Fat mass and obesity-associated protein (FTO) is the first reported RNA N6-methyladenosine (m6A) demethylase in eukaryotic cells. m6A is considered as the most abundant mRNA internal modification, ...which modulates several cellular processes including alternative splicing, stability, and expression. Genome-wide association studies (GWAS) identified single-nucleotide polymorphisms (SNPs) within
to be associated with obesity, as well as cancer including endometrial cancer, breast cancer, pancreatic cancer, and melanoma. Since the initial classification of FTO as an m6A demethylase, various studies started to unravel a connection between FTO's demethylase activity and the susceptibility to obesity on the molecular level. FTO was found to facilitate adipogenesis, by regulating adipogenic pathways and inducing pre-adipocyte differentiation. FTO has also been investigated in tumorigenesis, where emerging studies suggest m6A and FTO levels are dysregulated in various cancers, including acute myeloid leukemia (AML), glioblastoma, cervical squamous cell carcinoma (CSCC), breast cancer, and melanoma. Here we review the molecular bases of m6A in tumorigenesis and adipogenesis while highlighting the controversial role of FTO in obesity. We provide recent findings confirming FTO's causative link to obesity and discuss novel approaches using RNA demethylase inhibitors as targeted oncotherapies. Our review aims to confirm m6A demethylation as a risk factor in obesity and provoke new research in FTO and human disorders.
Posttranscriptional modifications in transfer RNA (tRNA) are often critical for normal development because they adapt protein synthesis rates to a dynamically changing microenvironment. However, the ...precise cellular mechanisms linking the extrinsic stimulus to the intrinsic RNA modification pathways remain largely unclear. Here, we identified the cytosine-5 RNA methyltransferase NSUN2 as a sensor for external stress stimuli. Exposure to oxidative stress efficiently repressed NSUN2, causing a reduction of methylation at specific tRNA sites. Using metabolic profiling, we showed that loss of tRNA methylation captured cells in a distinct catabolic state. Mechanistically, loss of NSUN2 altered the biogenesis of tRNA-derived noncoding fragments (tRFs) in response to stress, leading to impaired regulation of protein synthesis. The intracellular accumulation of a specific subset of tRFs correlated with the dynamic repression of global protein synthesis. Finally, NSUN2-driven RNA methylation was functionally required to adapt cell cycle progression to the early stress response. In summary, we revealed that changes in tRNA methylation profiles were sufficient to specify cellular metabolic states and efficiently adapt protein synthesis rates to cell stress.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Autosomal-recessive loss of the NSUN2 gene has been identified as a causative link to intellectual disability disorders in humans. NSun2 is an RNA methyltransferase modifying cytosine-5 in transfer ...RNAs (tRNAs), yet the identification of cytosine methylation in other RNA species has been hampered by the lack of sensitive and reliable molecular techniques. Here, we describe miCLIP as an additional approach for identifying RNA methylation sites in transcriptomes. miCLIP is a customized version of the individual-nucleotide-resolution crosslinking and immunoprecipitation (iCLIP) method. We confirm site-specific methylation in tRNAs and additional messenger and noncoding RNAs (ncRNAs). Among these, vault ncRNAs contained six NSun2-methylated cytosines, three of which were confirmed by RNA bisulfite sequencing. Using patient cells lacking the NSun2 protein, we further show that loss of cytosine-5 methylation in vault RNAs causes aberrant processing into Argonaute-associated small RNA fragments that can function as microRNAs. Thus, impaired processing of vault ncRNA may contribute to the etiology of NSun2-deficiency human disorders.
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•miCLIP detects NSun2-mediated cytosine-5 methylation in RNA•Vault noncoding RNA is methylated by NSun2•Cytosine-5 in Vault RNA determines its processing into small RNA (svRNA)•svRNAs bind to Argonaute proteins and exhibit microRNA-like functions
Comprehensive analyses of cytosine-5 methylation in the RNA transcriptome have previously been hampered by the lack of sensitive and reliable molecular techniques. In this work, Ule, Frye, and colleagues describe the methylation-iCLIP (miCLIP) method that they used to identify target sites of the RNA methyltransferase, NSun2. Among the targeted noncoding RNAs were vault RNAs, previously associated with resistance to chemotherapy in cancer. They further show how NSun2-mediated methylation of vault ncRNAs influences their processing into small microRNA-like molecules.
The presence and absence of RNA modifications regulates RNA metabolism by modulating the binding of writer, reader, and eraser proteins. For 5-methylcytosine (m
C) however, it is largely unknown how ...it recruits or repels RNA-binding proteins. Here, we decipher the consequences of m
C deposition into the abundant non-coding vault RNA VTRNA1.1. Methylation of cytosine 69 in VTRNA1.1 occurs frequently in human cells, is exclusively mediated by NSUN2, and determines the processing of VTRNA1.1 into small-vault RNAs (svRNAs). We identify the serine/arginine rich splicing factor 2 (SRSF2) as a novel VTRNA1.1-binding protein that counteracts VTRNA1.1 processing by binding the non-methylated form with higher affinity. Both NSUN2 and SRSF2 orchestrate the production of distinct svRNAs. Finally, we discover a functional role of svRNAs in regulating the epidermal differentiation programme. Thus, our data reveal a direct role for m
C in the processing of VTRNA1.1 that involves SRSF2 and is crucial for efficient cellular differentiation.
Organophosphates (OPs) are neurotoxic agents also used as pesticides that can permanently block the active site of the acetylcholinesterase (AChE). A robust and sensitive detection system of OPs ...utilising the enzyme mimic potential of the cysteamine capped gold nanoparticles (C-AuNPs) was developed. The detection assay was performed by stepwise addition of AChE, parathion ethyl (PE)-a candidate OP, acetylcholine chloride (ACh), C-AuNPs, and 3, 3′, 5, 5′-tetramethylbenzidine (TMB) in the buffer solution. The whole sensing protocol completes in 30–40 min, including both incubations. The Transmission Electron Microscopy (TEM) results indicated that the NPs are spherical and have an average size of 13.24 nm. The monomers of C-AuNPs exhibited intense catalytic activity (nanozyme) for the oxidization of TMB, revealed by the production of instant blue colour and confirmed by a sharp peak at 652 nm. The proposed biosensor’s detection limit and linear ranges were 5.8 ng·mL−1 and 11.6–92.8 ng·mL−1, respectively, for PE. The results strongly advocate that the suggested facile colorimetric biosensor may provide an excellent platform for on-site monitoring of OPs.
In the present study, five 4-aminophenol derivatives (4-chloro-2-(((4-hydroxyphenyl)imino)methyl)phenol(S-1), 4-((4-(dimethylamino)benzylidene)amino)phenol(S-2), ...4-((3-nitrobenzylidene)amino)phenol(S-3), 4-((thiophen-2-ylmethylene)amino)phenol(S-4) and 4-(((
)-3-phenylallylidene)amino)phenol(S-5)) were synthesized and characterized by FT-IR,
H-NMR,
C-NMR and elemental analyses. The synthesized compounds were tested for their antimicrobial (Gram-positive and Gram-negative bacteria and
fungus) and antidiabetic (α-amylase and α-glucosidase inhibitory) activities. All the compounds showed broad-spectrum activities against the
(ATCC 6538),
(ATCC 4698),
(ATCC 12228),
(ATCC 6633),
(ATCC 4617) and
(ATCC 9763) strains. The newly synthesized compounds showed a significant inhibition of amylase (93.2%) and glucosidase (73.7%) in a concentration-dependent manner. Interaction studies of Human DNA with the synthesized Schiff bases were also performed. The spectral bands of S-1, S-2, S-3 and S-5 all showed hyperchromism, whereas the spectral band of S-4 showed a hypochromic effect. Moreover, the spectral bands of the S-2, S-3 and S-4 compounds were also found to exhibit a bathochromic shift (red shift). The present studies delineate broad-spectrum antimicrobial and antidiabetic activities of the synthesized compounds. Additionally, DNA interaction studies highlight the potential of synthetic compounds as anticancer agents. The DNA interaction studies, as well as the antidiabetic activities articulated by the molecular docking methods, showed the promising aspects of synthetic compounds.
Here we report the generation of the first Emirati iPSC line in the United Arab Emirates and name it KUSTi001-A. CD34+ hematopoietic cells purified from peripheral blood of a 27-year-old healthy ...female donor were reprogrammed using Sendai vectors. Twenty days post-reprogramming colonies were manually picked, and expanded clones were verified for transgene clearance by RT-PCR. Pluripotency was validated by pluripotency genes and differentiation into all three germ layers. Finally, chromosome stability was confirmed by testing 8 common abnormality loci. KUSTi001-A, alternatively called UAE001, is an Emirati hiPSC line that holds great potential for UAE specific regenerative medicine, disease modelling and drug screening.
Ionic liquids (ILs) have emerged as active pharmaceutical ingredients because of their excellent antibacterial and biological activities. Herein, we used the green-chemistry-synthesis procedure, also ...known as the metathesis method, to develop three series of ionic liquids using 1-methyl-3-butyl imidazolium, butyl pyridinium, and diethyldibutylammonium as cations, and bromide (Br−), methanesulfonate (CH3SO3−), bis(trifluoromethanesulfonyl)imide (NTf2−), dichloroacetate (CHCl2CO2−), tetrafluoroborate (BF4−), and hydrogen sulfate (HSO4−) as anions. Spectroscopic methods were used to validate the structures of the lab-synthesized ILs. We performed an agar well diffusion assay by using pathogenic bacteria that cause various infections (Escherichia coli; Enterobacter aerogenes; Klebsiella pneumoniae; Proteus vulgaris; Pseudomonas aeruginosa; Streptococcus pneumoniae; Streptococcus pyogenes) to scrutinize the in vitro antibacterial activity of the ILs. It was established that the nature and unique combination of the cations and anions were responsible for the antibacterial activity of the ILs. Among the tested ionic liquids, the imidazolium cation and NTf2− and HSO4− anions exhibited the highest antibacterial activity. The antibacterial potential was further investigated by in silico studies, and it was observed that bis(trifluoromethanesulfonyl)imide (NTf2−) containing imidazolium and pyridinium ionic liquids showed the maximum inhibition against the targeted bacterial strains and could be utilized in antibiotics. These antibacterial activities float the ILs as a promising alternative to the existing antibiotics and antiseptics.
Abstract
The encapsulation of plant extract in nanomatrices has limitations due to its adhesion to walls, size control, high cost and long durations that results in low yield. Macroscale and ...microscale level techniques for development of micro/nanoparticles may impact the encapsulation of plant extract. This study aimed to evaluate the relative efficiency of microscale and macroscale techniques for encapsulation of plant extract, which is not compared yet. Keeping this in view, encapsulation of
Calotropis gigantea
leaves extract (CaG) was attained in silver-conjugated poliglusam nanomatrices (POL/Ag) to induce apoptosis in invasive ductal carcinoma (IDC) cells. The ethanolic CaG extract was prepared using percolation method and characterized by chemical tests for its active phytochemical compounds. The droplet-based microfluidic system was utilized as microscale encapsulation technique for CaG in nanomatrices at two different aqueous to oil flow rate ratios 1.0:1.5, and 1.0:3.0. Moreover, conventional batch system was utilized as macroscale encapsulation technique consisted of hot plate magnetic stirrer. The prepared nanomatrices were analysed for antioxidant activity using DPPH test and for cytotoxicity analysis using MCF-7 cells. The characteristic peaks of UV–Vis, FTIR and XRD spectrum confirmed the synthesis of CaG(POL/Ag) by both the encapsulation methods. However, microfluidic system was found to be more expedient because of attaining small and uniform sized silver nanoparticles (92 ± 19 nm) at high flow rate and achieving high encapsulation efficiency (80.25%) as compared to the conventional batch method (52.5%). CaG(POL/Ag) nanomatrices found to have significant antioxidant activity (
p
= 0.0014) against DPPH radical scavenging activity. The CaG(POL/Ag) of the smallest sized formulated by the microfluidic system has also shown the highest cytotoxicity (90%) as compared to batch method (70%) at 80 µg/mL. Our results indicate that the microscale technique using microfluidic system is a more efficient method to formulate size-controlled CaG(POL/Ag) nanomatrices and achieve high encapsulation of plant extract. Additionally, CaG(Pol/Ag) was found to be an efficient new combination for inducing potent (
p
< 0.0001) apoptosis in IDC cells. Therefore, CaG(Pol/Ag) can be further tested as an anti-cancer agent for in-vivo experiments.
Stem cells (SCs) are unique cells that have an inherent ability to self‐renew or differentiate. Both fate decisions are strongly regulated at the molecular level via intricate signaling pathways. The ...regulation of signaling networks promoting self‐renewal or differentiation was thought to be largely governed by the action of transcription factors. However, small noncoding RNAs (ncRNAs), such as vault RNAs, and their post‐transcriptional modifications (the epitranscriptome) have emerged as additional regulatory layers with essential roles in SC fate decisions. RNA post‐transcriptional modifications often modulate RNA stability, splicing, processing, recognition, and translation. Furthermore, modifications on small ncRNAs allow for dual regulation of RNA activity, at both the level of biogenesis and RNA‐mediated actions. RNA post‐transcriptional modifications act through structural alterations and specialized RNA‐binding proteins (RBPs) called writers, readers, and erasers. It is through SC‐context RBPs that the epitranscriptome coordinates specific functional roles. Small ncRNA post‐transcriptional modifications are today exploited by different mechanisms to facilitate SC translational studies. One mechanism readily being studied is identifying how SC‐specific RBPs of small ncRNAs regulate fate decisions. Another common practice of using the epitranscriptome for regenerative applications is using naturally occurring post‐transcriptional modifications on synthetic RNA to generate induced pluripotent SCs. Here, we review exciting insights into how small ncRNA post‐transcriptional modifications control SC fate decisions in development and disease. We hope, by illustrating how essential the epitranscriptome and their associated proteome are in SCs, they would be considered as novel tools to propagate SCs for regenerative medicine.
The multifunctional roles RNA post‐transcriptional modifications, the epitranscriptome, could play to regulate stem cell biology. Stem cells coordinate epitranscriptome responses by expressing particular combinations of readers, writers, and erasers, which deposit, process, and remove transcriptome modifications. It is through these orchestrates mechanisms that the epitranscriptome modulate transcriptomes and proteomes to fine‐tune stem cell fate decisions.
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