Difference of lipid-lowering efficacy of "Xinjianqu" before and after fermentation and its mechanism based on LKB1-AMPK pathway and 16S rDNA sequencing technology / 中国中药杂志

On the basis of establishing the prescription of Xinjianqu and clarifying the increase of the lipid-lowering active ingredients of Xinjianqu by fermentation, this paper further compared the differences in the lipid-lowering effects of Xinjianqu before and after fermentation, and studied the mechanism of Xinjianqu in the treatment of hyperlipidemia. Seventy SD rats were randomly divided into seven groups, including normal group, model group, positive drug simvastatin group(0.02 g·kg~(-1)), and low-dose and high-dose Xinjianqu groups before and after fermentation(1.6 g·kg~(-1) and 8 g·kg~(-1)), with ten rats in each group. Rats in each group were given high-fat diet continuously for six weeks to establish the model of hyperlipidemia(HLP). After successful modeling, the rats were given high-fat diet and gavaged by the corresponding drugs for six weeks, once a day, to compare the effects of Xinjianqu on the body mass, liver coefficient, and small intestine propulsion rate of rats with HLP before and after fermentation. The effects of Xinjianqu before and after fermentation on total cholesterol(TC), triacylglyceride(TG), high-density lipoprotein cholesterol(HDL-C), low-density lipoprotein cholesterol(LDL-C), alanine aminotransferase(ALT), aspartate aminotransferase(AST), blood urea nitrogen(BUN), creatinine(Cr), motilin(MTL), gastrin(GAS), and the Na~+-K~+-ATPase levels were determined by enzyme-linked immunosorbent assay(ELISA). The effects of Xinjianqu on liver morphology of rats with HLP were investigated by hematoxylin-eosin(HE) staining and oil red O fat staining. The effects of Xinjianqu on the protein expression of adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK), phosphorylated AMPK(p-AMPK), liver kinase B1(LKB1), and 3-hydroxy-3-methylglutarate monoacyl coenzyme A reductase(HMGCR) in liver tissues were investigated by immunohistochemistry. The effects of Xinjianqu on the regulation of intestinal flora structure of rats with HLP were studied based on 16S rDNA high-throughput sequencing technology. The results showed that compared with those in the normal group, rats in the model group had significantly higher body mass and liver coefficient(P<0.01), significantly lower small intestine propulsion rate(P<0.01), significantly higher serum levels of TC, TG, LDL-C, ALT, AST, BUN, Cr, and AQP2(P<0.01), and significantly lower serum levels of HDL-C, MTL, GAS, Na~+-K~+-ATP levels(P<0.01). The protein expression of AMPK, p-AMPK, and LKB1 in the livers of rats in the model group was significantly decreased(P<0.01), and that of HMGCR was significantly increased(P<0.01). In addition, the observed＿otus, Shannon, and Chao1 indices were significantly decreased(P<0.05 or P<0.01) in rat fecal flora in the model group. Besides, in the model group, the relative abundance of Firmicutes was reduced, while that of Verrucomicrobia and Proteobacteria was increased, and the relative abundance of beneficial genera such as Ligilactobacillus and Lachnospiraceae＿NK4A136＿group was reduced. Compared with the model group, all Xinjianqu groups regulated the body mass, liver coefficient, and small intestine index of rats with HLP(P<0.05 or P<0.01), reduced the serum levels of TC, TG, LDL-C, ALT, AST, BUN, Cr, and AQP2, increased the serum levels of HDL-C, MTL, GAS, and Na~+-K~+-ATP, improved the liver morphology, and increased the protein expression gray value of AMPK, p-AMPK, and LKB1 in the liver of rats with HLP and decreased that of LKB1. Xinjianqu groups could regulate the intestinal flora structure of rats with HLP, increased observed＿otus, Shannon, Chao1 indices, and increased the relative abundance of Firmicutes, Ligilactobacillus(genus), Lachnospiraceae＿NK4A136＿group(genus). Besides, the high-dose Xinjianqu-fermented group had significant effects on body mass, liver coefficient, small intestine propulsion rate, and serum index levels of rats with HLP(P<0.01), and the effects were better than those of Xinjianqu groups before fermentation. The above results show that Xinjianqu can improve the blood lipid level, liver and kidney function, and gastrointestinal motility of rats with HLP, and the improvement effect of Xinjianqu on hyperlipidemia is significantly enhanced by fermentation. The mechanism may be related to AMPK, p-AMPK, LKB1, and HMGCR protein in the LKB1-AMPK pathway and the regulation of intestinal flora structure.

Screening and functional study of key miRNAs in circulating exosomes of hypertension / 中国药理学通报

Aim To clarify the effect of circulating exosomes on hypertension, screen out miRNAs which plays a key role, and explore its function.Methods The plasma exosomes of spontaneously hypertensive rats were extracted and injected into Sprague Dawley rats.The blood pressure changes of rats were detected.Plasma exosomes and exosomal RNA of hypertensive patients and SHR were extracted.Real time PCR was used to verify the expression changes of the selected 8 miRNAs; Western blot was used to detect the expression changes of LKB1 and PTEN protein levels in human umbilical vein endothelial cells transfected with miR-17-5p mimics.Results The plasma exosomes of SHRs significantly increased the blood pressure of SD rats(P<0.05).The expression of miR-17-5p and miR-218-5p in the plasma exosomes of hypertensive patients and SHRs both significantly increased.miR-17-5p inhibitors significantly attenuated the effect of SHR-exos on raising blood pressure.miR-17-5p mimics down-regulated the expression of LKB1 and PTEN in HUVECs cultured in vitro.Conclusions The plasma exosomes of SHR can significantly increase blood pressure of Sprague Dawley rats.miR-17-5p may be the key miRNA.exo-miR-17-5p may promote the occurrence and development of hypertension by regulating the LKB1/PTEN signal.

Mechanism of Zexie Decoction in improvement of nonalcoholic fatty liver disease based on LKB1/AMPK/PGC-1α pathway / 中国中药杂志

The present study investigated the pharmaceutical effect and underlying mechanism of Zexie Decoction(ZXD) on nonalcoholic fatty liver disease(NAFLD) in vitro and in vivo via the LKB1/AMPK/PGC-1α pathway based on palmitic acid(PA)-induced lipid accumulation model and high-fat diet(HFD)-induced NAFLD model in mice. As revealed by the MTT assay, ZXD had no effect on HepG2 activity, but dose-dependently down-regulated alanine aminotransferase(ALT) and aspartate aminotransferase(AST) in the liver cell medium induced by PA, and decreased the plasma levels of ALT and AST, and total cholesterol(TC) and triglyceride(TG) levels in the liver. Nile red staining showed PA-induced intracellular lipid accumulation, significantly increased lipid accumulation of hepatocytes induced by PA, suggesting that the lipid accumulation model in vitro was properly induced. ZXD could effectively improve the lipid accumulation of hepatocytes induced by PA. Oil red O staining also demonstrated that ZXD improved the lipid accumulation in the liver of HFD mice. JC-1 staining for mitochondrial membrane potential indicated that ZXD effectively reversed the decrease in mitochondrial membrane potential caused by hepatocyte injury induced by PA, activated PGC-1α, and up-regulated the expression of its target genes, such as ACADS, CPT-1α, CPT-1β, UCP-1, ACSL-1, and NRF-1. In addition, as revealed by the Western blot and immunohistochemistry, ZXD up-regulated the protein expression levels of LKB1, p-AMPK, p-ACC, and PGC-1α in vivo and in vitro. In conclusion, ZXD can improve NAFLD and its mechanism may be related to the regulation of the LKB1/AMPK/PGC-1α pathway.

Study on effects and mechanism of Tibetan medicine Shanhu qishiwei pill in lowering blood lipid of hyperlipidemia model rats / 中国药房

OBJECTIVE To study the effects of Tibetan medi cine Shanhu qishiwei pill in lowering blood lipid of hyperlipidemia（HLP）model rats ，and to explore its mechanism primarily. METHODS According to their body weigh ，60 SD rats were randomly divide into normal group ，model group ，simvastatin group （positive control ，20 mg/kg）and Shanhu qishiwei pill low-dose，medium-dose and high-dose groups （50，100，200 mg/kg），with 10 rats in each group. Normal group was given conventional diet ，and other groups were given high-lipid diet to induce HLP model ，for consecutive 4 weeks. Administration groups were given relevant medicine intragastrically at the same time of modeling ；normal group and model group were given equal volume of normal saline intragastrically ，once a day ，for consecutive 4 weeks. After last administration ，the serum levels of TC ，TG， LDL-C and HDL-C were determined ；pathological changes of liver tissue were observed ；the protein expressions of AMPK ， p-AMPK，LKB1，and HMGCR in liver tissue were detected in each group. RESULTS Low-dose，medium-dose and high-dose of Shanhu qishiwei pill could significantly reduce the serum levels of TC ，TG and LDL-C and protein expression of HMGCR in liver tissue（P＜0.05），while significantly increased serum level of HDL-C ，phosphorylation level of AMPK ，protein expression of LKB 1 in liver tissue in HLP model rats （P＜0.05）；the pathological changes of liver tissue in HLP model rats were improved to different extents. CONCLUSIONS Shanhu qishiwei pill can reduce the blood lipid level of HLP model rats ，and its mechanism may be related to inhibiting the transmission of LKB 1/AMPK signal pathway and regulating lipid metabolism.

Expression of LKB1 gene in bone marrow of patients with acute non-lymphocytic leukemia and its clinical significance / 中国输血杂志

【Objective】 To investigate the expression level of liver kinase B1 (LKB1) gene in bone marrow of patients with acute non-lymphoblastic leukemia (AML) and its correlation with prognosis. 【Methods】 A total of 90 AML patients from May 2015 to January 2017 were selected as study subjects, and 30 cases of bone marrow specimens from non-malignant hematologic diseases were selected as control group. The expression of LKB1 mRNA in bone marrow was detected by real-time fluorescent quantitative PCR (qRT-PCR). The expression of LKB1 protein was detected by Western blot. The correlation between LKB1 mRNA and prognosis of AML was analyzed by Kaplan-Meier survival analysis. 【Results】 The mutation rate of LKB1 gene, the mRNA and LKB1 protein expression in bone marrow of AML patients was lower than those of control group (χ2=13.274, t=34.134, t=45.235, P<0.05). The mutation rate of LKB1 gene and the mRNA expression from high to low order is M1(81%, 17/21)>M5(78.6%, 11/14)>M6(75%, 3/4)>M2(42.4%, 14/33)>M4(41.7%, 5/12)>M3(35.3%, 6/17). Thefollow-up survival rate of patients with AML in the LKB1 high amplification group was higher than that of patients with LKB1 low amplification(χ2=8.039, P<0.05) The median survival time of the LKB1 high amplification group was higher than that of the LKB1low amplification group (27.3 months vs 19.8 months) (χ2=5.552, P<0.05). The incidence of post-chemotherapy infection, post-chemotherapy recurrence and extramedullary infiltration in the LKB1 high amplification group was lower than that in patients with LKB1 low amplification (P>0.05). 【Conclusion】 The expression level of LKB1 gene in patients with AML is low, moreover the more low expression level of LKB1 gene were, the more severe ill condition and more poor prognosis.

Metformina: interacciones moleculares, celulares y su repercusión en la Obstetricia. Revisión bibliográfica / Metformin: Cellular and molecular interactions and its' impact in obstetrics. Literature review

Resumen OBJETIVO: Identificar los mecanismos celulares más reconocidos de la metformina y su relación con patologías en Obstetricia y determinar las moléculas y vías involucradas con potencial terapéutico. METODOLOGÍA: Estudio retrospectivo efectuado con base en la búsqueda de artículos registrados en Pubmed y Cochrane publicados en inglés entre los años 2000 a 2019 que contuvieran las palabras clave (MeSH): "Metformin"; "Celular mechanisms"; "AMPK"; "LKB1"; "Gestational diabetes", "Abortion" y "Preeclampsia". RESULTADOS: Se encontraron 1750 artículos que contenían las palabras clave de búsqueda; al final solo se analizaron 57. En estos se concluye que la intervención con este fármaco inhibe el complejo I de la cadena respiratoria mitocondrial, con repercusión en varios procesos celulares. La diabetes gestacional, el aborto y la preeclampsia se consideraron por su incidencia y relevancia obstétrica, y por la indicación de la metformina en su tratamiento. Se identificaron los mecanismos involucrados en el efecto colateral gastrointestinal y la asociación con los mecanismos celulares influidos por la metformina. En los padecimientos obstétricos se identificaron los procesos metabólicos para tratamiento común, la diabetes gestacional fue la más identificada por la experiencia en diabetes mellitus. CONCLUSIONES: Si bien la metformina tiene una indicación clara en pacientes con diabetes gestacional, los resultados son insuficientes para aborto; en preeclampsia los mecanismos intervenidos pueden tener mayor potencial terapéutico y preventivo.

Abstract OBJECTIVE: Identify the most recognized cellular mechanisms and their relations to obstetric pathology, determining molecular pathways for potential therapeutic use. METHODOLOGY: After a bibliographical search done in Pubmed and Cochrane database of MeSH terms: "metformin", "cellular mechanisms", "AMPK", "LKB1", "gestational diabetes", "abortion", "preeclampsia", in the periods comprehending 2000 through 2019, a total of 49 references were selected, on the basis of the criteria established by the objective of this review. RESULTS: With 49 selected references, we found that metformin regulates adenosine monophosphate protein kinase (AMPK) and LKB1, both who which participate in metabolic mechanisms, activating second messengers who stimulate or inhibit processes like gluconeogenesis, steroid and protein synthesis and cellular growth. This drug actually acts by inhibiting complex I of the mitochondrial respiration process, impacting various cell functions. Gestational diabetes, abortion and preeclampsia are three obstetric pathologies selected due to their incidence and relevance, as well as the fact that metformin is being used for their treatment. We also identified the mechanisms for gastrointestinal symptoms where OCT-1, PMAT and 5-HT are involved and may be therapeutic targets. The association of cell mechanisms influenced by metformin are part of various metabolic pathways, being the ones in gestational diabetes the most, well known due to experience with diabetes mellitus. CONCLUSIONS: Although metformin has a clear role in gestational diabetes, results are insufficient to identify its' role in abortion. As for preeclampsia, the mechanisms identified have a greater preventive and therapeutic potential.

Loss of LKB1 Protein Expression Correlates with Increased Risk of Recurrence and Death in Patients with Resected, Stage II or III Colon Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to investigate the prognostic significance of liver kinase b1 (LKB1) loss in patients with operable colon cancer (CC). MATERIALS AND METHODS: Two hundred sixty-two specimens from consecutive patients with stage III or high-risk stage II CC, who underwent surgical resection with curative intent and received adjuvant chemotherapy with fluoropyrimidine and oxaliplatin, were analyzed for LKB1 protein expression loss, by immunohistochemistry as well as for KRAS exon 2 and BRAF(V600E) mutations by Sanger sequencing and TS, ERCC1, MYC, and NEDD9 mRNA expression by real-time quantitative reverse transcription polymerase chain reaction. RESULTS: LKB1 expression loss was observed in 117 patients (44.7%) patients and correlated with right-sided located primaries (p=0.032), and pericolic lymph nodes involvement (p=0.003), BRAF(V600E) mutations (p=0.024), and TS mRNA expression (p=0.041). Patients with LKB1 expression loss experienced significantly lower disease-free survival (DFS) (hazard ratio [HR], 1.287; 95% confidence interval [CI], 1.093 to 1.654; p=0.021) and overall survival (OS) (HR, 1.541; 95% CI, 1.197 to 1.932; p=0.002), compared to patients with LKB1 expressing expressing tumors. Multivariate analysis revealed LKB1 expression loss as independent prognostic factor for both decreased DFS (HR, 1.217; 95% CI, 1.074 to 1.812; p=0.034) and decreased OS (HR, 1.467; 95% CI, 1.226 to 2.122; p=0.019). CONCLUSION: Loss of tumoral LKB1 protein expression, constitutes an adverse prognostic factor in patients with operable CC.

Effect of Gandou Decoction on Autophagy of SH-SY5Y Cell Induced by High Copper and Its Mechanism / 中国实验方剂学杂志

Objective: To explore the effect of Gandou decoction on autophagy of SH-SY5Y cells induced by high copper and its mechanism, in order to provide new therapeutic targets and research ideas for the prevention and treatment of brain-type Wilson disease (WD) with traditional Chinese medicine. Method: CuSO4 model showed a certain dose-effect and time-effect relationship according to methyl thiazolyl tetrazolium(MTT); lactate dehydrogenase(LDH) leakage rate was detected by LDH release assay; flow cytometry method was used to detect intracellular reactive oxygen species (ROS) content. The fluorescent dye JC-1 was used to detect the mitochondrial membrane potential of the cells. Flow cytometry was used to quantify autophagy. The expressions of liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK), microtubule-associated protein 1 light chain 3 (LC3A/B), mammalian target of rapamycin (mTOR) and UNC-51-like kinase-1 (ULK1), phosphorylation-ULK (p-ULK), phosphorylation-AMPK (p-AMPK) were detected by Western blot. Result: According to MTT results, CuSO4 showed a dose-effect and time-effect relationship with cells (P4, the survival rate of cells showed a downward trend (P4-induced cell death (P4 compared with the normal group (P4-injured cells (P4 significantly increased the production of ROS in cells (P4-induced intracellular ROS production (P4 induced a significant decrease in mitochondrial membrane potential in cells (P4-induced mitochondrial membrane potential in a dose-dependent manner (P1, AMPK, LC3A/B, ULK, p-AMPK in the model group were significantly increased, while the protein expressions of mTOR and p-ULK were significantly decreased (P1, AMPK, LC3A/B, p-AMPK and ULK were significantly decreased, whereas the protein expressions of mTOR and p-ULK were significantly increased in the rabbit serum group containing Gandou decoction (PConclusion: High copper can induce autophagic apoptosis in SH-SY5Y cells by inducing intracellular mitochondrial oxidative stress, up-regulating the expressions of autophagy-related proteins LKB1, AMPK, LC3A/B, ULK, p-AMPK and down-regulating the expressions of mTOR and p-ULK. However, Gandou decoction can inhibit the occurrence of autophagy, and cut off high copper-induced neuronal damage by down-regulating the expressions of autophagy-related proteins LKB1, AMPK, LC3A/B, ULK, p-AMPK, and up-regulating the expression of mTOR and p-ULK, so as to exert a neuroprotective effect.

Hypolipidemic activity of total phenylpropanoid glycosides fromLigustrum robustum(Roxb.) Blume and its mechanisms on AMPK pathway / 中国药理学通报

Aim To evaluate the hypolipidemic effect of total phenylpropanoid glycoside extracted from Ligustrum robustum(Roxb.)Blume(CNTG)and its mecha-nisms.Methods The 60 hamsters were randomly divided into six groups,namely the control group,the model group,the positive control group(fenofibrate,150 mg·kg-1),the high(1 200 mg·kg-1),medium(600 mg·kg-1)and low(300 mg·kg-1)doses of CNTG groups.Only the control group was given control diet and other groups received high-fat diet.The changes of serum lipid were measured and analyzed in 1st week to ensure the successful establishment of the model.The drugs were administered daily for four weeks and the concentrations of lipids were determined in the 2nd week,3rd week and 4th week respectively.Quantitative real-time PCR and Western blot were used to assay the mRNA and protein expression of related signaling enzymes and proteins.Results Compared with the model group,the concentrations of serum TG,TC,LDL-C(P<0.05,P<0.01)and hepatic TG,TC(P<0.01)were effectively reduced in hamsters in CNTG-treated groups.Mechanism research found that CNTG increased the levels of phospho-AMPKα,LKB1 and phospho-LKB1 in liver(P<0.05).Conclusion CNTG prevents hyperlipidemia via activation of hepatic LKB1-AMPK pathway.

Odanacatib Inhibits Resistin-induced Hypertrophic H9c2 Cardiomyoblast Cells Through LKB1/AMPK Pathway

ABSTRACT Odanacatib (ODN) is a selective inhibitor of cathepsin K. The cysteine protease cathepsin K has been implicated in cardiac hypertrophy. Resistine is an adipokine which is identified to promote cardiac hypertrophy. Here, we hypothesize that ODN mitigates resistin-induced myocyte hypertrophy. Cell surface area and protein synthesis were measured after treatment with resistin and ODN in H9c2 cells. The expression of cardiomyocyte hypertrophy marker BNP and β-MHC was detected by RT-qPCR. The expression and phosphorylation of AMPK and LKB1 were analyzed with Western blot. Resistin could significantly increase cardiomyocyte cell surface area, protein synthesis, and embryonic gene BNP and β-MHC expression, inhibit phosphorylation of AMPK and LKB1. ODN could significantly reverse the effects of resistin. Collectively, our data suggest that ODN can inhibit cardiomyocyte hypertrophy induced by resistin and the underlying mechanism may be involved in LKB1/AMPK pathway.

Expression of LKB1 and p53 in gastric cancer and their clinical significance / 肿瘤研究与临床

Objective To investigate the expression of LKB1 and p53 in human gastric tissues and their correlation with clinical pathological factors.Methods The expression of LKB1 and p53 in 115 cases of gastric carcinoma and 20 cases of normal gastric tissues were detected by immunohistochemistry method,and the relation between the expression and the clinicopathological parameter of gastric carcinoma was analyzed.Results The positive rates of LKB1 in gastric carcinoma and normal tissues were 20.9 ％ (24/115) and 95.0 ％ (19/20),respectively (P ＜ 0.01).The positive rates of p53 in gastric carcinoma and normal tissues were 45.2 ％ (52/115) and 5.00 ％ (1/20),respectively (P ＜ 0.05).The analysis revealed that the high expression of LBK1 was associated with tumor lymph node metastasis,stage,Lauren classification and worse survival (P ＜ 0.05).The expression of p53 was associated with tumor lymph node metastasis,stage,distant metastasis and worse survival (P ＜ 0.05).Conclusions LKB1 protein expression may play an important role in the development and progression of gastric cancer.LKB1 may be used to assess the malignant biological behavior and prognosis of gastric cancer.

Minimal deviation adenocarcinoma of the cervix and tumorlets of sex-cord stromal tumor with annular tubules of the ovary in Peutz-Jeghers syndrome / 부인종양

We report 2 cases of minimal deviation adenocarcinoma of the cervix and tumorlets of sex cord tumor with annular tubules (SCTATs) of the ovaries, accompanied by Peutz-Jeghers syndrome. Case 1 is a 36-year-old woman and case 2 is a 35-year-old woman. Grossly, the cervix of both cases showed markedly barrel shaped enlargement with an infiltrating tumor. Microscopically, well-differentiated atypical glands were infiltrating into the entire thickness of the cervix. The ovarian masses in case 1 were diagnosed as metastatic carcinoma in mucinous cystadenoma with tumorlets of SCTATs of the ovaries. Multiple scattered tumorlets of SCTATs were also found in the ovary of case 2. By direct DNA sequencing analysis, a frame shift mutation of the STK11/LKB1 gene was identified in case 1. Case 1 represented the more aggressive clinical course, and although the patient received additional combined chemo-radiation therapy, she expired 1 year later. In general, mutation of the STK11/LKB1 gene is associated with poor clinical outcome in malignant tumors accompanied by Peutz-Jeghers syndrome.

Adiponectin activates AMP-activated protein kinase via LKB1 pathway / 中华内分泌代谢杂志

Objective To explore whether adiponectin activates AMP-activated protein kinase(AMPK) via LKB1 pathway or not in skeletal muscle and liver tissues.Methods Male Sprague-Dawley rats ( n =28 ) were divided into normal control diet( NC,n =15 ) and high-fat diet( HF,n =13 ) groups.After 16 weeks feeding,fasting blood free fatty acids( FFA ),triglyceride( TG ),total cholesterol( TC ),fasting plasma glucose( FPG ),fasting insulin(FINS),and adiponectin were determined.The protein levels of AMPKα,phosphorylated AMPKα ( p-AMPK ),and LKB1 in the skeletal muscle and liver tissues were analyzed with Western blot.Cultured primary skeletal muscle cells and hepatic cells were incubated with aditonectin and radicicol.The expression of AMPKα,p-AMPKα,and LKB1 inthese cells were analyzed with immunofluorescence method.Results Compared with NC group,body weight,FFA,TG,FPG,and FINS in rats of HF group were significantly higher( all P＜0.05 ) while serum adiponeetin level was lower( P＜0.05 ).The levels of AMPKα phosphorylation and LKB1 expression in the skeletal muscle and liver tissues of HF group were lower than those in NC group. In primary skeletal muscle cells and hepatic cells,adiponectin significantly increased the levels of AMPKα phosphorylation and LKB1 expression ( all P＜ 0.05 ),which were decreased by radicicol ( P＜0.05 ).Conclusion Adiponectin may activate AMPK via LKB1 pathway in skeletal muscle and liver tissues of rats.

Effects of AMP-activated Protein Kinase Activating Compounds and Its Mechanism / 영남의대학술지

AMP-activated protein kinase (AMPK) is an important cellular fuel sensor. Its activation requires phosphorylation at Thr-172, which resides in the activation loop of the alpha1 and alpha2 subunits. Several AMPK upstream kinases are capable of phosphorylating AMPK at Thr-172, including LKB1 and CaMKKbeta (Ca2+/calmodulin-dependent protein kinase kinasebeta). AMPK has been implicated in the regulation of physiological signals, such as in the inhibition of cholesterol fatty acid, and protein synthesis, and enhancement of glucose uptake and blood flow. AMPK activation also exhibits several salutary effects on the vascular function and improves vascular abnormalities. AMPK is modulated by numerous hormones and cytokines that regulate the energy balance in the whole body. These hormone and cytokines include leptin, adiponectin, ghrelin, and even thyroid hormones. Moreover, AMPK is activated by several drugs and xenobiotics. Some of these are in being clinically used to treat type 2 diabetes (e.g., metformin and thiazolidinediones), hypertension (e.g., nifedipine and losartan), and impaired blood flow (e.g., aspirin, statins, and cilostazol). I reviewed the precise mechanisms of the AMPK activation pathway and AMPK-modulating drugs.

AMP-activated protein kinase Activating Agent and Its Implication

AMP-activated protein kinase (AMPK) is an important cellular fuel sensor. Activation of AMPK requires phosphorylation at threonine (Thr)-172, which resides in the activation loop of the alpha1 and alpha2 subunits. Several AMPK upstream kinases are capable of phosphorylating AMPK at Thr-172, including LKB1 and CaMKKbeta. AMPK has been implicated in the regulation of physiological signals, such as inhibition of cholesterol, fatty acid, protein synthesis, and enhancement of glucose uptake and blood flow. AMPK activation also exhibits several salutary effects on vascular function and improves vascular abnormalities. AMPK is activated by numerous drugs and xenobiotics. Some of these are in clinical use for the treatment of type 2 diabetes (e.g., metformin and thiazolidinediones), hypertension (e.g., nifedipine and losartan), and impaired blood flow (e.g., aspirin, statins, and cilostazol). Plant-derived xenobiotics or nutraceuticals that were claimed to have health benefits in diabetes or cancer have been reported to activate AMPK. These include resveratrol from red wine, epigallocatechin gallate from green tea, capsaicin from peppers, berberine, which is a yellow dye of the genus berberis, genistein from soy bean, and ginsenoside from ginseng panax. AMPK is also modulated by numerous hormones and cytokines that regulate energy balance at the whole body level, including leptin, adiponectin, ghrelin, and even thyroid hormones. This work shows that the precise mechanisms of AMPK kinase and AMPK interaction.

Expression and correlation of Hedgehog signaling pathway and LKB1 gene in breast cancer / 国际肿瘤学杂志

Hedgehog signaling pathway is excessive activated in breast cancer.LKBl is currently accepted as a tumor-suppressor gene,which can inhibit the proliferation of breast cancer.The overexpression of LKB1 can regulate the expression of CyclinDl series gene which is a target gene of Hedgehog signaling pathway.Meanwhile,the study found that PKA gene play an important role in Hedgehog signaling pathway,its activation is related with the cAMP state,and LKB1 genes can influence the cAMP state.Therefore,LKB1 gene and the Hedgehog signaling pathway may exist some inevitable connection.

Sequence analysis of STK11 gene in a patient with Peutz-Jeghers syndrome / 中华皮肤科杂志

Objective To analyze the STK11 gene mutation in a sporadic Chinese Datient with Peutz Jeghers syndrome(PJS)so as to provide a basis for the genetic diagnosis and counseling of PJS.Methods Whole blood samples were obtained from a female patient with PJS,her parents and sister.as well as from 100 unrelated,normal individuals as control.Genomic DNA was extracted,and the whole coding region of STK11 gene was amplified by PCR followed by direct sequencing.Results Molecular analysis revealed a novel het-erozygous mutation C73S in the patient,which resulted from the substitution of thymine(T)for adenine(A) at codon 217 in exon 1 of STK11 gene.However, the novel mutation was not found in unaffected family mem-bers or unrelated controls.Conclusion A novel missense mutation C73S,which may contribute to the devel-opment of PJS,is found in the patient.

Tumor Suppressor Serine/Threonine Kinase LKB1 Expression, Not Kinase Activity, Increased in the Vascular Smooth Muscle Cells and Neointima in the Rat Carotid Artery Injury Model

BACKGROUND AND OBJECTIVES: Vascular smooth muscle cell (VSMC) proliferation is responsible for the restenosis of previously inserted coronary stents. Angiotensin II (Ang II) is known to regulate VSMC proliferation. LKB1, a serine/threonine kinase, interacts with the p53 pathway and acts as a tumor suppressor. MATERIALS AND METHODS: We assessed the association of Ang II and the expression of LKB1 in primary cultured murine VSMCs and neointima of the Sprague Dawley rat carotid artery injury model. We created carotid balloon injuries and harvested the injured carotid arteries 14 days after the procedure. RESULTS: Ang II increased LKB1 expression in a time-dependent manner and peaked at an Ang II concentration of 10(-7) mole/L in VSMCs. In the animal experiment, neointima was markedly increased after balloon injury compared to the control group. Immunohistochemical studies showed that LKB1 expression increased according to neointima thickness. Ang II augmented LKB1 expression after the injury. Western blot analysis of LKB1 with carotid artery lysate revealed the same pattern as LKB1 immunohistochemistry. Increased LKB1 expression started at 5 days after the balloon injury, and peaked at 14 days after the injury. Although LKB1 expression was increased after the injury, LKB1 kinase activity was not increased. Ang II or balloon-injury increased the expression of LKB1 although the LKB1 activity was reduced. CONCLUSION: Ang II increased LKB1 expression in VSMCs and neointima. These findings were not kinase dependant.

Regulatory effect of LKB1 gene on expression of vascular endothelial growth factor in lung cancer cells / 第二军医大学学报

Objective: To investigate the regulatory role of LKB1 gene on expression of vascular endothelial growth factor (VEGF) in lung cancer cell line A549. Methods: DNA fragment encoding LKB1 protein was amplified by Nest-PCR from human fetal brain cDNA library and was sub-cloned into the eukaryotic expression vector pcDNA3. 1. The recombinant vector was transferred into A549 cells by Lipofectamine and screened by G418. RT-PCR and Western blot were used to study the expression of LKB1, SP1 and VEGF in A549 cells. Transcription factor SP1 was silenced by small interference RNA (siRNA); RT-PCR and Western blot were applied to examine the changes of SP1 and VEGF gene. Results: DNA sequencing analysis revealed that the open reading frame of LKB1 gene was successfully cloned into the expression vector. Stable cell line of A549 expressing exogenous LKB1 was constructed. LKB1 remarkably suppressed SP1 and VEGF expression. SiRNA targeting SP1 effectively decreased the expression of SP1 and SP1 silencing caused remarkable down-regulation of VEGF expression. Conclusion: LKB1 can negatively regulate the expression of VEGF by negatively regulate the expression of transcription factor SP1.

The Clinical and Histopathologic Features according to Loss of LKB1 Protein Expression on Primary Lung Cancer / 결핵및호흡기질환

BACKGROUND: LKB1(STK11) is a serine/threonine kinase that functions as a tumor growth suppressor. The functions of LKB1 in lung cancer are not completely understood. This study evaluated the relationship between LKB1 protein expression and the clinicopathological features in lung cancer tissues. METHODS: The expression of LKB1 was studied in paraffin-embedded tumor blocks, which were obtained from 77 patients who had undergone surgery at Wonkwang University Hospital. The expression of the LKB1 protein was considered positive if the staining intensity in the tumor tissue adjacent to the normal airway epithelium was >30%. RESULTS: The LKB1 expression was positive in 31 (40%) of samples. Loss of LKB1 expression was significantly associated with being male, smoking history, and squamous cell carcinoma. In the peripheral sites, the loss of LKB1 expression was strongly associated with a smoking history. A loss of LKB1 expression was more frequently associated with progression according to TNM staging, particularly more than T2, N progression. CONCLUSION: There was a significant relationship between the loss of the LKB1 protein and gender, smoking history, and histological type in primary lung cancer. Although LKB1 expression was not found to be a significant prognostic factor, further studies with a larger cohort of patient's lung cancer tissue samples will be needed to confirm this.