scholarly journals Serotonin regulates mitochondrial biogenesis and function in rodent cortical neurons via the 5-HT2A receptor and SIRT1-PGC-1α axis

2018 ◽  
Author(s):  
Sashaina Fanibunda ◽  
Sukrita Deb ◽  
Babukrishna Maniyadath ◽  
Samir Gupta ◽  
Noelia Weisstaub ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Cortical Neurons ◽  
Neuronal Excitability ◽  
In Vivo Studies ◽  
Primary Role ◽  
Dependent Manner ◽  
Atp Levels ◽  
And Function ◽  
Neuroprotective Action

Mitochondria in neurons in addition to their primary role in bioenergetics also contribute to specialized functions including regulation of synaptic transmission, Ca2+ homeostasis, neuronal excitability and stress adaptation. However, the factors that influence mitochondrial biogenesis and function in neurons remain poorly elucidated. Here, we identify an important role for serotonin (5-HT) as a regulator of mitochondrial biogenesis and function in rodent cortical neurons, via a 5-HT2A receptor-mediated recruitment of the SIRT1-PGC-1α axis, which is relevant to the neuroprotective action of 5-HT. 5-HT increased mitochondrial biogenesis, reflected through enhanced mtDNA levels, mitotracker staining, and expression of mitochondrial genes. This was accompanied by increased cellular ATP levels, basal and maximal respiration, as well as spare respiratory capacity. Mechanistically the effects of 5-HT were mediated via the 5-HT2A receptor and master modulators of mitochondrial biogenesis, SIRT1 and PGC-1α. SIRT1 was required to mediate the effects of 5-HT on mitochondrial biogenesis and function in cortical neurons. In vivo studies revealed that 5-HT2A receptor stimulation increased cortical mtDNA and ATP levels, in a SIRT1 dependent manner. In cortical neurons, 5-HT enhanced expression of anti-oxidant enzymes, decreased cellular reactive oxygen species, and exhibited neuroprotection against excitotoxic and oxidative stress, an effect that required SIRT1. These findings identify 5-HT as a novel upstream regulator of mitochondrial biogenesis and function in cortical neurons, and implicate the mitochondrial effects of 5-HT in its neuroprotective action.

scholarly journals Serotonin regulates mitochondrial biogenesis and function in rodent cortical neurons via the 5-HT2A receptor and SIRT1–PGC-1α axis

2019 ◽  
Vol 116 (22) ◽  
pp. 11028-11037 ◽  
Author(s):  
Sashaina E. Fanibunda ◽  
Sukrita Deb ◽  
Babukrishna Maniyadath ◽  
Praachi Tiwari ◽  
Utkarsha Ghai ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Cortical Neurons ◽  
Neuronal Excitability ◽  
In Vivo Studies ◽  
Primary Role ◽  
Dependent Manner ◽  
Atp Levels ◽  
And Function ◽  
Neuroprotective Action

Mitochondria in neurons, in addition to their primary role in bioenergetics, also contribute to specialized functions, including regulation of synaptic transmission, Ca2+ homeostasis, neuronal excitability, and stress adaptation. However, the factors that influence mitochondrial biogenesis and function in neurons remain poorly elucidated. Here, we identify an important role for serotonin (5-HT) as a regulator of mitochondrial biogenesis and function in rodent cortical neurons, via a 5-HT2A receptor-mediated recruitment of the SIRT1–PGC-1α axis, which is relevant to the neuroprotective action of 5-HT. We found that 5-HT increased mitochondrial biogenesis, reflected through enhanced mtDNA levels, mitotracker staining, and expression of mitochondrial components. This resulted in higher mitochondrial respiratory capacity, oxidative phosphorylation (OXPHOS) efficiency, and a consequential increase in cellular ATP levels. Mechanistically, the effects of 5-HT were mediated via the 5-HT2A receptor and master modulators of mitochondrial biogenesis, SIRT1 and PGC-1α. SIRT1 was required to mediate the effects of 5-HT on mitochondrial biogenesis and function in cortical neurons. In vivo studies revealed that 5-HT2A receptor stimulation increased cortical mtDNA and ATP levels in a SIRT1-dependent manner. Direct infusion of 5-HT into the neocortex and chemogenetic activation of 5-HT neurons also resulted in enhanced mitochondrial biogenesis and function in vivo. In cortical neurons, 5-HT enhanced expression of antioxidant enzymes, decreased cellular reactive oxygen species, and exhibited neuroprotection against excitotoxic and oxidative stress, an effect that required SIRT1. These findings identify 5-HT as an upstream regulator of mitochondrial biogenesis and function in cortical neurons and implicate the mitochondrial effects of 5-HT in its neuroprotective action.

scholarly journals FRMPD2: a novel GluN2A-interacting scaffold protein in synaptic excitatory transmission

2018 ◽  
Author(s):  
Xi Lu ◽  
Haiqing Zhang ◽  
Xin Tian ◽  
Xuefeng Wang
Keyword(s):  
Neuronal Excitability ◽  
Scaffold Protein ◽  
Dependent Manner ◽  
Tight Junction Formation ◽  
Excitatory Transmission ◽  
C Terminus ◽  
Adult Hippocampus ◽  
And Function ◽  
Novel Scaffold

AbstractThe scaffold proteins FRMPD2 is localized at the basolateral membranes of polarized epithelial cells and associated with tight junction formation. But the expression and function of FRMPD2 in vivo remain unknown. Here, we found that postsynaptic FRMPD2 effectively alters the neuronal excitability by regulating NMDARs-component excitatory synaptic transmission in adult hippocampus. FRMPD2 anchors the NMDAR subunit GluN2A at the synapses without changing the total NMDAR expression. By using of Co-IP, Pull Down and SPR, the second PDZ (PDZ2) domain of FRMPD2 direct and binds to the C-terminus of GluN2A. Our study discover that a novel scaffold protein FRMPD2 regulates synaptic excitatory in a PDZ2 domain-dependent manner in adult hippocampus.

scholarly journals LMTK1 regulates dendritic formation by regulating movement of Rab11A-positive endosomes

2014 ◽  
Vol 25 (11) ◽  
pp. 1755-1768 ◽  
Author(s):  
Tetsuya Takano ◽  
Tomoki Urushibara ◽  
Nozomu Yoshioka ◽  
Taro Saito ◽  
Mitsunori Fukuda ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Phosphorylation Site ◽  
Dendrite Growth ◽  
Endosomal Trafficking ◽  
Dependent Manner ◽  
Dendrite Development ◽  
Membrane Components ◽  
And Function

Neurons extend two types of neurites—axons and dendrites—that differ in structure and function. Although it is well understood that the cytoskeleton plays a pivotal role in neurite differentiation and extension, the mechanisms by which membrane components are supplied to growing axons or dendrites is largely unknown. We previously reported that the membrane supply to axons is regulated by lemur kinase 1 (LMTK1) through Rab11A-positive endosomes. Here we investigate the role of LMTK1 in dendrite formation. Down-regulation of LMTK1 increases dendrite growth and branching of cerebral cortical neurons in vitro and in vivo. LMTK1 knockout significantly enhances the prevalence, velocity, and run length of anterograde movement of Rab11A-positive endosomes to levels similar to those expressing constitutively active Rab11A-Q70L. Rab11A-positive endosome dynamics also increases in the cell body and growth cone of LMTK1-deficient neurons. Moreover, a nonphosphorylatable LMTK1 mutant (Ser34Ala, a Cdk5 phosphorylation site) dramatically promotes dendrite growth. Thus LMTK1 negatively controls dendritic formation by regulating Rab11A-positive endosomal trafficking in a Cdk5-dependent manner, indicating the Cdk5-LMTK1-Rab11A pathway as a regulatory mechanism of dendrite development as well as axon outgrowth.

scholarly journals Modulatory Effects of Osthole on Lipopolysaccharides-Induced Inflammation in Caco-2 Cell Monolayer and Co-Cultures with THP-1 and THP-1-Derived Macrophages

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Natalia K. Kordulewska ◽  
Justyna Topa ◽  
Małgorzata Tańska ◽  
Anna Cieślińska ◽  
Ewa Fiedorowicz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Inflammatory Reaction ◽  
Wide Spectrum ◽  
Cell Monolayer ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.

scholarly journals Effect of Synchronous Versus Sequential Regimens on the Pharmacokinetics and Biodistribution of Regorafenib with Irradiation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Tung-Hu Tsai ◽  
Yu-Jen Chen ◽  
Li-Ying Wang ◽  
Chen-Hsi Hsieh
Keyword(s):  
Stereotactic Body Radiation Therapy ◽  
In Vivo Studies ◽  
Control Group ◽  
High Dose ◽  
Dependent Manner ◽  
Hep G2 ◽  
Time Curve ◽  
Dose Dependent

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)regorafenib by 74% (p = 0.001) in the RT2 Gy × 3 fraction (f’x) group and by 69% (p = 0.001) in the RT9 Gy × 3 f’x group. The AUCregorafenib was increased by 182.8% (p = 0.011) in the sequential RT2Gy × 1 f’x group and by 213.2% (p = 0.016) in the sequential RT9Gy × 1 f’x group. Both concurrent regimens, RT2Gy × 3 f’x and RT9Gy × 3 f’x, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib × 3 d) group. The concurrent regimens, both RT2Gy × 3 f’x and RT9Gy × 3 f’x, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).

scholarly journals Alcohol-and-HIV-Induced Lysosomal Dysfunction Regulates Extracellular Vesicles Secretion in Vitro and in Liver-Humanized Mice

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Raghubendra Singh Dagur ◽  
Moses New-Aaron ◽  
Murali Ganesan ◽  
Weimin Wang ◽  
Svetlana Romanova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Extracellular Vesicles ◽  
Treated Group ◽  
Human Hepatocytes ◽  
In Vivo Studies ◽  
People Living With Hiv ◽  
Humanized Mouse Model ◽  
And Function

Background: Alcohol abuse is common in people living with HIV-1 and dramaticallyenhances the severity of HIV-induced liver damage by inducing oxidative stress and lysosomaldysfunction in the liver cells. We hypothesize that the increased release of extracellular vesicles(EVs) in hepatocytes and liver humanized mouse model is linked to lysosome dysfunction. Methods:The study was performed on primary human hepatocytes and human hepatoma RLWXP-GFP (Huh7.5 cells stably transfected with CYP2E1 and XPack-GFP) cells and validated on ethanol-fed liverhumanizedfumarylacetoacetate hydrolase (Fah)-/-, Rag2-/-, common cytokine receptor gamma chainknockout (FRG-KO) mice. Cells and mice were infected with HIV-1ADA virus. Results: We observedan increase in the secretion of EVs associated with a decrease in lysosomal activity and expressionof lysosomal-associated membrane protein 1. Next-generation RNA sequencing of primary humanhepatocytes revealed 63 differentially expressed genes, with 13 downregulated and 50 upregulatedgenes in the alcohol–HIV-treated group. Upstream regulator analysis of differentially expressedgenes through Ingenuity Pathway Analysis identified transcriptional regulators affecting downstreamgenes associated with increased oxidative stress, lysosomal associated disease, and function andEVs biogenesis. Our in vitro findings were corroborated by in vivo studies on human hepatocytetransplantedhumanized mice, indicating that intensive EVs’ generation by human hepatocytes andtheir secretion to serum was associated with increased oxidative stress and reduction in lysosomalactivities triggered by HIV infection and ethanol diet. Conclusion: HIV-and-ethanol-metabolisminducedEVs release is tightly controlled by lysosome status in hepatocytes and participates in thedevelopment of double-insult-induced liver injury.

Abstract P153: Role of Nonreceptor Tyrosine Kinases in Cardiac Fibrosis in a Mouse Model of Pressure Overload Hypertrophy

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Sundaravadivel Balasubramanian ◽  
Harinath Kasiganesan ◽  
Lakeya Quinones ◽  
Yuhua Zhang ◽  
Amy Bradshaw ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Pressure Overload ◽  
In Vivo Studies ◽  
Survival Pathways ◽  
And Function ◽  
Nonreceptor Tyrosine Kinases

During prolonged hypertrophic insult to the myocardium, while the function of cardiomyocytes needs to be protected, the hyperactivation of cardiac fibroblasts has to be curbed to prevent fibrosis. Previously, we showed that integrin-mediated non-receptor tyrosine kinase (NRTK) activation is required for normal functioning of both cardiac fibroblasts and cardiomyocytes. We hypothesized that inhibition of NRTKs in cardiac fibroblasts without affecting cardiomyocytes would be beneficial to the stressed myocardium. Our initial studies using kinase inactive forms of Src, Pyk2 and FAK expressed adenovirally in isolated primary cardiac fibroblasts showed that the pro-fibrotic signaling events as studied by fibronectin and collagen deposition are downregulated. Our in vivo studies in mouse transverse aortic constriction (TAC) model suggest that dasatinib, a multikinase NRTK inhibitor administration via a peritoneally implanted mini-osmotic pump is able to preserve ventricular geometry and function and reduce the accumulation of fibrotic extracellular matrix (ECM) proteins upon 4 wk pressure overload. Data obtained from cell culture experiments with kinase inactive NRTKs and dasatinib suggest that NRTK inhibition is able to reduce the proliferation, migration and mitogenic signaling in cardiac fibroblasts without affecting the cell survival pathways in cardiomyocytes. These data indicate that NRTKs play a significant pro-fibrotic role in cardiac fibroblasts and curbing the activity of NRTKs could be a potential therapeutic approach to treat fibrosis in hypertrophic heart diseases.

Dynorphin A Elicits an Increase in Intracellular Calcium in Cultured Neurons Via a Non-Opioid, Non-NMDA Mechanism

2000 ◽  
Vol 83 (5) ◽  
pp. 2610-2615 ◽  
Author(s):  
Qingbo Tang ◽  
Ronald M. Lynch ◽  
Frank Porreca ◽  
Josephine Lai
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Intracellular Calcium ◽  
Cortical Neurons ◽  
Excitatory Amino Acid ◽  
Receptor Activation ◽  
Dependent Manner ◽  
Dynorphin A ◽  
Excitatory Effect

The opioid peptide dynorphin A is known to elicit a number of pathological effects that may result from neuronal excitotoxicity. An up-regulation of this peptide has also been causally related to the dysesthesia associated with inflammation and nerve injury. These effects of dynorphin A are not mediated through opioid receptor activation but can be effectively blocked by pretreatment with N-methyl-d-aspartate (NMDA) receptor antagonists, thus implicating the excitatory amino acid system as a mediator of the actions of dynorphin A and/or its fragments. A direct interaction between dynorphin A and the NMDA receptors has been well established; however the physiological relevance of this interaction remains equivocal. This study examined whether dynorphin A elicits a neuronal excitatory effect that may underlie its activation of the NMDA receptors. Calcium imaging of individual cultured cortical neurons showed that the nonopioid peptide dynorphin A(2-17) induced a time- and dose-dependent increase in intracellular calcium. This excitatory effect of dynorphin A(2-17) was insensitive to (+)-5-methyl-10,11-dihydro-5 H-dibenzo[ a,d]-cyclohepten-5,10-imine (MK-801) pretreatment in NMDA-responsive cells. Thus dynorphin A stimulates neuronal cells via a nonopioid, non-NMDA mechanism. This excitatory action of dynorphin A could modulate NMDA receptor activity in vivo by enhancing excitatory neurotransmitter release or by potentiating NMDA receptor function in a calcium-dependent manner. Further characterization of this novel site of action of dynorphin A may provide new insight into the underlying mechanisms of dynorphin excitotoxicity and its pathological role in neuropathy.

scholarly journals A novel Netrin-1–sensitive mechanism promotes local SNARE-mediated exocytosis during axon branching

2014 ◽  
Vol 205 (2) ◽  
pp. 217-232 ◽  
Author(s):  
Cortney C. Winkle ◽  
Leslie M. McClain ◽  
Juli G. Valtschanoff ◽  
Charles S. Park ◽  
Christopher Maglione ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cortical Neurons ◽  
Direct Interaction ◽  
Vesicle Fusion ◽  
Dependent Manner ◽  
Axon Branching ◽  
Spatial Regulation ◽  
Novel Model

Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as a critical catalytic link between Netrin-1 and exocytic SNARE machinery in murine cortical neurons. TRIM9 ligase activity promotes SNARE-mediated vesicle fusion and axon branching in a Netrin-dependent manner. We identified a direct interaction between TRIM9 and the Netrin-1 receptor DCC as well as a Netrin-1–sensitive interaction between TRIM9 and the SNARE component SNAP25. The interaction with SNAP25 negatively regulates SNARE-mediated exocytosis and axon branching in the absence of Netrin-1. Deletion of TRIM9 elevated exocytosis in vitro and increased axon branching in vitro and in vivo. Our data provide a novel model for the spatial regulation of axon branching by Netrin-1, in which localized plasma membrane expansion occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion.

Sign in / Sign up

Export Citation Format

Share Document