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
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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.Intermedin in Paraventricular Nucleus Attenuates Sympathoexcitation and Decreases TLR4-Mediated Sympathetic Activation via Adrenomedullin Receptors in Rats with Obesity-Related Hypertension.
Jing SUN ; Xing-Sheng REN ; Ying KANG ; Hang-Bing DAI ; Lei DING ; Ning TONG ; Guo-Qing ZHU ; Ye-Bo ZHOU
Neuroscience Bulletin 2019;35(1):34-46
Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.
Adrenomedullin
;
metabolism
;
Animals
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Blood Pressure
;
drug effects
;
physiology
;
Hypertension
;
etiology
;
Lipopolysaccharides
;
pharmacology
;
Male
;
Neuropeptides
;
metabolism
;
Obesity
;
complications
;
Rats, Sprague-Dawley
;
Receptors, Adrenomedullin
;
drug effects
;
metabolism
;
Sympathetic Nervous System
;
drug effects
;
metabolism
;
Toll-Like Receptor 4
;
metabolism
3.Mechanisms of action and clinical applications of anti-obesity drugs currently available in Korea
Journal of the Korean Medical Association 2019;62(11):588-597
Over the last 5 years, the Korean Ministry of Food and Drug Safety has approved four anti-obesity drugs for long-term weight management. In this review, the mechanisms of action and clinical applications of lorcaserin, naltrexone/bupropion, liraglutide, and phentermine/topiramate have been clarified. Lorcaserin stimulates proopiomelanocortin/cocaine- and amphetamine-regulated transcript neurons in the arcuate nucleus. Naltrexone/bupropion reduces body weight by controlling the hedonic reward system of food intake. The hypophagic effect of liraglutide depends on the direct activation of the proopiomelanocortin/cocaine- and amphetamine-regulated transcript neurons and indirect suppression of neuropeptide Y/agouti-related peptide neurons through gammaaminobutyric acid-dependent signaling, with an additional thermogenic effect. Phentermine/topiramate induces weight loss by elevating the norepinephrine levels in the hypothalamus, reducing energy deposition in the adipose tissue and skeletal muscle, and elevating the corticotropin-releasing hormone in the hypothalamus. In patients with high cardiovascular risks or type 2 diabetes mellitus, lorcaserin and liraglutide are appropriate. In patients with mood disorders, naltrexone/bupropion could be considered as the first choice of therapy. Notably, lorcaserin and liraglutide are neutral in the aspect of sleep disorder. In case of obese individuals with obstructive sleep apnea, liraglutide or phentermine/topiramate would be selected as the treatment option. These four drugs should be used after considering the patients' co-morbidities of obesity.
Adipose Tissue
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Anti-Obesity Agents
;
Arcuate Nucleus of Hypothalamus
;
Body Weight
;
Corticotropin-Releasing Hormone
;
Diabetes Mellitus, Type 2
;
Eating
;
Humans
;
Hypothalamus
;
Korea
;
Liraglutide
;
Mood Disorders
;
Muscle, Skeletal
;
Neurons
;
Neuropeptides
;
Norepinephrine
;
Obesity
;
Pharmacology
;
Reward
;
Sleep Apnea, Obstructive
;
Sleep Wake Disorders
;
Weight Loss
4.Extract Promotes Neurogenesis in the Hippocampal Dentate Gyrus of the Adult Mouse through Increasing Expressions of Brain-Derived Neurotrophic Factor and Tropomyosin-Related Kinase B.
Joon Ha PARK ; Bich Na SHIN ; Ji Hyeon AHN ; Jeong Hwi CHO ; Tae-Kyeong LEE ; Jae-Chul LEE ; Yong Hwan JEON ; Il Jun KANG ; Ki-Yeon YOO ; In Koo HWANG ; Choong Hyun LEE ; Yoo Hun NOH ; Sung-Su KIM ; Moo-Ho WON ; Jong Dai KIM
Chinese Medical Journal 2018;131(6):689-695
BackgroundGlehnia littoralis has been used for traditional Asian medicine, which has diverse therapeutic activities. However, studies regarding neurogenic effects of G. littoralis have not yet been considered. Therefore, in this study, we examined effects of G. littoralis extract on cell proliferation, neuroblast differentiation, and the maturation of newborn neurons in the hippocampus of adult mice.
MethodsA total of 39 male ICR mice (12 weeks old) were randomly assigned to vehicle-treated and 100 and 200 mg/kg G. littoralis extract-treated groups (n = 13 in each group). Vehicle and G. littoralis extract were orally administrated for 28 days. To examine neurogenic effects of G. littoralis extract, we performed immunohistochemistry for 5-bromo-2-deoxyuridine (BrdU, an indicator for cell proliferation) and doublecortin (DCX, an immature neuronal marker) and double immunofluorescence staining for BrdU and neuronal nuclear antigen (NeuN, a mature neuronal marker). In addition, we examined expressional changes of brain-derived neurotrophic factor (BDNF) and its major receptor tropomyosin-related kinase B (TrkB) using Western blotting analysis.
ResultsTreatment with 200 mg/kg, not 100 mg/kg, significantly increased number of BrdU-immunoreactive () and DCX cells (48.0 ± 3.1 and 72.0 ± 3.8 cells/section, respectively) in the subgranular zone (SGZ) of the dentate gyrus (DG) and BrdU/NeuN cells (17.0 ± 1.5 cells/section) in the granule cell layer as well as in the SGZ. In addition, protein levels of BDNF and TrkB (about 232% and 244% of the vehicle-treated group, respectively) were significantly increased in the DG of the mice treated with 200 mg/kg of G. littoralis extract.
ConclusionG. littoralis extract promots cell proliferation, neuroblast differentiation, and neuronal maturation in the hippocampal DG, and neurogenic effects might be closely related to increases of BDNF and TrkB proteins by G. littoralis extract treatment.
Animals ; Apiaceae ; chemistry ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; metabolism ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Dentate Gyrus ; cytology ; drug effects ; Hippocampus ; cytology ; drug effects ; Immunohistochemistry ; Male ; Mice ; Microtubule-Associated Proteins ; metabolism ; Neurogenesis ; drug effects ; Neuropeptides ; metabolism ; Plant Extracts ; pharmacology ; Receptor, trkB ; metabolism
5.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
;
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
6.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
7.Effects of polygala on the neurogenesis of manganese poisoned mice.
Xuechao JING ; Li QIN ; Boning YANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2015;33(3):207-210
OBJECTIVETo investigate the effects of polygala on leaning and memory and the expression of Microtubule associated protein on manganese poisoned mice.
METHODS60 female Kunming mice were randomly and equally divided into 5 group. They are normal control group (CG), manganese poisoned group (MG), manganese poisoned with polygala high dose group (MHG), manganese poisoned with polygala middle dose group (MMG), manganese poisoned with polygala low dose group (MLG). The model of manganese poisoned mice was prepared of the way of intraperitoneal injection of manganese chloride (MnCl2 15 mg/kg), the spatial learning and memory ability was tested by Morris water maze, the Doublecortin (DCX) was tested by the way of immunofluorescent staining in the SVZ and SGZ.
RESULTIn the navigation test, compared with MG, the escape latency of MHG, MMG and MLG were significantly decreased (P < 0.05), in space exploration experiments, MHG, MMG, MLG compared with MG, the number increased significantly across platforms (P < 0.05). compared with MG, the DCX expression of MHG, MMG and MLG were significantly increased (P < 0.05).
CONCLUTIONThe leaning and memory ability of manganese poisoned mice can be improved by the polygala, and the mechanism may be related to promote the expression of DCX and neurogenesis in the brain.
Animals ; Female ; Manganese Poisoning ; drug therapy ; Maze Learning ; drug effects ; Memory ; drug effects ; Mice ; Microtubule-Associated Proteins ; drug effects ; Neurogenesis ; drug effects ; Neuropeptides ; drug effects ; Plant Extracts ; pharmacology ; Polygala ; chemistry
8.Cell proliferation and neuroblast differentiation in the dentate gyrus of high-fat diet-fed mice are increased after rosiglitazone treatment.
Dae Young YOO ; Woosuk KIM ; Dae Won KIM ; Sung Min NAM ; Hyo Young JUNG ; Jong Whi KIM ; Choong Hyun LEE ; Jung Hoon CHOI ; Moo Ho WON ; Yeo Sung YOON ; In Koo HWANG
Journal of Veterinary Science 2014;15(1):27-33
In this study, we determined how rosiglitazone (RSG) differentially affected hippocampal neurogenesis in mice fed a low-fat diet (LFD) or high-fat diet (HFD; 60% fat). LFD and HFD were given to the mice for 8 weeks. Four weeks after initiating the LFD and HFD feeding, vehicle or RSG was administered orally once a day to both groups of mice. We measured cell proliferation and neuroblast differentiation in the subgranular zone of the dentate gyrus using Ki67 and doublecortin (DCX), respectively, as markers. In addition, we monitored the effects of RSG on the levels of DCX and brain-derived neurotrophic factor (BDNF) in hippocampal homogenates. At 8 weeks after the LFD feeding, the numbers of Ki67- and DCX-positive cells as well as hippocampal levels of DCX and BDNF were significantly decreased in the RSG-treated group compared to the vehicle-treated animals. In contrast, the numbers of Ki67- and DCX-positive cells along with hippocampal levels of DCX and BDNF in the HFD fed mice were significantly increased in the RSG-treated mice compared to the vehicle-treated group. Our data demonstrate that RSG can modulate the levels of BDNF, which could play a pivotal role in cell proliferation and neuroblast differentiation in the hippocampal dentate gyrus.
Animals
;
Blotting, Western
;
Brain-Derived Neurotrophic Factor/metabolism
;
Cell Differentiation/*drug effects
;
Cell Proliferation/drug effects
;
Dentate Gyrus/growth & development/physiology
;
Diet, Fat-Restricted
;
*Diet, High-Fat
;
Hippocampus/growth & development/physiology
;
Hypoglycemic Agents/*pharmacology
;
Immunohistochemistry
;
Ki-67 Antigen/metabolism
;
Male
;
Mice, Inbred C57BL
;
Microtubule-Associated Proteins/metabolism
;
Neurogenesis/*drug effects
;
Neuropeptides/metabolism
;
Thiazolidinediones/*pharmacology
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
;
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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