Cancerous perturbations within the ERK, PI3K/Akt, and Wnt/β-catenin signaling network constitutively activate inter-pathway positive feedback loops

2017 ◽  
Vol 13 (5) ◽  
pp. 830-840 ◽  
Author(s):  
Rahul Rao Padala ◽  
Rishabh Karnawat ◽  
Satish Bharathwaj Viswanathan ◽  
Abhishek Vijay Thakkar ◽  
Asim Bikas Das

Perturbations in molecular signaling pathways result in a constitutively activated state, leading to malignant transformation of cells.

2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Renato Francesco Maria Scalise ◽  
Rosalba De Sarro ◽  
Alessandro Caracciolo ◽  
Rita Lauro ◽  
Francesco Squadrito ◽  
...  

The ischemic injury caused by myocardial infarction activates a complex healing process wherein a powerful inflammatory response and a reparative phase follow and balance each other. An intricate network of mediators finely orchestrate a large variety of cellular subtypes throughout molecular signaling pathways that determine the intensity and duration of each phase. At the end of this process, the necrotic tissue is replaced with a fibrotic scar whose quality strictly depends on the delicate balance resulting from the interaction between multiple actors involved in fibrogenesis. An inflammatory or reparative dysregulation, both in term of excess and deficiency, may cause ventricular dysfunction and life-threatening arrhythmias that heavily affect clinical outcome. This review discusses cellular process and molecular signaling pathways that determine fibrosis and the imaging technique that can characterize the clinical impact of this process in-vivo.


2020 ◽  
Author(s):  
Vera A van der Weijden ◽  
Meret Schmidhauser ◽  
Mayuko Kurome ◽  
Johannes Knubben ◽  
Veronika L Flöter ◽  
...  

Abstract Background: The transcriptional changes around the time of embryonic genome activation in pre-implantation embryos indicate that this process is highly dynamic. In vitro produced porcine blastocysts are known to be less competent than in vivo developed blastocysts. To understand the conditions that compromise developmental competence of in vitro embryos, it is crucial to evaluate the transcriptional profile of porcine embryos during pre-implantation stages. In this study, we investigated the transcriptome dynamics in in vivo developed and in vitro produced 4-cell embryos, morulae and hatched blastocysts.Results: In vivo developed and in vitro produced embryos displayed largely similar transcriptome profiles during development. Enriched canonical pathways from the 4-cell to the morula transition that were shared between in vivo developed and in vitro produced embryos included oxidative phosphorylation, tRNA charging, and EIF2 signaling. The shared canonical pathways from the morula to the hatched blastocyst transition were 14-3-3-mediated signaling, signaling of Rho family GTPases, and NRF2-mediated oxidative stress response. The in vivo developed and in vitro produced hatched blastocysts were compared to identify molecular signaling pathways indicative of lower developmental competence of in vitro produced hatched blastocysts. A higher metabolic rate and expression of the arginine transporter SLC7A1 were found in in vitro produced hatched blastocysts.Conclusions: Our findings suggest that embryos with compromised developmental potential are arrested at an early stage of development, while embryos developing to the hatched blastocyst stage display largely similar transcriptome profiles, irrespective of the embryo source. The hatched blastocysts derived from the in vitro fertilization-pipeline showed an enrichment in molecular signaling pathways associated with lower developmental competence, compared to the in vivo developed embryos.


2020 ◽  
Vol 21 (7) ◽  
pp. 2346 ◽  
Author(s):  
Jicheng Yue ◽  
José M. López

MAPK (mitogen-activated protein kinase) signaling pathways regulate a variety of biological processes through multiple cellular mechanisms. In most of these processes, such as apoptosis, MAPKs have a dual role since they can act as activators or inhibitors, depending on the cell type and the stimulus. In this review, we present the main pro- and anti-apoptotic mechanisms regulated by MAPKs, as well as the crosstalk observed between some MAPKs. We also describe the basic signaling properties of MAPKs (ultrasensitivity, hysteresis, digital response), and the presence of different positive feedback loops in apoptosis. We provide a simple guide to predict MAPKs’ behavior, based on the intensity and duration of the stimulus. Finally, we consider the role of MAPKs in osmostress-induced apoptosis by using Xenopus oocytes as a cell model. As we will see, apoptosis is plagued with multiple positive feedback loops. We hope this review will help to understand how MAPK signaling pathways engage irreversible cellular decisions.


2014 ◽  
Vol 30 (6) ◽  
pp. 331-343 ◽  
Author(s):  
Arakkaveettil Kabeer Farha ◽  
Sethumadhavannair Rajalekshmi Dhanya ◽  
Sivasankaran Nair Mangalam ◽  
Balakrishnan Sreedevi Geetha ◽  
Panickamparambil Gopalakrishnan Latha ◽  
...  

2018 ◽  
Vol 115 (9) ◽  
pp. E1963-E1972 ◽  
Author(s):  
Mariusz Matyszewski ◽  
Seamus R. Morrone ◽  
Jungsan Sohn

The AIM2-ASC inflammasome is a filamentous signaling platform essential for mounting host defense against cytoplasmic dsDNA arising not only from invading pathogens but also from damaged organelles. Currently, the design principles of its underlying signaling network remain poorly understood at the molecular level. We show here that longer dsDNA is more effective in inducing AIM2 assembly, its self-propagation, and downstream ASC polymerization. This observation is related to the increased probability of forming the base of AIM2 filaments, and indicates that the assembly discerns small dsDNA as noise at each signaling step. Filaments assembled by receptor AIM2, downstream ASC, and their joint complex all persist regardless of dsDNA, consequently generating sustained signal amplification and hysteresis. Furthermore, multiple positive feedback loops reinforce the assembly, as AIM2 and ASC filaments accelerate the assembly of nascent AIM2 with or without dsDNA. Together with a quantitative model of the assembly, our results indicate that an ultrasensitive digital circuit drives the assembly of the AIM2-ASC inflammasome.


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