283 research outputs found
The embryonic development and formation of Bunnei (Barbus sharpeyi Gunther, 1874)
Understanding the embryogenesis of Bunni is a useful tool for finding the time and suitable environmental conditions for spawning, growth requirements and use of techniques to increase the growth rate and survival. The stages of embryonic development for Bunnei (Barbus sharpeyi) was investigated in 22°C. The reared brood stocks were spawned in captivity condition. The oocytes were spherical, brown and very adhesive. The cleavage was fast and the first division was recorded within 15-20 minutes after fertilization. The blastulation and gastrulation were investigated in 7:40 and 13:10 hours after fertilization with the yolk sac diameter of 1.18±0.061mm (Mean±SD), respectively. The organogenesis was started 21 hours after the fertilization, when the blastopore was closed and notochord was formed. The embryonic stages were continued by appearance the brain, the somites and the melanophores on the yolk sac. The heart was beaten and shown the blood circulation 65 hours after the fertilization. The head, tail and pectoral fins were moved frequently. The embryo reached to pre hatching and final hatching 79:10 and 84:10 hours after fertilization, respectively, and the embryo existed from corion with the length of about 5.29±0/121mm (Mean±SD)
LncRNA RP11-19E11 is an E2F1 target required for proliferation and survival of basal breast cancer
Long non-coding RNAs (lncRNAs) play key roles in the regulation of breast cancer initiation and progression. LncRNAs are differentially expressed in breast cancer subtypes. Basal-like breast cancers are generally poorly differentiated tumors, are enriched in embryonic stem cell signatures, lack expression of estrogen receptor, progesterone receptor, and HER2 (triple-negative breast cancer), and show activation of proliferation-associated factors. We hypothesized that lncRNAs are key regulators of basal breast cancers. Using The Cancer Genome Atlas, we identified lncRNAs that are overexpressed in basal tumors compared to other breast cancer subtypes and expressed in at least 10% of patients. Remarkably, we identified lncRNAs whose expression correlated with patient prognosis. We then evaluated the function of a subset of lncRNA candidates in the oncogenic process in vitro. Here, we report the identification and characterization of the chromatin-associated lncRNA, RP11-19E11.1, which is upregulated in 40% of basal primary breast cancers. Gene set enrichment analysis in primary tumors and in cell lines uncovered a correlation between RP11-19E11.1 expression level and the E2F oncogenic pathway. We show that this lncRNA is chromatin-associated and an E2F1 target, and its expression is necessary for cancer cell proliferation and survival. Finally, we used lncRNA expression levels as a tool for drug discovery in vitro, identifying protein kinase C (PKC) as a potential therapeutic target for a subset of basal-like breast cancers. Our findings suggest that lncRNA overexpression is clinically relevant. Understanding deregulated lncRNA expression in basal-like breast cancer may lead to potential prognostic and therapeutic applications
The Transcription Factor Zfx Regulates Peripheral T Cell Self-Renewal and Proliferation
Peripheral T lymphocytes share many functional properties with hematopoietic stem cells (HSCs), including long-term maintenance, quiescence, and latent proliferative potential. In addition, peripheral T cells retain the capacity for further differentiation into a variety of subsets, much like HSCs. While the similarities between T cells and HSC have long been hypothesized, the potential common genetic regulation of HSCs and T cells has not been widely explored. We have studied the T cell-intrinsic role of Zfx, a transcription factor specifically required for HSC maintenance. We report that T cell-specific deletion of Zfx caused age-dependent depletion of naïve peripheral T cells. Zfx-deficient T cells also failed to undergo homeostatic proliferation in a lymphopenic environment, and showed impaired antigen-specific expansion and memory response. In addition, the invariant natural killer T cell compartment was severely reduced. RNA-Seq analysis revealed that the most dysregulated genes in Zfx-deficient T cells were similar to those observed in Zfx-deficient HSC and B cells. These studies identify Zfx as an important regulator of peripheral T cell maintenance and expansion and highlight the common molecular basis of HSC and lymphocyte homeostasis
Notch Signaling Facilitates In Vitro Generation of Cross-Presenting Classical Dendritic Cells
Beliefs, attitude, and knowledge of the Iranian physiatrists towards neuromusculoskeletal ultrasound and common barriers in its application
Background: Regarding the increasing application of neuromusculoskeletal sonography among medical specialties, specifically physiatrists, this study aims to assess the knowledge and skill level of these specialists in neuromusculoskeletal sonography in Iran. Methods: This descriptive, cross-sectional study was performed in 2018. The utilized questionnaire developed based on previous studies in collaboration with 6 university lecturers of Shaheed Beheshti, Iran, and Tabriz medical universities and a physiatrist from Hacettepe University (Turkey); it included questions entailing demographic data, knowledge, and performance levels. Its validity and reliability were evaluated through face validation, pilot study, and the Cronbach α calculated via SPSS. Data extraction and analysis were also performed by SPSS-25. Results: Of 364 questionnaires distributed, 300 were properly filled and entered into the study, of which, 38 were filled by clinical residents, 10 university lecturers, and 52 other categories (e.g. private sector). The average number of musculoskeletal patient visits was 140.6 ± 119 and the mean number of musculoskeletal sonographies requested was 8.2 ± 5.2 per month (the three most common indications reported as the shoulder, carpal tunnel syndrome, and tendon injuries). 95 of the participants considered the importance of sonography for physiatrists to be �very high� or �high�; with the most valuable applications �as a guide for procedures (90), its diagnostic utility (68), and follow up/evaluating the response to treatment (45). 86 of physiatrists reported they had participated in musculoskeletal sonography courses, 60 during residency, and the rest through workshops. Also, the participants mentioned safety (83), the possibility of performing simultaneous diagnosis and intervention procedures (70), repeatability (58), and dynamic imagery (52) as the major advantages of musculoskeletal ultrasound. Conclusion: a large number of doctors consider musculoskeletal sonography to be essential for physiatrists, though insufficient education on the subject and the low number of ultrasound devices are some of the obstacles in enhancing the use of this technology in PM&R setting. Presenting certified specific training courses during residency, provision of necessary rotations, using the capacities of the PM&R scientific committee, and the private sector for running workshops and professional training courses are suggested for enhancing the knowledge and skills of neuromusculoskeletal sonography. © 2020, The Author(s)
Evidence of coexistence of change of caged dynamics at Tg and the dynamic transition at Td in solvated proteins
Mossbauer spectroscopy and neutron scattering measurements on proteins
embedded in solvents including water and aqueous mixtures have emphasized the
observation of the distinctive temperature dependence of the atomic mean square
displacements, , commonly referred to as the dynamic transition at some
temperature Td. At low temperatures, increases slowly, but it assume
stronger temperature dependence after crossing Td, which depends on the
time/frequency resolution of the spectrometer. Various authors have made
connection of the dynamics of solvated proteins including the dynamic
transition to that of glass-forming substances. Notwithstanding, no connection
is made to the similar change of temperature dependence of obtained by
quasielastic neutron scattering when crossing the glass transition temperature
Tg, generally observed in inorganic, organic and polymeric glass-formers.
Evidences are presented to show that such change of the temperature dependence
of from neutron scattering at Tg is present in hydrated or solvated
proteins, as well as in the solvents used unsurprisingly since the latter is
just another organic glass-formers. The obtained by neutron scattering at
not so low temperatures has contributions from the dissipation of molecules
while caged by the anharmonic intermolecular potential at times before
dissolution of cages by the onset of the Johari-Goldstein beta-relaxation. The
universal change of at Tg of glass-formers had been rationalized by
sensitivity to change in volume and entropy of the beta-relaxation, which is
passed onto the dissipation of the caged molecules and its contribution to
. The same rationalization applies to hydrated and solvated proteins for
the observed change of at Tg.Comment: 28 pages, 10 figures, 1 Tabl
Comparison between direct and reverse electroporation of cells in situ: a simulation study.
The discovery of the human genome has unveiled new fields of genomics, transcriptomics, and proteomics, which has produced paradigm shifts on how to study disease mechanisms, wherein a current central focus is the understanding of how gene signatures and gene networks interact within cells. These gene function studies require manipulating genes either through activation or inhibition, which can be achieved by temporarily permeabilizing the cell membrane through transfection to deliver cDNA or RNAi. An efficient transfection technique is electroporation, which applies an optimized electric pulse to permeabilize the cells of interest. When the molecules are applied on top of seeded cells, it is called “direct” transfection and when the nucleic acids are printed on the substrate and the cells are seeded on top of them, it is termed “reverse” transfection. Direct transfection has been successfully applied in previous studies, whereas reverse transfection has recently gained more attention in the context of high-throughput experiments. Despite the emerging importance, studies comparing the efficiency of the two methods are lacking. In this study, a model for electroporation of cells in situ is developed to address this deficiency. The results indicate that reverse transfection is less efficient than direct transfection. However, the model also predicts that by increasing the concentration of deliverable molecules by a factor of 2 or increasing the applied voltage by 20%, reverse transfection can be approximately as efficient as direct transfection
Spleen tyrosine kinase-mediated autophagy is required for epithelial-mesenchymal plasticity and metastasis in breast cancer
The ability of breast cancer cells to transiently transition between epithelial and mesenchymal states contributes to their metastatic potential. Therefore, driving tumor cells into a stable mesenchymal state, as opposed to complete tumor cell eradication, presents an opportunity to pharmacologically limit disease progression by promoting an asymptomatic state of dormancy. Here we compare a reversible model of epithelial-mesenchymal transition (EMT) induced by TGF-β to a stable mesenchymal phenotype induced by chronic exposure to the ErbB kinase inhibitor lapatinib. Only cells capable of returning to an epithelial phenotype resulted in skeletal metastasis. Gene expression analyses of the two mesenchymal states indicated similar transition expression profiles. A potently downregulated gene in both datasets was spleen tyrosine kinase (SYK). In contrast to this similar diminution in mRNA, kinome analyses using a peptide array and DNA-conjugated peptide substrates showed a robust increase in SYK activity upon TGF-β-induced EMT only. SYK was present in cytoplasmic RNA processing depots known as P-bodies formed during the onset of EMT, and SYK activity was required for autophagy-mediated clearance of P-bodies during mesenchymal-epithelial transition (MET). Genetic knockout of autophagy related 7 (ATG7) or pharmacological inhibition of SYK activity with fostamatib, a clinically approved inhibitor of SYK, prevented P-body clearance and MET, inhibiting metastatic tumor outgrowth. Overall, the current study suggests assessment of SYK activity as a biomarker for metastatic disease and the use of fostamatinib as a means to stabilize the latency of disseminated tumor cells
Cross-talk between PRMT1-mediated methylation and ubiquitylation on RBM15 controls RNA splicing
RBM15, an RNA binding protein, determines cell-fate specification of many tissues including blood. We demonstrate that RBM15 is methylated by protein arginine methyltransferase 1 (PRMT1) at residue R578 leading to its degradation via ubiquitylation by an E3 ligase (CNOT4). Overexpression of PRMT1 in acute megakaryocytic leukemia cell lines blocks megakaryocyte terminal differentiation by downregulation of RBM15 protein level. Restoring RBM15 protein level rescues megakaryocyte terminal differentiation blocked by PRMT1 overexpression. At the molecular level, RBM15 binds to pre-mRNA intronic regions of genes important for megakaryopoiesis such as GATA1, RUNX1, TAL1 and c-MPL. Furthermore, preferential binding of RBM15 to specific intronic regions recruits the splicing factor SF3B1 to the same sites for alternative splicing. Therefore, PRMT1 regulates alternative RNA splicing via reducing RBM15 protein concentration. Targeting PRMT1 may be a curative therapy to restore megakaryocyte differentiation for acute megakaryocytic leukemia
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