scholarly journals SARS-CoV-2 highly conserved s2m element dimerizes via a kissing complex and interacts with host miRNA-1307-3p

2020 ◽  
Author(s):  
Joshua A. Imperatore ◽  
Caylee L. Cunningham ◽  
Kendy A. Pellegrene ◽  
Robert G. Brinson ◽  
John P. Marino ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Complex Structure ◽  
Protein Translation ◽  
Therapeutic Drug ◽  
Stem Loop ◽  
Multiple Copies ◽  
Genome Dimerization ◽  
Kissing Complex ◽  
Discontinuous Transcription ◽  
Viral Nucleocapsid

ABSTRACTThe ongoing COVID-19 pandemic highlights the necessity for a more fundamental understanding of the coronavirus life cycle. The causative agent of the disease, SARS-CoV-2, is being studied extensively from a structural standpoint in order to gain insight into key molecular mechanisms required for its survival. Contained within the untranslated regions of the SARS-CoV-2 genome are various conserved stem-loop elements that are believed to function in RNA replication, viral protein translation, and discontinuous transcription. While the majority of these regions are variable in sequence, a 41-nucleotide s2m element within the 3’ UTR is highly conserved among coronaviruses and three other viral families. In this study, we demonstrate that the s2m element of SARS-CoV-2 dimerizes by forming an intermediate homodimeric kissing complex structure that is subsequently converted to a thermodynamically stable duplex conformation. This process is aided by the viral nucleocapsid protein, potentially indicating a role in mediating genome dimerization. Furthermore, we demonstrate that the s2m element interacts with multiple copies of host cellular miRNA-1307-3p. Taken together, our results highlight the potential significance of the dimer structures formed by the s2m element in key biological processes and implicate the motif as a possible therapeutic drug target for COVID-19 and other coronavirus-related diseases.

Neuroblastoma: An Updated Review on Biology and Treatment

2020 ◽  
Vol 20 (13) ◽  
pp. 1014-1022 ◽  
Author(s):  
Suresh Mallepalli ◽  
Manoj Kumar Gupta ◽  
Ramakrishna Vadde
Keyword(s):  
Survival Rate ◽  
High Risk ◽  
Molecular Mechanisms ◽  
Definitive Treatment ◽  
Therapeutic Drug ◽  
Mycn Amplification ◽  
Dependent Manner ◽  
High Risk Patients ◽  
Treatment And Prevention ◽  
Risk Patients

Background: Neuroblastoma (NB) is the second leading extracranial solid tumors of early childhood and clinically characterized by the presence of round, small, monomorphic cells with excess nuclear pigmentation (hyperchromasia).Owing to a lack of definitive treatment against NB and less survival rate in high-risk patients, there is an urgent requirement to understand molecular mechanisms associated with NB in a better way, which in turn can be utilized for developing drugs towards the treatment of NB in human. Objectives: In this review, an approach was adopted to understand major risk factors, pathophysiology, the molecular mechanism associated with NB, and various therapeutic agents that can serve as drugs towards the treatment of NB in humans. Conclusions: Numerous genetic (e.g., MYCN amplification), perinatal, and gestational factors are responsible for developing NB. However, no definite environmental or parental exposures responsible for causing NB have been confirmed to date. Though intensive multimodal treatment approaches, namely, chemotherapy, surgery &radiation, may help in improving the survival rate in children, these approaches have several side effects and do not work efficiently in high-risk patients. However, recent studies suggested that numerous phytochemicals, namely, vincristine, and matrine have a minimal side effect in the human body and may serve as a therapeutic drug during the treatment of NB. Most of these phytochemicals work in a dose-dependent manner and hence must be prescribed very cautiously. The information discussed in the present review will be useful in the drug discovery process as well as treatment and prevention on NB in humans.

scholarly journals The Role of Laboratory Tests in Crohn's Disease

2016 ◽  
Vol 9 ◽  
pp. CGast.S38203 ◽  
Author(s):  
Maria Cappello ◽  
Gaetano Cristian Morreale
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Laboratory Tests ◽  
Molecular Mechanisms ◽  
Latent Tuberculosis ◽  
Fecal Calprotectin ◽  
Screening Tests ◽  
Hematological Toxicity ◽  
Therapeutic Drug ◽  
Personalized Care

In the past, laboratory tests were considered of limited value in Crohn's disease (CD). In the era of biologics, laboratory tests have become essential to evaluate the inflammatory burden of the disease (C-reactive protein, fecal calprotectin) since symptoms-based scores are subjective, to predict the response to pharmacological options and the risk of relapse, to discriminate CD from ulcerative colitis, to select candidates to anti-tumor necrosis factors [screening tests looking for hepatitis B virus and hepatitis C virus status and latent tuberculosis], to assess the risk of adverse events (testing for thiopurine metabolites and thiopurine-methyltransferase activity), and to personalize and optimize therapy (therapeutic drug monitoring). Pharmacogenetics, though presently confined to the assessment of thiopurineme methyltransferase polymorphisms and hematological toxicity associated with thiopurine treatment, is a promising field that will contribute to a better understanding of the molecular mechanisms of the variability in response to the drugs used in CD with the attempt to expand personalized care and precision medicine strategies.

scholarly journals Zingerone Suppresses Tumor Development through Decreasing Cyclin D1 Expression and Inducing Mitotic Arrest

2018 ◽  
Vol 19 (9) ◽  
pp. 2832 ◽  
Author(s):  
Jae-Sun Choi ◽  
Jaewook Ryu ◽  
Woom-Yee Bae ◽  
Aron Park ◽  
Seungyoon Nam ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Molecular Mechanisms ◽  
Neuroblastoma Cells ◽  
Mitotic Arrest ◽  
Therapeutic Drug ◽  
Mouse Tumor ◽  
Human Neuroblastoma Cells ◽  
Human Neuroblastoma ◽  
Mitotic Cells

Cancer cells undergo uncontrolled proliferation resulting from aberrant activity of various cell-cycle proteins. Therefore, despite recent advances in intensive chemotherapy, it is difficult to cure cancer completely. Recently, cell-cycle regulators became attractive targets in cancer therapy. Zingerone, a phenolic compound isolated from ginger, is a nontoxic and inexpensive compound with varied pharmacological activities. In this study, the therapeutic effect of zingerone as an anti-mitotic agent in human neuroblastoma cells was investigated. Following treatment of BE(2)-M17 cells with zingerone, we performed a 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and colony-formation assay to evaluate cellular proliferation, in addition to immunofluorescence cytochemistry and flow cytometry to examine the mitotic cells. The association of gene expression with tumor stage and survival was analyzed. Furthermore, to examine the anti-cancer effect of zingerone, we applied a BALB/c mouse-tumor model using a BALB/c-derived adenocarcinoma cell line. In human neuroblastoma cells, zingerone inhibited cellular viability and survival. Moreover, the number of mitotic cells, particularly those in prometaphase, increased in zingerone-treated neuroblastoma cells. Regarding specific molecular mechanisms, zingerone decreased cyclin D1 expression and induced the cleavage of caspase-3 and poly (ADP-ribose) polymerase 1 (PARP-1). The decrease in cyclin D1 and increase in histone H3 phosphorylated (p)-Ser10 were confirmed by immunohistochemistry in tumor tissues administered with zingerone. These results suggest that zingerone induces mitotic arrest followed by inhibition of growth of neuroblastoma cells. Collectively, zingerone may be a potential therapeutic drug for human cancers, including neuroblastoma.

Melatonin ameliorates ovarian dysfunction by regulating autophagy in PCOS via the PI3K-Akt pathway

Reproduction ◽  
2021 ◽  
Author(s):  
Fenfen Xie ◽  
Junhui Zhang ◽  
Muxin Zhai ◽  
Yajing Liu ◽  
Hui Hu ◽  
...  
Keyword(s):  
Rat Model ◽  
Follicular Fluid ◽  
Molecular Mechanisms ◽  
Ovarian Function ◽  
Polycystic Ovary ◽  
Akt Pathway ◽  
Therapeutic Drug ◽  
Ovarian Dysfunction ◽  
Protective Function ◽  
Expression Levels

Emerging evidence has demonstrated that melatonin (MT) plays a crucial role in regulating mammalian reproductive functions. It has been reported that MT has a protective effect on polycystic ovary syndrome (PCOS). However, the protective mechanisms of MT remain poorly understood. This study aims to explore the effect of MT on ovarian function in PCOS and to elucidate the relevant molecular mechanisms in vivo and in vitro. Here, we first analysed MT expression levels in the follicular fluid of PCOS patients. A significant reduction in MT expression levels was noted in PCOS patients. Intriguingly, reduced MT levels correlated with serum testosterone and inflammatory cytokine levels in follicular fluid. Moreover, we confirmed the protective function of MT through regulating autophagy in a dehydroepiandrosterone (DHEA)-induced PCOS rat model. Autophagy was activated in the ovarian tissue of the PCOS rat model, whereas additional MT inhibited autophagy by increasing PI3K-Akt pathway expression. In addition, serum-free testosterone, inflammatory and apoptosis indexes were reduced after MT supplementation. Furthermore, we also found that MT suppressed autophagy and apoptosis by activating the PI3K-Akt pathway in the DHEA-exposed human granulosa cell line KGN. Our study showed that MT ameliorated ovarian dysfunction by regulating autophagy in DHEA-induced PCOS via the PI3K-Akt pathway, revealing a potential therapeutic drug target for PCOS.

scholarly journals Studying the Role and Molecular Mechanisms of MAP4K3 in Sorafenib Resistance of Hepatocellular Carcinoma

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yi Shi ◽  
Xiaofei Mo ◽  
Simei Hong ◽  
Tianbao Li ◽  
Baozhen Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Flow Cytometry ◽  
Cell Proliferation ◽  
Molecular Mechanisms ◽  
Cellular Proliferation ◽  
Resistant Cell ◽  
Therapeutic Drug ◽  
Specific Gene ◽  
Sorafenib Treatment ◽  
Proliferation And Apoptosis

Sorafenib is the first FDA-approved therapeutic drug for molecular target medication on advanced-stage hepatocellular carcinoma. It is reported that sorafenib could improve the survival of progression-free patients for 4 to 6 months; however, most of the patients developed drug resistance. Thus, it is critical to reveal the biological mechanisms behind sorafenib resistance. In this study, a sorafenib-resistant model was developed by exposing HepG2 cells to sorafenib with gradient increasing concentration, and the resistance-related genes were screened by microarray. Real-time qPCR was used to validate selected gene expression of the resistance model, and lentivirus vector-mediated RNA interference was applied for specific gene knockdown. In addition, high-throughput High Celigo Select (HCS) and flow cytometry were used to measure the effect on cellular proliferation and apoptosis. As a result, our study established a sorafenib-resistant model with IC50 of 9.988 μM. The Affymetrix expression profile of the sorafenib-resistant model showed 35 resistant-related genes, and 91.4% of the resistant genes showed upregulation in HepG2 resistance cells. In addition, 20 genes were knocked down to measure cell proliferation, and MAP4K3 with high proliferation inhibiting phenotype was chosen for further study. Meanwhile, the HCS results revealed that shMAP4K3 transfection could downregulate resistant cell proliferation, and the flow cytometry results showed that cell apoptosis was significantly increased in the MAP4K3 knockdown group. In summary, MAP4K3 is a novel molecular marker for improving the drug sensitivity of sorafenib treatment in hepatocellular carcinoma.

scholarly journals Genomics of autism spectrum disorder: approach to therapy

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 627 ◽  
Author(s):  
Fatma Ayhan ◽  
Genevieve Konopka
Keyword(s):  
Autism Spectrum Disorder ◽  
Genetic Variants ◽  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Protein Translation ◽  
Autism Spectrum ◽  
Current Treatment ◽  
Spectrum Disorder ◽  
Current State ◽  
Genetics And Genomics

Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental condition with no current treatment available. Although advances in genetics and genomics have identified hundreds of genes associated with ASD, very little is known about the pathophysiology of ASD and the functional contribution of specific genes to ASD phenotypes. Improved understanding of the biological function of ASD-associated genes and how this heterogeneous group of genetic variants leads to the disease is needed in order to develop therapeutic strategies. Here, we review the current state of ASD research related to gene discovery and examples of emerging molecular mechanisms (protein translation and alternative splicing). In addition, we discuss how patient-derived three-dimensional brain organoids might provide an opportunity to model specific genetic variants in order to define molecular and cellular defects that could be amenable for developing and screening personalized therapies related to ASD.

scholarly journals Conservation of the pentanucleotide motif at the top of the yellow fever virus 17D 3′ stem–loop structure is not required for replication

2007 ◽  
Vol 88 (6) ◽  
pp. 1738-1747 ◽  
Author(s):  
Patrícia A. G. C. Silva ◽  
Richard Molenkamp ◽  
Tim J. Dalebout ◽  
Nathalie Charlier ◽  
Johan H. Neyts ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Molecular Mechanisms ◽  
Yellow Fever Virus ◽  
Animal Cell ◽  
Fever Virus ◽  
Loop Structure ◽  
Animal Cells ◽  
Pn Sequence ◽  
Stem Loop ◽  
Stem Loop Structure

The pentanucleotide (PN) sequence 5′-CACAG-3′ at the top of the 3′ stem–loop structure of the flavivirus genome is well conserved in the arthropod-borne viruses but is more variable in flaviviruses with no known vector. In this study, the sequence requirements of the PN motif for yellow fever virus 17D (YFV) replication were determined. In general, individual mutations at either the second, third or fourth positions were tolerated and resulted in replication-competent virus. Mutations at the fifth position were lethal. Base pairing of the nucleotide at the first position of the PN motif and a nucleotide four positions downstream of the PN (ninth position) was a major determinant for replication. Despite the fact that the majority of the PN mutants were able to replicate efficiently, they were outcompeted by parental YFV-17D virus following repeated passages in double-infected cell cultures. Surprisingly, some of the virus mutants at the first and/or the ninth position that maintained the possibility of forming a base pair were found to have a similar fitness to YFV-17D under these conditions. Overall, these experiments suggest that YFV is less dependent on sequence conservation of the PN motif for replication in animal cells than West Nile virus. However, in animal cell culture, YFV has a preference for the wt CACAG PN sequence. The molecular mechanisms behind this preference remain to be elucidated.

Cellular Cholesterol Modulates VEGFR-1 Function on Acute Leukemia Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1847-1847
Author(s):  
Rita Fragoso ◽  
Cristina Casalou ◽  
Sergio Dias
Keyword(s):  
Cell Migration ◽  
Growth Factor ◽  
Acute Leukemia ◽  
Molecular Mechanisms ◽  
Cholesterol Metabolism ◽  
Leukemia Cell ◽  
Protein Translation ◽  
Leukemia Cells ◽  
Cholesterol Levels

Abstract Vascular endothelial growth factor (VEGF) and its receptors play a crucial role in malignancy and in disease, regulating the survival, proliferation, and migration of several cell types, such as endothelium and also leukemia cells. Following our recent report on the role of VEGFR-1 (FLT-1) in ALL (Fragoso R et al, 2006), in the present study we analyzed the molecular mechanisms whereby it modulates acute leukemia cell migration in response to VEGF/Placental Growth Factor (PLGF). First, we observed the formation of cell protrusions on ALL cells after VEGF/PLGF stimulation, with evidence for polymerized actin and FLT-1 co-localization (as determined by phalloidin, immunofluorescence staining, and confocal microscopy). Western blot analysis revealed that PLGF/VEGF stimulation resulted in increased RhoA and Rac1 GTPases expression. Co-treatment with LY200942 significantly decreased RhoA and Rac1 induction and cell migration by PLGF/VEGF, demonstrating this effect is modulated via Pi3 kinase. Next, we investigated the mechanisms whereby FLT-1 and actin co-localize at the cell “leading edge” (protrusions), after VEGF/PLGF stimulation, and the relevance of such co-localization for cell migration. We addressed this question by impairing the formation of lipid rafts/caveolae using drugs that either sequester (nystatin) or deplete (methyl-β-ciclodextrin) total cholesterol. Accordingly, co-treatment of leukemia cells with nystatin or MβCD and PLGF/VEGF blocked cell migration, an effect that was associated with a decrease in FLT-1 polarization and co-localization with actin filaments. Instead, FLT-1 was now found mostly in the cell cytosol. Given that leukemia cells have an increased rate of cholesterol up-take we sought to understand if increased cholesterol levels affected FLT-1 function in leukemia cells. Cholesterol repletion in leukemia cells enhanced leukemia cells migration in response to VEGF/PlGF (about 3 folds). This significant increase was associated with an increase in FLT-1 protein expression that, very interestingly, was particularly concentrated intracellulary in the cytoplasm. At this time we are trying to understand if this increase in FLT-1 expression after cholesterol repletion is associated with increase protein translation or impairment in proteasome activity. Finally, our preliminary in vivo experiments using Nod-Scid mice subjected (n=3) or not (n=3) to high fat diet (that results in increased cholesterol levels in the BM and in the spleen), showed this metabolic condition worsens disease symptoms and significantly decreases mouse survival. These results reveal for the first time some of the molecular mechanisms involved in FLT-1-mediated leukemia migration, namely the involvement of cholesterol metabolism, which may be crucial for new therapeutics delineation.

scholarly journals Folic acid inhibits nasopharyngeal cancer cell proliferation and invasion via activation of FRα/ERK1/2/TSLC1 pathway

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Zhibiao Liu ◽  
Xin Jin ◽  
Wen Pi ◽  
Shouhou Liu
Keyword(s):  
Cell Proliferation ◽  
Folic Acid ◽  
Molecular Mechanisms ◽  
Folate Receptor ◽  
Nasopharyngeal Cancer ◽  
Therapeutic Drug ◽  
Invasion And Migration ◽  
Treatment Dose ◽  
And Migration ◽  
Proliferation And Invasion

Folic acid (FA), which is necessary for normal cell division of mammals, has been implicated to be involved in many tumors. Dietary FA intake has been reported to be associated with a lower risk of nasopharyngeal cancer (NPC). However, the molecular mechanisms of FA in NPC cells remain unclear. In the present study, we found that FA treatment dose dependently inhibited the proliferation, invasion and migration of NPC cells, via folate receptor α (FRα). We further found that FA, bound to FRα, induced the activation of MEK/ERK1/2, and increased the expressions of TSLC1 and E-cadherin. Moreover, blocking of ERK1/2 activation attenuated FA-mediated increase in TSLC1 expression. In addition, knockdown of TSLC1 abolished the FA-mediated inhibition of cell proliferation, invasion and migration, and suppressed the FA-mediated increase oinE-cadherin expression in NPC cells. Taken together, our data suggest that FA treatment inhibits NPC cell proliferation and invasion via activation of FRα/ERK1/2/ TSLC1 signaling pathway. Therefore, FA could be explored as a therapeutic drug for the treatment of NPC, and TSLC1 may act as a tumor suppressor in NPC.

scholarly journals How AMPK and PKA Interplay to Regulate Mitochondrial Function and Survival in Models of Ischemia and Diabetes

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jingdian Zhang ◽  
Yumeng Wang ◽  
Xiaofeng Liu ◽  
Ruben K. Dagda ◽  
Ying Zhang
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cardiovascular Diseases ◽  
Protein Kinase ◽  
Cell Survival ◽  
Mitochondrial Function ◽  
Molecular Mechanisms ◽  
Temporal Dynamics ◽  
Protein Translation ◽  
Conservation Of Energy

Adenosine monophosphate-activated protein kinase (AMPK) is a conserved, redox-activated master regulator of cell metabolism. In the presence of oxidative stress, AMPK promotes cytoprotection by enhancing the conservation of energy by suppressing protein translation and by stimulating autophagy. AMPK interplays with protein kinase A (PKA) to regulate oxidative stress, mitochondrial function, and cell survival. AMPK and dual-specificity A-kinase anchoring protein 1 (D-AKAP1), a mitochondrial-directed scaffold of PKA, interact to regulate mitochondrial function and oxidative stress in cardiac and endothelial cells. Ischemia and diabetes, a chronic disease that increases the onset of cardiovascular diseases, suppress the cardioprotective effects of AMPK and PKA. Here, we review the molecular mechanisms by which AMPK and D-AKAP1/PKA interplay to regulate mitochondrial function, oxidative stress, and signaling pathways that prime endothelial cells, cardiac cells, and neurons for cytoprotection against oxidative stress. We discuss recent literature showing how temporal dynamics and localization of activated AMPK and PKA holoenzymes play a crucial role in governing cellular bioenergetics and cell survival in models of ischemia, cardiovascular diseases, and diabetes. Finally, we propose therapeutic strategies that tout localized PKA and AMPK signaling to reverse mitochondrial dysfunction, oxidative stress, and death of neurons and cardiac and endothelial cells during ischemia and diabetes.

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