scholarly journals AUTS2 controls neuronal lineage choice through a novel PRC1-independent complex and BMP inhibition

2021 ◽  
Author(s):  
Zhuangzhuang Geng ◽  
Qiang Wang ◽  
Weili Miao ◽  
Trevor Wolf ◽  
Jessenia Chavez ◽  
...  
Keyword(s):  
Risk Factor ◽  
Neuronal Differentiation ◽  
Cortical Neurons ◽  
Bmp Signaling ◽  
Neuronal Progenitors ◽  
Ubiquitin Ligase Complex ◽  
Neuronal Genes ◽  
Neuronal Lineage ◽  
Biochemical Analyses

Despite a prominent risk factor for Neurodevelopmental disorders (NDD), it remains unclear how Autism Susceptibility Candidate 2 (AUTS2) controls the neurodevelopmental program. Our studies investigated the role of AUTS2 in neuronal differentiation and discovered that AUTS2, together with WDR68 and SKI, forms a novel protein complex (AWS) specifically in neuronal progenitors and promotes neuronal differentiation through inhibiting BMP signaling. Genomic and biochemical analyses demonstrated that the AWS complex achieves this effect by recruiting the CUL4 E3 ubiquitin ligase complex to mediate poly-ubiquitination and subsequent proteasomal degradation of phosphorylated SMAD1/5/9. Furthermore, using primary cortical neurons, we observed aberrant BMP signaling and dysregulated expression of neuronal genes upon manipulating the AWS complex, indicating that the AWS-CUL4-BMP axis plays a role in regulating neuronal lineage specification in vivo. Thus, our findings uncover a sophisticated cellular signaling network mobilized by a prominent NDD risk factor, presenting multiple potential therapeutic targets for NDD.

scholarly journals KBP interacts with SCG10, linking Goldberg–Shprintzen syndrome to microtubule dynamics and neuronal differentiation

2010 ◽  
Vol 19 (18) ◽  
pp. 3642-3651 ◽  
Author(s):  
Maria M. Alves ◽  
Grzegorz Burzynski ◽  
Jean-Marie Delalande ◽  
Jan Osinga ◽  
Annemieke van der Goot ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Neuronal Differentiation ◽  
Cortical Neurons ◽  
Neuronal Development ◽  
Direct Interaction ◽  
Clinical Disorder ◽  
Neurite Development

Abstract Goldberg–Shprintzen syndrome (GOSHS) is a rare clinical disorder characterized by central and enteric nervous system defects. This syndrome is caused by inactivating mutations in the Kinesin Binding Protein (KBP) gene, which encodes a protein of which the precise function is largely unclear. We show that KBP expression is up-regulated during neuronal development in mouse cortical neurons. Moreover, KBP-depleted PC12 cells were defective in nerve growth factor-induced differentiation and neurite outgrowth, suggesting that KBP is required for cell differentiation and neurite development. To identify KBP interacting proteins, we performed a yeast two-hybrid screen and found that KBP binds almost exclusively to microtubule associated or related proteins, specifically SCG10 and several kinesins. We confirmed these results by validating KBP interaction with one of these proteins: SCG10, a microtubule destabilizing protein. Zebrafish studies further demonstrated an epistatic interaction between KBP and SCG10 in vivo . To investigate the possibility of direct interaction between KBP and microtubules, we undertook co-localization and in vitro binding assays, but found no evidence of direct binding. Thus, our data indicate that KBP is involved in neuronal differentiation and that the central and enteric nervous system defects seen in GOSHS are likely caused by microtubule-related defects.

scholarly journals Nono deficiency compromises TET1 chromatin association and impedes neuronal differentiation of mouse embryonic stem cells

2020 ◽  
Vol 48 (9) ◽  
pp. 4827-4838 ◽  
Author(s):  
Wenjing Li ◽  
Violetta Karwacki-Neisius ◽  
Chun Ma ◽  
Li Tan ◽  
Yang Shi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Neuronal Differentiation ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Epigenetic Mechanism ◽  
Lineage Commitment ◽  
Cell Functions ◽  
Neuronal Genes ◽  
Neuronal Lineage

Abstract NONO is a DNA/RNA-binding protein, which plays a critical regulatory role during cell stage transitions of mouse embryonic stem cells (mESCs). However, its function in neuronal lineage commitment and the molecular mechanisms of its action in such processes are largely unknown. Here we report that NONO plays a key role during neuronal differentiation of mESCs. Nono deletion impedes neuronal lineage commitment largely due to a failure of up-regulation of specific genes critical for neuronal differentiation. Many of the NONO regulated genes are also DNA demethylase TET1 targeted genes. Importantly, re-introducing wild type NONO to the Nono KO cells, not only restores the normal expression of the majority of NONO/TET1 coregulated genes but also rescues the defective neuronal differentiation of Nono-deficient mESCs. Mechanistically, our data shows that NONO directly interacts with TET1 via its DNA binding domain and recruits TET1 to genomic loci to regulate 5-hydroxymethylcytosine levels. Nono deletion leads to a significant dissociation of TET1 from chromatin and dysregulation of DNA hydroxymethylation of neuronal genes. Taken together, our findings reveal a key role and an epigenetic mechanism of action of NONO in regulation of TET1-targeted neuronal genes, offering new functional and mechanistic understanding of NONO in stem cell functions, lineage commitment and specification.

scholarly journals Septin 14 Is Involved in Cortical Neuronal Migration via Interaction with Septin 4

2010 ◽  
Vol 21 (8) ◽  
pp. 1324-1334 ◽  
Author(s):  
Tomoyasu Shinoda ◽  
Hidenori Ito ◽  
Kaori Sudo ◽  
Ikuko Iwamoto ◽  
Rika Morishita ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Neuronal Migration ◽  
Cortical Neurons ◽  
Neuronal Development ◽  
Cell Cycle Control ◽  
Coiled Coil ◽  
Cortical Plate ◽  
Process Formation ◽  
Biochemical Analyses

Septins are a family of conserved guanosine triphosphate/guanosine diphosphate-binding proteins implicated in a variety of cellular functions such as cell cycle control and cytokinesis. Although several members of septin family, including Septin 14 (Sept14), are abundantly expressed in nervous tissues, little is known about their physiological functions, especially in neuronal development. Here, we report that Sept14 is strongly expressed in the cortical plate of developing cerebral cortex. Knockdown experiments by using the method of in utero electroporation showed that reduction of Sept14 caused inhibition of cortical neuronal migration. Whereas cDNA encoding RNA interference-resistant Sept14 rescued the migration defect, the C-terminal deletion mutant of Sept14 did not. Biochemical analyses revealed that C-terminal coiled-coil region of Sept14 interacts with Septin 4 (Sept4). Knockdown experiments showed that Sept4 is also involved in cortical neuronal migration in vivo. In addition, knockdown of Sept14 or Sept4 inhibited leading process formation in migrating cortical neurons. These results suggest that Sept14 is involved in neuronal migration in cerebral cortex via interaction with Sept4.

scholarly journals Mechanism of CK2.3, a Novel Mimetic Peptide of Bone Morphogenetic Protein Receptor Type IA, Mediated Osteogenesis

2019 ◽  
Vol 20 (10) ◽  
pp. 2500 ◽  
Author(s):  
Vrathasha Vrathasha ◽  
Hilary Weidner ◽  
Anja Nohe
Keyword(s):  
Signaling Pathways ◽  
Treatment Options ◽  
Time Frame ◽  
Bmp Signaling ◽  
C2c12 Cells ◽  
Molecular Sequence ◽  
Sequence Of Events ◽  
Protein Receptor

Background: Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. Methods: Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. Results: Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. Conclusion: CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.

scholarly journals TRAF3 mediates neuronal apoptosis in early brain injury following subarachnoid hemorrhage via targeting TAK1-dependent MAPKs and NF-κB pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yan Zhou ◽  
Tao Tao ◽  
Guangjie Liu ◽  
Xuan Gao ◽  
Yongyue Gao ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Brain Injury ◽  
Therapeutic Target ◽  
Cortical Neurons ◽  
Neuronal Apoptosis ◽  
Early Brain Injury ◽  
Neurological Deficits ◽  
Human Brain Tissue

AbstractNeuronal apoptosis has an important role in early brain injury (EBI) following subarachnoid hemorrhage (SAH). TRAF3 was reported as a promising therapeutic target for stroke management, which covered several neuronal apoptosis signaling cascades. Hence, the present study is aimed to determine whether downregulation of TRAF3 could be neuroprotective in SAH-induced EBI. An in vivo SAH model in mice was established by endovascular perforation. Meanwhile, primary cultured cortical neurons of mice treated with oxygen hemoglobin were applied to mimic SAH in vitro. Our results demonstrated that TRAF3 protein expression increased and expressed in neurons both in vivo and in vitro SAH models. TRAF3 siRNA reversed neuronal loss and improved neurological deficits in SAH mice, and reduced cell death in SAH primary neurons. Mechanistically, we found that TRAF3 directly binds to TAK1 and potentiates phosphorylation and activation of TAK1, which further enhances the activation of NF-κB and MAPKs pathways to induce neuronal apoptosis. Importantly, TRAF3 expression was elevated following SAH in human brain tissue and was mainly expressed in neurons. Taken together, our study demonstrates that TRAF3 is an upstream regulator of MAPKs and NF-κB pathways in SAH-induced EBI via its interaction with and activation of TAK1. Furthermore, the TRAF3 may serve as a novel therapeutic target in SAH-induced EBI.

scholarly journals Cortical neurons exhibit diverse myelination patterns that scale between mouse brain regions and regenerate after demyelination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cody L. Call ◽  
Dwight E. Bergles
Keyword(s):  
Cortical Neurons ◽  
Regional Differences ◽  
Brain Regions ◽  
Axon Diameter ◽  
Neuronal Identity ◽  
Cortical Areas ◽  
Myelin Sheaths ◽  
Parvalbumin Interneurons ◽  
Selection Of

ABSTRACTAxons in the cerebral cortex show a broad range of myelin coverage. Oligodendrocytes establish this pattern by selecting a cohort of axons for myelination; however, the distribution of myelin on distinct neurons and extent of internode replacement after demyelination remain to be defined. Here we show that myelination patterns of seven distinct neuron subtypes in somatosensory cortex are influenced by both axon diameter and neuronal identity. Preference for myelination of parvalbumin interneurons was preserved between cortical areas with varying myelin density, suggesting that regional differences in myelin abundance arises through local control of oligodendrogenesis. By imaging loss and regeneration of myelin sheaths in vivo we show that myelin distribution on individual axons was altered but overall myelin content on distinct neuron subtypes was restored. Our findings suggest that local changes in myelination are tolerated, allowing regenerated oligodendrocytes to restore myelin content on distinct neurons through opportunistic selection of axons.

scholarly journals SARS-CoV-2-Laden Respiratory Aerosol Deposition in the Lung Alveolar-Interstitial Region Is a Potential Risk Factor for Severe Disease: A Modeling Study

2021 ◽  
Vol 11 (5) ◽  
pp. 431
Author(s):  
Sabine Hofer ◽  
Norbert Hofstätter ◽  
Albert Duschl ◽  
Martin Himly
Keyword(s):  
Risk Factor ◽  
Particle Deposition ◽  
Early Stage ◽  
Severe Disease ◽  
Ambient Air ◽  
Aerosol Deposition ◽  
Pulmonary Involvement ◽  
Mild Disease ◽  
Disease Initiation

COVID-19, predominantly a mild disease, is associated with more severe clinical manifestation upon pulmonary involvement. Virion-laden aerosols and droplets target different anatomical sites for deposition. Compared to droplets, aerosols more readily advance into the peripheral lung. We performed in silico modeling to confirm the secondary pulmonary lobules as the primary site of disease initiation. By taking different anatomical aerosol origins into consideration and reflecting aerosols from exhalation maneuvers breathing and vocalization, the physicochemical properties of generated respiratory aerosol particles were defined upon conversion to droplet nuclei by evaporation at ambient air. To provide detailed, spatially-resolved information on particle deposition in the thoracic region of the lung, a top-down refinement approach was employed. Our study presents evidence for hot spots of aerosol deposition in lung generations beyond the terminal bronchiole, with a maximum in the secondary pulmonary lobules and a high preference to the lower lobes of both lungs. In vivo, initial chest CT anomalies, the ground glass opacities, resulting from partial alveolar filling and interstitial thickening in the secondary pulmonary lobules, are likewise localized in these lung generations, with the highest frequency in both lower lobes and in the early stage of disease. Hence, our results suggest a disease initiation right there upon inhalation of virion-laden respiratory aerosols, linking the aerosol transmission route to pathogenesis associated with higher disease burden and identifying aerosol transmission as a new independent risk factor for developing a pulmonary phase with a severe outcome.

scholarly journals Heterodimer Formation of the Homodimeric ABC Transporter OpuA

2021 ◽  
Vol 22 (11) ◽  
pp. 5912
Author(s):  
Patricia Alvarez-Sieiro ◽  
Hendrik R. Sikkema ◽  
Bert Poolman
Keyword(s):  
Abc Transporter ◽  
Conformational Dynamics ◽  
Host Organism ◽  
Affinity Tag ◽  
Practical Applications ◽  
Fundamental Research ◽  
Protein Multimerization ◽  
Biochemical Analyses

Many proteins have a multimeric structure and are composed of two or more identical subunits. While this can be advantageous for the host organism, it can be a challenge when targeting specific residues in biochemical analyses. In vitro splitting and re-dimerization to circumvent this problem is a tedious process that requires stable proteins. We present an in vivo approach to transform homodimeric proteins into apparent heterodimers, which then can be purified using two-step affinity-tag purification. This opens the door to both practical applications such as smFRET to probe the conformational dynamics of homooligomeric proteins and fundamental research into the mechanism of protein multimerization, which is largely unexplored for membrane proteins. We show that expression conditions are key for the formation of heterodimers and that the order of the differential purification and reconstitution of the protein into nanodiscs is important for a functional ABC-transporter complex.

scholarly journals Machine learning-based classification of mitochondrial morphology in primary neurons and brain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Garrett M. Fogo ◽  
Anthony R. Anzell ◽  
Kathleen J. Maheras ◽  
Sarita Raghunayakula ◽  
Joseph M. Wider ◽  
...  
Keyword(s):  
Image Analysis ◽  
Cortical Neurons ◽  
Mitochondrial Dynamics ◽  
Automated Image Analysis ◽  
Mitochondrial Morphology ◽  
Analysis Pipeline ◽  
Genetic Ablation ◽  
Block Face

AbstractThe mitochondrial network continually undergoes events of fission and fusion. Under physiologic conditions, the network is in equilibrium and is characterized by the presence of both elongated and punctate mitochondria. However, this balanced, homeostatic mitochondrial profile can change morphologic distribution in response to various stressors. Therefore, it is imperative to develop a method that robustly measures mitochondrial morphology with high accuracy. Here, we developed a semi-automated image analysis pipeline for the quantitation of mitochondrial morphology for both in vitro and in vivo applications. The image analysis pipeline was generated and validated utilizing images of primary cortical neurons from transgenic mice, allowing genetic ablation of key components of mitochondrial dynamics. This analysis pipeline was further extended to evaluate mitochondrial morphology in vivo through immunolabeling of brain sections as well as serial block-face scanning electron microscopy. These data demonstrate a highly specific and sensitive method that accurately classifies distinct physiological and pathological mitochondrial morphologies. Furthermore, this workflow employs the use of readily available, free open-source software designed for high throughput image processing, segmentation, and analysis that is customizable to various biological models.

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