1.Mechanism of Guben Jiannao Liquid on Alzheimer's disease by regulating autophagy based on LKB1/AMPK/mTOR pathway.
Jing-Fan ZHANG ; Qing-Hua LONG ; Chu-Hua ZENG ; Yi-Min CHEN ; Zhe-Yao XIE ; Yuan-Qin CAI ; Xi WANG
China Journal of Chinese Materia Medica 2025;50(2):293-300
This study explores the mechanism of Guben Jiannao Liquid on Alzheimer's disease(AD) by regulating autophagy based on the liver kinase B1(LKB1)/adenosine monophosphate-activated protein kinase(AMPK)/mammalian target of rapamycin(mTOR) pathway. Male SD rats were randomly divided into the blank group, model group, low-dose and high-dose groups of Guben Jiannao Liquid, and rapamycin group, with 10 rats in each group. Except for the blank group, all other groups of rats were injected bilaterally in the hippocampus with β-amyloid(Aβ)_(1-42) to establish the AD model. The low-dose(6.21 g·kg~(-1)) and high-dose(12.42 g·kg~(-1)) groups of Guben Jiannao Liquid and rapamycin group(1 mg·kg~(-1)) were given the corresponding drugs by gavage, and the blank and model groups were given an equal volume of saline by gavage for four weeks. Morris water maze was used to test the learning and memory ability of rats in each group; hematoxylin-eosin(HE) and Nissl staining were used to observe the morphological and quantitative changes of neurons and Nissl bodies in the CA1 region of rat hippocampus; immunohistochemistry was utilized to detect Aβ-positive cell expression in the CA1 region of rat hippocampus; transmission electron microscopy was employed to observe ultrastructural changes in rat hippocampal tissue, and Western blot was used to examine the protein expression levels of LKB1, p-AMPK/AMPK, p-mTOR/mTOR, Beclin1, p62, and LC3-Ⅱ in the hippocampal tissue of the rats. The results showed that compared with those in the blank group, rats in the model group had elevated evasion latency and decreased number of platform transversal and residence time in the platform quadrant. The number of neurons in the hippocampal area was reduced, and the morphology was impaired. The average integral optical density value of Aβ-positive cells was elevated; the expression levels of LKB1, p-AMPK/AMPK, Beclin1, and LC3-Ⅱ were decreased, and the expression levels of p-mTOR/mTOR and p62 were increased. Compared with those in the model group, rats in the low-dose and high-dose groups of Guben Jiannao Liquid had shorter evasion latency, higher number of platform transversal, longer residence time in the platform quadrant, increased number of neurons, decreased expression of Aβ-positive cells and average integral optical density values, and increased number of autophagic lysosomes in hippocampal tissue. The expression levels of LKB1, Beclin1, and LC3-Ⅱ were elevated in the hippocampus of rats in the low-dose group of Guben Jiannao Liquid. The expression levels of LKB1, p-AMPK/AMPK, Beclin1, and LC3-Ⅱ were elevated in the hippocampal tissue of rats in the high-dose group of Guben Jiannao Liquid, and the expression levels of p-mTOR/mTOR and p62 were decreased. The findings suggest that Guben Jiannao Liquid can improve cognitive impairment in AD rats, and its mechanism of action may be related to the activation of the LKB1/AMPK/mTOR signaling pathway and the up-regulation of autophagy level.
Animals
;
Alzheimer Disease/physiopathology*
;
Male
;
TOR Serine-Threonine Kinases/genetics*
;
Autophagy/drug effects*
;
Rats, Sprague-Dawley
;
Protein Serine-Threonine Kinases/genetics*
;
AMP-Activated Protein Kinases/genetics*
;
Rats
;
Drugs, Chinese Herbal/administration & dosage*
;
Signal Transduction/drug effects*
;
AMP-Activated Protein Kinase Kinases
;
Humans
;
Hippocampus/metabolism*
2.Impacts of curcumin on proliferation, migration and cisplatin resistance of bladder cancer cells by regulating LKB1-AMPK-LC3 signaling pathway.
Chinese Journal of Cellular and Molecular Immunology 2025;41(1):9-16
Objective To study the impacts of curcumin on the proliferation, migration and cisplatin (DDP) resistance of bladder cancer cells by regulating the liver kinase B1-AMP activated protein kinase-microtubule-associated protein 1 light chain 3 (LKB1-AMPK-LC3) signaling pathway. Methods Human bladder cancer cell line T24 was cultured in vitro, and its DDP resistant T24/DDP cells were induced by cisplatin (DDP). After treating T24 and T24/DDP cells with different concentrations of curcumin, the optimal concentration of curcumin was screened by MTT assay. T24 cells were randomly grouped into control group, curcumin group, metformin group, and combination group of curcumin and metformin. After treatment with curcumin and LKB1-AMPK activator metformin, the proliferation, autophagy, migration, and apoptosis of T24 cells in each group were detected by MTT assay, monodansylcadavrine (MDC) fluorescence staining, cell scratch assay, and flow cytometry, respectively. Western blot was used to detect the expression of proteins related to LKB1-AMPK-LC3 signaling pathway in T24 cells of each group. T24/DDP cells were randomly assigned into control group, curcumin group, metformin group, and combination group of curcumin and metformin. Cells were treated with curcumin and metformin according to grouping and treated with different concentrations of DDP simultaneously. Then, the effect of curcumin on the DDP resistance coefficient of T24/DDP cells was detected by MTT assay. T24/DDP cells were randomly grouped into control group, DDP group, combination groups of DDP and curcumin, DDP and metformin, DDP, curcumin and metformi. After treatment with DDP, curcumin, and metformin, the proliferation, autophagy, migration, apoptosis, drug resistance, and the expression of proteins related to LKB1-AMPK-LC3 signaling pathway in T24/DDP cells of each group were detected with the same methods. Results Compared with the control group, the activity of T24 cells, relative number of autophagosomes, migration rate, Phosphorylated-LKB1 (p-LKB1)/LKB1, Phosphorylated-AMPK (p-AMPK)/AMPK, LC3II/LC3I, and the DDP resistance coefficient of T24/DDP cells in the curcumin group were lower, and the apoptosis rate of T24 cells was higher; the changes in various indicators in the metformin group were opposite to those in the curcumin group. Compared with the curcumin group, the activity of T24 cells, relative number of autophagosomes, migration rate, p-LKB1/LKB1, p-AMPK/AMPK, LC3II/LC3I, and the DDP resistance coefficient of T24/DDP cells in the combination group of curcumin and metformin were higher, and the apoptosis rate of T24 cells was lower. Compared with the control group, there were no obvious changes in various indicators of T24/DDP cells in the DDP group. Compared with the control group and DDP group, the viability of T24/DDP cells, relative number of autophagosomes, migration rate, P-glycoprotein (P-gp) protein expression, p-LKB1/LKB1, p-AMPK/AMPK, and LC3II/LC3I in the combination group of DDP and curcumin were lower, and the apoptosis rate of T24/DDP cells was higher; the changes in the above indicators in the combination group of DDP and metformin were opposite to those in the combination group of DDP and curcumin. Compared with the combination group of DDP and curcumin, the viability of T24/DDP cells, relative number of autophagosomes, migration rate, P-gp protein expression, p-LKB1/LKB1, p-AMPK/AMPK, and LC3II/LC3I in the combination group of DDP, curcumin and metformin were higher, and the apoptosis rate of T24/DDP cells was lower. Conclusion Curcumin can reduce the activity of LKB1-AMPK-LC3 signaling pathway, thereby inhibiting autophagy, proliferation and migration of bladder cancer cells, promoting their apoptosis, and weakening their resistance to DDP.
Humans
;
Cisplatin/pharmacology*
;
Curcumin/pharmacology*
;
Cell Proliferation/drug effects*
;
Signal Transduction/drug effects*
;
Protein Serine-Threonine Kinases/genetics*
;
AMP-Activated Protein Kinases/metabolism*
;
Drug Resistance, Neoplasm/drug effects*
;
Urinary Bladder Neoplasms/pathology*
;
Cell Line, Tumor
;
Cell Movement/drug effects*
;
AMP-Activated Protein Kinase Kinases
;
Microtubule-Associated Proteins/metabolism*
;
Apoptosis/drug effects*
;
Antineoplastic Agents/pharmacology*
;
Metformin/pharmacology*
;
Autophagy/drug effects*
3.Role of AMPKα2 in regulating the IRE1α-JNK pathway in metabolic dysfunction-associated fatty liver disease.
Shujie ZHAO ; Weilun FANG ; Yu WEI ; Jiahui MENG ; Qiao JIN ; Weijin FANG
Journal of Central South University(Medical Sciences) 2024;49(12):1891-1901
OBJECTIVES:
Over 25% of the global population is affected by metabolic dysfunction-associated fatty liver disease (MAFLD), yet its pathogenesis remains unclear. Endoplasmic reticulum stress (ERS) may be involved in the onset and progression of MAFLD. Adenosine 5'-monophosphate-activated protein kinase α2 (AMPKα2), a key regulator of hepatic energy metabolism, may influence MAFLD development via ERS modulation. This study aims to investigate the role of AMPKα2 in a high-fat diet-induced MAFLD mouse model and its regulatory effect on the inositol-requiring enzyme 1 alpha (IRE1α)-c-Jun N-terminal kinase (JNK) signaling pathway.
METHODS:
Liver-specific AMPKα2 knockout mice on a C57BL/6 background were generated and subjected to MAFLD induction. Mice were divided into four groups: wild-type control (WT+Chow, basic diet for 12 weeks), wild-type high-fat diet (WT+HFD, high-fat diet for 12 weeks), AMPKα2 knockout control (AMPKα2 KO+Chow), and AMPKα2 knockout high-fat diet (AMPKα2 KO+HFD). Blood glucose, lipid levels, and liver function were assessed post-treatment. Liver histology was analyzed using Oil Red O, hematoxylin-eosin, Masson, and Sirius Red staining. Western blotting was used to evaluate the expression of AMPKα2, ERS markers, autophagy, apoptosis, and ferroptosis-related proteins.
RESULTS:
Compared with the WT+Chow group, the WT+HFD group showed significantly elevated blood glucose, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels (all P<0.01); histological analyses revealed hepatic steatosis, vacuolization, and fibrosis, with a significantly increased non-alcoholic steatohepatitis activity score (NAS) (P<0.001). Phosphorylated IRE1α and the autophagy marker microtubule-associated protein light chain (LC) 3II/LC3I were markedly upregulated, while apoptotic proteins (Cleaved-Caspase 3, BAX, Bcl-2) and ferroptosis markers (SLC7A11, GPX4) showed no significant change (P>0.05). In the AMPKα2 KO+HFD group, blood glucose, ALT, and AST levels were significantly reduced compared to the WT+HFD group. Histological improvements were observed with reduced vacuolization and lipid accumulation. Expression of p-IRE1α, JNK, and LC3II/LC3I was significantly decreased (P<0.05).
CONCLUSIONS
Hepatic AMPKα2 knockout alleviates high-fat induced MAFLD, potentially by inhibiting the IRE1α-JNK pathway and reducing autophagy.
Animals
;
AMP-Activated Protein Kinases/physiology*
;
Protein Serine-Threonine Kinases/metabolism*
;
Mice, Knockout
;
Diet, High-Fat/adverse effects*
;
Mice, Inbred C57BL
;
Mice
;
Endoplasmic Reticulum Stress
;
Endoribonucleases/metabolism*
;
Male
;
Liver/pathology*
;
Non-alcoholic Fatty Liver Disease/metabolism*
;
MAP Kinase Signaling System/physiology*
;
Fatty Liver/metabolism*
;
Signal Transduction
4.Qihuang Jianpi Zishen Granules improves thrombocytopenia in mice with systemic lupus erythematosus by suppressing platelet autophagy via the Ca2+/CaMKK2/AMPK/mTOR signaling pathway.
Yunfei LI ; Lijun PANG ; Longwu SHU ; Ming LI ; Chuanbing HUANG
Journal of Southern Medical University 2024;44(12):2327-2334
OBJECTIVES:
To explore the mechanism of Qihuang Jianpi Zishen Granules (QJZG) for improving thrombocytopenia in a mouse model of systemic lupus erythematosus (SLE).
METHODS:
Twenty-four MRL/lpr lupus mice were randomized equally into 4 groups for treatment with daily gavage of saline, QJZG or prednisone (Pred) or intraperitoneal injection (twice a week) of CaMKK2 activator, with 6 C57BL/6 mice with saline gavage as the control group. After 8 weeks of treatment, the mice were examined for PLT, PCT, PDW, MPV, serum levels of TPO, IL-6, IL-10, TNF-α and IFN-γ, and calcium ion fluorescence intensity using ELISA or flow-through assay. RT-qPCR was used to detect platelet CaMKK2, AMPK2α, mTOR, Beclin1 and p62 mRNA expression levels, and the protein expressions of CaMKK2, p-CaMKK2, AMPK, p-AMPK, mTOR, p-mTOR, LC3, Beclin1 and p62 were detected using Western blotting.
RESULTS:
The saline-treated MRL/lpr lupus mice showed significantly lowered levels of PLT, PCT, IL-10, mTOR, p62 mRNA, p-mTOR and P62 with increased PDW, MPV, serum TPO, IL-6, TNF-α and IFN-γ levels, and platelet expressions of CaMKK2, AMPK, Bcl-1 mRNA, p-CaMKK2, p-AMPK, LC3II and Beclin1. These abnormalities were significantly improved in QJZG group and Pred group but worsened after treatment with the CaMKK2 activator.
CONCLUSIONS
QJZG can ameliorate thrombocytopenia in mouse models of SLE by reducing inflammation and inhibiting platelet autophagy via regulating the Ca2+/CaMKK2/AMPK/mTOR signaling pathways.
Animals
;
Lupus Erythematosus, Systemic/metabolism*
;
Mice
;
Calcium-Calmodulin-Dependent Protein Kinase Kinase/metabolism*
;
Drugs, Chinese Herbal/pharmacology*
;
TOR Serine-Threonine Kinases/metabolism*
;
Thrombocytopenia/metabolism*
;
Signal Transduction/drug effects*
;
Autophagy/drug effects*
;
AMP-Activated Protein Kinases/metabolism*
;
Disease Models, Animal
;
Mice, Inbred C57BL
;
Mice, Inbred MRL lpr
;
Calcium/blood*
;
Blood Platelets/metabolism*
5.Methyl ferulic acid ameliorates ethanol-induced L02 cell steatosis through microRNA-378b-mediated CaMKK2-AMPK pathway.
Ping HUANG ; Xing CHEN ; Rong-Hua MENG ; Jun LU ; Yan ZHANG ; Li LI ; Yong-Wen LI
China Journal of Chinese Materia Medica 2023;48(1):193-201
Alcoholic liver disease(ALD), with its increasing morbidity and mortality, has seriously and extensively affected the health of people worldwide. Methyl ferulic acid(MFA) has been proven to significantly inhibit alcohol-induced lipid production in L02 cells through the AMP-activated protein kinase(AMPK) pathway, but its in-depth mechanism remains unclear. This study aimed to further clarify the mechanism of MFA in improving lipid accumulation in L02 cells through the microRNA-378b(miR-378b)-mediated calcium/calmodulin-dependent protein kinase kinase 2(CaMKK2)-AMPK signaling pathway based on existing researches. L02 cells were induced by 100 mmol·L~(-1) ethanol for 48 h to establish the model of ALD in vitro, and 100, 50, and 25 μmol·L~(-1) concentration of MFA was treated. MiR-378b plasmids(containing the overexpression plasmid-miR-378b mimics, silence plasmid-miR-378b inhibitor, and their respective negative control-miR-378b NCs) were transfected into L02 cells by electroporation to up-regulate or down-regulate the levels of miR-378b in L02 cells. The levels of total cholesterol(TC) and triglyceride(TG) in cells were detected by commercial diagnostic kits and automatic biochemical analyzers. The expression levels of miR-378b in L02 cells were detected by real-time quantitative polymerase chain reaction(qRT-PCR). CaMKK2 mRNA levels were detected by PCR, and protein expressions of related factors involved in lipid synthesis, decomposition, and transport in lipid metabolism were detected by Western blot. The results displayed that ethanol significantly increased TG and TC levels in L02 cells, while MFA decreased TG and TC levels. Ethanol up-regulated the miR-378b level, while MFA effectively inhibited the miR-378b level. The overexpression of miR-378b led to lipid accumulation in ethanol-induced L02 cells, while the silence of miR-378b improved the lipid deposition induced by ethanol. MFA activated the CaMKK2-AMPK signaling pathway by lowering miR-378b, thus improving lipid synthesis, decomposition, and transport, which improved lipid deposition in L02 cells. This study shows that MFA improves lipid deposition in L02 cells by regulating the CaMKK2-AMPK pathway through miR-378b.
Humans
;
Ethanol/toxicity*
;
AMP-Activated Protein Kinases/metabolism*
;
Fatty Liver
;
Triglycerides
;
MicroRNAs/genetics*
;
Calcium-Calmodulin-Dependent Protein Kinase Kinase/genetics*
7.cPKCγ Deficiency Exacerbates Autophagy Impairment and Hyperphosphorylated Tau Buildup through the AMPK/mTOR Pathway in Mice with Type 1 Diabetes Mellitus.
Jiayin ZHENG ; Yue WANG ; Yue LIU ; Song HAN ; Ying ZHANG ; Yanlin LUO ; Yi YAN ; Junfa LI ; Li ZHAO
Neuroscience Bulletin 2022;38(10):1153-1169
Type 1 diabetes mellitus (T1DM)-induced cognitive dysfunction is common, but its underlying mechanisms are still poorly understood. In this study, we found that knockout of conventional protein kinase C (cPKC)γ significantly increased the phosphorylation of Tau at Ser214 and neurofibrillary tangles, but did not affect the activities of GSK-3β and PP2A in the hippocampal neurons of T1DM mice. cPKCγ deficiency significantly decreased the level of autophagy in the hippocampal neurons of T1DM mice. Activation of autophagy greatly alleviated the cognitive impairment induced by cPKCγ deficiency in T1DM mice. Moreover, cPKCγ deficiency reduced the AMPK phosphorylation levels and increased the phosphorylation levels of mTOR in vivo and in vitro. The high glucose-induced Tau phosphorylation at Ser214 was further increased by the autophagy inhibitor and was significantly decreased by an mTOR inhibitor. In conclusion, these results indicated that cPKCγ promotes autophagy through the AMPK/mTOR signaling pathway, thus reducing the level of phosphorylated Tau at Ser214 and neurofibrillary tangles.
AMP-Activated Protein Kinases/metabolism*
;
Animals
;
Autophagy
;
Diabetes Mellitus, Type 1
;
Glucose
;
Glycogen Synthase Kinase 3 beta/metabolism*
;
Mice
;
Phosphorylation
;
Protein Kinase C/metabolism*
;
TOR Serine-Threonine Kinases/metabolism*
;
tau Proteins/metabolism*
8.Fructus Zanthoxyli extract improves glycolipid metabolism disorder of type 2 diabetes mellitus via activation of AMPK/PI3K/Akt pathway: Network pharmacology and experimental validation.
Ting ZHANG ; Qing ZHANG ; Wei ZHENG ; Ting TAO ; Ruo-Lan LI ; Li-Yu WANG ; Wei PENG ; Chun-Jie WU
Journal of Integrative Medicine 2022;20(6):543-560
OBJECTIVE:
This study investigated the potential mechanisms behind the beneficial effects of Fructus Zanthoxyli (FZ) against type 2 diabetes mellitus (T2DM) based on network pharmacology and experimental validation.
METHODS:
Ultra-high-performance liquid chromatography coupled with hybrid quadrupole-orbitrap high-resolution mass spectrometry, and gas chromatography-mass spectrometry were used to identify the constituents of FZ. Next, the differentially expressed genes linked to the treatment of diabetes with FZ were screened using online databases (including Gene Expression Omnibus database and Swiss Target Prediction online database), and the overlapping genes and their enrichment were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, the pathway was verified by in vitro experiments, and cell staining with oil red and Nile red showed that the extract of FZ had a therapeutic effect on T2DM.
RESULTS:
A total of 43 components were identified from FZ, and 39 differentially expressed overlapping genes were screened as the possible targets of FZ in T2DM. The dug component-target network indicated that PPARA, PPARG, PIK3R3, JAK2 and GPR88 might be the core genes targeted by FZ in the treatment of T2DM. Interestingly, the enrichment analysis of KEGG showed that effects of FZ against T2DM were closely correlated with the adenosine monophosphate-activated protein kinase (AMPK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathways. In vitro experiments further confirmed that FZ significantly inhibited palmitic acid-induced lipid formation in HepG2 cells. Moreover, FZ treatment was able to promote the AMPK and PI3K/Akt expressions in HepG2 cells.
CONCLUSION
Network pharmacology combined with experimental validation revealed that FZ extract can improve the glycolipid metabolism disorder of T2DM via activation of the AMPK/PI3K/Akt pathway.
Humans
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Phosphatidylinositol 3-Kinase/metabolism*
;
Diabetes Mellitus, Type 2/metabolism*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
AMP-Activated Protein Kinases/metabolism*
;
Glycolipids/therapeutic use*
;
Network Pharmacology
;
Plant Extracts/therapeutic use*
;
Drugs, Chinese Herbal/therapeutic use*
9.Increased glucose metabolism and alpha-glucosidase inhibition in Cordyceps militaris water extract-treated HepG2 cells.
Dae Jung KIM ; Yun Hwan KANG ; Kyoung Kon KIM ; Tae Woo KIM ; Jae Bong PARK ; Myeon CHOE
Nutrition Research and Practice 2017;11(3):180-189
BACKGROUND/OBJECTIVES: Recent living condition improvements, changes in dietary habits, and reductions in physical activity are contributing to an increase in metabolic syndrome symptoms including diabetes and obesity. Through such societal developments, humankind is continuously exposed to metabolic diseases such as diabetes, and the number of the victims is increasing. This study investigated Cordyceps militaris water extract (CMW)-induced glucose uptake in HepG2 cells and the effect of CMW treatment on glucose metabolism. MATERIALS/METHODS: Colorimetric assay kits were used to determine the glucokinase (GK) and pyruvate dehydrogenase (PDH) activities, glucose uptake, and glycogen content. Either RT-PCR or western blot analysis was performed for quantitation of glucose transporter 2 (GLUT2), hepatocyte nuclear factor 1 alpha (HNF-1α), phosphatidylinositol 3-kinase (PI3k), protein kinase B (Akt), phosphorylated AMP-activated protein kinase (pAMPK), phosphoenolpyruvate carboxykinase, GK, PDH, and glycogen synthase kinase 3 beta (GSK-3β) expression levels. The α-glucosidase inhibitory activities of acarbose and CMW were evaluated by absorbance measurement. RESULTS: CMW induced glucose uptake in HepG2 cells by increasing GLUT2 through HNF-1α expression stimulation. Glucose in the cells increased the CMW-induced phosphorylation of AMPK. In turn, glycolysis was stimulated, and glyconeogenesis was inhibited. Furthermore, by studying the mechanism of action of PI3k, Akt, and GSK-3β, and measuring glycogen content, the study confirmed that the glucose was stored in the liver as glycogen. Finally, CMW resulted in a higher level of α-glucosidase inhibitory activity than that from acarbose. CONCLUSION: CMW induced the uptake of glucose into HepG2 cells, as well, it induced metabolism of the absorbed glucose. It is concluded that CMW is a candidate or potential use in diabetes prevention and treatment.
Acarbose
;
alpha-Glucosidases*
;
AMP-Activated Protein Kinases
;
Blotting, Western
;
Cordyceps*
;
Food Habits
;
Glucokinase
;
Glucose Transport Proteins, Facilitative
;
Glucose*
;
Glycogen
;
Glycogen Synthase Kinase 3
;
Glycolysis
;
Hep G2 Cells*
;
Hepatocyte Nuclear Factor 1-alpha
;
Hypoglycemic Agents
;
Liver
;
Metabolic Diseases
;
Metabolism*
;
Motor Activity
;
Obesity
;
Oxidoreductases
;
Phosphatidylinositol 3-Kinase
;
Phosphoenolpyruvate
;
Phosphorylation
;
Proto-Oncogene Proteins c-akt
;
Pyruvic Acid
;
Social Conditions
;
Water*
10.Angiotensin II Modulates p130Cas of Podocytes by the Suppression of AMP-Activated Protein Kinase.
Tae Sun HA ; Hye Young PARK ; Su Bin SEONG ; Hee Yul AHN
Journal of Korean Medical Science 2016;31(4):535-541
Angiotensin II (Ang II) induces the pathological process of vascular structures, including renal glomeruli by hemodynamic and nonhemodynamic direct effects. In kidneys, Ang II plays an important role in the development of proteinuria by the modification of podocyte molecules. We have previously found that Ang II suppressed podocyte AMP-activated protein kinase (AMPK) via Ang II type 1 receptor and MAPK signaling pathway. In the present study, we investigated the roles of AMPK on the changes of p130Cas of podocyte by Ang II. We cultured mouse podocytes and treated them with various concentrations of Ang II and AMPK-modulating agents and analyzed the changes of p130Cas by confocal imaging and western blotting. In immunofluorescence study, Ang II decreased the intensity of p130Cas and changed its localization from peripheral cytoplasm into peri-nuclear areas in a concentrated pattern in podocytes. Ang II also reduced the amount of p130Cas in time and dose-sensitive manners. AMPK activators, metformin and AICAR, restored the suppressed and mal-localized p130Cas significantly, whereas, compound C, an AMPK inhibitor, further aggravated the changes of p130Cas. Losartan, an Ang II type 1 receptor antagonist, recovered the abnormal changes of p130Cas suppressed by Ang II. These results suggest that Ang II induces the relocalization and suppression of podocyte p130Cas by the suppression of AMPK via Ang II type 1 receptor, which would contribute to Ang II-induced podocyte injury.
AMP-Activated Protein Kinases/antagonists & inhibitors/chemistry/*metabolism
;
Aminoimidazole Carboxamide/analogs & derivatives/pharmacology
;
Angiotensin II/*pharmacology
;
Angiotensin II Type 1 Receptor Blockers/pharmacology
;
Animals
;
Blotting, Western
;
Cell Line
;
Cell Nucleus/metabolism
;
Crk-Associated Substrate Protein/*metabolism
;
Cytoplasm/metabolism
;
Focal Adhesion Kinase 1/metabolism
;
Losartan/pharmacology
;
Metformin/pharmacology
;
Mice
;
Microscopy, Confocal
;
Podocytes/cytology/drug effects/metabolism
;
Protein Kinase Inhibitors/*pharmacology
;
Ribonucleotides/pharmacology
;
Signal Transduction/*drug effects

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