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1.
Mol Psychiatry ; 28(3): 1219-1231, 2023 03.
Article in English | MEDLINE | ID: mdl-36604604

ABSTRACT

ATP9A, a lipid flippase of the class II P4-ATPases, is involved in cellular vesicle trafficking. Its homozygous variants are linked to neurodevelopmental disorders in humans. However, its physiological function, the underlying mechanism as well as its pathophysiological relevance in humans and animals are still largely unknown. Here, we report two independent families in which the nonsense mutations c.433C>T/c.658C>T/c.983G>A (p. Arg145*/p. Arg220*/p. Trp328*) in ATP9A (NM_006045.3) cause autosomal recessive hypotonia, intellectual disability (ID) and attention deficit hyperactivity disorder (ADHD). Atp9a null mice show decreased muscle strength, memory deficits and hyperkinetic movement disorder, recapitulating the symptoms observed in patients. Abnormal neurite morphology and impaired synaptic transmission are found in the primary motor cortex and hippocampus of the Atp9a null mice. ATP9A is also required for maintaining neuronal neurite morphology and the viability of neural cells in vitro. It mainly localizes to endosomes and plays a pivotal role in endosomal recycling pathway by modulating small GTPase RAB5 and RAB11 activation. However, ATP9A pathogenic mutants have aberrant subcellular localization and cause abnormal endosomal recycling. These findings provide strong evidence that ATP9A deficiency leads to neurodevelopmental disorders and synaptic dysfunctions in both humans and mice, and establishes novel regulatory roles for ATP9A in RAB5 and RAB11 activity-dependent endosomal recycling pathway and neurological diseases.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Animals , Humans , Mice , Attention Deficit Disorder with Hyperactivity/metabolism , Endosomes/metabolism , Protein Transport , rab5 GTP-Binding Proteins/genetics , rab5 GTP-Binding Proteins/metabolism
2.
Proc Natl Acad Sci U S A ; 118(16)2021 04 20.
Article in English | MEDLINE | ID: mdl-33850017

ABSTRACT

Epilepsy, a common neurological disorder, is featured with recurrent seizures. Its underlying pathological mechanisms remain elusive. Here, we provide evidence for loss of neogenin (NEO1), a coreceptor for multiple ligands, including netrins and bone morphological proteins, in the development of epilepsy. NEO1 is reduced in hippocampi from patients with epilepsy based on transcriptome and proteomic analyses. Neo1 knocking out (KO) in mouse brains displays elevated epileptiform spikes and seizure susceptibility. These phenotypes were undetectable in mice, with selectively depleted NEO1 in excitatory (NeuroD6-Cre+) or inhibitory (parvalbumin+) neurons, but present in mice with specific hippocampal astrocytic Neo1 KO. Additionally, neurons in hippocampal dentate gyrus, a vulnerable region in epilepsy, in mice with astrocyte-specific Neo1 KO show reductions in inhibitory synaptic vesicles and the frequency of miniature inhibitory postsynaptic current(mIPSC), but increase of the duration of miniature excitatory postsynaptic current and tonic NMDA receptor currents, suggesting impairments in both GABAergic transmission and extracellular glutamate clearance. Further proteomic and cell biological analyses of cell-surface proteins identified GLAST, a glutamate-aspartate transporter that is marked reduced in Neo1 KO astrocytes and the hippocampus. NEO1 interacts with GLAST and promotes GLAST surface distribution in astrocytes. Expressing NEO1 or GLAST in Neo1 KO astrocytes in the hippocampus abolishes the epileptic phenotype. Taken together, these results uncover an unrecognized pathway of NEO1-GLAST in hippocampal GFAP+ astrocytes, which is critical for GLAST surface distribution and function, and GABAergic transmission, unveiling NEO1 as a valuable therapeutic target to protect the brain from epilepsy.


Subject(s)
Astrocytes/metabolism , Hippocampus/metabolism , Membrane Proteins/metabolism , Animals , Astrocytes/physiology , Biological Transport/physiology , Epilepsy/physiopathology , Epilepsy/prevention & control , Excitatory Amino Acid Transporter 1/metabolism , Excitatory Amino Acid Transporter 2/metabolism , Female , Glutamic Acid/metabolism , Male , Membrane Proteins/physiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Neurons/metabolism , Seizures/metabolism , Signal Transduction , Synaptic Potentials/physiology
3.
J Neurosci ; 42(11): 2356-2370, 2022 03 16.
Article in English | MEDLINE | ID: mdl-35105676

ABSTRACT

Anxiety disorders are debilitating psychiatric diseases that affect ∼16% of the world's population. Although it has been proposed that the central nucleus of the amygdala (CeA) plays a role in anxiety, the molecular and circuit mechanisms through which CeA neurons modulate anxiety-related behaviors are largely uncharacterized. Soluble epoxide hydrolase (sEH) is a key enzyme in the metabolism of polyunsaturated fatty acids (PUFAs), and has been shown to play a role in psychiatric disorders. Here, we reported that sEH was enriched in neurons in the CeA and regulated anxiety-related behaviors in adult male mice. Deletion of sEH in CeA neurons but not astrocytes induced anxiety-like behaviors. Mechanistic studies indicated that sEH was required for maintaining the the excitability of sEH positive neurons (sEHCeA neurons) in the CeA. Using chemogenetic manipulations, we found that sEHCeA neurons bidirectionally regulated anxiety-related behaviors. Notably, we identified that sEHCeA neurons directly projected to the bed nucleus of the stria terminalis (BNST; sEHCeA-BNST). Optogenetic activation and inhibition of the sEHCeA-BNST pathway produced anxiolytic and anxiogenic effects, respectively. In summary, our studies reveal a set of molecular and circuit mechanisms of sEHCeA neurons underlying anxiety.SIGNIFICANCE STATEMENT Soluble epoxide hydrolase (sEH), a key enzyme that catalyzes the degradation of EETs, is shown to play a key role in mood disorders. It is well known that sEH is mostly localized in astrocytes in the prefrontal cortex and regulates depressive-like behaviors. Notably, sEH is also expressed in central nucleus of the amygdala (CeA) neurons. While the CeA has been studied for its role in the regulation of anxiety, the molecular and circuit mechanism is quite complex. In the present study, we explored a previously unknown cellular and circuitry mechanism that guides sEHCeA neurons response to anxiety. Our findings reveal a critical role of sEH in the CeA, sEHCeA neurons and CeA-bed nucleus of the stria terminalis (BNST) pathway in regulation of anxiety-related behaviors.


Subject(s)
Central Amygdaloid Nucleus , Septal Nuclei , Amygdala/metabolism , Animals , Anxiety/psychology , Central Amygdaloid Nucleus/metabolism , Cerebellar Nuclei/metabolism , Epoxide Hydrolases , Humans , Male , Mice , Septal Nuclei/physiology
4.
Proc Natl Acad Sci U S A ; 115(10): 2508-2513, 2018 03 06.
Article in English | MEDLINE | ID: mdl-29463705

ABSTRACT

Neuregulin3 (NRG3) is a growth factor of the neuregulin (NRG) family and a risk gene of various severe mental illnesses including schizophrenia, bipolar disorders, and major depression. However, the physiological function of NRG3 remains poorly understood. Here we show that loss of Nrg3 in GFAP-Nrg3f/f mice increased glutamatergic transmission, but had no effect on GABAergic transmission. These phenotypes were observed in Nex-Nrg3f/f mice, where Nrg3 was specifically knocked out in pyramidal neurons, indicating that Nrg3 regulates glutamatergic transmission by a cell-autonomous mechanism. Consequently, in the absence of Nrg3 in pyramidal neurons, mutant mice displayed various behavioral deficits related to mental illnesses. We show that the Nrg3 mutation decreased paired-pulse facilitation, increased decay of NMDAR currents when treated with MK801, and increased minimal stimulation-elicited response, providing evidence that the Nrg3 mutation increases glutamate release probability. Notably, Nrg3 is a presynaptic protein that regulates the SNARE-complex assembly. Finally, increased Nrg3 levels, as observed in patients with severe mental illnesses, suppressed glutamatergic transmission. Together, these observations indicate that, unlike the prototype Nrg1, the effect of which is mediated by activating ErbB4 in interneurons, Nrg3 is critical in controlling glutamatergic transmission by regulating the SNARE complex at the presynaptic terminals, identifying a function of Nrg3 and revealing a pathophysiological mechanism for hypofunction of the glutamatergic pathway in Nrg3-related severe mental illnesses.


Subject(s)
Glutamic Acid/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , SNARE Proteins/metabolism , Animals , Behavior, Animal/physiology , Intracellular Signaling Peptides and Proteins/genetics , Mental Disorders/genetics , Mice , Mice, Transgenic , Neuregulins , Pyramidal Cells/metabolism
5.
Brain Behav Immun ; 88: 748-762, 2020 08.
Article in English | MEDLINE | ID: mdl-32413556

ABSTRACT

Depression is a severe neuropsychiatric disorder, of which the underlying pathological mechanisms remain unclear. The ketogenic diet (KD) has been reported to exhibit preventative effects on depressive-like behaviors in rodents. However, the therapeutic effects of KD on depressive-like behaviors have not been illustrated thus far. Here, we found that KD treatment dramatically ameliorated depressive-like behaviors in both repeated social defeat stress (R-SDS) and lipopolysaccharide (LPS) models, indicating the potential therapeutic effects of KD on depression. Our electrophysiological studies further showed that neuronal excitability was increased in the lateral habenula (LHb) of mice exposed to R-SDS or LPS, which can be reversed in the presence of KD treatment. Moreover, R-SDS and LPS were also found to induce robust microglial inflammatory activation in the LHb. Importantly, these phenotypes were rescued in mice fed with KD. In addition, we found that the protein level of innate immune receptor Trem2 in the LHb was significantly decreased in depression models. Specific knockdown of Trem2 in LHb microglia induced depressive-like behaviors, increased neuronal excitability as well as robust microglial inflammatory activation. Altogether, we demonstrated the therapeutic effects of KD on depressive-like behaviors, which are probably mediated via the restoration of microglial inflammatory activation and neuronal excitability. Besides, we also proposed an unrecognized function of Trem2 in the LHb for depression. Our study sheds light on the pathogenesis of depression and thereby offers a potential therapeutic intervention.


Subject(s)
Diet, Ketogenic , Habenula , Neurons , Animals , Depression , Membrane Glycoproteins , Mice , Receptors, Immunologic
6.
Proc Natl Acad Sci U S A ; 114(5): 1177-1182, 2017 01 31.
Article in English | MEDLINE | ID: mdl-28096412

ABSTRACT

Neurotransmission in dentate gyrus (DG) is critical for spatial coding, learning memory, and emotion processing. Although DG dysfunction is implicated in psychiatric disorders, including schizophrenia, underlying pathological mechanisms remain unclear. Here we report that transmembrane protein 108 (Tmem108), a novel schizophrenia susceptibility gene, is highly enriched in DG granule neurons and its expression increased at the postnatal period critical for DG development. Tmem108 is specifically expressed in the nervous system and enriched in the postsynaptic density fraction. Tmem108-deficient neurons form fewer and smaller spines, suggesting that Tmem108 is required for spine formation and maturation. In agreement, excitatory postsynaptic currents of DG granule neurons were decreased in Tmem108 mutant mice, indicating a hypofunction of glutamatergic activity. Further cell biological studies indicate that Tmem108 is necessary for surface expression of AMPA receptors. Tmem108-deficient mice display compromised sensorimotor gating and cognitive function. Together, these observations indicate that Tmem108 plays a critical role in regulating spine development and excitatory transmission in DG granule neurons. When Tmem108 is mutated, mice displayed excitatory/inhibitory imbalance and behavioral deficits relevant to schizophrenia, revealing potential pathophysiological mechanisms of schizophrenia.


Subject(s)
Cognition Disorders/genetics , Dentate Gyrus/physiology , Sensory Gating/genetics , Vesicular Transport Proteins/physiology , Animals , Animals, Newborn , Cognition Disorders/physiopathology , Dentate Gyrus/metabolism , Disease Models, Animal , Electroporation , Excitatory Postsynaptic Potentials/physiology , Fear , Genes, Reporter , Glutamic Acid/physiology , HEK293 Cells , Humans , Male , Maze Learning , Mice , Mice, Knockout , Neurons/physiology , Neurons/ultrastructure , Post-Synaptic Density/chemistry , RNA Interference , RNA, Small Interfering/genetics , Receptors, AMPA/biosynthesis , Schizophrenia/genetics , Sensory Gating/physiology , Synaptic Transmission/physiology , Vesicular Transport Proteins/deficiency , Vesicular Transport Proteins/genetics
7.
J Neurosci ; 38(44): 9600-9613, 2018 10 31.
Article in English | MEDLINE | ID: mdl-30228230

ABSTRACT

Fear learning and memory are vital for livings to survive, dysfunctions in which have been implicated in various neuropsychiatric disorders. Appropriate neuronal activation in amygdala is critical for fear memory. However, the underlying regulatory mechanisms are not well understood. Here we report that Neogenin, a DCC (deleted in colorectal cancer) family receptor, which plays important roles in axon navigation and adult neurogenesis, is enriched in excitatory neurons in BLA (Basolateral amygdala). Fear memory is impaired in male Neogenin mutant mice. The number of cFos+ neurons in response to tone-cued fear training was reduced in mutant mice, indicating aberrant neuronal activation in the absence of Neogenin. Electrophysiological studies show that Neogenin mutation reduced the cortical afferent input to BLA pyramidal neurons and compromised both induction and maintenance of Long-Term Potentiation evoked by stimulating cortical afferent, suggesting a role of Neogenin in synaptic plasticity. Concomitantly, there was a reduction in spine density and in frequency of miniature excitatory postsynaptic currents (mEPSCs), but not miniature inhibitory postsynaptic currents, suggesting a role of Neogenin in forming excitatory synapses. Finally, ablating Neogenin in the BLA in adult male mice impaired fear memory likely by reducing mEPSC frequency in BLA excitatory neurons. These results reveal an unrecognized function of Neogenin in amygdala for information processing by promoting and maintaining neurotransmission and synaptic plasticity and provide insight into molecular mechanisms of neuronal activation in amygdala.SIGNIFICANCE STATEMENT Appropriate neuronal activation in amygdala is critical for information processing. However, the underlying regulatory mechanisms are not well understood. Neogenin is known to regulate axon navigation and adult neurogenesis. Here we show that it is critical for neurotransmission and synaptic plasticity in the amygdala and thus fear memory by using a combination of genetic, electrophysiological, behavioral techniques. Our studies identify a novel function of Neogenin and provide insight into molecular mechanisms of neuronal activation in amygdala for fear processing.


Subject(s)
Basolateral Nuclear Complex/metabolism , Fear/physiology , Learning/physiology , Membrane Proteins/genetics , Membrane Proteins/metabolism , Neurons/metabolism , Animals , Excitatory Postsynaptic Potentials/physiology , Fear/psychology , Male , Mice , Mice, Transgenic , Organ Culture Techniques
8.
J Neurosci ; 38(41): 8860-8873, 2018 10 10.
Article in English | MEDLINE | ID: mdl-30171091

ABSTRACT

During aging, acetylcholine receptor (AChR) clusters become fragmented and denervated at the neuromuscular junction (NMJ). Underpinning molecular mechanisms are not well understood. We showed that LRP4, a receptor for agrin and critical for NMJ formation and maintenance, was reduced at protein level in aged mice, which was associated with decreased MuSK tyrosine phosphorylation, suggesting compromised agrin-LRP4-MuSK signaling in aged muscles. Transgenic expression of LRP4 in muscles alleviated AChR fragmentation and denervation and improved neuromuscular transmission in aged mice. LRP4 ubiquitination was augmented in aged muscles, suggesting increased LRP4 degradation as a mechanism for reduced LRP4. We found that sarcoglycan α (SGα) interacted with LRP4 and delayed LRP4 degradation in cotransfected cells. AAV9-mediated expression of SGα in muscles mitigated AChR fragmentation and denervation and improved neuromuscular transmission in aged mice. These observations support a model where compromised agrin-LRP4-MuSK signaling serves as a pathological mechanism of age-related NMJ decline and identify a novel function of SGα in stabilizing LRP4 for NMJ stability in aged mice.SIGNIFICANCE STATEMENT This study provides evidence that LRP4, a receptor of agrin that is critical for NMJ formation and maintenance, is reduced at protein level in aged muscles. Transgenic expression of LRP4 in muscles ameliorates AChR fragmentation and denervation and improves neuromuscular transmission in aged mice, demonstrating a critical role of the agrin-LRP4-MuSK signaling. Our study also reveals a novel function of SGα to prevent LRP4 degradation in aged muscles. Finally, we show that NMJ decline in aged mice can be mitigated by AAV9-mediated expression of SGα in muscles. These observations provide insight into pathological mechanisms of age-related NMJ decline and suggest that improved agrin-LRP4-MuSK signaling may be a target for potential therapeutic intervention.


Subject(s)
Aging , Muscle, Skeletal/metabolism , Neuromuscular Junction/metabolism , Receptors, Cholinergic/metabolism , Receptors, LDL/metabolism , Sarcoglycans/metabolism , Animals , Female , LDL-Receptor Related Proteins , Male , Mice, Inbred C57BL , Mice, Transgenic , Muscle, Skeletal/innervation , Phosphorylation , Receptor Protein-Tyrosine Kinases/metabolism
10.
J Neurosci ; 37(13): 3465-3477, 2017 03 29.
Article in English | MEDLINE | ID: mdl-28213440

ABSTRACT

Yes-associated protein (Yap) is a major effector of the Hippo pathway that regulates cell proliferation and differentiation during development and restricts tissue growth in adult animals. However, its role in synapse formation remains poorly understood. In this study, we characterized Yap's role in the formation of the neuromuscular junction (NMJ). In HSA-Yap-/- mice where Yap was mutated specifically in muscle cells, AChR clusters were smaller and were distributed in a broader region in the middle of muscle fibers, suggesting that muscle Yap is necessary for the size and location of AChR clusters. In addition, HSA-Yap-/- mice also exhibited remarkable presynaptic deficits. Many AChR clusters were not or less covered by nerve terminals; miniature endplate potential frequency was reduced, which was associated with an increase in paired-pulse facilitation, indicating structural and functional defects. In addition, muscle Yap mutation prevented reinnervation of denervated muscle fibers. Together, these observations indicate a role of muscle Yap in NMJ formation and regeneration. We found that ß-catenin was reduced in the cytoplasm and nucleus of mutant muscles, suggesting compromised ß-catenin signaling. Both NMJ formation and regeneration deficits of HSA-Yap-/- mice were ameliorated by inhibiting ß-catenin degradation, further corroborating a role of ß-catenin or Wnt-dependent signaling downstream of Yap to regulate NMJ formation and regeneration.SIGNIFICANCE STATEMENT This paper explored the role of Yes-associated protein (Yap) in neuromuscular junction (NMJ) formation and regeneration. Yap is a major effector of the Hippo pathway that regulates cell proliferation and differentiation during development and restricts tissue growth in adult animals. However, its role in synapse formation remains poorly understood. We provide evidence that muscle Yap mutation impairs both postsynaptic and presynaptic differentiation and function and inhibits NMJ regeneration after nerve injury, indicating a role of muscle Yap in these events. Further studies suggest compromised ß-catenin signaling as a potential mechanism. Both NMJ formation and regeneration deficits of HSA-Yap-/- mice were ameliorated by inhibiting ß-catenin degradation, corroborating a role of ß-catenin or Wnt-dependent signaling downstream of Yap to regulate NMJ formation and regeneration.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Muscle Strength/physiology , Muscle, Skeletal/physiology , Nerve Regeneration/physiology , Neuromuscular Junction/physiology , Phosphoproteins/metabolism , Synaptic Transmission/physiology , Animals , Cell Cycle Proteins , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Muscle, Skeletal/innervation , Receptors, Cholinergic/metabolism , Wnt Signaling Pathway/physiology , YAP-Signaling Proteins , beta Catenin/metabolism
11.
Stroke ; 49(1): 165-174, 2018 01.
Article in English | MEDLINE | ID: mdl-29212737

ABSTRACT

BACKGROUND AND PURPOSE: Lrp4 (low-density lipoprotein receptor-related protein 4) is predominantly expressed in astrocytes, where it regulates glutamatergic neurotransmission by suppressing ATP release. Here, we investigated Lrp4's function in ischemia/stroke-induced brain injury response, which includes glutamate-induced neuronal death and reactive astrogliosis. METHODS: The brain-specific Lrp4 conditional knockout mice (Lrp4GFAP-Cre), astrocytic-specific Lrp4 conditional knockout mice (Lrp4GFAP-creER), and their control mice (Lrp4f/f) were subjected to photothrombotic ischemia and the transient middle cerebral artery occlusion. After ischemia/stroke, mice or their brain samples were subjected to behavior tests, brain histology, immunofluorescence staining, Western blot, and quantitative real-time polymerase chain reaction. In addition, primary astrocytes and neurons were cocultured with or without oxygen and glucose deprivation and in the presence or absence of the antagonist for adenosine-A2AR (adenosine A2A receptor) or ATP-P2X7R (P2X purinoceptor 7) signaling. Gliotransmitters, such as glutamate, d-serine, ATP, and adenosine, in the condition medium of cultured astrocytes were also measured. RESULTS: Lrp4, largely expressed in astrocytes, was increased in response to ischemia/stroke. Both Lrp4GFAP-Cre and Lrp4GFAP-creER mice showed less brain injury, including reduced neuronal death, and impaired reactive astrogliosis. Mechanistically, Lrp4 conditional knockout in astrocytes increased ATP release and the production of ATP derivative, adenosine, which were further elevated by oxygen and glucose deprivation. Pharmacological inhibition of ATP-P2X7R or adenosine-A2AR signaling diminished Lrp4GFAP-creER's protective effect. CONCLUSIONS: The astrocytic Lrp4 plays an important role in ischemic brain injury response. Lrp4 deficiency in astrocytes seems to be protective in response to ischemic brain injury, likely because of the increased ATP release and adenosine-A2AR signaling.


Subject(s)
Adenosine Triphosphate/metabolism , Astrocytes/metabolism , Brain Injuries/metabolism , Brain Ischemia/metabolism , Receptor, Adenosine A2A/metabolism , Receptors, LDL/metabolism , Signal Transduction , Adenosine Triphosphate/genetics , Animals , Astrocytes/pathology , Brain Injuries/genetics , Brain Injuries/pathology , Brain Ischemia/genetics , Brain Ischemia/pathology , LDL-Receptor Related Proteins , Mice , Mice, Knockout , Receptor, Adenosine A2A/genetics , Receptors, LDL/genetics , Receptors, Purinergic P2X7/genetics , Receptors, Purinergic P2X7/metabolism
12.
J Sci Food Agric ; 97(13): 4445-4450, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28266012

ABSTRACT

BACKGROUND: As a by-product of the oil industry, corn germ meal is mainly applied as a high-protein ingredient in animal feeds, without any application of the specific functional properties of corn germ protein (CGP). Factors influencing the gelation properties of CGP in relation to its dynamic rheology are still unclear owing to limited information. RESULTS: CGP concentrate was recovered by the isoelectric precipitation method, and factors affecting its gelation properties were investigated using a rheometer. A weak gel formed at natural pH with 0.3 mol L-1 NaCl, and the minimum gel-forming concentration was observed at 150 g kg-1 . Higher CGP protein concentrations induced stiffer gels, and linear relationships were found between protein concentration and gel stiffness (G') as well as between protein concentration and gel viscosity (G″). Lower heating and cooling rate promoted the formation of stiffer gels. CGP gelation was both NaCl- and pH-dependent. Sodium tripolyphosphate significantly increased gel stiffness with increasing concentration. No difference in gel elasticity (tanδ) was observed with the inclusion of various concentrations of sodium tripolyphosphate or sodium polyphosphate. CONCLUSION: Heating and cooling rate, NaCl, protein concentration, pH and phosphates all impact the gel-forming ability of CGP concentrate. Desired gel properties can be obtained through adjustment of these factors. © 2017 Society of Chemical Industry.


Subject(s)
Plant Proteins/chemistry , Zea mays/chemistry , Elasticity , Gels/chemistry , Hot Temperature , Hydrogen-Ion Concentration , Seeds/chemistry , Sodium Chloride/chemistry , Viscosity
13.
Compr Rev Food Sci Food Saf ; 16(5): 835-849, 2017 Sep.
Article in English | MEDLINE | ID: mdl-33371610

ABSTRACT

China is a major cereal-producing country and almost one third of the annual cereal yield is maize. The maize plant and kernel are prone to infection by fungal attack and are most likely to be contaminated with mycotoxins under suitable temperature and humidity conditions, during both the growing and storage period. A number of investigations conducted in China have demonstrated that maize had been infected by fungi and contaminated with mycotoxins to varying degrees. Although most of the maize produced in China is used as feed and raw materials for the chemistry industry, a small amount of maize is consumed directly by humans and the hazards of mycotoxin to humans cannot be ignored. The state of mycotoxin contamination of maize in China is analyzed in this review. Due to unfavorable weather and poor storage conditions, the high incidences of mycotoxin contamination of maize are of great concern to the Chinese. It is imperative for the national and local governments to increase investments on building large-scale modern warehouses and instructing farmers to grow, harvest, and store maize safely. Meanwhile, due to accumulative toxic effects of mycotoxins, quality control should be enforced to guarantee that animal products are safe for human consumption.

14.
J Neurosci ; 33(49): 19295-303, 2013 Dec 04.
Article in English | MEDLINE | ID: mdl-24305825

ABSTRACT

The trophic factor neuregulin 1 (Nrg1) and its receptor ErbB4 are schizophrenia candidate genes. NRG1-ErbB4 signaling was thought to regulate spine formation and function in a cell-autonomous manner. Yet, recent studies indicate that ErbB4 expression is largely restricted to GABAergic interneurons and is very low or absent in pyramidal cells. Here, we generated and characterized cell type-specific ErbB4 mutant and transgenic mice. Spine density and the number of excitatory synapses were unaltered by neither deletion nor overexpression of ErbB4 in pyramidal neurons. However, spine density and excitatory synapse number were reduced in PV-ErbB4(-/-) mice where ErbB4 was selectively ablated in parvalbumin-positive GABAergic interneurons. Concurrently, basal glutamate transmission was impaired in PV-ErbB4(-/-) mice, but not in mice where ErbB4 was deleted or overexpressed in pyramidal neurons. Our results demonstrate a role of ErbB4 in PV-positive interneurons for spine formation in excitatory neurons.


Subject(s)
Dendritic Spines/physiology , ErbB Receptors/physiology , Interneurons/physiology , Parvalbumins/physiology , Analysis of Variance , Animals , Blotting, Western , CA1 Region, Hippocampal/physiology , CA1 Region, Hippocampal/ultrastructure , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Electrophysiological Phenomena , ErbB Receptors/genetics , Fluorescent Antibody Technique , Mice , Mice, Knockout , Microscopy, Electron , Neuregulin-1/physiology , Prefrontal Cortex/cytology , Prefrontal Cortex/physiology , Pyramidal Cells/physiology , Receptor, ErbB-4 , gamma-Aminobutyric Acid/physiology
15.
J Huazhong Univ Sci Technolog Med Sci ; 34(6): 882-888, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25480585

ABSTRACT

This study investigated the effects of miRNA-155 on malignant biological characteristics of NK/T-cell lymphoma cell lines and the possible mechanism. The expression of miRNA-155 was detected in lymphoma cell lines from different sources (SNK-6, YTS, Jurkat and DOHH2) by real-time PCR. Lentiviral vectors (pLL3.7) that could overexpress or downexpress miRNA-155 were constructed. Recombinant lentiviral particles were prepared and purified, and their titers determined. The expression of miRNA-155 in the infected SNK-6 cells and the cell proliferation were detected by PCR and CCK-8, respectively. Flow cytometry was used to determine the apoptosis of infected SNK-6 cells. The target of miRNA155 was predicted from Targetscan website. The effect of miRNA155 on FOXO3a expression was examined by Western blotting. The results showed that among the human NK/T-cell lymphoma cell lines SNK-6, YTS, Jurkat and DOHH2, the expression of miRNA-155 was highest in SNK-6. The infection efficiency of the recombinant lentivirus in SNK-6 was more than 70% at multiplicity of infection (MOI) of 100. The expression of miRNA-155 was significantly increased in SNK-6 cells infected by lentivirus vectors with high expression of miRNA-155 (4 times higher than the control group), and profoundly decreased in those infected with lentiviruses with low expression of miRNA-155. The proliferation of letivirus-infected SNK-6 cells was decreased as the expression of miRNA-155 reduced. The apoptosis rate was increased with the reduction in the expression of miRNA-155. FOXO3a was found to be a possible target of miRNA155, as suggested by Targetscan website. Western blotting showed that the expression of FOXO3a was significantly elevated in SNK-6 cells with miRNA-155 inhibition. It was concluded that reduction in miRNA-155 expression can inhibit the proliferation of SNK-6 lymphoma cells and promote their apoptosis, which may be associated with regulation of FOXO3a gene.


Subject(s)
Forkhead Transcription Factors/metabolism , Gene Expression Regulation, Neoplastic , Lymphoma, T-Cell/metabolism , MicroRNAs/biosynthesis , Natural Killer T-Cells/metabolism , Neoplasm Proteins/metabolism , RNA, Neoplasm/biosynthesis , Apoptosis/genetics , Forkhead Box Protein O3 , Forkhead Transcription Factors/genetics , Humans , Jurkat Cells , Lymphoma, T-Cell/genetics , Lymphoma, T-Cell/pathology , MicroRNAs/genetics , Natural Killer T-Cells/pathology , Neoplasm Proteins/genetics , RNA, Neoplasm/genetics , Transduction, Genetic
16.
Cell Biosci ; 14(1): 66, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38783336

ABSTRACT

BACKGROUND: Human patients often experience an episode of serious seizure activity, such as status epilepticus (SE), prior to the onset of temporal lobe epilepsy (TLE), suggesting that SE can trigger the development of epilepsy. Yet, the underlying mechanisms are not fully understood. The low-density lipoprotein receptor related protein (Lrp4), a receptor for proteoglycan-agrin, has been indicated to modulate seizure susceptibility. However, whether agrin-Lrp4 pathway also plays a role in the development of SE-induced TLE is not clear. METHODS: Lrp4f/f mice were crossed with hGFAP-Cre and Nex-Cre mice to generate brain conditional Lrp4 knockout mice (hGFAP-Lrp4-/-) and pyramidal neuron specific knockout mice (Nex-Lrp4-/-). Lrp4 was specifically knocked down in hippocampal astrocytes by injecting AAV virus carrying hGFAP-Cre into the hippocampus. The effects of agrin-Lrp4 pathway on the development of SE-induced TLE were evaluated on the chronic seizure model generated by injecting kainic acid (KA) into the amygdala. The spontaneous recurrent seizures (SRS) in mice were video monitored. RESULTS: We found that Lrp4 deletion from the brain but not from the pyramidal neurons elevated the seizure threshold and reduced SRS numbers, with no change in the stage or duration of SRS. More importantly, knockdown of Lrp4 in the hippocampal astrocytes after SE induction decreased SRS numbers. In accord, direct injection of agrin into the lateral ventricle of control mice but not mice with Lrp4 deletion in hippocampal astrocytes also increased the SRS numbers. These results indicate a promoting effect of agrin-Lrp4 signaling in hippocampal astrocytes on the development of SE-induced TLE. Last, we observed that knockdown of Lrp4 in hippocampal astrocytes increased the extracellular adenosine levels in the hippocampus 2 weeks after SE induction. Blockade of adenosine A1 receptor in the hippocampus by DPCPX after SE induction diminished the effects of Lrp4 on the development of SE-induced TLE. CONCLUSION: These results demonstrate a promoting role of agrin-Lrp4 signaling in hippocampal astrocytes in the development of SE-induced development of epilepsy through elevating adenosine levels. Targeting agrin-Lrp4 signaling may serve as a potential therapeutic intervention strategy to treat TLE.

17.
Cell Rep ; 43(3): 113905, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38446660

ABSTRACT

Motivation-driven mating is a basic affair for the maintenance of species. However, the underlying molecular mechanisms that control mating motivation are not fully understood. Here, we report that NRG1-ErbB4 signaling in the medial amygdala (MeA) is pivotal in regulating mating motivation. NRG1 expression in the MeA negatively correlates with the mating motivation levels in adult male mice. Local injection and knockdown of MeA NRG1 reduce and promote mating motivation, respectively. Consistently, knockdown of MeA ErbB4, a major receptor for NRG1, and genetic inactivation of its kinase both promote mating motivation. ErbB4 deletion decreases neuronal excitability, whereas chemogenetic manipulations of ErbB4-positive neuronal activities bidirectionally modulate mating motivation. We also identify that the effects of NRG1-ErbB4 signaling on neuronal excitability and mating motivation rely on hyperpolarization-activated cyclic nucleotide-gated channel 3. This study reveals a critical molecular mechanism for regulating mating motivation in adult male mice.


Subject(s)
Motivation , Signal Transduction , Mice , Male , Animals , Neurons/metabolism , Receptor, ErbB-4/metabolism , Amygdala/metabolism , Neuregulin-1/metabolism
18.
Nat Commun ; 14(1): 729, 2023 02 09.
Article in English | MEDLINE | ID: mdl-36759610

ABSTRACT

Alterations in energy metabolism are associated with depression. However, the role of glycolysis in the pathogenesis of depression and the underlying molecular mechanisms remain unexplored. Through an unbiased proteomic screen coupled with biochemical verifications, we show that the levels of glycolysis and lactate dehydrogenase A (LDHA), a glycolytic enzyme that catalyzes L-lactate production, are reduced in the dorsomedial prefrontal cortex (dmPFC) of stress-susceptible mice in chronic social defeat stress (CSDS) model. Conditional knockout of LDHA from the brain promotes depressive-like behaviors in both male and female mice, accompanied with reduced L-lactate levels and decreased neuronal excitability in the dmPFC. Moreover, these phenotypes could be duplicated by knockdown of LDHA in the dmPFC or specifically in astrocytes. In contrast, overexpression of LDHA reverses these phenotypic changes in CSDS-susceptible mice. Mechanistic studies demonstrate that L-lactate promotes neuronal excitability through monocarboxylic acid transporter 2 (MCT2) and by inhibiting large-conductance Ca2+-activated potassium (BK) channel. Together, these results reveal a role of LDHA in maintaining neuronal excitability to prevent depressive-like behaviors.


Subject(s)
Astrocytes , Lactic Acid , Mice , Male , Female , Animals , Lactate Dehydrogenase 5/metabolism , Astrocytes/metabolism , L-Lactate Dehydrogenase/metabolism , Proteomics , Carrier Proteins
19.
One Health ; 17: 100615, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37638210

ABSTRACT

Rabies is an acute zoonotic infectious disease caused by rabies virus. In 2015, the World Health Organization proposed the goal of eliminating dog-induced human rabies by 2030. In response to this goal positively, China has been dedicated to the control and elimination of rabies mainly caused by dogs, for nearly 10 years. By applying infectious disease dynamics, in this paper, we establish a dog-human rabies transmission model to forecast future epidemic trends of rabies, assess whether the goal of eliminating dog-induced human rabies cases in China can be achieved in 2030, and further evaluate and suggest the follow-up sustained preventive measures after the elimination of human rabies. By analyzing and simulating above dynamic model, it is concluded that rabies has been well controlled in China in recent years, but dog-induced human rabies cannot be eliminated by 2030 according to current situation. In addition, we propose to improve rabies control efforts by increasing the immunization coverage rate of rural domestic dogs, controlling the number of stray dogs and preventing the import of rabies virus in wild animals. Immunization coverage rate of rural domestic dogs which is currently less than 10% is far from requirement, and it needs to reach 50%-60% to meet the goal of 2030. Since it is difficult to immunize stray dogs, we suggest to control the number of stray dogs below 15.27 million to achieve the goal. If the goal of eliminating human rabies is reached in 2030, the essential immunization coverage needs to be maintained for 18 years to reduce the number of canine rabies cases to zero. Lastly, to prevent transmission of rabies virus from wild animals to dogs, the thresholds of the number of dogs and the immunization coverage rate of dogs after eliminating canine rabies cases are also discussed.

20.
J Clin Invest ; 133(9)2023 05 01.
Article in English | MEDLINE | ID: mdl-36917193

ABSTRACT

Chronic pain can cause both hyperalgesia and anxiety symptoms. However, how the two components are encoded in the brain remains unclear. The prelimbic cortex (PrL), a critical brain region for both nociceptive and emotional modulations, serves as an ideal medium for comparing how the two components are encoded. We report that PrL neurons projecting to the basolateral amygdala (PrLBLA) and those projecting to the ventrolateral periaqueductal gray (PrLl/vlPAG) were segregated and displayed elevated and reduced neuronal activity, respectively, during pain chronicity. Consistently, optogenetic suppression of the PrL-BLA circuit reversed anxiety-like behaviors, whereas activation of the PrL-l/vlPAG circuit attenuated hyperalgesia in mice with chronic pain. Moreover, mechanistic studies indicated that elevated TNF-α/TNFR1 signaling in the PrL caused increased insertion of GluA1 receptors into PrLBLA neurons and contributed to anxiety-like behaviors in mice with chronic pain. Together, these results provide insights into the circuit and molecular mechanisms in the PrL for controlling pain-related hyperalgesia and anxiety-like behaviors.


Subject(s)
Basolateral Nuclear Complex , Chronic Pain , Mice , Animals , Chronic Pain/genetics , Hyperalgesia , Anxiety/genetics , Cerebral Cortex
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