RNA therapeutics to control fibrinolysis: review on applications in biology and medicine.

Regulation of fibrinolysis, the process that degrades blood clots, is pivotal in maintaining hemostasis. Dysregulation leads to thrombosis or excessive bleeding. Proteins in the fibrinolysis system include fibrinogen, coagulation factor XIII, plasminogen, tissue plasminogen activator, urokinase plasminogen activator, α2-antiplasmin, thrombin-activatable fibrinolysis inhibitor, plasminogen activator inhibitor-1, α2-macroglobulin, and others. While each of these is a potential therapeutic target for diseases, they lack effective or long-acting inhibitors. Rapid advances in RNA-based technologies are creating powerful tools to control the expression of proteins. RNA agents can be long-acting and tailored to either decrease or increase production of a specific protein. Advances in nucleic acid delivery, such as by lipid nanoparticles, have enabled the delivery of RNA to the liver, where most proteins of coagulation and fibrinolysis are produced. This review will summarize the classes of RNA that induce 1) inhibition of protein synthesis, including small interfering RNA and antisense oligonucleotides; 2) protein expression, including messenger RNA and self-amplifying RNA; and 3) gene editing for gene knockdown and precise editing. It will review specific examples of RNA therapies targeting proteins in the coagulation and fibrinolysis systems and comment on the wide range of opportunities for controlling fibrinolysis for biological applications and future therapeutics using state-of-the-art RNA therapies.

The Possibility of Systematic Research Fraud Targeting Under-Studied Human Genes: Causes, Consequences, and Potential Solutions.

A major reason for biomarker failure is the selection of candidate biomarkers based on inaccurate or incorrect published results. Incorrect research results leading to the selection of unproductive biomarker candidates are largely considered to stem from unintentional research errors. The additional possibility that biomarker research may be actively misdirected by research fraud has been given comparatively little consideration. This review discusses what we believe to be a new threat to biomarker research, namely, the possible systematic production of fraudulent gene knockdown studies that target under-studied human genes. We describe how fraudulent papers may be produced in series by paper mills using what we have described as a 'theme and variations' model, which could also be considered a form of salami slicing. We describe features of these single-gene knockdown publications that may allow them to evade detection by journal editors, peer reviewers, and readers. We then propose a number of approaches to facilitate their detection, including improved awareness of the features of publications constructed in series, broader requirements to post submitted manuscripts to preprint servers, and the use of semi-automated literature screening tools. These approaches may collectively improve the detection of fraudulent studies that might otherwise impede future biomarker research.

Stable Knockdown of Adenosine Kinase by Lentiviral Anti-ADK miR-shRNAs in Wharton's Jelly Stem Cells.

OBJECTIVES: In this study, we describe an efficient approach for stable knockdown of adenosine kinase (ADK) using lentiviral system, in an astrocytoma cell line and in human Wharton's jelly mesenchymal stem cells (hWJMSCs). These sources of stem cells besides having multilineage differentiation potential and immunomodulatory activities, are easily available in unlimited numbers, do not raise ethical concerns and are attractive for gene manipulation and cell-based gene therapy. MATERIALS AND METHODS: In this experimental study, we targeted adenosine kinase mRNA at 3' and performed coding sequences using eight miR-based expressing cassettes of anti-ADK short hairpin RNA (shRNAs). First, these cassettes with scrambled control sequences were cloned into expressing lentiviral pGIPZ vector. Quantitative real time-polymerase chain reaction (qRT-PCR) was used to screen multi-cassettes anti-ADK miR-shRNAs in stably transduced U-251 MG cell line and measuring ADK gene expression at mRNA level. Extracted WJMSCs were characterized using flow cytometry for expressing mesenchymal specific marker (CD44+) and lack of expression of hematopoietic lineage marker (CD45-). Then, the lentiviral vector that expressed the most efficient anti-ADK miR-shRNA, was employed to stably transduce WJMSCs. RESULTS: Transfection of anti-ADK miR-shRNAs in HEK293T cells using CaPO4 method showed high efficiency. We successfully transduced U-251 cell line by recombinant lentiviruses and screened eight cassettes of anti-ADK miRshRNAs in stably transduced U-251 MG cell line by qRT-PCR. RNAi-mediated down-regulation of ADK by lentiviral system indicated up to 95% down-regulation of ADK. Following lentiviral transduction of WJMSCs with anti-ADK miRshRNA expression cassette, we also implicated, down-regulation of ADK up to 95% by qRT-PCR and confirmed it by western blot analysis at the protein level. CONCLUSIONS: Our findings indicate efficient usage of shRNA cassette for ADK knockdown. Engineered WJMSCs with genome editing methods like CRISPR/cas9 or more safe viral systems such as adeno-associated vectors (AAV) might be an attractive source in cell-based gene therapy and may have therapeutic potential for epilepsy.

ARHGAP18 is a novel gene under positive natural selection that influences HbF levels in ß-thalassaemia.

Foetal haemoglobin (HbF) plays a dominant role in ameliorating the morbidity and mortality of ß-thalassaemia. A better understanding of the loci and genes involved in HbF expression would be beneficial for the treatment of ß-thalassaemia major. However, the genes associated with HbF expression remain largely unknown. In this study, we first explored large-scale data sets and examined the human genome for evidence of positive natural selection to screen out single nucleotide polymorphisms (SNPs). A genetic analysis of HbF levels was conducted in a Chinese cohort of patients with ß-thalassaemia to confirm the bioinformatics results. A total of 1141 subjects with ß-thalassaemia were recruited. The results showed that the SNP rs11759328 in the ARHGAP18 gene was significantly associated with HbF levels (Ρ = 5.1 × 10-4). ARHGAP18 belongs to the RhoGAP family and controls angiogenesis, cellular morphology and motility. Second, after determining that ARHGAP18 was highly expressed in the human K562 cell line, we used lentiviral-mediated small interfering RNA to knock down ARHGAP18 expression and subsequently assessed cell proliferation and apoptosis using cell proliferation assays and flow cytometry, respectively. ARHGAP18 downregulation in K562 cells significantly increased HBG1/2 expression and apoptosis, but proliferation was not significantly affected in vitro. Our data suggest that ARHGAP18, which was located by the SNP rs11759328 via positive selection, plays a potential role in regulating HbF expression in ß-thalassaemia and may be a promising therapeutic target. Knockout studies of ARHGAP18 warrant further investigation into its aetiology in HbF.

Knockdown of CMTM3 promotes migration and invasion of PC3 cell in vitro / 北京大学学报(医学版)

Objective:To investigate the change of biological characteristics after stable knockdown of CKLF-like MARVEL transmembrane domain containing 3 (CMTM3)expression in PC3 by lentivirus shRNA and to reveal new therapeutic targets.Methods:The research includes two groups:sh393 is the experimental group in which CMTM3 is knocked down in PC3 cell line;shN is the control group in which CMTM3 is negatively knocked down.The expression of CMTM3 was detected by Western blot.The mi-gration ability of PC3 after stable knockdown was detected by Transwell and Wound healing assay.The invasion ability of PC3 was detected by Matrigel assay.Results were obtained from at least three indivi-dual experiments.Results:The expression of CMTM3 in sh393 group is significant lower than shN group (0.004 0 ±0.000 4 vs.0.490 0 ±0.055 7,P <0.001)detected by Western blot.It also had statistical significance in Matrigel assays (248.6 ±4.5 vs.113.0 ±3.3),Transwell (203.6 ±1.9 vs.103.0 ± 1.2)and Wound healing assays (95.0 ±2.9 vs.33.0 ±1.5)that knockdown of CMTM3 promoted mi-gration,and invasion of PC3 cells in vitro (P <0.001).Conclusion:Negative correlation exists between the stable knockdown of CMTM3 and change of biological characteristics in PC3 cells,and knocking down CMTM3 affects migration,and invasion ability in PC3 cells.

Platelet Derived Growth Factor Has a Role in Pressure Induced Bladder Smooth Muscle Cell Hyperplasia and Acts in a Paracrine Way.

PURPOSE: Bladder outlet obstruction is a finding in many urological disorders, leading to bladder wall hyperplasia. We investigated platelet derived growth factor and its receptor in human bladder smooth muscle cells and urothelial cells exposed to hydrostatic pressure or PDGF in vitro. MATERIALS AND METHODS: Bladder smooth muscle cells and urothelial cells were exposed to elevated hydrostatic pressure for 1 hour. The expression of PDGF and PDGFR was evaluated using reverse transcriptase-polymerase chain reaction and Western blot analysis. Pressure or PDGF induced proliferation of bladder smooth muscle cells with or without pretreatment with lovastatin or imatinib was measured by enzyme-linked immunosorbent assay. PDGFRα was knocked down with siRNA. RESULTS: After hydrostatic pressure bladder smooth muscle cells showed increased PDGFRα and ß expression. PDGF was not expressed in bladder smooth muscle cells. Urothelial cells showed no expression of PDGFR but PDGF expression was noted. Western blot analysis of bladder smooth muscle cells revealed a pressure induced increase in PDGFR in the membrane fraction. Phosphorylation of PDGFR occurred with pressure induction. Bladder smooth muscle cell proliferation was increased in pressure and PDGF mediated fashion. Pretreatment with lovastatin or imatinib prevented proliferation. There was no cell proliferation after PDGFRα knockdown. CONCLUSIONS: Increased expression and phosphorylation of PDGFR in bladder smooth muscle cells after hydrostatic pressure suggests a pivotal role of the PDGF pathway in pressure induced hyperplasia of bladder smooth muscle cells. PDGF expressed in urothelial cells may act in a paracrine way. Cholesterol depletion, inhibition of receptor tyrosine kinase activity and knockdown of PDGFRα in bladder smooth muscle cells prevent pressure and PDGF mediated cell proliferation. Targeting PDGFR seems a promising way to influence pressure induced bladder wall hyperplasia.