1.Bile acids regulate anorexigenic neuropeptide through p-STAT3-SOCS3 signaling in mouse hypothalamic cells.
Chunxiu CHEN ; Yong ZHOU ; Rongfeng HUANG ; Miaoran WANG ; Yue LI ; Jibin LI
Journal of Zhejiang University. Medical sciences 2020;40(7):1001-1007
OBJECTIVE:
To explore the effects of taurolithocholic acid (tLCA) and chenodeoxycholic acid (CDCA) on the expression of aorexigenic neuropeptide in mouse hypothalamus GT1-7 cells.
METHODS:
Mouse hypothalamic GT1-7 cells were treated with culture medium containing 10% FBS (control group, =3) or with 10 nmol/L, 100 nmol/L, 1 μmol/L and 10 μmol/L tLCA (tLCA group, =3) or CDCA (CDCA group, =3) for 12, 24 or 48 h. Real-time PCR was performed to determine the expression levels of proopiomelanocortin (POMC) mRNA in the cells, and the production levels of α-melanocyte-stimulating hormone (α-MSH) were assessed using an ELISA kit. Signal transduction and activator of transcription 3 phosphorylation (p-STAT3), threonine kinase phosphorylation (p-AKT), suppressor of cytokine signaling 3 (SOCS3), G protein-coupled bile acid receptor-1 (TGR5) and farnesoid X receptor (FXR) protein were detected by Western blotting.
RESULTS:
Western blotting results showed that mouse hypothalamic GT1-7 cells expressed two bile acid receptors, TGR5 and FXR, whose expressions were regulated by bile acids. Real-time PCR showed that the expression of POMC mRNA was significantly increased in the cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. POMC-derived anorexigenic peptide α-MSH increased significantly in GT1-7 cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. Treatment of the cells with tLCA or CDCA significantly increased the expressions of intracellular signaling proteins including p-STAT3, p-AKT and SOCS3.
CONCLUSIONS
Mouse hypothalamic GT1-7 cells express bile acid receptors TGR5 and FXR. Bile acids tLCA or CDCA can promote the expression of POMC mRNA and increase the production of the anorexigenic peptide α-MSH. The intracellular signaling proteins p-AKT, p-STAT3 and SOCS3 are likely involved in bile acid-induced anorexigenic peptide production.
Animals
;
Cell Line
;
Chenodeoxycholic Acid
;
pharmacology
;
Gene Expression Regulation
;
drug effects
;
Hypothalamus
;
cytology
;
Mice
;
Neuropeptides
;
genetics
;
metabolism
;
Pro-Opiomelanocortin
;
genetics
;
RNA, Messenger
;
genetics
;
STAT3 Transcription Factor
;
metabolism
;
Signal Transduction
;
drug effects
;
Suppressor of Cytokine Signaling 3 Protein
;
metabolism
;
Taurolithocholic Acid
;
pharmacology
;
alpha-MSH
;
genetics
2.Role of transient receptor potential cation channel subfamily M member 2 in hepatic ischemia-reperfusion injury in the mouse and the underlying mechanisms.
Yue LI ; Zhuhai REN ; Yong XU ; Shurong WU
Journal of Central South University(Medical Sciences) 2020;45(7):766-773
OBJECTIVES:
To investigate the role of transient receptor potential cation channel subfamily M member 2 (TRPM2) in hepatic ischemia-reperfusion injury of mouse (HIRI) and the possible mechanisms.
METHODS:
Sixty adult male C57BL/6 mice were randomly divided into 4 groups: a sham group (S group), a HIRI model group (M group), a TRPM2 adenovirus interference vector group (T group), and a TRPM2 adenovirus control vector group (C group) (=15 in each group). The liver tissues of mice before perfusion were obtained. The efficiency of adenovirus infection was detected by fluorescence microscopy, and the silencing efficiency of adenovirus against TRPM2 was detected by real-time PCR.The abdominal aorta blood and liver tissues were collected from mice at 2, 4 and 8 h after reperfusion. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum of mice were detected. Hepatic pathological changes were examined by hematoxylin-eosin (HE) staining. The protein expression of TRPM2 and Rac family small GTPase 1 (RAC1) in liver tissues was detected by Western blotting. Changes of malondialdehyde (MDA), superoxide dismutase (SOD) and myeloperoxidase (MPO) activities in liver tissues were detected by enzyme-linked immunosorbent assay.
RESULTS:
A strong signal of green fluorescence was observed in the liver tissues of mice in the T and C groups compared to the S or M group. Compared with the S, M or C group, the expression of TRPM2 mRNA in liver tissue in the T group was significantly down-regulated (all <0.05). The morphology of hepatocytes was normal in the S group under light microscope.Hepatic sinus dilatation, congestion, hepatocyte degeneration, central necrosis of lobule, and massive inflammatory granulocyte infiltration were observed in the M and C group, respectively. The degree of hepatocyte damage in the T group was significantly reduced compared with that in the M and C group, respectively. Compared with the S group, the serum ALT and AST activities in the M, T and C groups were significantly increased at 2, 4 and 8 h after reperfusion (all <0.05). Compared with the M or C group, the serum ALT and AST activities in the T group were significantly lower in serum of mice at 2, 4, and 8 h after reperfusion (all <0.05). Compared with the M or C group, the serum SOD activity in the T group was significantly increased at 2, 4, and 8 h after reperfusion (all <0.05), while the serum MDA and MPO activities were significantly decreased (all <0.05). The protein expression of TRPM2 and RAC1 in liver tissues in the T group were significantly lower than those in the M and C groups at 2, 4 and 8 h after reperfusion (all <0.05).
CONCLUSIONS
Pretreatment with TRPM2 adenovirus interference vector can effectively silence TRPM2 gene expression in liver tissues of mice and attenuate HIRI, which may be related to inhibiting oxidative stress and reducing the expression of RAC1 protein.
Alanine Transaminase
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Animals
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Aspartate Aminotransferases
;
Liver
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Neuropeptides
;
Rats, Sprague-Dawley
;
Reperfusion Injury
;
TRPM Cation Channels
;
genetics
;
Transient Receptor Potential Channels
;
rac1 GTP-Binding Protein
3.Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation.
Gang CHEN ; Shi-Fen PAN ; Xiang-Li CUI ; Li-Hong LIU
Chinese Journal of Natural Medicines (English Ed.) 2018;16(1):41-52
The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.
Angiotensin II
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pharmacology
;
Angiotensin II Type 1 Receptor Blockers
;
pharmacology
;
Animals
;
Animals, Newborn
;
Catalase
;
genetics
;
metabolism
;
Cell Proliferation
;
drug effects
;
Cells, Cultured
;
Extracellular Signal-Regulated MAP Kinases
;
antagonists & inhibitors
;
metabolism
;
Fibroblasts
;
Gene Expression Regulation
;
drug effects
;
Heart
;
drug effects
;
Hydrogen Peroxide
;
metabolism
;
pharmacology
;
Isoflavones
;
pharmacology
;
Mice
;
Myocardium
;
cytology
;
enzymology
;
metabolism
;
NADPH Oxidases
;
antagonists & inhibitors
;
metabolism
;
Neuropeptides
;
metabolism
;
Signal Transduction
;
drug effects
;
Transcription Factor AP-1
;
antagonists & inhibitors
;
metabolism
;
Transcriptional Activation
;
drug effects
;
rac1 GTP-Binding Protein
;
metabolism
4.Optogenetic activation of dorsal hippocampal astrocytic Rac1 blocks the learning of associative memory.
Xiao-Mu GUO ; Zhao-Hui LIAO ; Ye-Zheng TAO ; Fei-Fei WANG ; Lan MA
Acta Physiologica Sinica 2017;69(3):241-251
Rac1 belongs to the family of Rho GTPases, and plays important roles in the brain function. It affects the cell migration and axon guidance via regulating the cytoskeleton and cellular morphology. However, the effect of its dynamic activation in regulating physiological function remains unclear. Recently, a photoactivatable analogue of Rac1 (PA-Rac1) has been developed, allowing the activation of Rac1 by the specific wavelength of light in living cells. Thus, we constructed recombinant adeno-associated virus (AAV) of PA-Rac1 and its light-insensitive mutant PA-Rac1-C450A under the control of the mouse glial fibrillary acidic protein (mGFAP) promoter to manipulate Rac1 activity in astrocytes by optical stimulation. Primary culture of hippocampal astrocytes was infected with the recombinant AAV-PA-Rac1 or AAV-PA-Rac1-C450A. Real-time fluorescence imaging showed that the cell membrane of the astrocyte expressing PA-Rac1 protruded near the light spot, while the astrocyte expressing PA-Rac1-C450A did not. We injected AAV-PA-Rac1 and AAV-PA-Rac1-C450A into dorsal hippocampus to investigate the role of the activation of Rac1 in regulating the associative learning. With optical stimulation, the PA-Rac1 group, rather than the PA-Rac1-C450A group, showed slower learning curve during the fear conditioning compared with the control group, indicating that activating astrocytic Rac1 blocks the formation of contextual memory. Our data suggest that the activation of Rac1 in dorsal hippocampal astrocyte plays an important role in the associative learning.
Animals
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Astrocytes
;
physiology
;
Cell Membrane
;
Cell Movement
;
Conditioning, Classical
;
Cytoskeleton
;
Dependovirus
;
Fear
;
Hippocampus
;
physiology
;
Memory
;
Mice
;
Mice, Inbred C57BL
;
Neuropeptides
;
genetics
;
physiology
;
Optogenetics
;
rac1 GTP-Binding Protein
;
genetics
;
physiology
5.Role of Rheb in Human Acute Myeloid Leukemia.
Xiao-Min WANG ; Qiao-Zhu XU ; Ya-Nan GAO ; Juan GAO ; Ming-Hao LI ; Wan-Zhu YANG ; Jiang-Xiang WANG ; Wei-Ping YUAN
Journal of Experimental Hematology 2016;24(3):662-666
OBJECTIVETo investigate the role of Rheb (mTOR activator) in AML development by measuring Rheb expression in bone marrow of adult AML patients and in AML cell line HL-60.
METHODSReal-time PCR assay was used to measure the Rheb mRNA expression in 27 AML patients and 29 ITP patients as control. The relationship between Rheb mRNA expression and age, AML subtype, fusion gene, splenomegaly, hepatomegaly and survival of AML patients was analyzed and compared. In addition, HL-60 cell line over-expressing Rheb was established, and the HL-60 cells and HL-60 cells with overexpression of Rheb were treated with Ara-C of different concentrations, the proliferation level was detected by CCK-8 method, and the IC50 was calculated.
RESULTSThe mRNA level of Rheb in AML patients was similar to that in ITP patients (control). Interestingly, higher expression of Rheb was associated with better survival and was sensitive to Ara-C treatment. However, the expression level of Rheb was not associated with age, AML subtype, fusion gene, and hepatomegaly of patients. Lower expression level of Rheb was associated with splenomegaly. In vitro analysis of HL-60 line indicated that overexpression of Rheb could increased the cell sensitivity to Ara-C treatment (IC50=0.54 µmol/L) and caused HL-60 cell apoptosis.
CONCLUSIONThe lower Rheb expression is a poor prognostic indicator for AML patients, which is associated with AML splenomegaly, the patients and HL-60 cells with low expression of Rheb are insensitive to Ara-C treatment.
Adult ; Apoptosis ; Bone Marrow ; metabolism ; Cytarabine ; pharmacology ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; pathology ; Monomeric GTP-Binding Proteins ; genetics ; metabolism ; Neuropeptides ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Ras Homolog Enriched in Brain Protein ; Real-Time Polymerase Chain Reaction ; Spleen ; pathology
6.Increased orexin expression promotes sleep/wake disturbances in the SOD1-G93A mouse model of amyotrophic lateral sclerosis.
Rong LIU ; Zhao-Fu SHENG ; Bing CAI ; Yong-He ZHANG ; Dong-Sheng FAN
Chinese Medical Journal 2015;128(2):239-244
BACKGROUNDSleep/wake disturbances in patients with amyotrophic lateral sclerosis (ALS) are well-documented, however, no animal or mechanistic studies on these disturbances exist. Orexin is a crucial neurotransmitter in promoting wakefulness in sleep/wake regulation, and may play an important role in sleep disturbances in ALS. In this study, we used SOD1-G93A transgenic mice as an ALS mouse model to investigate the sleep/wake disturbances and their possible mechanisms in ALS.
METHODSElectroencephalogram/electromyogram recordings were performed in SOD1-G93A transgenic mice and their littermate control mice at the ages of 90 and 120 days, and the samples obtained from these groups were subjected to quantitative reverse transcriptase-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay.
RESULTSFor the first time in SOD1-G93A transgenic mice, we observed significantly increased wakefulness, reduced sleep time, and up-regulated orexins (prepro-orexin, orexin A and B) at both 90 and 120 days. Correlation analysis confirmed moderate to high correlations between sleep/wake time (total sleep time, wakefulness time, rapid eye movement [REM] sleep time, non-REM sleep time, and deep sleep time) and increase in orexins (prepro-orexin, orexin A and B).
CONCLUSIONSleep/wake disturbances occur before disease onset in this ALS mouse model. Increased orexins may promote wakefulness and result in these disturbances before and after disease onset, thus making them potential therapeutic targets for amelioration of sleep disturbances in ALS. Further studies are required to elucidate the underlying mechanisms in the future.
Amyotrophic Lateral Sclerosis ; genetics ; metabolism ; Animals ; Female ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Male ; Mice ; Mice, Transgenic ; Neuropeptides ; genetics ; metabolism ; Orexins ; Reverse Transcriptase Polymerase Chain Reaction ; Sleep ; physiology ; Superoxide Dismutase ; genetics ; metabolism ; Superoxide Dismutase-1 ; Wakefulness ; physiology
7.Electroacupuncture at Feishu (BL13) and Zusanli (ST36) down-regulates the expression of orexins and their receptors in rats with chronic obstructive pulmonary disease.
Xin-fang ZHANG ; Ji ZHU ; Wen-ye GENG ; Shu-jun ZHAO ; Chuan-wei JIANG ; Sheng-rong CAI ; Miao CHENG ; Chuan-yun ZHOU ; Zi-bing LIU ; E-mail: ZIBINGLIU@163.COM.
Journal of Integrative Medicine 2014;12(5):417-424
OBJECTIVEInflammation and lung function decline are the main pathophysiological features of chronic obstructive pulmonary disease (COPD). Acupuncture can improve lung function in patients with COPD, but the underlying mechanisms are not well understood. Orexins (OXs), which are found in peripheral plasma, are neuropeptides that regulate respiration and their levels are related to COPD. Therefore, we hypothesized that acupuncture might alter OXs, reduce lung inflammation and improve lung function in COPD.
METHODSCOPD was induced in rats by exposure to cigarette smoke for 8 weeks and injecting with lipopolysaccharide twice. Electroacupuncture (EA) was performed at Feishu (BL13) and Zusanli (ST36) for 30 min/d for 2 weeks. Rat lung function and morphology were assessed after EA. The levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in bronchoalveolar lavage fluid (BALF) and orexin A and B levels in the lung tissue were detected by enzyme-linked immunosorbent assay. OX receptor mRNA levels and immunopositive cells were assessed with real-time polymerase chain reaction and immunohistochemical methods, respectively. The relationships among lung function, cell factors, and OX levels were analyzed by Pearson correlation analyses.
RESULTSCompared with the control group, lung function was significantly decreased in the rats with COPD (P<0.05). There were increases in TNF-α and IL-1β levels in BALF (P<0.05 and P<0.01, respectively), orexin A level in lung tissue (P<0.01; but not orexin B) and mRNA expressions of OX (OXR1) and OX 2 (OXR2) in lung tissue (P<0.05 and P<0.01, respectively); the integrative optical densities (IODs) of both receptors were greater in the COPD group (P<0.05). For rats with COPD subjected to EA, lung function was improved (P<0.05). There were notable decreases in TNF-α and IL-1β levels (P<0.05 and <0.01, respectively) in BALF. Orexin A, but not orexinB, levels in lung tissue also decreased (P<0.01), as did mRNA expression of OX1R and OX2R in lung tissue (P<0.05 and P<0.01, respectively). Receptor IODs were also reduced after EA treatment (P<0.05). Furthermore, orexin A levels and ratio of forced expiratory volume in 0.3 s to forced vital capacity were strongly negatively correlated (P<0.01), and orexin A was positively correlated with TNF-α and IL-1β (P<0.001 and P<0.05, respectively).
CONCLUSIONEA at Zusanli and Feishu improved lung function of rats with COPD and had an anti-inflammatory effect, which may be related to down-regulation of OXA and its receptors.
Animals ; Down-Regulation ; Electroacupuncture ; Interleukin-1beta ; analysis ; Intracellular Signaling Peptides and Proteins ; analysis ; genetics ; Lung ; physiopathology ; Male ; Neuropeptides ; analysis ; genetics ; Orexin Receptors ; analysis ; genetics ; Orexins ; Pulmonary Disease, Chronic Obstructive ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; analysis
8.MicroRNA-29a modulates axon branching by targeting doublecortin in primary neurons.
Hanqin LI ; Susu MAO ; Haitao WANG ; Ke ZEN ; Chenyu ZHANG ; Liang LI
Protein & Cell 2014;5(2):160-169
MicroRNAs (miRNAs) are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothesized to play pivotal roles during neural development. In the present study, we analyzed miRNAs expression in mice cerebral cortex and hippocampus at different developmental stages and found miR-29a increased dramatically at postnatal stages. In addition, we provided strong evidences that miR-29a is enriched in mature neurons both in vitro and in vivo. Further investigation demonstrated that the activation of glutamate receptors induced endogenous miR-29a level in primary neurons. Moreover, we showed that miR-29a directly regulated its target protein Doublecortin (DCX) expression, which further modulated axon branching in primary culture. Together, our results suggested that miR-29a play an important role in neuronal development of mice cerebrum.
Animals
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Axons
;
metabolism
;
physiology
;
Hippocampus
;
growth & development
;
metabolism
;
Mice
;
MicroRNAs
;
genetics
;
metabolism
;
Microtubule-Associated Proteins
;
genetics
;
Neurogenesis
;
Neurons
;
metabolism
;
Neuropeptides
;
genetics
;
Primary Cell Culture
9.Analysis of DCX gene mutation in a patient featuring X-linked subcortical laminar heterotopia and epilepsy.
Wen LI ; Mei-pin ZHANG ; Zhong-jun HOU ; Tao ZENG ; Bin TANG ; Xiao-rong LIU
Chinese Journal of Medical Genetics 2013;30(1):74-78
OBJECTIVETo detect potential mutation of Doublecortin (DCX) gene in a patient featuring X-linked subcortical laminar heterotopia (X-SCLH) and epilepsy.
METHODSMutation of the DCX gene was screened by PCR and direct sequencing. Pathogenicity of the mutation was analyzed with a PolyPhen-2 software.
RESULTSA de novo missense mutation c.971T>C (p.Phe324Ser) was discovered.
CONCLUSIONA diagnostic method for X-SCLH has been established, which may facilitate diagnosis and genetic counseling of patients featuring this disease.
Agenesis of Corpus Callosum ; diagnosis ; genetics ; Base Sequence ; Brain ; pathology ; Child ; Classical Lissencephalies and Subcortical Band Heterotopias ; diagnosis ; genetics ; Electroencephalography ; Epilepsy ; diagnosis ; genetics ; Exons ; Female ; Humans ; Magnetic Resonance Imaging ; Microtubule-Associated Proteins ; genetics ; Mutation ; Neuropeptides ; genetics
10.Apoptosis signal-regulating kinase 1 (ASK1) is linked to neural stem cell differentiation after ischemic brain injury.
Juhyun SONG ; Kyoung Joo CHO ; So Yeong CHEON ; Sa Hyun KIM ; Kyung Ah PARK ; Won Taek LEE ; Jong Eun LEE
Experimental & Molecular Medicine 2013;45(12):e69-
Neural stem cells (NSCs) have been suggested as a groundbreaking solution for stroke patients because they have the potential for self-renewal and differentiation into neurons. The differentiation of NSCs into neurons is integral for increasing the therapeutic efficiency of NSCs during inflammation. Apoptosis signal-regulating kinase 1 (ASK1) is preferentially activated by oxidative stress and inflammation, which is the fundamental pathology of brain damage in stroke. ASK1 may be involved in the early inflammation response after stroke and may be related to the differentiation of NSCs because of the relationship between ASK1 and the p38 mitogen-activated protein kinase pathway. Therefore, we investigated whether ASK1 is linked to the differentiation of NSCs under the context of inflammation. On the basis of the results of a microarray analysis, we performed the following experiments: western blot analysis to confirm ASK1, DCX, MAP2, phospho-p38 expression; fluorescence-activated cell sorting assay to estimate cell death; and immunocytochemistry to visualize and confirm the differentiation of cells in brain tissue. Neurosphere size and cell survival were highly maintained in ASK1-suppressed, lipopolysaccharide (LPS)-treated brains compared with only LPS-treated brains. The number of positive cells for MAP2, a neuronal marker, was lower in the ASK1-suppressed group than in the control group. According to our microarray data, phospho-p38 expression was inversely linked to ASK1 suppression, and our immunohistochemistry data showed that slight upregulation of ASK1 by LPS promoted the differentiation of endogenous, neuronal stem cells into neurons, but highly increased ASK1 levels after cerebral ischemic damage led to high levels of cell death. We conclude that ASK1 is regulated in response to the early inflammation phase and regulates the differentiation of NSCs after inflammatory-inducing events, such as ischemic stroke.
Animals
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Cell Death
;
Infarction, Middle Cerebral Artery/*metabolism
;
Lipopolysaccharides/pharmacology
;
MAP Kinase Kinase Kinase 5/genetics/*metabolism
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Microtubule-Associated Proteins/genetics/metabolism
;
Neural Stem Cells/cytology/drug effects/*metabolism
;
*Neurogenesis
;
Neuropeptides/genetics/metabolism
;
p38 Mitogen-Activated Protein Kinases/genetics/metabolism

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