scholarly journals In VitroStudies of Neuronal Networks and Synaptic Plasticity in Invertebrates and in Mammals Using Multielectrode Arrays

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Paolo Massobrio ◽  
Jacopo Tessadori ◽  
Michela Chiappalone ◽  
Mirella Ghirardi

Brain functions are strictly dependent on neural connections formed during development and modified during life. The cellular and molecular mechanisms underlying synaptogenesis and plastic changes involved in learning and memory have been analyzed in detail in simple animals such as invertebrates and in circuits of mammalian brains mainly by intracellular recordings of neuronal activity. In the last decades, the evolution of techniques such as microelectrode arrays (MEAs) that allow simultaneous, long-lasting, noninvasive, extracellular recordings from a large number of neurons has proven very useful to study long-term processes in neuronal networksin vivoandin vitro. In this work, we start off by briefly reviewing the microelectrode array technology and the optimization of the coupling between neurons and microtransducers to detect subthreshold synaptic signals. Then, we report MEA studies of circuit formation and activity in invertebrate models such asLymnaea,Aplysia, andHelix. In the following sections, we analyze plasticity and connectivity in cultures of mammalian dissociated neurons, focusing on spontaneous activity and electrical stimulation. We conclude by discussing plasticity in closed-loop experiments.

2020 ◽  
Author(s):  
M.S. Profes ◽  
A. Saghatelyan ◽  
M. Lévesque

AbstractMesodiencephalic dopamine (mDA) neurons play a wide range of brain functions. Distinct subtypes of mDA neurons regulate these functions but the molecular mechanisms that drive the mDA circuit formation are largely unknown. Here we show that autophagy, the main recycling cellular pathway, is present in the growth cones of developing mDA neurons and its level changes dynamically in response to guidance cues. To characterize the role of autophagy in mDA axon growth/guidance, we knocked-out (KO) essential autophagy genes (Atg12, Atg5) in mice mDA neurons. Autophagy deficient mDA axons exhibit axonal swellings and decreased branching both in vitro and in vivo, likely due to aberrant microtubule looping. Strikingly, deletion of autophagy-related genes, blunted completely the response of mDA neurons to chemo-repulsive and chemo-attractive guidance cues. Our data demonstrate that autophagy plays a central role in regulating mDA neurons development, orchestrating axonal growth and guidance.


2019 ◽  
Vol 26 (27) ◽  
pp. 5152-5164 ◽  
Author(s):  
Barbara Budzynska ◽  
Caterina Faggio ◽  
Marta Kruk-Slomka ◽  
Dunja Samec ◽  
Seyed Fazel Nabavi ◽  
...  

Flavonoids are major dietary constituents of plant-based food found ubiquitously in plant kingdom where they are usually present in substantial amounts. Rutin is a flavonol-type polyphenol which consists of the flavonol quercetin and the disaccharide rutinose. Rutin has been reported to exert diverse biological effects such as antitumor and antimicrobial mainly associated to its antioxidant and anti-inflammatory activities. Mental, neurological, and behavioural disorders are an important and growing cause of morbidity. Most of these disorders combine a high prevalence, early onset, progressive clinical course, and impairment of critical brain functions making them a major contributor to the global disease burden. In the present work, the biological in vitro and in vivo effects and the potential therapeutic applications of rutin in neurodegenerative processes are reviewed, as well as their bioavailability and pharmacokinetics, which are essential for a better understanding of its biological effectiveness. Moreover, the present review also provides an overview of the molecular mechanisms through which rutin is proposed to exert its neuroprotective effects.


2019 ◽  
Vol 26 (25) ◽  
pp. 4799-4831 ◽  
Author(s):  
Jiahua Cui ◽  
Xiaoyang Liu ◽  
Larry M.C. Chow

P-glycoprotein, also known as ABCB1 in the ABC transporter family, confers the simultaneous resistance of metastatic cancer cells towards various anticancer drugs with different targets and diverse chemical structures. The exploration of safe and specific inhibitors of this pump has always been the pursuit of scientists for the past four decades. Naturally occurring flavonoids as benzopyrone derivatives were recognized as a class of nontoxic inhibitors of P-gp. The recent advent of synthetic flavonoid dimer FD18, as a potent P-gp modulator in reversing multidrug resistance both in vitro and in vivo, specifically targeted the pseudodimeric structure of the drug transporter and represented a new generation of inhibitors with high transporter binding affinity and low toxicity. This review concerned the recent updates on the structure-activity relationships of flavonoids as P-gp inhibitors, the molecular mechanisms of their action and their ability to overcome P-gp-mediated MDR in preclinical studies. It had crucial implications on the discovery of new drug candidates that modulated the efflux of ABC transporters and also provided some clues for the future development in this promising area.


2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.


2018 ◽  
Vol 18 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Jiaqiang Wang ◽  
Chien-shan Cheng ◽  
Yan Lu ◽  
Xiaowei Ding ◽  
Minmin Zhu ◽  
...  

Background: Propofol, a widely used intravenous anesthetic agent, is traditionally applied for sedation and general anesthesia. Explanation: Recent attention has been drawn to explore the effect and mechanisms of propofol against cancer progression in vitro and in vivo. Specifically, the proliferation-inhibiting and apoptosis-inducing properties of propofol in cancer have been studied. However, the underlying mechanisms remain unclear. Conclusion: This review focused on the findings within the past ten years and aimed to provide a general overview of propofol's malignance-modulating properties and the potential molecular mechanisms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroaki Kanzaki ◽  
Tetsuhiro Chiba ◽  
Junjie Ao ◽  
Keisuke Koroki ◽  
Kengo Kanayama ◽  
...  

AbstractFGF19/FGFR4 autocrine signaling is one of the main targets for multi-kinase inhibitors (MKIs). However, the molecular mechanisms underlying FGF19/FGFR4 signaling in the antitumor effects to MKIs in hepatocellular carcinoma (HCC) remain unclear. In this study, the impact of FGFR4/ERK signaling inhibition on HCC following MKI treatment was analyzed in vitro and in vivo assays. Serum FGF19 in HCC patients treated using MKIs, such as sorafenib (n = 173) and lenvatinib (n = 40), was measured by enzyme-linked immunosorbent assay. Lenvatinib strongly inhibited the phosphorylation of FRS2 and ERK, the downstream signaling molecules of FGFR4, compared with sorafenib and regorafenib. Additional use of a selective FGFR4 inhibitor with sorafenib further suppressed FGFR4/ERK signaling and synergistically inhibited HCC cell growth in culture and xenograft subcutaneous tumors. Although serum FGF19high (n = 68) patients treated using sorafenib exhibited a significantly shorter progression-free survival and overall survival than FGF19low (n = 105) patients, there were no significant differences between FGF19high (n = 21) and FGF19low (n = 19) patients treated using lenvatinib. In conclusion, robust inhibition of FGF19/FGFR4 is of importance for the exertion of antitumor effects of MKIs. Serum FGF19 levels may function as a predictive marker for drug response and survival in HCC patients treated using sorafenib.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhenghui Cheng ◽  
Yawen Zhang ◽  
Yinchao Tian ◽  
Yuhan Chen ◽  
Fei Ding ◽  
...  

Abstract Background Schwann cells (SCs) play a crucial role in the repair of peripheral nerves. This is due to their ability to proliferate, migrate, and provide trophic support to axon regrowth. During peripheral nerve injury, SCs de-differentiate and reprogram to gain the ability to repair nerves. Cysteine-rich 61 (Cyr61/CCN1) is a member of the CCN family of matrix cell proteins and have been reported to be abundant in the secretome of repair mediating SCs. In this study we investigate the function of Cyr61 in SCs. Results We observed Cyr61 was expressed both in vivo and in vitro. The promoting effect of Cyr61 on SC proliferation and migration was through autocrine and paracrine mechanisms. SCs expressed αvβ3 integrin and the effect of Cyr61 on SC proliferation and migration could be blocked via αvβ3 integrin. Cyr61 could influence c-Jun protein expression in cultured SCs. Conclusions In this study, we found that Cyr61 promotes SC proliferation and migration via αvβ3 integrin and regulates c-Jun expression. Our study contributes to the understanding of cellular and molecular mechanisms underlying SC’s function during nerve injury, and thus, may facilitate the regeneration of peripheral nerves after injury.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Yu Tian ◽  
Bo Tang ◽  
Chengye Wang ◽  
Yan Wang ◽  
Jiakai Mao ◽  
...  

AbstractOncogenic ubiquitin-specific protease 22 (USP22) is implicated in a variety of tumours; however, evidence of its role and underlying molecular mechanisms in cholangiocarcinoma (CCA) development remains unknown. We collected paired tumour and adjacent non-tumour tissues from 57 intrahepatic CCA (iCCA) patients and evaluated levels of the USP22 gene and protein by qPCR and immunohistochemistry. Both the mRNA and protein were significantly upregulated, correlated with the malignant invasion and worse OS of iCCA. In cell cultures, USP22 overexpression increased CCA cell proliferation and mobility, and induced epithelial-to-mesenchymal transition (EMT). Upon an interaction, USP22 deubiquitinated and stabilized sirtuin-1 (SIRT1), in conjunction with Akt/ERK activation. In implantation xenografts, USP22 overexpression stimulated tumour growth and metastasis to the lungs of mice. Conversely, the knockdown by USP22 shRNA attenuated the tumour growth and invasiveness in vitro and in vivo. Furthermore, SIRT1 overexpression reversed the USP22 functional deficiency, while the knockdown acetylated TGF-β-activated kinase 1 (TAK1) and Akt. Our present study defines USP22 as a poor prognostic predictor in iCCA that cooperates with SIRT1 and facilitates tumour development.


Author(s):  
Naresh Damuka ◽  
Miranda Orr ◽  
Paul W. Czoty ◽  
Jeffrey L. Weiner ◽  
Thomas J. Martin ◽  
...  

AbstractMicrotubules (MTs) are structural units in the cytoskeleton. In brain cells they are responsible for axonal transport, information processing, and signaling mechanisms. Proper function of these processes is critical for healthy brain functions. Alcohol and substance use disorders (AUD/SUDs) affects the function and organization of MTs in the brain, making them a potential neuroimaging marker to study the resulting impairment of overall neurobehavioral and cognitive processes. Our lab reported the first brain-penetrant MT-tracking Positron Emission Tomography (PET) ligand [11C]MPC-6827 and demonstrated its in vivo utility in rodents and non-human primates. To further explore the in vivo imaging potential of [11C]MPC-6827, we need to investigate its mechanism of action. Here, we report preliminary in vitro binding results in SH-SY5Y neuroblastoma cells exposed to ethanol (EtOH) or cocaine in combination with multiple agents that alter MT stability. EtOH and cocaine treatments increased MT stability and decreased free tubulin monomers. Our initial cell-binding assay demonstrated that [11C]MPC-6827 may have high affinity to free/unbound tubulin units. Consistent with this mechanism of action, we observed lower [11C]MPC-6827 uptake in SH-SY5Y cells after EtOH and cocaine treatments (e.g., fewer free tubulin units). We are currently performing in vivo PET imaging and ex vivo biodistribution studies in rodent and nonhuman primate models of AUD and SUDs and Alzheimer's disease.


2021 ◽  
Vol 22 (13) ◽  
pp. 6663
Author(s):  
Maurycy Jankowski ◽  
Mariusz Kaczmarek ◽  
Grzegorz Wąsiatycz ◽  
Claudia Dompe ◽  
Paul Mozdziak ◽  
...  

Next-generation sequencing (RNAseq) analysis of gene expression changes during the long-term in vitro culture and osteogenic differentiation of ASCs remains to be important, as the analysis provides important clues toward employing stem cells as a therapeutic intervention. In this study, the cells were isolated from adipose tissue obtained during routine surgical procedures and subjected to 14-day in vitro culture and differentiation. The mRNA transcript levels were evaluated using the Illumina platform, resulting in the detection of 19,856 gene transcripts. The most differentially expressed genes (fold change >|2|, adjusted p value < 0.05), between day 1, day 14 and differentiated cell cultures were extracted and subjected to bioinformatical analysis based on the R programming language. The results of this study provide molecular insight into the processes that occur during long-term in vitro culture and osteogenic differentiation of ASCs, allowing the re-evaluation of the roles of some genes in MSC progression towards a range of lineages. The results improve the knowledge of the molecular mechanisms associated with long-term in vitro culture and differentiation of ASCs, as well as providing a point of reference for potential in vivo and clinical studies regarding these cells’ application in regenerative medicine.


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