scholarly journals PDK1–Akt pathway regulates radial neuronal migration and microtubules in the developing mouse neocortex

2016 ◽  
Vol 113 (21) ◽  
pp. E2955-E2964 ◽  
Author(s):  
Yasuhiro Itoh ◽  
Maiko Higuchi ◽  
Koji Oishi ◽  
Yusuke Kishi ◽  
Tomohiko Okazaki ◽  
...  
Keyword(s):  
Neuronal Migration ◽  
Molecular Mechanisms ◽  
Radial Glia ◽  
Radial Distance ◽  
Cytoplasmic Dynein ◽  
Cortical Plate ◽  
Akt Pathway ◽  
Saltatory Movement ◽  
Dependent Protein ◽  
Intermediate Chain

Neurons migrate a long radial distance by a process known as locomotion in the developing mammalian neocortex. During locomotion, immature neurons undergo saltatory movement along radial glia fibers. The molecular mechanisms that regulate the speed of locomotion are largely unknown. We now show that the serine/threonine kinase Akt and its activator phosphoinositide-dependent protein kinase 1 (PDK1) regulate the speed of locomotion of mouse neocortical neurons through the cortical plate. Inactivation of the PDK1–Akt pathway impaired the coordinated movement of the nucleus and centrosome, a microtubule-dependent process, during neuronal migration. Moreover, the PDK1–Akt pathway was found to control microtubules, likely by regulating the binding of accessory proteins including the dynactin subunit p150glued. Consistent with this notion, we found that PDK1 regulates the expression of cytoplasmic dynein intermediate chain and light intermediate chain at a posttranscriptional level in the developing neocortex. Our results thus reveal an essential role for the PDK1–Akt pathway in the regulation of a key step of neuronal migration.

scholarly journals Genetic mapping and transcriptomic characterization of a new fuzzless-tufted cottonseed mutant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qian-Hao Zhu ◽  
Warwick Stiller ◽  
Philippe Moncuquet ◽  
Stuart Gordon ◽  
Yuman Yuan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Agronomic Traits ◽  
Gene Families ◽  
Mutant Phenotype ◽  
Wild Type ◽  
Calcium Dependent ◽  
Dependent Protein ◽  
Flanking Region ◽  
Comparative Transcriptomic Analysis

Abstract Fiber mutants are unique and valuable resources for understanding the genetic and molecular mechanisms controlling initiation and development of cotton fibers that are extremely elongated single epidermal cells protruding from the seed coat of cottonseeds. In this study, we reported a new fuzzless-tufted cotton mutant (Gossypium hirsutum) and showed that fuzzless-tufted near-isogenic lines (NILs) had similar agronomic traits and a higher ginning efficiency compared to their recurrent parents with normal fuzzy seeds. Genetic analysis revealed that the mutant phenotype is determined by a single incomplete dominant locus, designated N5. The mutation was fine mapped to an approximately 250-kb interval containing 33 annotated genes using a combination of bulked segregant sequencing, SNP chip genotyping, and fine mapping. Comparative transcriptomic analysis using 0–6 days post-anthesis (dpa) ovules from NILs segregating for the phenotypes of fuzzless-tufted (mutant) and normal fuzzy cottonseeds (wild-type) uncovered candidate genes responsible for the mutant phenotype. It also revealed that the flanking region of the N5 locus is enriched with differentially expressed genes (DEGs) between the mutant and wild-type. Several of those DEGs are members of the gene families with demonstrated roles in cell initiation and elongation, such as calcium-dependent protein kinase and expansin. The transcriptome landscape of the mutant was significantly reprogrammed in the 6 dpa ovules and, to a less extent, in the 0 dpa ovules, but not in the 2 and 4 dpa ovules. At both 0 and 6 dpa, the reprogrammed mutant transcriptome was mainly associated with cell wall modifications and transmembrane transportation, while transcription factor activity was significantly altered in the 6 dpa mutant ovules. These results imply a similar molecular basis for initiation of lint and fuzz fibers despite certain differences.

scholarly journals Targeting fibroblast growth factor receptors to combat aggressive ependymoma

2021 ◽  
Author(s):  
Daniela Lötsch ◽  
Dominik Kirchhofer ◽  
Bernhard Englinger ◽  
Li Jiang ◽  
Konstantin Okonechnikov ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Molecular Mechanisms ◽  
Radial Glia ◽  
Growth Factor Receptors ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Fibroblast Growth ◽  
Cell Models ◽  
Fibroblast Growth Factor Receptors

AbstractEpendymomas (EPN) are central nervous system tumors comprising both aggressive and more benign molecular subtypes. However, therapy of the high-risk subtypes posterior fossa group A (PF-A) and supratentorial RELA-fusion positive (ST-RELA) is limited to gross total resection and radiotherapy, as effective systemic treatment concepts are still lacking. We have recently described fibroblast growth factor receptors 1 and 3 (FGFR1/FGFR3) as oncogenic drivers of EPN. However, the underlying molecular mechanisms and their potential as therapeutic targets have not yet been investigated in detail. Making use of transcriptomic data across 467 EPN tissues, we found that FGFR1 and FGFR3 were both widely expressed across all molecular groups. FGFR3 mRNA levels were enriched in ST-RELA showing the highest expression among EPN as well as other brain tumors. We further identified high expression levels of fibroblast growth factor 1 and 2 (FGF1, FGF2) across all EPN subtypes while FGF9 was elevated in ST-EPN. Interrogation of our EPN single-cell RNA-sequencing data revealed that FGFR3 was further enriched in cycling and progenitor-like cell populations. Corroboratively, we found FGFR3 to be predominantly expressed in radial glia cells in both mouse embryonal and human brain datasets. Moreover, we detected alternative splicing of the FGFR1/3-IIIc variant, which is known to enhance ligand affinity and FGFR signaling. Dominant-negative interruption of FGFR1/3 activation in PF-A and ST-RELA cell models demonstrated inhibition of key oncogenic pathways leading to reduced cell growth and stem cell characteristics. To explore the feasibility of therapeutically targeting FGFR, we tested a panel of FGFR inhibitors in 12 patient-derived EPN cell models revealing sensitivity in the low-micromolar to nano-molar range. Finally, we gain the first clinical evidence for the activity of the FGFR inhibitor nintedanib in the treatment of a patient with recurrent ST-RELA. Together, these preclinical and clinical data suggest FGFR inhibition as a novel and feasible approach to combat aggressive EPN.

scholarly journals Baicalin Attenuates High Fat Diet-Induced Obesity and Liver Dysfunction: Dose-Response and Potential Role of CaMKKβ/AMPK/ACC Pathway

2015 ◽  
Vol 35 (6) ◽  
pp. 2349-2359 ◽  
Author(s):  
Youli Xi ◽  
Miaozong Wu ◽  
Hongxia Li ◽  
Siqi Dong ◽  
Erfei Luo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fatty Liver ◽  
High Fat Diet ◽  
Molecular Mechanisms ◽  
Liver Steatosis ◽  
Serum Levels ◽  
Whole Body ◽  
Therapeutic Effects ◽  
High Fat ◽  
Dependent Protein

Background/Aims: Obesity-associated fatty liver disease affects millions of individuals. This study aimed to evaluate the therapeutic effects of baicalin to treat obesity and fatty liver in high fat diet-induced obese mice, and to study the potential molecular mechanisms. Methods: High fat diet-induced obese animals were treated with different doses of baicalin (100, 200 and 400 mg/kg/d). Whole body, fat pad and liver were weighed. Hyperlipidemia, liver steatosis, liver function, and hepatic Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ) / AMP-activated protein kinase (AMPK) / acetyl-CoA carboxylase (ACC) were further evaluated. Results: Baicalin significantly decreased liver, epididymal fat and body weights in high fat diet-fed mice, which were associated with decreased serum levels of triglycerides, total cholesterol, LDL, alanine transaminase and aspartate transaminase, but increased serum HDL level. Pathological analysis revealed baicalin dose-dependently decreased the degree of hepatic steatosis, with predominantly diminished macrovesicular steatosis at lower dose but both macrovesicular and microvesicular steatoses at higher dose of baicalin. Baicalin dose-dependently inhibited hepatic CaMKKβ/AMPK/ACC pathway. Conclusion: These data suggest that baicalin up to 400 mg/kg/d is safe and able to decrease the degree of obesity and fatty liver diseases. Hepatic CaMKKβ/AMPK/ACC pathway may mediate the therapeutic effects of baicalin in high fat diet animal model.

scholarly journals Ganoderic Acid A Protects Rat H9c2 Cardiomyocytes from Hypoxia-Induced Injury via Up-Regulating miR-182-5p

2018 ◽  
Vol 50 (6) ◽  
pp. 2086-2096 ◽  
Author(s):  
Xiaohong  Zhang ◽  
Can Xiao ◽  
Hong Liu
Keyword(s):  
Cell Viability ◽  
Molecular Mechanisms ◽  
Akt Pathway ◽  
H9c2 Cell ◽  
H9c2 Cells ◽  
Ganoderic Acid ◽  
Expression Levels ◽  
Protein Levels ◽  
Viability Loss ◽  
H9c2 Cardiomyocytes

Background/Aims: Ganoderic acid A (GAA) isolated from Ganoderma lucidum, shows various benefit activities, such as anti-tumor activity, anti-HIV activity and hepatoprotective activity. However, the potential effects of GAA on hypoxia-induced injury of cardiomyocytes are still unclear. In this study, we aimed to reveal the effects of GAA on hypoxic-induced H9c2 cell injury, as well as potential underlying molecular mechanisms. Methods: Rat H9c2 cardiomyocytes were cultured in hypoxia condition with different doses of GAA. Cell viability and apoptosis were detected by CCK-8 assay and flow cytometry, respectively. qRT-PCR was performed to assess the expression levels of microRNA-182-5p (miR-182-5p) and phosphatase and tensin homologue (PTEN). Cell transfection was conducted to change the expression levels of miR-182-5p and PTEN in H9c2 cells. Finally, protein levels of key factors involved in cell proliferation, cell apoptosis and PTEN/PI3K/AKT pathway were evaluated using western blotting. Results: Hypoxia treatment significantly induced H9c2 cell viability loss and apoptosis. GAA incubation remarkably protected H9c2 cells from hypoxia-induced viability loss, proliferation inhibition and apoptosis. In addition, GAA obviously enhanced the expression level of miR-182-5p in H9c2 cells. Suppression of miR-182-5p notably alleviated the protective effects of GAA on hypoxia-treated H9c2 cells. Furthermore, miR-182-5p negatively regulated the mRNA and protein levels of PTEN in H9c2 cells. GAA attenuated hypoxia-induced inactivation of PI3K/AKT pathway in H9c2 cells by up-regulating miR-182-5p and then down-regulating PTEN. Conclusion: GAA protected rat H9c2 cardiomyocytes from hypoxia-induced injury might via up-regulating miR-182-5p, down-regulating PTEN and then activating PI3K/AKT signaling pathway.

scholarly journals Functional Dissection of LIS1 and NDEL1 Towards Understanding the Molecular Mechanisms of Cytoplasmic Dynein Regulation

2010 ◽  
Vol 286 (3) ◽  
pp. 1959-1965 ◽  
Author(s):  
Takayuki Torisawa ◽  
Akiko Nakayama ◽  
Ken'ya Furuta ◽  
Masami Yamada ◽  
Shinji Hirotsune ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cytoplasmic Dynein

scholarly journals Localization of Cytoplasmic Dynein Light-intermediate Chain mRNA in the Rat Testis Using In Situ Hybridization.

1998 ◽  
Vol 23 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Seishi Maeda ◽  
Sang-Yoon Nam ◽  
Masahiko Fujisawa ◽  
Nobuaki Nakamuta ◽  
Kenji Ogawa ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Cytoplasmic Dynein ◽  
Rat Testis ◽  
Intermediate Chain

Transient Removal of Extracellular Mg2+ Elicits Persistent Suppression of LTP at Hippocampal CA1 Synapses Via PKC Activation

2000 ◽  
Vol 84 (3) ◽  
pp. 1279-1288 ◽  
Author(s):  
Kuei-Sen Hsu ◽  
Wen-Chia Ho ◽  
Chiung-Chun Huang ◽  
Jing-Jane Tsai
Keyword(s):  
Nmda Receptor ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Hippocampal Slices ◽  
Long Term Potentiation ◽  
Receptor Activation ◽  
Suppressive Effect ◽  
Dependent Protein Kinase ◽  
Dependent Protein

Previous work has shown that seizure-like activity can disrupt the induction of long-term potentiation (LTP). However, how seizure-like event disrupts the LTP induction remains unknown. To understand the cellular and molecular mechanisms underlying this process better, a set of studies was implemented in area CA1 of rat hippocampal slices using extracellular recording methods. We showed here that prior transient seizure-like activity generated by perfused slices with Mg2+-free artificial cerebrospinal fluid (ACSF) exhibited a persistent suppression of LTP induction. This effect lasted between 2 and 3 h after normal ACSF replacement and was specifically inhibited by N-methyl-d-aspartate (NMDA) receptor antagonistd-2-amino-5-phosphovaleric acid (d-APV) and L-type voltage-operated Ca2+ channel (VOCC) blocker nimodipine, but not by non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). In addition, this suppressive effect was specifically blocked by the selective protein kinase C (PKC) inhibitor NPC-15437. However, neither Ca2+/calmodulin-dependent protein kinase II inhibitor KN-62 nor cAMP-dependent protein kinase inhibitor Rp-adenosine 3′,5′-cyclic monophosphothioate (Rp-cAMPS) affected this suppressive effect. This persistent suppression of LTP was not secondary to the long-lasting changes in NMDA receptor activation, because the isolated NMDA receptor–mediated responses did not show a long-term enhancement in response to a 30-min Mg2+-free ACSF application. Additionally, in prior Mg2+-free ACSF–treated slices, the entire frequency-response curve of LTP and long-term depression (LTD) is shifted systematically to favor LTD. These results suggest that the increase of Ca2+ influx through NMDA channels and L-type VOCCs in turn triggering a PKC-dependent signaling cascade is a possible cellular basis underlying this seizure-like activity-induced inhibition of LTP.

scholarly journals Structure of Tctex-1 and Its Interaction with Cytoplasmic Dynein Intermediate Chain

2001 ◽  
Vol 276 (17) ◽  
pp. 14067-14074 ◽  
Author(s):  
Yu-Keung Mok ◽  
Kevin W.-H. Lo ◽  
Mingjie Zhang
Keyword(s):  
Cytoplasmic Dynein ◽  
Dynein Intermediate Chain ◽  
Intermediate Chain

Topical Review: Neuronal Migration in Cortical Development

2004 ◽  
Vol 19 (3) ◽  
pp. 274-279
Author(s):  
Shigeaki Kanatani ◽  
Hidenori Tabata ◽  
Kazunori Nakajima
Keyword(s):  
Neuronal Migration ◽  
Radial Glia ◽  
Asymmetric Cell Division ◽  
Time Lapse ◽  
Radial Glial Cells ◽  
Daughter Cells ◽  
Radial Glial ◽  
Time Lapse Imaging ◽  
Mitotic Behavior

Cortical formation in the developing brain is a highly complicated process involving neuronal production (through symmetric or asymmetric cell division) interaction of radial glia with neuronal migration, and multiple modes of neuronal migration. It has been convincingly demonstrated by numerous studies that radial glial cells are neural stem cells. However, the processes by which neurons arise from radial glia and migrate to their final destinations in vivo are not yet fully understood. Recent studies using time-lapse imaging of neuronal migration are giving investigators an increasingly more detailed understanding of the mitotic behavior of radial glia and the migrating behavior of their daughter cells. In this review, we describe recent progress in elucidating neuronal migration in brain formation and how neuronal migration is disturbed by mutations in genes that control this process. ( J Child Neurol 2005;20:274—279).

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.

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