hMSCs) from bone marrow are considered a promising cell source for bone tissue engineering applications because of their ability to differentiate into cells of the osteoblastic lineage. Mechanical stimulation is able to promote osteogenic differentiation of hMSC; however, the use of hydrostatic pressure (HP) has not been well studied. Artificial extracellular matrices containing collagen and chondroitin sulfate (CS) have promoted the expression of an osteoblastic phenotype by hMSCs. However, there has been little research into the combined effects of biochemical stimulation by matrices and simultaneous mechanical stimulation. In this study, artificial extracellular matrices generated from collagen and/or CS were coated onto polycaprolactone-co-lactide substrates, seeded with hMSCs and subjected to cyclic HP at various time points during 21 days after cell seeding to investigate the effects of biochemical, mechanical, and combined biochemical and mechanical stimulations. Cell differentiation was assessed by analyzing the expression of alkaline phosphatase (ALP) at the protein- and mRNA levels, as well as for calcium accumulation. The timing of HP stimulation affected hMSC proliferation and expression of ALP activity. HP stimulation after 6 days was most effective at promoting ALP activity. CS-containing matrices promoted the osteogenic differentiation of hMSCs. A combination of both CS-containing matrices and cyclic HP yields optimal effects on osteogenic differentiation of hMSCs on scaffolds compared with individual responses.


2016 ◽  
Vol 38 (2) ◽  
pp. 427-448 ◽  
Author(s):  
Yanping Gao ◽  
Bing Feng ◽  
Siqi Han ◽  
Kai Zhang ◽  
Jing Chen ◽  
...  

Cancer remains one of the most threatening causes of human health impairment, and the mechanisms underlying tumorigenesis have not been completely characterized. MicroRNAs (miRNAs) are a group of endogenous, small (18∼25 nucleotides) non-coding RNAs which negatively regulate gene expressions by directly binding to the 3'-untranslated regions (3'-UTRs) of the target messenger RNAs (mRNAs). Increasing evidence has demonstrated abnormal miRNA profiles and confirmed their involvement in tumor initiation and progression. As one important member of the miR-200 family, microRNA (miR)-141 is aberrantly expressed in many human malignant tumors, participating in various cellular processes including epithelial-mesenchymal transition (EMT), proliferation, migration, invasion, and drug resistance. In the present review, we briefly describe the mechanisms underlying miR-141-mediated tumorigenesis and the possible future of miR-141 as a potential diagnostic and prognostic parameter as well as therapeutic target in clinical applications.


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