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1.
Stud Health Technol Inform ; 309: 33-37, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37869801

ABSTRACT

In this study, we automated the diagnostic procedure of autism spectrum disorder (ASD) with the help of anatomical alterations found in structural magnetic resonance imaging (sMRI) data of the ASD brain and machine learning tools. Initially, the sMRI data was preprocessed using the FreeSurfer toolbox. Further, the brain regions were segmented into 148 regions of interest using the Destrieux atlas. Features such as volume, thickness, surface area, and mean curvature were extracted for each brain region, and the morphological connectivity was computed using Pearson correlation. These morphological connections were fed to XGBoost for feature reduction and to build the diagnostic model. The results showed an average accuracy of 94.16% for the top 18 features. The frontal and limbic regions contributed more features to the classification model. Our proposed method is thus effective for the classification of ASD and can also be useful for the screening of other similar neurological disorders.


Subject(s)
Autism Spectrum Disorder , Brain Mapping , Humans , Brain Mapping/methods , Autism Spectrum Disorder/diagnostic imaging , Brain/diagnostic imaging , Brain/pathology , Magnetic Resonance Imaging/methods , Machine Learning
2.
Cells ; 12(13)2023 06 21.
Article in English | MEDLINE | ID: mdl-37443709

ABSTRACT

Oral cancer patients suffer pain at the site of the cancer. Calcitonin gene related polypeptide (CGRP), a neuropeptide expressed by a subset of primary afferent neurons, promotes oral cancer growth. CGRP also mediates trigeminal pain (migraine) and neurogenic inflammation. The contribution of CGRP to oral cancer pain is investigated in the present study. The findings demonstrate that CGRP-immunoreactive (-ir) neurons and neurites innervate orthotopic oral cancer xenograft tumors in mice. Cancer increases anterograde transport of CGRP in axons innervating the tumor, supporting neurogenic secretion as the source of CGRP in the oral cancer microenvironment. CGRP antagonism reverses oral cancer nociception in preclinical oral cancer pain models. Single-cell RNA-sequencing is used to identify cell types in the cancer microenvironment expressing the CGRP receptor components, receptor activity modifying protein 1 Ramp1 and calcitonin receptor like receptor (CLR, encoded by Calcrl). Ramp1 and Calcrl transcripts are detected in cells expressing marker genes for Schwann cells, endothelial cells, fibroblasts and immune cells. Ramp1 and Calcrl transcripts are more frequently detected in cells expressing fibroblast and immune cell markers. This work identifies CGRP as mediator of oral cancer pain and suggests the antagonism of CGRP to alleviate oral cancer pain.


Subject(s)
Cancer Pain , Mouth Neoplasms , Peptide Hormones , Humans , Mice , Animals , Calcitonin Gene-Related Peptide/metabolism , Calcitonin , Procalcitonin , Receptors, Calcitonin Gene-Related Peptide/genetics , Receptors, Calcitonin Gene-Related Peptide/metabolism , Cancer Pain/drug therapy , Endothelial Cells/metabolism , Mouth Neoplasms/drug therapy , Tumor Microenvironment
3.
J Vis Exp ; (186)2022 08 31.
Article in English | MEDLINE | ID: mdl-36121271

ABSTRACT

Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts. Osteoanabolic drugs have the potential to augment the repair of fractures but have constraints like high costs or undesirable side effects. The bone healing potential of a drug can initially be determined by in vitro studies, but in vivo studies are needed for the final proof of concept. Our objective was to develop a femur osteotomy rodent model that could help researchers understand the development of callus formation following fracture of the shaft of the femur and that could help establish whether a potential drug has bone healing properties. Adult male Wistar albino rats were used after Institutional Animal Ethics Committee clearance. The rodents were anesthetized, and under aseptic conditions, complete transverse fractures at the middle one-third of the shafts of the femurs were created using open osteotomy. The fractures were reduced and internally fixed using intramedullary K-wires, and secondary fracture healing was allowed to take place. After surgery, intraperitoneal analgesics and antibiotics were given for 5 days. Sequential weekly x-rays assessed callus formation. The rats were sacrificed based on radiologically pre-determined time points, and the development of the fracture callus was analyzed radiologically and using immunohistochemistry.


Subject(s)
Femoral Fractures , Animals , Femoral Fractures/diagnostic imaging , Femoral Fractures/surgery , Femur/diagnostic imaging , Femur/surgery , Fracture Healing/physiology , Male , Osteotomy , Rats , Rats, Wistar
4.
Adv Biol (Weinh) ; 6(9): e2200190, 2022 09.
Article in English | MEDLINE | ID: mdl-35925599

ABSTRACT

Oral squamous cell carcinoma (OSCC) patients suffer from poor survival due to metastasis or locoregional recurrence, processes that are both facilitated by perineural invasion (PNI). OSCC has higher rates of PNI than other cancer subtypes, with PNI present in 80% of tumors. Despite the impact of PNI on oral cancer prognosis and pain, little is known about the genes that drive PNI, which in turn drive pain, invasion, and metastasis. In this study, clinical data, preclinical, and in vitro models are leveraged to elucidate the role of neurotrophins in OSCC metastasis, PNI, and pain. The expression data in OSCC patients with metastasis, PNI, or pain demonstrate dysregulation of neurotrophin genes. TrkA and nerve growth factor receptor (NGFR) are focused, two receptors that are activated by NGF, a neurotrophin expressed at high levels in OSCC. It is demonstrated that targeted knockdown of these two receptors inhibits proliferation and invasion in an in vitro and preclinical model of OSCC, and metastasis, PNI, and pain. It is further determined that TrkA knockdown alone inhibits thermal hyperalgesia, whereas NGFR knockdown alone inhibits mechanical allodynia. Collectively the results highlight the ability of OSCC to co-opt different components of the neurotrophin pathway in metastasis, PNI, and pain.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Carcinoma, Squamous Cell/genetics , Humans , Mouth Neoplasms/genetics , Neoplasm Invasiveness/genetics , Neoplasm Recurrence, Local , Neoplastic Processes , Nerve Growth Factors , Nerve Tissue Proteins , Pain , Receptor Protein-Tyrosine Kinases , Receptor, Nerve Growth Factor , Receptor, trkA , Receptors, Nerve Growth Factor/genetics , Squamous Cell Carcinoma of Head and Neck
5.
Mol Autism ; 13(1): 34, 2022 07 18.
Article in English | MEDLINE | ID: mdl-35850732

ABSTRACT

BACKGROUND: Mutations in the postsynaptic transmembrane protein neuroligin-3 are highly correlative with autism spectrum disorders (ASDs) and intellectual disabilities (IDs). Fear learning is well studied in models of these disorders, however differences in fear response behaviours are often overlooked. We aim to examine fear behaviour and its cellular underpinnings in a rat model of ASD/ID lacking Nlgn3. METHODS: This study uses a range of behavioural tests to understand differences in fear response behaviour in Nlgn3-/y rats. Following this, we examined the physiological underpinnings of this in neurons of the periaqueductal grey (PAG), a midbrain area involved in flight-or-freeze responses. We used whole-cell patch-clamp recordings from ex vivo PAG slices, in addition to in vivo local-field potential recordings and electrical stimulation of the PAG in wildtype and Nlgn3-/y rats. We analysed behavioural data with two- and three-way ANOVAS and electrophysiological data with generalised linear mixed modelling (GLMM). RESULTS: We observed that, unlike the wildtype, Nlgn3-/y rats are more likely to response with flight rather than freezing in threatening situations. Electrophysiological findings were in agreement with these behavioural outcomes. We found in ex vivo slices from Nlgn3-/y rats that neurons in dorsal PAG (dPAG) showed intrinsic hyperexcitability compared to wildtype. Similarly, stimulating dPAG in vivo revealed that lower magnitudes sufficed to evoke flight behaviour in Nlgn3-/y than wildtype rats, indicating the functional impact of the increased cellular excitability. LIMITATIONS: Our findings do not examine what specific cell type in the PAG is likely responsible for these phenotypes. Furthermore, we have focussed on phenotypes in young adult animals, whilst the human condition associated with NLGN3 mutations appears during the first few years of life. CONCLUSIONS: We describe altered fear responses in Nlgn3-/y rats and provide evidence that this is the result of a circuit bias that predisposes flight over freeze responses. Additionally, we demonstrate the first link between PAG dysfunction and ASD/ID. This study provides new insight into potential pathophysiologies leading to anxiety disorders and changes to fear responses in individuals with ASD.


Subject(s)
Autistic Disorder , Animals , Autistic Disorder/metabolism , Fear/physiology , Freezing , Humans , Neurons/physiology , Periaqueductal Gray/metabolism , Rats
6.
J Cell Sci ; 135(9)2022 05 01.
Article in English | MEDLINE | ID: mdl-35319067

ABSTRACT

Stress response pathways protect the lung from the damaging effects of environmental toxicants. Here we investigate the role of the fragile X mental retardation protein (FMRP), a multifunctional protein implicated in stress responses, in the lung. We report that FMRP is expressed in murine and human lungs, in the airways and more broadly. Analysis of airway stress responses in mice and in a murine cell line ex vivo, using the well-established naphthalene injury model, reveals that FMRP-deficient cells exhibit increased expression of markers of oxidative and genotoxic stress and increased cell death. Further inquiry shows that FMRP-deficient cells fail to actuate the integrated stress response pathway (ISR) and upregulate the transcription factor ATF4. Knockdown of ATF4 expression phenocopies the loss of FMRP. We extend our analysis of the role of FMRP to human bronchial BEAS-2B cells, using a 9,10-phenanthrenequinone air pollutant model, to find that FMRP-deficient BEAS-2B cells also fail to actuate the ISR and exhibit greater susceptibility. Taken together, our data suggest that FMRP has a conserved role in protecting the airways by facilitating the ISR. This article has an associated First Person interview with the first author of the paper.


Subject(s)
Fragile X Mental Retardation Protein , Xenobiotics , Animals , Fragile X Mental Retardation Protein/genetics , Fragile X Mental Retardation Protein/metabolism , Gene Expression Regulation , Humans , Lung/metabolism , Mice , Transcription Factors/metabolism
8.
Biomed J ; 44(5): 611-619, 2021 10.
Article in English | MEDLINE | ID: mdl-34736875

ABSTRACT

BACKGROUND: Methotrexate (MTX) is widely used in chemotherapy but its associated hepatotoxicity is a major complication, limiting its use. This study evaluates possible therapeutic effect of oral alpha-ketoglutarate (AKG) supplementation against MTX-induced hepatotoxicity. METHODS: HepG2 cells were used to evaluate in-vitro cyto-protection conferred by AKG against MTX induced cytotoxicity. For in-vivo animal study, rats were divided into three groups. Group-I served as control. Group-II animals were administered single intraperitoneal injection of MTX (20 mg/kg/body weight), while Group-III received MTX as in group-II followed by oral AKG (2 gm/kg body weight) for 5 days. 99mTc-Mebrofenin hepatobiliary study was performed under a gamma camera to determine real time functional status of rats' livers. Multiple parameters concerning hepatic mebrofenin uptake and excretion, including Tpeak and T1/2 peak in control and treated animals were determined. Biochemical analysis of the liver homogenate in terms of hepatic enzyme activities in serum, antioxidant status, tissue factor activity, tissue collagen content and histological analysis of the liver tissue were also done. RESULTS: AKG supplementation significantly reversed MTX induced derangement in activities of serum liver enzymes [ALT and ALP (p = 0.003); AST (p = 0.005)], antioxidant status [LPO and GSH (p = 0.005); CAT (p = 0.004)], tissue factor activity (p = 0.005) and tissue collagen content (p = 0.005). Functional imaging confirmed that hepatic retention and fractional biliary excretion were significantly abnormal in MTX treated group (Tpeak: 234 s ± 40 s; T1/2 peak: 846sec ± 32sec) as compared to AKG supplemented group (Tpeak: 144 s ± 35sec; T1/2peak: 468sec ± 27sec). Hepatic extraction fraction (HEF) was 92.2 ± 1.8%, 48.7 ± 2.6% and 69.8 ± 4.3% in control, MTX and AKG supplemented rats respectively. CONCLUSION: 99mTc-mebrofenin imaging strongly suggests therapeutic action of AKG in protecting liver damage by MTX in rats. Functional imaging parameters correlated well with biochemical and histopathological findings.


Subject(s)
Chemical and Drug Induced Liver Injury, Chronic , Chemical and Drug Induced Liver Injury , Aniline Compounds , Animals , Chemical and Drug Induced Liver Injury/drug therapy , Chemical and Drug Induced Liver Injury, Chronic/metabolism , Glycine , Ketoglutaric Acids/metabolism , Liver/metabolism , Methotrexate/metabolism , Methotrexate/toxicity , Oxidative Stress , Rats
9.
Science ; 374(6564): 189-193, 2021 Oct 08.
Article in English | MEDLINE | ID: mdl-34618565

ABSTRACT

Grain boundary velocity has been believed to be correlated to curvature, and this is an important relationship for modeling how polycrystalline materials coarsen during annealing. We determined the velocities and curvatures of approximately 52,000 grain boundaries in a nickel polycrystal using three-dimensional orientation maps measured by high-energy diffraction microscopy before and after annealing at 800°C. Unexpectedly, the grain boundary velocities and curvatures were uncorrelated. Instead, we found strong correlations between the boundary velocity and the five macroscopic parameters that specify grain boundary crystallography. The sensitivity of the velocity to grain boundary crystallography might be the result of defect-mediated grain boundary migration or the anisotropy of the grain boundary energy. The absence of a correlation between velocity and curvature likely results from the constraints imposed by the grain boundary network and implies the need for a new model for grain boundary migration.

10.
Int J Biol Macromol ; 174: 240-253, 2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33515570

ABSTRACT

In this report, we discuss the design of a novel collagen/pectin (CP) hybrid composite hydrogel (CPBG) containing in-situ mineralized bioactive glass (BG) particles to simulate an integrative 3D cell environment. Systematic analysis of the CP sol revealed collagen and pectin molecules interacted regardless of both possessing similar net negative charge through the mechanism of surface patch binding interaction. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed this associative interaction which resulted in the formation of a hybrid crosslinked network with the BG nanoparticles acting as pseudo crosslink junctions. Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX) and Transmission Electron Microscopy (TEM) results confirmed uniform mineralization of BG particles, and their synergetic interaction with the network. The in-vitro bioactivity tests on CPBG indicated the formation of bone-like hydroxyapatite (Ca10(PO4)6(OH)2) microcrystals on its surface after interaction with simulated body fluid. This hydrogel was loaded with a model antifungal drug amphotericin-B (AmB) and tested against Candida albicans. The AmB release kinetics from the hydrogel followed the Fickian mechanism and showed direct proportionality to gel swelling behavior. Rheological analysis revealed the viscoelastic compatibility of CPBG for the mechanical load bearing applications. Cell viability tests indicated appreciable compatibility of the hydrogel against U2OS and HaCaT cell lines. FDA/PI on the hydrogel portrayed preferential U2OS cell adhesion on hydrophobic hydroxyapatite layer compared to hydrophilic surfaces, thereby promising the regeneration of both soft and hard tissues.


Subject(s)
Amphotericin B/pharmacology , Candida albicans/drug effects , Collagen/chemistry , Durapatite/chemical synthesis , Pectins/chemistry , Amphotericin B/chemistry , Cell Adhesion , Cell Line , Durapatite/chemistry , Glass/chemistry , Humans , Hydrogels/chemistry , Materials Testing , Microscopy, Electron, Scanning , Nanoparticles , Rheology , Spectroscopy, Fourier Transform Infrared , Thermogravimetry
11.
J Gastrointest Cancer ; 52(3): 882-891, 2021 Sep.
Article in English | MEDLINE | ID: mdl-32816148

ABSTRACT

BACKGROUND: Colon cancer cells can migrate and metastasize by undergoing epithelial-to-mesenchymal transition (EMT). Mesenchymal stem cells (MSCs) are non-cancerous, multipotent adult stem cells, which can also migrate. In this study, we wanted to compare the biological, physical, and functional properties of these migratory cells. MATERIALS AND METHODS: HT-29 and HCT-116, two human colon carcinoma cell lines, represent less aggressive and more aggressive cancer cells, respectively. MSCs were isolated from human bone marrow. After confirming the identity of all the cell types, they were evaluated for E-cadherin, ß1-integrin, Vimentin, ZEB-1, ß-catenin, and 18S rRNA using Q-PCR. MMP-2 and MMP-9 activity were evaluated using gelatin zymography. Functional tests like wound healing assay, migration assay, and invasion assay were also done. Biomechanical properties like cell stiffness and non-specific adhesion (between indenter probe and cell membrane) were evaluated through nanoindentation using atomic force microscopy (AFM). RESULTS: Expression of EMT and stem cell markers showed typical expression patterns for HT-29, HCT-116, and MSCs. Functional tests showed that MSCs migrated faster than malignant cells. MMP-2 and MMP-9 activity reinforced this behavior. Interestingly, the migration/invasion capacity of MSCs was comparable to aggressive HCT-116, and more than HT-29. MSCs also showed the maximum cell stiffness and non-specific cell-probe adhesions, followed by HCT116 and HT29 cells. CONCLUSIONS: Our findings indicate that the migratory properties of MSCs is comparable or even greater than that of cancer cells and despite their high migration potential, they also have the maximum stiffness.


Subject(s)
Colonic Neoplasms/physiopathology , Epithelial-Mesenchymal Transition/physiology , Mesenchymal Stem Cells/metabolism , Adaptor Proteins, Signal Transducing/analysis , Cadherins/analysis , Cell Line, Tumor , Cell Movement , Colonic Neoplasms/pathology , Humans , In Vitro Techniques , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/pathology
12.
Sci Rep ; 10(1): 14724, 2020 09 07.
Article in English | MEDLINE | ID: mdl-32895418

ABSTRACT

Oral cancer patients experience pain at the site of the primary cancer. Patients with metastatic oral cancers report greater pain. Lack of pain identifies patients at low risk of metastasis with sensitivity = 0.94 and negative predictive value = 0.89. In the same cohort, sensitivity and negative predictive value of depth of invasion, currently the best predictor, were 0.95 and 0.92, respectively. Cancer pain is attributed to cancer-derived mediators that sensitize neurons and is associated with increased neuronal density. We hypothesized that pain mediators would be overexpressed in metastatic cancers from patients reporting high pain. We identified 40 genes overexpressed in metastatic cancers from patients reporting high pain (n = 5) compared to N0 cancers (n = 10) and normal tissue (n = 5). The genes are enriched for functions in extracellular matrix organization and angiogenesis. They have oncogenic and neuronal functions and are reported in exosomes. Hierarchical clustering according to expression of neurotrophic and axon guidance genes also separated cancers according to pain and nodal status. Depletion of exosomes from cancer cell line supernatant reduced nociceptive behavior in a paw withdrawal assay, supporting a role for exosomes in cancer pain. The identified genes and exosomes are potential therapeutic targets for stopping cancer and attenuating pain.


Subject(s)
Cancer Pain/genetics , Exosomes/genetics , Mouth Neoplasms/genetics , Oncogenes/genetics , Aged , Carcinogenesis/genetics , Cell Line, Tumor , Extracellular Matrix/genetics , Female , Humans , Male , Patients
13.
J Proteome Res ; 19(9): 3856-3866, 2020 09 04.
Article in English | MEDLINE | ID: mdl-32786687

ABSTRACT

Aberrant protein synthesis and protein expression are a hallmark of many conditions ranging from cancer to Alzheimer's. Blood-based biomarkers indicative of changes in proteomes have long been held to be potentially useful with respect to disease prognosis and treatment. However, most biomarker efforts have focused on unlabeled plasma proteomics that include nonmyeloid origin proteins with no attempt to dynamically tag acute changes in proteomes. Herein we report a method for evaluating de novo protein synthesis in whole blood liquid biopsies. Using a modification of the "bioorthogonal noncanonical amino acid tagging" (BONCAT) protocol, rodent whole blood samples were incubated with l-azidohomoalanine (AHA) to allow incorporation of this selectively reactive non-natural amino acid within nascent polypeptides. Notably, failure to incubate the blood samples with EDTA prior to implementation of azide-alkyne "click" reactions resulted in the inability to detect probe incorporation. This live-labeling assay was sensitive to inhibition with anisomycin and nascent, tagged polypeptides were localized to a variety of blood cells using FUNCAT. Using labeled rodent blood, these tagged peptides could be consistently identified through standard LC/MS-MS detection of known blood proteins across a variety of experimental conditions. Furthermore, this assay could be expanded to measure de novo protein synthesis in human blood samples. Overall, we present a rapid and convenient de novo protein synthesis assay that can be used with whole blood biopsies that can quantify translational change as well as identify differentially expressed proteins that may be useful for clinical applications.


Subject(s)
Alkynes , Azides , Click Chemistry , Cycloaddition Reaction , Protein Biosynthesis
14.
Pain ; 161(11): 2592-2602, 2020 11.
Article in English | MEDLINE | ID: mdl-32658150

ABSTRACT

Cancer invading into nerves, termed perineural invasion (PNI), is associated with pain. Here, we show that oral cancer patients with PNI report greater spontaneous pain and mechanical allodynia compared with patients without PNI, suggesting that unique mechanisms drive PNI-induced pain. We studied the impact of PNI on peripheral nerve physiology and anatomy using a murine sciatic nerve PNI model. Mice with PNI exhibited spontaneous nociception and mechanical allodynia. Perineural invasion induced afterdischarge in A high-threshold mechanoreceptors (HTMRs), mechanical sensitization (ie, decreased mechanical thresholds) in both A and C HTMRs, and mechanical desensitization in low-threshold mechanoreceptors. Perineural invasion resulted in nerve damage, including axon loss, myelin damage, and axon degeneration. Electrophysiological evidence of nerve injury included decreased conduction velocity, and increased percentage of both mechanically insensitive and electrically unexcitable neurons. We conclude that PNI-induced pain is driven by nerve injury and peripheral sensitization in HTMRs.


Subject(s)
Cancer Pain/etiology , Mouth Neoplasms , Peripheral Nerve Injuries , Animals , Female , Male , Mice , Mouth Neoplasms/complications , Neoplasm Invasiveness , Peripheral Nerve Injuries/etiology , Peripheral Nerves , Sciatic Nerve
15.
Brain Sci ; 10(6)2020 Jun 10.
Article in English | MEDLINE | ID: mdl-32531912

ABSTRACT

Recent advances in neurobiology have provided several molecular entrees for targeted treatments for Fragile X syndrome (FXS). However, the efficacy of these treatments has been demonstrated mainly in animal models and has not been consistently predictive of targeted drugs' response in the preponderance of human clinical trials. Because of the heterogeneity of FXS at various levels, including the molecular level, phenotypic manifestation, and drug response, it is critically important to identify biomarkers that can help in patient stratification and prediction of therapeutic efficacy. The primary objective of this study was to assess the ability of molecular biomarkers to predict phenotypic subgroups, symptom severity, and treatment response to metformin in clinically treated patients with FXS. We specifically tested a triplex protein array comprising of hexokinase 1 (HK1), RAS (all isoforms), and Matrix Metalloproteinase 9 (MMP9) that we previously demonstrated were dysregulated in the FXS mouse model and in blood samples from patient with FXS. Seventeen participants with FXS, 12 males and 5 females, treated clinically with metformin were included in this study. The disruption in expression abundance of these proteins was normalized and associated with significant self-reported improvement in clinical phenotypes (CGI-I in addition to BMI) in a subset of participants with FXS. Our preliminary findings suggest that these proteins are of strong molecular relevance to the FXS pathology that could make them useful molecular biomarkers for this syndrome.

16.
EMBO Rep ; 21(6): e48037, 2020 06 04.
Article in English | MEDLINE | ID: mdl-32351028

ABSTRACT

Neuronal activity is responsible for the high energy consumption in the brain. However, the cellular mechanisms draining ATP upon the arrival of a stimulus are yet to be explored systematically at the post-synapse. Here, we provide evidence that a significant fraction of ATP is consumed upon glutamate stimulation to energize mGluR-induced protein synthesis. We find that both mGluR and NMDAR alter protein synthesis and ATP consumption with distinct kinetics at the synaptic-dendritic compartments. While mGluR activation leads to a rapid and sustained reduction in neuronal ATP levels, NMDAR activation has no immediate impact on the same. ATP consumption correlates inversely with the kinetics of protein synthesis for both receptors. We observe a persistent elevation in protein synthesis within 5 minutes of mGluR activation and a robust inhibition of the same within 2 minutes of NMDAR activation, assessed by the phosphorylation status of eEF2 and metabolic labeling. However, a delayed protein synthesis-dependent ATP expenditure ensues after 15 minutes of NMDAR stimulation. We identify a central role for AMPK in the correlation between protein synthesis and ATP consumption. AMPK is dephosphorylated and inhibited upon mGluR activation, while it is phosphorylated upon NMDAR activation. Perturbing AMPK activity disrupts receptor-specific modulations of eEF2 phosphorylation and protein synthesis. Our observations, therefore, demonstrate that the regulation of the AMPK-eEF2 signaling axis by glutamate receptors alters neuronal protein synthesis and bioenergetics.


Subject(s)
Receptors, N-Methyl-D-Aspartate , Synapses , Energy Metabolism , Peptide Elongation Factor 2 , Phosphorylation , Receptors, N-Methyl-D-Aspartate/genetics , Receptors, N-Methyl-D-Aspartate/metabolism , Synapses/metabolism
17.
Neurobiol Learn Mem ; 171: 107203, 2020 05.
Article in English | MEDLINE | ID: mdl-32147585

ABSTRACT

The ribosomal p70 S6 Kinase 1 (S6K1) has been implicated in the etiology of complex neurological diseases including autism, depression and dementia. Though no major gene disruption has been reported in humans in RPS6KB1, single nucleotide variants (SNVs) causing missense mutations have been identified, which have not been assessed for their impact on protein function. These S6K1 mutations have the potential to influence disease progression and treatment response. We mined the Simon Simplex Collection (SSC) and SPARK autism database to find inherited SNVs in S6K1 and characterized the effect of two missense SNVs, Asp14Asn (allele frequency = 0.03282%) and Glu44Gln (allele frequency = 0.0008244%), on S6K1 function in HEK293, human ES cells and primary neurons. Expressing Asp14Asn in HEK293 cells resulted in increased basal phosphorylation of downstream targets of S6K1 and increased de novo translation. This variant also showed blunted response to the specific S6K1 inhibitor, FS-115. In human embryonic cell line Shef4, Asp14Asn enhanced spontaneous neural fate specification in the absence of differentiating growth factors. In addition to enhanced translation, neurons expressing Asp14Asn exhibited impaired dendritic arborization and increased levels of phosphorylated ERK 1/2. Finally, in the SSC families tracked, Asp14Asn segregated with lower IQ scores when found in the autistic individual rather than the unaffected sibling. The Glu44Gln mutation showed a milder, but opposite phenotype in HEK cells as compared to Asp14Asn. Although the Glu44Gln mutation displayed increased neuronal translation, it had no impact on neuronal morphology. Our results provide the first characterization of naturally occurring human S6K1 variants on cognitive phenotype, neuronal morphology and maturation, underscoring again the importance of translation control in neural development and plasticity.


Subject(s)
Hippocampus/metabolism , Neurons/metabolism , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Signal Transduction/physiology , Alleles , Animals , Cell Shape/genetics , Gene Frequency , HEK293 Cells , Hippocampus/cytology , Humans , Mutation , Neurogenesis/physiology , Neurons/cytology , Phosphorylation , Rats , Rats, Sprague-Dawley , Ribosomal Protein S6 Kinases, 70-kDa/genetics
18.
Neuroscience ; 439: 319-331, 2020 07 15.
Article in English | MEDLINE | ID: mdl-30970266

ABSTRACT

Serotonin is an important neurotransmitter and neuromodulator. Disruption of the serotonergic system has been implicated in various psychiatric disorders such as schizophrenia and bipolar disorder. Most of the drugs targeting these neurotransmitter systems are classified primarily as agonists or inverse agonists/antagonists, with their described function being limited to activating the canonical signaling pathway(s), or inhibiting the pathway(s) respectively. Previous work with the human 5-HT2A has shown the receptor to be activated by dopamine, also an endogenous ligand. Dopamine is the cognate ligand of the dopaminergic system, which significantly overlaps with the serotonergic system in the brain. The two systems innervate many of the same brain areas, and the central serotonergic systems also regulate dopamine functions. Our aim was to investigate the downstream signaling set up by the receptor on being activated by dopamine. We show that dopamine is a functionally selective ligand at 5-HT2A and have examined dopamine as a ligand with respect to some receptor-dependent phenotypes. Our results show that dopamine acts as an agonist at the human serotonin 2A receptor and brings about its activation and internalization. Using in vitro assays, we have established differences in the signaling pathways set up by dopamine as compared to serotonin. Using site-specific mutagenesis we have identified residues important for this functional selectivity, shown by dopamine at this receptor. Our identification of specific residues important in the functional selectivity of dopamine at 5-HT2A could have far reaching implications for the field of GPCR signaling and drug-design. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.


Subject(s)
Dopamine , Receptor, Serotonin, 5-HT2A , Humans , Receptors, Dopamine D2 , Serotonin , Serotonin 5-HT2 Receptor Agonists
19.
Surg Oncol Clin N Am ; 29(1): 127-144, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31757309

ABSTRACT

Oral squamous cell carcinoma (OSCC) is one of the leading cancers in the world. OSCC patients are managed with surgery and/or chemoradiation. Prognoses and survival rates are dismal, however, and have not improved for more than 20 years. Recently, the concept of precision medicine was introduced, and the introduction of targeted therapeutics demonstrated promising outcomes. This article reviews the current understanding of initiation, progression, and metastasis of OSCC from both genetic and epigenetic perspectives. In addition, the applications and integration of omics technologies in biomarker discovery and drug development for treating OSCC are reviewed.


Subject(s)
Antineoplastic Agents/therapeutic use , Biomarkers, Tumor/genetics , Molecular Targeted Therapy/methods , Mouth Neoplasms/drug therapy , Pharmacogenetics/methods , Precision Medicine/trends , Humans , Mouth Neoplasms/genetics , Precision Medicine/methods
20.
Nat Commun ; 10(1): 1710, 2019 04 12.
Article in English | MEDLINE | ID: mdl-30979884

ABSTRACT

Whether fragile X mental retardation protein (FMRP) target mRNAs and neuronal activity contributing to elevated basal neuronal protein synthesis in fragile X syndrome (FXS) is unclear. Our proteomic experiments reveal that the de novo translational profile in FXS model mice is altered at steady state and in response to metabotropic glutamate receptor (mGluR) stimulation, but the proteins expressed differ under these conditions. Several altered proteins, including Hexokinase 1 and Ras, also are expressed in the blood of FXS model mice and pharmacological treatments previously reported to ameliorate phenotypes modify their abundance in blood. In addition, plasma levels of Hexokinase 1 and Ras differ between FXS patients and healthy volunteers. Our data suggest that brain-based de novo proteomics in FXS model mice can be used to find altered expression of proteins in blood that could serve as disease-state biomarkers in individuals with FXS.


Subject(s)
Fragile X Syndrome/metabolism , Receptors, Metabotropic Glutamate/metabolism , Adolescent , Adult , Animals , Biomarkers/blood , Disease Models, Animal , Female , Fragile X Syndrome/genetics , Hexokinase/blood , Hippocampus/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Phenotype , Young Adult , ras Proteins/metabolism
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