scholarly journals Human OAS1 activation is highly dependent on both RNA sequence and context of activating RNA motifs

2020 ◽  
Author(s):  
Samantha L Schwartz ◽  
Esther N Park ◽  
Virginia K Vachon ◽  
Shamika Danzy ◽  
Anice C Lowen ◽  
...  
Keyword(s):  
Structural Changes ◽  
Strong Dependence ◽  
Consensus Sequence ◽  
Critical Role ◽  
A549 Cells ◽  
Rna Motifs ◽  
Rna Sequences ◽  
Dsrna Binding ◽  
The Impact

Abstract 2′-5′-Oligoadenylate synthetases (OAS) are innate immune sensors of cytosolic double-stranded RNA (dsRNA) and play a critical role in limiting viral infection. dsRNA binding induces allosteric structural changes in OAS1 that reorganize its catalytic center to promote synthesis of 2′-5′-oligoadenylate and thus activation of endoribonuclease L. Specific RNA sequences and structural motifs can also enhance activation of OAS1 through currently undefined mechanisms. To better understand these drivers of OAS activation, we tested the impact of defined sequence changes within a short dsRNA that strongly activates OAS1. Both in vitro and in human A549 cells, appending a 3′-end single-stranded pyrimidine (3′-ssPy) can strongly enhance OAS1 activation or have no effect depending on its location, suggesting that other dsRNA features are necessary for correct presentation of the motif to OAS1. Consistent with this idea, we also find that the dsRNA binding position is dictated by an established consensus sequence (WWN9WG). Unexpectedly, however, not all sequences fitting this consensus activate OAS1 equivalently, with strong dependence on the identity of both partially conserved (W) and non-conserved (N9) residues. A picture thus emerges in which both specific RNA features and the context in which they are presented dictate the ability of short dsRNAs to activate OAS1.

VDAC1 Mediated Anticancer Activity of Gallic Acid in Human Lung Adenocarcinoma A549 Cells

2018 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Aikebaier Maimaiti ◽  
Amier Aili ◽  
Hureshitanmu Kuerban ◽  
Xuejun Li
Keyword(s):  
Western Blot ◽  
Cell Viability ◽  
Gallic Acid ◽  
Molecular Mechanisms ◽  
A549 Cells ◽  
Dependent Manner ◽  
Lung Carcinoma Cells ◽  
Induced Apoptosis ◽  
The Impact

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.

scholarly journals NLRP7 Promotes Choriocarcinoma Growth and Progression through the Establishment of an Immunosuppressive Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2999
Author(s):  
Deborah Reynaud ◽  
Roland Abi Nahed ◽  
Nicolas Lemaitre ◽  
Pierre-Adrien Bolze ◽  
Wael Traboulsi ◽  
...  
Keyword(s):  
Immune Response ◽  
Tumor Cells ◽  
Major Gene ◽  
Critical Role ◽  
Orthotopic Model ◽  
Independent Manner ◽  
Maternal Immune Response ◽  
The Impact

The inflammatory gene NLRP7 is the major gene responsible for recurrent complete hydatidiform moles (CHM), an abnormal pregnancy that can develop into gestational choriocarcinoma (CC). However, the role of NLRP7 in the development and immune tolerance of CC has not been investigated. Three approaches were employed to define the role of NLRP7 in CC development: (i) a clinical study that analyzed human placenta and sera collected from women with normal pregnancies, CHM or CC; (ii) an in vitro study that investigated the impact of NLRP7 knockdown on tumor growth and organization; and (iii) an in vivo study that used two CC mouse models, including an orthotopic model. NLRP7 and circulating inflammatory cytokines were upregulated in tumor cells and in CHM and CC. In tumor cells, NLRP7 functions in an inflammasome-independent manner and promoted their proliferation and 3D organization. Gravid mice placentas injected with CC cells invalidated for NLRP7, exhibited higher maternal immune response, developed smaller tumors, and displayed less metastases. Our data characterized the critical role of NLRP7 in CC and provided evidence of its contribution to the development of an immunosuppressive maternal microenvironment that not only downregulates the maternal immune response but also fosters the growth and progression of CC.

scholarly journals Acid Challenge on Push-Out Bond Strength of Three Different Tricalcium Silicate Cements: An In-vitro Study

2021 ◽  
pp. 72-79
Author(s):  
Mattapudi Basavaiah Babu ◽  
T. B. V. G. Raju ◽  
N. Mahendra Varma ◽  
Gowtam Dev Dondapati ◽  
Srivalli Podili ◽  
...  
Keyword(s):  
Bond Strength ◽  
Critical Role ◽  
Compressive Load ◽  
Clinical Importance ◽  
Filling Material ◽  
Significant Difference ◽  
The Impact ◽  
Push Out ◽  
Acid Challenge

Aim: To evaluate the impact of environmental pH on intra-radicular dentin push-out bond strengths of MTA, MTA HP, and Biodentine. Materials and Methodology: Freshly extracted human mandibular single-rooted premolars or maxillary anterior incisors that were either intact or contained only small carious lesions were selected.120 mid root dentins is horizontally divided into 1.0 mm thick slices and divided into 3 MTA, MTA HP, BIODENTINE groups. The compressive load is applied at a speed of 0.5 mm/min by exerting a downward pressure on the outer surface of MTA using a 1.00 mm diameter cylindrical stainless-steel plunger. Maximum load to MTA was reported in newtons at the time of dislodgement and converted to megapascals. The 1-way analysis of variance test was used to compare the push-out bond strength of the groups with the same storage time (4 or 34 days), followed by the pair-wise comparison of the Tukey post hoc test. The Student's t-test was used to evaluate 3-group means. At P = .005, the degree of significance was set. Thus the clinical importance of the present study states that considering several factors like microhardness, composition by products, particle sizes and the environmental pH plays a critical role in selection of root end filling material. Results: There was significant difference between groups (P = .001) after 4 days of PBS and Acid condition, where Bio dentine had significantly the highest bond strength. Conclusion: The strength of MTA HP, BIODENTINE, MTA materials at dentine interface increases over 30 days in the storage of PBS solution at pH 7.4, after an initial acid challenge by acetic acid of pH 5.4, which decreases initial bond strength.

scholarly journals Triplet Analysis That Identifies Unpaired Regions of Functional RNAs

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Junji Kawakami ◽  
Yoshie Yamaguchi ◽  
Naoki Sugimoto
Keyword(s):  
Consensus Sequence ◽  
Structural Features ◽  
Analysis Method ◽  
Primary Sequence ◽  
Rna Sequences ◽  
Unpaired Region ◽  
Novel Method ◽  
Functional Rnas ◽  
Hiv 1

We developed a novel method for analyzing RNA sequences, deemed triplet analysis, and applied the method in anin vitroRNA selection experiment in which HIV-1 Tat was the target. Aptamers are nucleic acids that bind a desired target (bait), and to date, many aptamers have been identified byin vitroselection from enough concentrated libraries in which many RNAs had an obvious consensus primary sequence after sufficient cycles of the selection. Therefore, the higher-order structural features of the aptamers that are indispensable for interaction with the bait must be determined by additional investigation of the aptamers. In contrast, our triplet analysis enabled us to extract important information on functional primary and secondary structure from minimally concentrated RNA libraries. As a result, by using our method, an important unpaired region that is similar to the bulge of TAR was readily predicted from a partially concentrated library in which no consensus sequence was revealed by a conventional sequence analysis. Moreover, our analysis method may be used to assess a variety of structural motifs with desired function.

scholarly journals MicroRNA-28-5p Regulates Liver Cancer Stem Cell Expansion via IGF-1 Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Qing Xia ◽  
Tao Han ◽  
Pinghua Yang ◽  
Ruoyu Wang ◽  
Hengyu Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Liver Cancer ◽  
Critical Role ◽  
Self Renewal ◽  
Sorafenib Treatment ◽  
The Impact

Background. MicroRNAs (miRNAs) play a critical role in the regulation of cancer stem cells (CSCs). However, the role of miRNAs in liver CSCs has not been fully elucidated. Methods. Real-time PCR was used to detect the expression of miR-miR-28-5p in liver cancer stem cells (CSCs). The impact of miR-28-5p on liver CSC expansion was investigated both in vivo and in vitro. The correlation between miR-28-5p expression and sorafenib benefits in HCC was further evaluated in patient-derived xenografts (PDXs). Results. Our data showed that miR-28-5p was downregulated in sorted EpCAM- and CD24-positive liver CSCs. Biofunctional investigations revealed that knockdown miR-28-5p promoted liver CSC self-renewal and tumorigenesis. Consistently, miR-28-5p overexpression inhibited liver CSC’s self-renewal and tumorigenesis. Mechanistically, we found that insulin-like growth factor-1 (IGF-1) was a direct target of miR-28-5p in liver CSCs, and the effects of miR-28-5p on liver CSC’s self-renewal and tumorigenesis were dependent on IGF-1. The correlation between miR-28-5p and IGF-1 was confirmed in human HCC tissues. Furthermore, the miR-28-5p knockdown HCC cells were more sensitive to sorafenib treatment. Analysis of patient-derived xenografts (PDXs) further demonstrated that the miR-28-5p may predict sorafenib benefits in HCC patients. Conclusion. Our findings revealed the crucial role of the miR-28-5p in liver CSC expansion and sorafenib response, rendering miR-28-5p an optimal therapeutic target for HCC.

scholarly journals Can Hypoxic Conditioning Improve Bone Metabolism? A Systematic Review

2019 ◽  
Vol 16 (10) ◽  
pp. 1799 ◽  
Author(s):  
Marta Camacho-Cardenosa ◽  
Alba Camacho-Cardenosa ◽  
Rafael Timón ◽  
Guillermo Olcina ◽  
Pablo Tomas-Carus ◽  
...  
Keyword(s):  
Bone Metabolism ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Experimental Studies ◽  
Hormonal Responses ◽  
Hypoxia Exposure ◽  
Ambient Oxygen ◽  
The Impact

Among other functions, hypoxia-inducible factor plays a critical role in bone–vascular coupling and bone formation. Studies have suggested that hypoxic conditioning could be a potential nonpharmacological strategy for treating skeletal diseases. However, there is no clear consensus regarding the bone metabolism response to hypoxia. Therefore, this review aims to examine the impact of different modes of hypoxia conditioning on bone metabolism. The PubMed and Web of Science databases were searched for experimental studies written in English that investigated the effects of modification of ambient oxygen on bone remodelling parameters of healthy organisms. Thirty-nine studies analysed the effect of sustained or cyclic hypoxia exposure on genetic and protein expression and mineralisation capacity of different cell models; three studies carried out in animal models implemented sustained or cyclic hypoxia; ten studies examined the effect of sustained, intermittent or cyclic hypoxia on bone health and hormonal responses in humans. Different modes of hypoxic conditioning may have different impacts on bone metabolism both in vivo and in vitro. Additional research is necessary to establish the optimal cyclical dose of oxygen concentration and exposure time.

scholarly journals Aging predisposes to acute inflammatory induced pathology after tumor immunotherapy

2013 ◽  
Vol 210 (11) ◽  
pp. 2223-2237 ◽  
Author(s):  
Myriam N. Bouchlaka ◽  
Gail D. Sckisel ◽  
Mingyi Chen ◽  
Annie Mirsoian ◽  
Anthony E. Zamora ◽  
...  
Keyword(s):  
Critical Role ◽  
The Elderly ◽  
Mouse Tumor ◽  
Aged Mice ◽  
Liver Histopathology ◽  
Multiple Organs ◽  
The Impact ◽  
Young Mice

Cancer commonly occurs in the elderly and immunotherapy (IT) is being increasingly applied to this population. However, the majority of preclinical mouse tumor models assessing potential efficacy and toxicities of therapeutics use young mice. We assessed the impact of age on responses to systemic immune stimulation. In contrast to young mice, systemic cancer IT regimens or LPS given to aged mice resulted in rapid and lethal toxicities affecting multiple organs correlating with heightened proinflammatory cytokines systemically and within the parenchymal tissues. This inflammatory response and increased morbidity with age was independent of T cells or NK cells. However, prior in vivo depletion of macrophages in aged mice resulted in lesser cytokine levels, increased survival, and decreased liver histopathology. Furthermore, macrophages from aged mice and normal human elderly volunteers displayed heightened TNF and IL-6 production upon in vitro stimulation. Treatment of both TNF knockout mice and in vivo TNF blockade in aged mice resulted in significant increases in survival and lessened pathology. Importantly, TNF blockade in tumor-bearing, aged mice receiving IT displayed significant anti-tumor effects. These data demonstrate the critical role of macrophages in the age-associated hyper-inflammatory cytokine responses to systemic immunostimulation and underscore the importance of performing preclinical assessments in aged mice.

scholarly journals Identification of Upstream Sequences Essential for Activation of a Bacteriophage P2 Late Promoter

2003 ◽  
Vol 185 (15) ◽  
pp. 4609-4614 ◽  
Author(s):  
Gail E. Christie ◽  
Douglas L. Anders ◽  
Victor McAlister ◽  
Tina S. Goodwin ◽  
Bryan Julien ◽  
...  
Keyword(s):  
Consensus Sequence ◽  
Critical Role ◽  
Constitutive Expression ◽  
Upstream Region ◽  
Activation Of Transcription ◽  
Bacteriophage P2 ◽  
Dyad Symmetry ◽  
Rna Polymerase Holoenzyme

ABSTRACT We have carried out a mutational scan of the upstream region of the bacteriophage P2 FETUD late operon promoter, PF, which spans an element of hyphenated dyad symmetry that is conserved among all six of the P2 and P4 late promoters. All mutants were assayed for activation by P4 Delta in vivo, by using a lacZ reporter plasmid, and a subset of mutants was assayed in vitro for Delta binding. The results confirm the critical role of the three complementary nucleotides in each half site of the upstream element for transcription factor binding and for activation of transcription. A trinucleotide DNA recognition site is consistent with a model in which these transcription factors bind via a zinc finger motif. The mutational scan also led to identification of the −35 region of the promoter. Introduction of a σ70 −35 consensus sequence resulted in increased constitutive expression, which could be further stimulated by Delta. These results indicate that activator binding to the upstream region of P2 late promoters compensates in part for poor σ70 contacts and helps to recruit RNA polymerase holoenzyme.

SH3-mediated targeting of Wrch1/RhoU by multiple adaptor proteins

2013 ◽  
Vol 394 (3) ◽  
pp. 421-432 ◽  
Author(s):  
Sarah L. Risse ◽  
Belen Vaz ◽  
Matthew F. Burton ◽  
Pontus Aspenström ◽  
Roland P. Piekorz ◽  
...  
Keyword(s):  
Consensus Sequence ◽  
Adaptor Protein ◽  
Structural Difference ◽  
Adaptor Proteins ◽  
Sh3 Domain ◽  
High Avidity ◽  
Sh3 Domains ◽  
Pxxp Motif ◽  
The Impact

Abstract Wrch1/RhoU is an atypical member of the Rho family. A major structural difference is the extended N-terminus of Wrch1 (nWrch1) containing three putative SH3 domain-binding motifs whose specificities are unknown. To define the impact of this extended region on coupling Wrch1 to cellular signaling, we analyzed in this study nWrch1 interaction with Src homology 3 (SH3) domains of different adaptor proteins. Using sedimentation and isothermal titration calorimetric (ITC) measurements, we identified isolated SH3 domains of growth factor receptor-bound protein 2 (Grb2), noncatalytic region of tyrosine kinase adaptor protein 1 (Nck1), c-Src, chicken tumor virus no. 10 (CT 10) regulator kinase 1 (Crk1), and p120 as low-affinity Wrch1-binding partners. Interestingly, under cell-based conditions, nWrch1 bound tightly to endogenous Grb2 and Nck, but not to Crk, c-Src, or p120. Consistent with this, a very tight nWrch1 interaction with full-length Grb2 and Nck1 was confirmed in vitro by ITC measurements indicating that high avidity of the adaptor proteins can compensate for the low affinity of their SH3 domains. Peptide analysis revealed that the central PxxP motif of nWrch1, which employs a minimal consensus sequence of eight amino acids with an essential arginine next to the PxxP motif, is responsible for these interactions. Thus, novel functional insights from this study suggest that multiple upstream signals may converge on Wrch1 directly through its SH3 domain-binding properties.

scholarly journals IGF-I Regulates Pheochromocytoma Cell Proliferation and Survival In Vitro and In Vivo

Endocrinology ◽  
2012 ◽  
Vol 153 (8) ◽  
pp. 3724-3734 ◽  
Author(s):  
María Celia Fernández ◽  
Marcela Venara ◽  
Susana Nowicki ◽  
Héctor E. Chemes ◽  
Marta Barontini ◽  
...  
Keyword(s):  
Critical Role ◽  
Tumor Development ◽  
Receptor Expression ◽  
Vascular Density ◽  
Receptor System ◽  
Igf I ◽  
Tumor Phenotype ◽  
The Impact

IGFs are involved in malignant transformation and growth of several tissues, including the adrenal medulla. The present study was designed to evaluate the impact of IGF-I on pheochromocytoma development. We used a murine pheochromocytoma (MPC) cell line (MPC4/30) and an animal model with a reduction of 75% in circulating IGF-I levels [liver-IGF-I-deficient (LID) mice] to perform studies in vitro and in vivo. We found that, in culture, IGF-I stimulation increases proliferation, migration, and anchorage-independent growth, whereas it inhibits apoptosis of MPC cells. When injected to control and to LID mice, MPC cells grow and form tumors with features of pheochromocytoma. Six weeks after cell inoculation, all control mice developed sc tumors. In contrast, in 73% of LID mice, tumor development was delayed to 7–12 wk, and the remaining 27% did not develop tumors up to 12 wk after inoculation. LID mice harboring MPC cells and treated with recombinant human IGF-I (LID+) developed tumors as controls. Tumors developed in control, LID, and LID+ mice had similar histology and were similarly positive for IGF-I receptor expression. The apoptotic index was higher in tumors from LID mice compared with those from control mice, whereas vascular density was decreased. In summary, our work demonstrates that IGF-I has a critical role in maintaining tumor phenotype and survival of already transformed pheochromocytoma cells and is required for the initial establishment of these tumors, providing encouragement to carry on research studies to address the IGF-I/IGF-I receptor system as a target of therapeutic strategies for pheochromocytoma treatment in the future.

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