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1.
Mol Neurobiol ; 61(2): 1119-1139, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37688710

ABSTRACT

Although uncoupling protein 4 (UCP4) is the most abundant protein reported in the brain, the biological function of UCP4 in cerebellum and pathological outcome of UCP4 deficiency in cerebellum remain obscure. To evaluate the role of Ucp4 in the cerebellar Purkinje cells (PCs), we generated the conditional knockdown of Ucp4 in PCs (Pcp2cre;Ucp4fl/fl mice) by breeding Ucp4fl/fl mice with Pcp2cre mice. Series results by Western blot, immunofluorescent staining, and triple RNAscope in situ hybridization confirmed the specific ablation of Ucp4 in PCs in Pcp2cre;Ucp4fl/fl mice, but did not affect the expression of Ucp2, the analog of Ucp4. Combined behavioral tests showed that Pcp2cre;Ucp4fl/fl mice displayed a characteristic bradykinesia in the spontaneous movements. The electromyogram recordings detection excluded the possibility of hypotonia in Pcp2cre;Ucp4fl/fl mice. And the electrical patch clamp recordings showed the altered properties of PCs in Pcp2cre;Ucp4fl/fl mice. Moreover, transmission electron microscope (TEM) results showed the increased mitochondrial circularity in PCs; ROS probe imaging showed the increased ROS generation in molecular layer; and finally, microplate reader assay showed the significant changes of mitochondrial functions, including ROS, ATP, and MMP in the isolated cerebellum tissue. The results suggested that the specific knockdown of mitochondrial protein Ucp4 could damage PCs possibly by attacking their mitochondrial function. The present study is the first to report a close relationship between UCP4 deletion with PCs impairment, and suggests the importance of UCP4 in the substantial support of mitochondrial function homeostasis in bradykinesia. UCP4 might be a therapeutic target for the cerebellar-related movement disorder.


Subject(s)
Hypokinesia , Purkinje Cells , Animals , Mice , Brain , Cerebellum , Hypokinesia/metabolism , Purkinje Cells/metabolism , Reactive Oxygen Species/metabolism
2.
J Affect Disord ; 348: 283-296, 2024 03 01.
Article in English | MEDLINE | ID: mdl-38159656

ABSTRACT

AIMS: To assess the effect of the translocator protein 18 kDa (TSPO) on postpartum depression and explore its mechanism. METHODS: Postpartum depression (PPD) mouse model was established, and flow cytometry, immunofluorescence, Western blot analysis, real-time quantitative PCR, adeno-associated virus (AAV), co-immunoprecipitation-mass spectrometry and immunofluorescence co-staining were used to detect the effect of TSPO ligand ZBD-2 on PPD mice. RESULTS: ZBD-2 inhibits the overactivation of microglia in the hippocampus and amygdala of PPD model mice. ZBD-2 not only inhibited the inflammation but also repressed the burst of reactive oxygen species (ROS) and mitochondrial ROS (mtROS). Meanwhile, ZBD-2 protects mitochondria from LPS-induced damages through inhibiting the influx of calcium. ZBD-2 modulated the calcium influx by increasing the level of translocase of the outer mitochondrial membrane 40 (TOM40) and reducing the interaction of TSPO and TOM40. In addition, the effect of ZBD-2 was partially dependent on anti-oxidative process. Knockdown of TOM40 by adeno-associated virus (AAV) in the hippocampus or amygdala dramatically reduced the effect of ZBD-2 on PPD, indicating that TOM40 mediates the effect of ZBD-2 on PPD. CONCLUSIONS: TOM40 is required for the effect of ZBD-2 on treating anxiety and depression in PPD mice. This study reveals the role of microglia TSPO in PPD development and provides the new therapeutic strategy for PPD.


Subject(s)
Depression, Postpartum , Microglia , Animals , Female , Mice , Calcium/metabolism , Carrier Proteins , Depression, Postpartum/drug therapy , Depression, Postpartum/metabolism , Homeostasis , Microglia/metabolism , Mitochondrial Membranes/metabolism , Reactive Oxygen Species/metabolism , Receptors, GABA/metabolism
3.
Cancer Res ; 83(19): 3176-3183, 2023 10 02.
Article in English | MEDLINE | ID: mdl-37556505

ABSTRACT

RAS proteins are GTPases that regulate a wide range of cellular processes. RAS activity is dependent on its nucleotide-binding status, which is modulated by guanine nucleotide exchange factors (GEF) and GTPase-activating proteins (GAP). KRAS can be acetylated at lysine 104 (K104), and an acetylation-mimetic mutation of K104 to glutamine (K104Q) attenuates the in vitro-transforming capacity of oncogenic KRAS by interrupting GEF-induced nucleotide exchange. To assess the effect of this mutation in vivo, we used CRISPR-Cas9 to generate mouse models carrying the K104Q point mutation in wild-type and conditional KrasLSL-G12D alleles. Homozygous animals for K104Q were viable, fertile, and arose at the expected Mendelian frequency, indicating that K104Q is not a complete loss-of-function mutation. Consistent with our previous findings from in vitro studies, however, the oncogenic activity of KRASG12D was significantly attenuated by mutation at K104. Biochemical and structural analysis indicated that the G12D and K104Q mutations cooperate to suppress GEF-mediated nucleotide exchange, explaining the preferential effect of K104Q on oncogenic KRAS. Furthermore, K104 functioned in an allosteric network with M72, R73, and G75 on the α2 helix of the switch-II region. Intriguingly, point mutation of glycine 75 to alanine (G75A) also showed a strong negative regulatory effect on KRASG12D. These data demonstrate that lysine at position 104 is critical for the full oncogenic activity of mutant KRAS and suggest that modulating the sites in its allosteric network may provide a unique therapeutic approach in cancers expressing mutant KRAS. SIGNIFICANCE: An allosteric network formed by interaction between lysine 104 and residues in the switch-II domain is required for KRAS oncogenicity, which could be exploited for developing inhibitors of the activated oncoprotein.


Subject(s)
Lysine , Proto-Oncogene Proteins p21(ras) , Animals , Mice , Allosteric Regulation , Guanine Nucleotide Exchange Factors/metabolism , Lysine/metabolism , Mutation , Nucleotides/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , ras Proteins/metabolism
4.
Brain Res Bull ; 202: 110734, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37586426

ABSTRACT

Abnormalities in hippocampal synaptic plasticity contribute to the pathogenesis of post-traumatic stress disorder (PTSD). The Wnt/ß-catenin signaling pathway is critical for the regulation of synaptic plasticity. PTSD symptoms can be alleviated by correcting impaired neural plasticity in the hippocampus (Hipp). Electroacupuncture (EA) has a therapeutic effect by relieving PTSD-like behaviors. However, little is known about whether the Wnt/ß-catenin pathway is involved in EA-mediated improvements of PTSD symptoms. In this study, we found that enhanced single prolonged stress (ESPS)-induced PTSD led to abnormal neural plasticity, characterized by the decline of dendritic spines, the expression of postsynaptic density 95 (PSD95), and synaptophysin (Syn) in the stressed Hipp along with the reduction of Wnt3a and ß-catenin, and increased GSK-3ß. EA significantly alleviated PTSD-like behaviors, as assessed by the open field test, elevated platform maze test and conditioning fear test. This was paralleled by correcting abnormal neural plasticity by promoting the expression of PSD95 and Syn, as well as the number of dendritic spines in the Hipp. Importantly, EA exerted anti-PTSD effects by augmenting the expression levels of Wnt3a and ß-catenin, and decreasing that of GSK-3ß. The effects mediated by EA were abolished by XAV939, an inhibitor of the Wnt/ß-catenin pathway. This suggests that EA relieved ESPS-induced PTSD-like behaviors, which can largely be ascribed to impaired neural plasticity in the Hipp. These findings provide new insights into possible mechanisms linking neural plasticity in the Hipp as potential novel targets for PTSD treatment in EA therapy.


Subject(s)
Electroacupuncture , Stress Disorders, Post-Traumatic , Animals , beta Catenin/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Hippocampus/metabolism , Neuronal Plasticity , Stress Disorders, Post-Traumatic/therapy , Stress Disorders, Post-Traumatic/metabolism , Transcription Factors/metabolism , Wnt Signaling Pathway , Mice
5.
Mol Neurobiol ; 60(11): 6410-6423, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37453994

ABSTRACT

Fragile X syndrome (FXS) is an inherited human mental retardation that arises from expansion of a CGG repeat in the Fmr1 gene, causing loss of the fragile X mental retardation protein (FMRP). It is reported that N-methyl-D-aspartate receptor (NMDAR)-mediated facilitation of long-term potentiation (LTP) and fear memory are impaired in Fmr1 knockout (KO) mice. In this study, biological, pharmacological, and electrophysiological techniques were performed to determine the roles of D-aspartate (D-Asp), a modulator of NMDAR, and its metabolizing enzyme D-aspartate oxidase (DDO) in Fmr1 KO mice. Levels of D-Asp were decreased in the medial prefrontal cortex (mPFC ); however, the levels of its metabolizing enzyme DDO were increased. Electrophysiological recordings indicated that oral drinking of D-Asp recovered LTP induction in mPFC from Fmr1 KO mice. Moreover, chronic oral administration of D-Asp reversed behavioral deficits of cognition and locomotor coordination in Fmr1 KO mice. The therapeutic action of D-Asp was partially through regulating functions of NMDARs and mGluR5/mTOR/4E-BP signaling pathways. In conclusion, supplement of D-Asp may benefit for synaptic plasticity and behaviors in Fmr1 KO mice and offer a potential therapeutic strategy for FXS.


Subject(s)
D-Aspartic Acid , Fragile X Syndrome , Mice , Animals , Humans , Fragile X Syndrome/drug therapy , Fragile X Syndrome/metabolism , Learning , Long-Term Potentiation/physiology , Fragile X Mental Retardation Protein/metabolism , Mice, Knockout , Brain/metabolism , Disease Models, Animal , Mice, Inbred C57BL
6.
Mol Cell ; 83(14): 2509-2523.e13, 2023 07 20.
Article in English | MEDLINE | ID: mdl-37402366

ABSTRACT

K-Ras frequently acquires gain-of-function mutations (K-RasG12D being the most common) that trigger significant transcriptomic and proteomic changes to drive tumorigenesis. Nevertheless, oncogenic K-Ras-induced dysregulation of post-transcriptional regulators such as microRNAs (miRNAs) during oncogenesis is poorly understood. Here, we report that K-RasG12D promotes global suppression of miRNA activity, resulting in the upregulation of hundreds of targets. We constructed a comprehensive profile of physiological miRNA targets in mouse colonic epithelium and tumors expressing K-RasG12D using Halo-enhanced Argonaute pull-down. Combining this with parallel datasets of chromatin accessibility, transcriptome, and proteome, we uncovered that K-RasG12D suppressed the expression of Csnk1a1 and Csnk2a1, subsequently decreasing Ago2 phosphorylation at Ser825/829/832/835. Hypo-phosphorylated Ago2 increased binding to mRNAs while reducing its activity to repress miRNA targets. Our findings connect a potent regulatory mechanism of global miRNA activity to K-Ras in a pathophysiological context and provide a mechanistic link between oncogenic K-Ras and the post-transcriptional upregulation of miRNA targets.


Subject(s)
MicroRNAs , Neoplasms , Animals , Mice , Carcinogenesis/genetics , Cell Transformation, Neoplastic/genetics , Genes, ras , MicroRNAs/genetics , MicroRNAs/metabolism , Neoplasms/genetics , Proteomics
7.
Phytother Res ; 37(10): 4838-4850, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37458182

ABSTRACT

Diabetic encephalopathy is a common consequence of diabetes mellitus that causes cognitive dysfunction and neuropsychiatric disorders. Praeruptorin C (Pra-C) from the traditional Chinese medicinal herb Peucedanum praeruptorum Dunn. is a potential antioxidant and neuroprotective agent. This study was conducted to investigate the molecular mechanisms underlying the effect of Pra-C on diabetic cognitive impairment. A novel object recognition test and the Morris water maze test were performed to assess the behavioral performance of mice. Electrophysiological recordings were made to monitor synaptic plasticity in the hippocampus. A protein-protein interaction network of putative Pra-C targets was constructed, and molecular docking simulations were performed to predict the potential mechanisms of the action of Pra-C. Protein expression levels were detected by western blotting. Pra-C administration significantly lowered body weight and fasting blood glucose levels and alleviated learning and memory deficits in type 2 diabetic mice. Network pharmacology and molecular docking results suggested that Pra-C affects the PI3K/AKT/GSK3ß signaling pathway. Western blot analysis confirmed significant increases in phosphorylated PI3K, AKT, and GSK3ß levels in vivo and in vitro upon Pra-C administration. Pra-C alleviated cognitive impairment in type 2 diabetic mice by activating PI3K/AKT/GSK3ß pathway.

8.
Aging (Albany NY) ; 15(10): 4319-4333, 2023 05 23.
Article in English | MEDLINE | ID: mdl-37227808

ABSTRACT

To explore the plasticity of adipose tissues, C57BL/6J mice at the age of 1 month, 3 months, and 15 months corresponding to adolescence, adulthood, and middle-aged transitional period, respectively, were fasted and refed subsequently at different times. Body adipose tissues ratio (BATR) was calculated, the morphology of adipose tissue and the area of adipocytes were observed by histological analysis, and the mitochondria in adipocytes were observed under the transmission electron microscope. Furthermore, the expression levels of Ucp-1, Cidea, Cox7a1, Cpt-1m, Atgl, and Hsl were detected by qRT-PCR. Our results showed a significant increase in the adipocytes area and body visceral adipose tissue (VAT) ratio in all groups of mice with aging. Moreover, body mesenteric white adipose tissue (mWAT) ratio decreased the most after 72 h fasting. In the middle-aged transitional mice, the white adipocytes did not decrease until 72 h fasting, and most of them still appeared as unaffected unilocular cells. Besides, the number of mitochondria and the expression of Ucp-1, Cidea, Cox7a1, Cpt-1m, Atgl and Hsl were lower in these mice. After 72h refeeding, the body subcutaneous white adipose tissue (sWAT) ratio returned to normal, while the VAT kept decreasing. The above results indicated an impairment in adipose tissue plasticity in mice with aging, suggesting that age modulated the metabolic adaptiveness of adipose tissues in mice.


Subject(s)
Adipose Tissue , Fasting , Mice , Animals , Mice, Inbred C57BL , Adipose Tissue/metabolism , Fasting/metabolism , Adipocytes , Aging/metabolism
9.
Mol Pain ; 19: 17448069231177634, 2023.
Article in English | MEDLINE | ID: mdl-37207346

ABSTRACT

Chronic pain, along with comorbid psychiatric disorders, is a common problem worldwide. A growing number of studies have focused on non-opioid-based medicines, and billions of funds have been put into digging new analgesic mechanisms. Peripheral inflammation is one of the critical causes of chronic pain, and drugs with anti-inflammatory effects usually alleviate pain hypersensitivity. Sophoridine (SRI), one of the most abundant alkaloids in Chinese herbs, has been proved to exert antitumor, antivirus and anti-inflammation effects. Here, we evaluated the analgesic effect of SRI in an inflammatory pain mouse model induced by complete Freund's adjuvant (CFA) injection. SRI treatment significantly decreased pro-inflammatory factors release after LPS stimuli in microglia. Three days of SRI treatment relieved CFA-induced mechanical hypersensitivity and anxiety-like behavior, and recovered abnormal neuroplasticity in the anterior cingulate cortex of mice. Therefore, SRI may be a candidate compound for the treatment of chronic inflammatory pain and may serve as a structural basis for the development of new drugs.


Subject(s)
Chronic Pain , Hyperalgesia , Mice , Animals , Hyperalgesia/complications , Hyperalgesia/drug therapy , Hyperalgesia/chemically induced , Freund's Adjuvant/toxicity , Matrines , Chronic Pain/drug therapy , Analgesics/pharmacology , Analgesics/therapeutic use , Anxiety/complications , Anxiety/drug therapy
10.
Mol Neurobiol ; 60(6): 3379-3395, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36854997

ABSTRACT

Fragile X syndrome (FXS) is one of the most common inherited mental retardation diseases and is caused by the loss of fragile X mental retardation protein (FMRP) expression. The metabotropic glutamate receptor (mGluR) theory of FXS states that enhanced mGluR-dependent long-term depression (LTD) due to FMRP loss is involved in aberrant synaptic plasticity and autistic-like behaviors, but little is known about the underlying molecular mechanism. Here, we found that only hippocampal mGluR-LTD was exaggerated in adolescent Fmr1 KO mice, while N-methyl-D-aspartate receptor (NMDAR)-LTD was intact in mice of all ages. This development-dependent alteration was related to the differential expression of caveolin-1 (Cav1), which is essential for caveolae formation. Knockdown of Cav1 restored the enhanced mGluR-LTD in Fmr1 KO mice. Moreover, hippocampal Cav1 expression in Fmr1 KO mice induced excessive endocytosis of the α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit GluA2. This process relied on mGluR1/5 activation rather than NMDAR. Interference with Cav1 expression reversed these changes. Furthermore, massive cholesterol accumulation contributed to redundant caveolae formation, which provided the platform for mGluR-triggered Cav1 coupling to GluA2. Importantly, injection of the cholesterol scavenger methyl-ß-cyclodextrin (Mß-CD) recovered AMPA receptor trafficking and markedly alleviated hyperactivity, hippocampus-dependent fear memory, and spatial memory defects in Fmr1 KO mice. Together, our findings elucidate the important role of Cav1 in mediating mGluR-LTD enhancement and further inducing AMPA receptor endocytosis and suggest that cholesterol depletion by Mß-CD during caveolae formation may be a novel and safe strategy to treat FXS.


Subject(s)
Fragile X Syndrome , Receptors, Metabotropic Glutamate , Mice , Animals , Mice, Knockout , Caveolin 1/metabolism , Receptors, AMPA/metabolism , Depression , Fragile X Mental Retardation Protein/metabolism , Hippocampus/metabolism , Neuronal Plasticity , Fragile X Syndrome/metabolism , Receptors, Metabotropic Glutamate/metabolism , Cognition , Mice, Inbred C57BL
11.
Int J Biol Sci ; 18(14): 5317-5328, 2022.
Article in English | MEDLINE | ID: mdl-36147478

ABSTRACT

Background: Macau is a densely populated international tourist city. Compared to most tensely populated countries/territories, the prevalence and mortality of COVID-19 in Macau are lower. The experiences in Macau could be helpful for other areas to combat the COVID-19 pandemic. This article introduced the endeavours and achievements of Macau in combatting the COVID-19 pandemic. Method: Both qualitative and quantitative analysis methods were used to explore the work, measures, and achievements of Macau in dealing with the COVID-19 pandemic. Results: The results revealed that Macau has provided undifferentiated mask purchase reservation services, COVID-19 vaccination services to all residents and non-residents in Macau along with delivering multilingual services, in Chinese, English and Portuguese, to different groups of the population. To facilitate the travels of people, business and trades between Macau and mainland China, the Macau government launched the Macau Health Code System, which uses the health status declaration, residence history declaration, contact history declaration of the declarant to match various relevant backend databases within the health authority and provide a risk-related colour code operations. The Macau Health Code System connects to the Chinese mainland's own propriety health code system seamlessly, whilst effectively protecting the privacy of the residents. Macau has also developed the COVID-19 Vaccination Appointment system, the Nucleic Acid Test Appointment system, the Port and Entry/Exit Quarantine system, the medical and other supporting systems. Conclusion: The efforts in Macau have achieved remarkable results in COVID-19 prevention and control, effectively safeguarding the lives and health of the people and manifesting the core principle of "serving the public". The measures used are sustainable and can serve as an important reference for other countries/regions.


Subject(s)
COVID-19 , Nucleic Acids , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Macau/epidemiology , Pandemics/prevention & control
12.
Neuroscience ; 498: 289-299, 2022 08 21.
Article in English | MEDLINE | ID: mdl-35872251

ABSTRACT

The beneficial effects of exercise on human brain function have been demonstrated in previous studies. Myokines secreted by muscle have attracted increasing attention because of their bridging role between exercise and brain health. Regulated by PPARγ coactivator 1α, fibronectin type III domain-containing protein 5 releases irisin after proteolytic cleavage. Irisin, a type of myokine, is secreted during exercise, which induces white adipose tissue browning and relates to energy metabolism. Recently, irisin has been shown to exert a protective effect on the central nervous system. Irisin secretion triggers an increase in brain-derived neurotrophic factor levels in the hippocampus, contributing to the amelioration of cognition impairments. Irisin also plays an important role in the survival, differentiation, growth, and development of neurons. This review summarizes the role of irisin in neurodegenerative diseases and other neurological disorders. As a novel positive mediator of exercise in the brain, irisin may effectively prevent or decelerate the progress of neurodegenerative diseases in models and also improve cognitive functions. We place emphasis herein on the potential of irisin for prevention rather than treatment in neurodegenerative diseases. In ischemic diseases, irisin can alleviate the pathophysiological processes associated with stroke. Meanwhile, irisin has anxiolytic and antidepressant effects. The potential therapeutic effects of irisin in epilepsy and pain have been initially revealed. Due to the pleiotropic and beneficial properties of irisin, the possibility of irisin treating other neurological diseases could be gradually explored in the future.


Subject(s)
Fibronectins , Neurodegenerative Diseases , Exercise , Hippocampus , Humans , Muscle, Skeletal , Transcription Factors
13.
Phytother Res ; 36(10): 3932-3948, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35801985

ABSTRACT

Posttraumatic stress disorder (PTSD) is one of the most common psychiatric diseases, which is characterized by the typical symptoms such as re-experience, avoidance, and hyperarousal. However, there are few drugs for PTSD treatment. In this study, conditioned fear and single-prolonged stress were employed to establish PTSD mouse model, and we investigated the effects of Tanshinone IIA (TanIIA), a natural product isolated from traditional Chinese herbal Salvia miltiorrhiza, as well as the underlying mechanisms in mice. The results showed that the double stress exposure induced obvious PTSD-like symptoms, and TanIIA administration significantly decreased freezing time in contextual fear test and relieved anxiety-like behavior in open field and elevated plus maze tests. Moreover, TanIIA increased the spine density and upregulated synaptic plasticity-related proteins as well as activated CREB/BDNF/TrkB signaling pathway in the hippocampus. Blockage of CREB remarkably abolished the effects of TanIIA in PTSD model mice and reversed the upregulations of p-CREB, BDNF, TrkB, and synaptic plasticity-related protein induced by TanIIA. The molecular docking simulation indicated that TanIIA could interact with the CREB-binding protein. These findings indicate that TanIIA ameliorates PTSD-like behaviors in mice by activating the CREB/BDNF/TrkB pathway, which provides a basis for PTSD treatment.


Subject(s)
Biological Products , Brain-Derived Neurotrophic Factor , Abietanes , Animals , Anxiety/drug therapy , Biological Products/pharmacology , Brain-Derived Neurotrophic Factor/metabolism , CREB-Binding Protein/metabolism , CREB-Binding Protein/pharmacology , Fear , Hippocampus/metabolism , Mice , Molecular Docking Simulation , Signal Transduction
14.
mBio ; 13(4): e0125022, 2022 08 30.
Article in English | MEDLINE | ID: mdl-35861543

ABSTRACT

The intracellular EscE protein tightly controls the secretion of the type III secretion system (T3SS) middle and late substrates in Edwardsiella piscicida. However, the regulation of secretion by EscE is incompletely understood. In this work, we reveal that EscE interacts with EsaH and EsaG. The crystal structures of the EscE-EsaH complex and EscE-EsaG-EsaH complex were resolved at resolutions of 1.4 Å and 1.8 Å, respectively. EscE and EsaH form a hydrophobic groove to engulf the C-terminal region of EsaG (56 to 73 amino acids [aa]), serving as the cochaperones of T3SS needle protein EsaG in E. piscicida. V61, K62, M64, and M65 of EsaG play a pivotal role in maintaining the conformation of the ternary complex of EscE-EsaG-EsaH, thereby maintaining the stability of EsaG. An in vivo experiment revealed that EscE and EsaH stabilize each other, and both of them stabilize EsaG. Meanwhile, either EscE or EsaH can be secreted through the T3SS. The secondary structure of EsaH lacks the fourth and fifth α helices presented in its homologs PscG, YscG, and AscG. Insertion of the α4 and α5 helices of PscG or swapping the N-terminal 25 aa of PscG with those of EsaH starkly decreases the protein level of the chimeric EsaH, resulting in instability of EsaG and deactivation of the T3SS. To the best of our knowledge, these data represent the first reported structure of the T3SS needle complex of pathogens from Enterobacteriaceae and the first evidence for the secretion of T3SS needle chaperones. IMPORTANCE Edwardsiella piscicida causes severe hemorrhagic septicemia in fish. Inactivation of the type III secretion system (T3SS) increases its 50% lethal dose (LD50) by ~10 times. The secretion of T3SS middle and late substrates in E. piscicida is tightly controlled by the intracellular steady-state protein level of EscE, but the mechanism is incompletely understood. In this study, EscE was found to interact with and stabilize EsaH in E. piscicida. The EscE-EsaH complex is structurally analogous to T3SS needle chaperones. Further study revealed that EscE and EsaH form a hydrophobic groove to engulf the C-terminal region of EsaG, serving as the cochaperones stabilizing the T3SS needle protein EsaG. Interestingly, both EscE and EsaH are secreted. Our study reveals that the EscE-EsaH complex controls T3SS protein secretion by stabilizing EsaG, whose secretion in turn leads to the secretion of the middle and late T3SS substrates.


Subject(s)
Edwardsiella , Enterobacteriaceae Infections , Fish Diseases , Animals , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Edwardsiella/genetics , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Protein Structure, Secondary , Type III Secretion Systems/genetics , Type III Secretion Systems/metabolism
15.
Brain Res Bull ; 188: 11-20, 2022 10 01.
Article in English | MEDLINE | ID: mdl-35850187

ABSTRACT

Exercise not only builds up our body but also improves cognitive function. Skeletal muscle secretes myokine during exercise as a large reservoir of signaling molecules, which can be considered as a medium between exercise and brain health. Irisin is a circulating myokine derived from the Fibronectin type III domain-containing protein 5 (FNDC5). Irisin regulates energy metabolism because it can stimulate the "Browning" of white adipose tissue. It has been reported that irisin can cross the blood-brain barrier and increase the expression of a brain-derived neurotrophic factor (BDNF) in the hippocampus, which improves learning and memory. In addition, the neuroprotective effect of irisin has been verified in various disease models. Therefore, this review summarizes how irisin plays a neuroprotective role, including its signal pathway and mechanism. In addition, we will briefly discuss the therapeutic potential of irisin for neurological diseases.


Subject(s)
Fibronectins , Neuroprotective Agents , Brain/metabolism , Exercise/physiology , Fibronectins/metabolism , Muscle, Skeletal/metabolism , Neuroprotective Agents/metabolism , Transcription Factors/metabolism
16.
Front Endocrinol (Lausanne) ; 13: 887238, 2022.
Article in English | MEDLINE | ID: mdl-35712239

ABSTRACT

Background: Chronic pain is defined as pain that persists typically for a period of over six months. Chronic pain is often accompanied by an anxiety disorder, and these two tend to exacerbate each other. This can make the treatment of these conditions more difficult. Glucose-dependent insulinotropic polypeptide (GIP) is a member of the incretin hormone family and plays a critical role in glucose metabolism. Previous research has demonstrated the multiple roles of GIP in both physiological and pathological processes. In the central nervous system (CNS), studies of GIP are mainly focused on neurodegenerative diseases; hence, little is known about the functions of GIP in chronic pain and pain-related anxiety disorders. Methods: The chronic inflammatory pain model was established by hind paw injection with complete Freund's adjuvant (CFA) in C57BL/6 mice. GIP receptor (GIPR) agonist (D-Ala2-GIP) and antagonist (Pro3-GIP) were given by intraperitoneal injection or anterior cingulate cortex (ACC) local microinjection. Von Frey filaments and radiant heat were employed to assess the mechanical and thermal hypersensitivity. Anxiety-like behaviors were detected by open field and elevated plus maze tests. The underlying mechanisms in the peripheral nervous system and CNS were explored by GIPR shRNA knockdown in the ACC, enzyme-linked immunosorbent assay, western blot analysis, whole-cell patch-clamp recording, immunofluorescence staining and quantitative real-time PCR. Results: In the present study, we found that hind paw injection with CFA induced pain sensitization and anxiety-like behaviors in mice. The expression of GIPR in the ACC was significantly higher in CFA-injected mice. D-Ala2-GIP administration by intraperitoneal or ACC local microinjection produced analgesic and anxiolytic effects; these were blocked by Pro3-GIP and GIPR shRNA knockdown in the ACC. Activation of GIPR inhibited neuroinflammation and activation of microglia, reversed the upregulation of NMDA and AMPA receptors, and suppressed the enhancement of excitatory neurotransmission in the ACC of model mice. Conclusions: GIPR activation was found to produce analgesic and anxiolytic effects, which were partially due to attenuation of neuroinflammation and inhibition of excitatory transmission in the ACC. GIPR may be a suitable target for treatment of chronic inflammatory pain and pain-related anxiety.


Subject(s)
Chronic Pain , Receptors, Gastrointestinal Hormone , Animals , Chronic Pain/drug therapy , Chronic Pain/metabolism , Freund's Adjuvant , Gastric Inhibitory Polypeptide/physiology , Gyrus Cinguli/metabolism , Mice , Mice, Inbred C57BL , RNA, Small Interfering , Receptors, Gastrointestinal Hormone/agonists , Receptors, Gastrointestinal Hormone/antagonists & inhibitors , Receptors, Gastrointestinal Hormone/metabolism
17.
J Neurol ; 269(9): 4939-4954, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35486215

ABSTRACT

Sleep-related hypermotor epilepsy (SHE) is a focal epilepsy syndrome. The underlying pathophysiology is presumed to be closely related with disruption of GABAergic neurotransmission, which is mainly medicated by γ-aminobutyric acid type A receptor (GABAAR). Thus, it is reasonable to assume that rare GABAAR variants might contribute to the pathogenesis of SHE. To test this hypothesis, we performed next-generation sequencing in 58 SHE patients and analyzed the functional effects of the identified variants in both neuronal and non-neuronal cells using a combination of electrophysiology recordings, western blot, flow cytometry, and confocal microscopy. In our study, we detected three rare variants (NM_198904.2: c.269C > T, p.T90M; NM_198904.2: c.950C > A, p.T317N and NM_198903.2: c.649C > T, p.Q217X) in GABRG2 (MIM:137,164, encoding GABAAR γ2 subunit) in three unrelated patients. Two of the three rare variants were transmitted unaffected maternally (T90M) or unaffected paternally (Q217X), whereas the T317N variant arose de novo. The mother of proband carrying the T90M variant was unaffected and being mosaicism for this variant. Functional analysis showed that T90M and T317N variants decreased GABA-evoked current amplitudes by diverse mechanisms including impaired surface expression, endoplasmic reticulum retention, and channel gating defects. And Q217X variant reduced synaptic clustering and distribution of GABAAR. While a causal role of these variants cannot be established directly from these results, the functional assessment together with the genetic sequencing suggests that these rare GABRG2 variants may constitute genetic risk factors for SHE. Our study further expands the GABRG2 phenotypic spectrum and supports the view that GABAergic neurotransmission participates in the epileptogenesis of SHE.


Subject(s)
Epilepsy , Receptors, GABA-A , Humans , Neurons/metabolism , Receptors, GABA-A/genetics , Receptors, GABA-A/metabolism , Sleep , gamma-Aminobutyric Acid
18.
PLoS Biol ; 20(3): e3001556, 2022 03.
Article in English | MEDLINE | ID: mdl-35235560

ABSTRACT

Evaluating the relationship between the human gut microbiome and disease requires computing reliable statistical associations. Here, using millions of different association modeling strategies, we evaluated the consistency-or robustness-of microbiome-based disease indicators for 6 prevalent and well-studied phenotypes (across 15 public cohorts and 2,343 individuals). We were able to discriminate between analytically robust versus nonrobust results. In many cases, different models yielded contradictory associations for the same taxon-disease pairing, some showing positive correlations and others negative. When querying a subset of 581 microbe-disease associations that have been previously reported in the literature, 1 out of 3 taxa demonstrated substantial inconsistency in association sign. Notably, >90% of published findings for type 1 diabetes (T1D) and type 2 diabetes (T2D) were particularly nonrobust in this regard. We additionally quantified how potential confounders-sequencing depth, glucose levels, cholesterol, and body mass index, for example-influenced associations, analyzing how these variables affect the ostensible correlation between Faecalibacterium prausnitzii abundance and a healthy gut. Overall, we propose our approach as a method to maximize confidence when prioritizing findings that emerge from microbiome association studies.


Subject(s)
Bacteria/genetics , Biomedical Research/methods , Gastrointestinal Microbiome/genetics , Metagenome/genetics , Metagenomics/methods , Algorithms , Bacteria/classification , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/microbiology , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/microbiology , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/microbiology , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/microbiology , Feces/microbiology , Humans , Inflammatory Bowel Diseases/metabolism , Inflammatory Bowel Diseases/microbiology , Liver Cirrhosis/metabolism , Liver Cirrhosis/microbiology , Models, Theoretical , RNA, Ribosomal, 16S/genetics
19.
Trends Cancer ; 8(5): 384-396, 2022 05.
Article in English | MEDLINE | ID: mdl-35093302

ABSTRACT

K-RAS is frequently mutated in cancers, and its overactivation can lead to oncogene-induced senescence (OIS), a barrier to cellular transformation. Feedback onto K-RAS limits its signaling to avoid senescence while achieving the appropriate level of activation that promotes proliferation and survival. Such regulation could be mediated by miRNAs, as aberrant RAS signaling and miRNA activity coexist in several cancers, with miRNAs acting both up- and downstream of K-RAS. Several miRNAs both regulate and are regulated by K-RAS, suggesting a noncoding RNA-based feedback mechanism. Functional interactions between K-RAS and the miRNA machinery have also begun to unfold. This review comprehensively surveys the state of knowledge connecting K-RAS to miRNA function and proposes a model for the regulation of K-RAS signaling by noncoding RNAs.


Subject(s)
MicroRNAs , Neoplasms , Cell Transformation, Neoplastic/genetics , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , Neoplasms/genetics , Signal Transduction/genetics
20.
Brain Res Bull ; 181: 77-86, 2022 04.
Article in English | MEDLINE | ID: mdl-35093468

ABSTRACT

Hormone therapy (HT) has failed to improve learning and memory in postmenopausal women according to recent clinical studies; however, the reason for failure of HT in improving cognitive performance is unknown. In our research, we found cognitive flexibility was improved by 17ß-Estradiol (E2) in mice 1 week after ovariectomy (OVXST), but not in mice 3 months after ovariectomy (OVXLT). Isobaric tags for relative and absolute quantitation (iTRAQ) revealed increased cannabinoid receptor interacting protein 1 (CNRIP1) in E2-treated OVXLT mice compared with E2-treated OVXST mice. Adeno-associated virus 2/9 (AAV2/9) delivery of Cnrip1 short-hairpin small interfering RNA (Cnrip1-shRNA) rescued the impaired cognitive flexibility in E2 treated OVXLT mice. This effect is dependent on CB1 function, which could be blocked by AM251-a CB1 antagonist. Our results indicated a new method to increasing cognitive flexibility in women receiving HT by disrupting CNRIP1.


Subject(s)
Cannabinoid Receptor Antagonists/pharmacology , Carrier Proteins/drug effects , Carrier Proteins/metabolism , Cognitive Dysfunction/drug therapy , Cognitive Dysfunction/metabolism , Estradiol/pharmacology , Hormone Replacement Therapy , Prefrontal Cortex/drug effects , Animals , Disease Models, Animal , Female , Mice , Ovariectomy , Piperidines/pharmacology , Postmenopause , Pyrazoles/pharmacology , RNA, Small Interfering , Receptor, Cannabinoid, CB1/antagonists & inhibitors
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