Publications by authors named "Darzynkiewicz"
Background: Uncontrolled pediatric asthma leads to poorer outcomes; school-based telehealth (SBTH) is an opportunity to intervene.
Local Problem: The connection rate to primary care after SBTH visits for asthma exacerbations was below organizational goals. Additionally, there was a gap in assessing SBTH's role in providing access to rescue medication.
All cells in our body are equipped with receptors to recognize pathogens and trigger a rapid defense response. As a result, foreign molecules are blocked, and cells are alerted to the danger. Among the many molecules produced in response to viral infection are interferon-induced proteins with tetratricopeptide repeats (IFITs).
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- mRNA-based drugs are rapidly advancing, particularly as viral vaccines, with potential uses in various diseases due to their easy and adaptable production process.
- The structure of mRNA components, especially modifications at the 5' cap, significantly influences its effectiveness and longevity in medical applications.
- This study focuses on synthesizing modified cap analogues and testing these compounds for their ability to act as translation inhibitors and improve mRNA preparation.
Eukaryotic initiation factor 4E (eIF4E) is a pivotal protein involved in the regulatory mechanism for global protein synthesis in both physiological and pathological conditions. MicroRNAs (miRNAs) play a significant role in regulating gene expression by targeting mRNA. However, the ability of miRNAs to regulate eIF4E and its phosphorylation remains relatively unknown.
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- Nudt15 is a well-studied enzyme from the NUDIX protein family, primarily for its effects on thiopurine drugs used in cancer and inflammatory disease treatment.
- Besides its known activity on thiopurines, Nudt15 also acts on various nucleotide substrates, and there's speculation about its role in the degradation of mRNA through hydrolysis of mGDP.
- Recent research showed that Nudt15 has moderate activity with methylated forms of GDP and GTP, suggesting these can inform the design of new small molecule inhibitors targeting Nudt15.
Mesenchymal stem cell engineering by ARCA analog-capped mRNA.
Mol Ther Nucleic Acids
September 2023
Article Synopsis
- The study examines factors affecting mRNA engineering of mesenchymal stem cells (MSCs), focusing on transfection methods, mRNA purification, and capping types.
- Results show that Lipofectamine 2000 is superior to TransIT for MSC transfection, while HPLC purification is essential for maintaining MSC health.
- It concludes that using Lipofectamine 2000 with HPLC-purified mRNA and β-S-ARCA D1 capping achieves enhanced protein production, albeit with reduced MSC metabolic activity.
Recent findings have substantially broadened our knowledge about the diversity of modifications of the 5'end of RNAs, an issue generally attributed to mRNA cap structure (mGpppN). Nudt12 is one of the recently described new enzymatic activities involved in cap metabolism. However, in contrast to its roles in metabolite-cap turnover (e.
View Article and Find Full Text PDFThyroid cancer (TC) is the most common endocrine malignancy, with an approximately three-fold higher incidence in women. TCGA data indicate that androgen receptor (AR) RNA is significantly downregulated in PTC. In this study, AR-expressing 8505C (anaplastic TC) (84E7) and K1 (papillary TC) cells experienced an 80% decrease in proliferation over 6 days of exposure to physiological levels of 5α-dihydrotestosterone (DHT).
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- mRNA-based vaccines are innovative technologies that have recently gained attention from research centers and pharmaceutical companies, offering advantages over DNA-based vaccines due to their safety and flexibility.
- These vaccines avoid risks of genomic integration and can be easily engineered to improve their efficiency and stability.
- The study discusses the use of N2 modified dinucleotide cap analogs in mRNA, which enhance translation efficiency and proper attachment, showing promising results in both in vitro and human cell experiments.
Article Synopsis
- Transcribed synthetic mRNAs (IVT mRNAs) are in high demand for therapeutic applications due to their efficient and scalable production using bacteriophage RNA polymerases (RNAP).
- However, IVT mRNA preparations often have contaminants like double-stranded RNA (dsRNA) that trigger unwanted immune responses when introduced into cells, making it essential to remove these contaminants.
- The study found that using a genetically modified polymerase (HiT7 RNAP) at higher temperatures reduced dsRNA levels and immune responses compared to a standard polymerase (SP6 RNAP), and incorporating pseudouridine nucleotides further improved translation efficiency and reduced immune detection.
Article Synopsis
- Nudt16, part of the NUDIX hydrolase family, selectively works on nucleoside diphosphates but there are conflicting reports on its substrates and biological roles.* -
- A study found that hNudt16 has the strongest affinity for IDP and GppG, with K values under 100 nM, while other substrates displayed significantly weaker binding.* -
- The research identified GppG as a new substrate for hNudt16 and suggested the enzyme's strong binding is enhanced by interactions with specific amino acids, hinting at its regulatory functions.*
Article Synopsis
- The m7G cap is crucial for RNA produced by RNA Polymerase II and is important for gene expression in eukaryotes, but its specific function in mammals was previously unclear.
- Researchers found that the methyltransferase RNMT plays a significant role in T cell activation by regulating the production of mRNA and ribosomes, which are essential for metabolic changes and rapid cell division.
- RNMT's induction during T cell receptor stimulation leads to increased expression of certain mRNAs and snoRNAs, vital for ribosome biogenesis, and its absence results in decreased ribosome production and impaired T cell proliferation.
The American Cancer Society predicted more than 52 000 new cases of thyroid cancer in 2020, making it the most prevalent endocrine malignancy. Due to the approximately threefold higher incidence of thyroid cancer in women, we hypothesize that androgens and/or androgen receptors play a protective role and that thyroid cancer in men represents an escape from androgen-mediated cell regulation. The analysis of androgen receptor (AR) expression in patient tissue samples identified a 2.
View Article and Find Full Text PDFWe showed that intrarenal suppression of TNF (tumor necrosis factor) production under low salt (LS) conditions increases renal cortical AGT (angiotensinogen) mRNA and protein expression. Intrarenal injection of murine recombinant TNF attenuated increases of AGT in mice ingesting LS. Moreover, AGT mRNA and protein expression increased ≈6-fold and 2-fold, respectively, in mice ingesting LS that also received an intrarenal injection of a lentivirus construct that specifically silenced TNF in the kidney (U6-TNF-ex4).
View Article and Find Full Text PDFB-cell chronic lymphocytic leukemia (CLL) results from accumulation of leukemic cells that are subject to iterative re-activation cycles and clonal expansion in lymphoid tissues. The effects of the well-tolerated alkaloid Berberine (BRB), used for treating metabolic disorders, were studied on ex-vivo leukemic cells activated in vitro by microenvironment stimuli. BRB decreased expression of survival/proliferation-associated molecules (e.
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- IFITs are RNA-binding proteins that are crucial for the immune system's antiviral response by recognizing and binding to foreign viral RNA particles.
- They form stable complexes with the RNA, which leads to a shutdown of translation for non-self transcripts.
- The study developed a fluorescent assay to explore the interaction between RNA and IFIT proteins, focusing on IFIT1 and IFIT5, and found a probe that helps compare the binding affinities of various mRNAs based on their 5' end structures.
Briefly depicted are the publications in CYTOMETRY that received the highest frequency of citations. Among them are seminal papers describing application of metachromatic fluorochrome acridine orange to differentially stain DNA versus RNA or to analyze susceptibility of DNA in situ to denaturation; both features being markers of different sections of the cell cycle including identification of noncycling quiescent cells. The papers reviewing detection of cyclins D1, E, A or B1, each in relation to cell cycle phase, were also among the highly cited ones.
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- DcpS enzymes are crucial for mRNA degradation in eukaryotes and are linked to conditions like spinal muscular atrophy and acute myeloid leukemia, with recent connections to intellectual disability.* -
- This study is the first to analyze the effects of different tags (N-terminus vs. C-terminus) on DcpS enzymes from humans and other species, noting that native forms were created through tag removal.* -
- While the thermal stability of most DcpS versions remained stable, the catalytic activity showed that tagged DcpSs had enhanced efficiency with specific substrates compared to their native counterparts, except for mGDP which was resistant to cleavage.*
Eukaryotic messenger RNA (mRNA) is modified by the addition of an inverted guanosine cap to the 5' triphosphate. The cap guanosine and initial transcribed nucleotides are further methylated by a series of cap methyltransferases to generate the mature cap structures which protect RNA from degradation and recruit proteins involved in RNA processing and translation. Research demonstrating that the cap methyltransferases are regulated has generated interest in determining the methylation status of the mRNA cap structures present in cells.
View Article and Find Full Text PDFRecent data suggest that paternal age can have major impact on reproductive outcomes, and with increased age, there is increased likelihood of chromosomal abnormalities in the sperm. Here, we studied DNA damage and repair as a function of male aging and assessed whether sphingosine-1-phosphate (S1P), a ceramide-induced death inhibitor, can prevent sperm aging by enhancing DNA double-strand breaks (DSB) repair. We observed a significant increase in DNA damage with age and this increase was associated with a decline in the expression of key DNA DSB repair genes in mouse sperm.
View Article and Find Full Text PDFThe susceptibility of DNA in situ to denaturation is modulated by its interactions with histone and nonhistone proteins, as well as with other chromatin components related to the maintenance of the 3D nuclear structure. Measurement of DNA proclivity to denature by cytometry provides insight into chromatin structure and thus can be used to recognize cells in different phases of the cell cycle, including mitosis, quiescence (G ), and apoptosis, as well as to identify the effects of drugs that modify chromatin structure. Particularly useful is the method's ability to detect chromatin changes in sperm cells related to DNA fragmentation and infertility.
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- Cellular antiviral responses increase the levels of interferon-induced proteins with tetratricopeptide repeats (IFITs) that bind to the 5' end of mRNA, which has a unique cap structure.* -
- Research focused on IFIT1 and IFIT5 showed that the stability of their binding to various capped and uncapped mRNAs is affected by the modifications to the cap structure.* -
- Interaction studies revealed that certain modified synthetic cap analogs can somewhat protect mRNA from translational inhibition by IFIT1, highlighting their potential in biotechnology and medicine.*
Article Synopsis
- mRNA degradation plays a crucial role in regulating gene expression, specifically through the 3' → 5' decay pathway involving the exosome complex and decapping enzymes.
- The study focuses on the decapping scavenger enzyme DcpS from humans, Caenorhabditis elegans (CeDcpS), and Aspergillus species (AsDcpS), examining their activity toward modified cap analogues.
- Results showed that longer alkyl chains on cap analogues led to resistance against hydrolysis by hDcpS and CeDcpS, likely due to weaker binding interactions between the modified caps and the enzymes.
DNA polymerase δ (Pol δ) plays a central role in lagging strand DNA synthesis in eukaryotic cells, as well as an important role in DNA repair processes. Human Pol δ4 is a heterotetramer of four subunits, the smallest of which is p12. Pol δ3 is a trimeric form that is generated in vivo by the degradation of the p12 subunit in response to DNA damage, and during entry into S-phase.
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