scholarly journals Liraglutide Exerts Antidiabetic Effect via PTP1B and PI3K/Akt2 Signaling Pathway in Skeletal Muscle of KKAy Mice

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Wenjun Ji ◽  
Xinlin Chen ◽  
Juan Lv ◽  
Meng Wang ◽  
Shuting Ren ◽  
...  

Background. Liraglutide (a glucagon-like peptide 1 analog) was used for the treatment of type 2 diabetes (T2DM) which could produce glucose-dependent insulin secretion.Aim. The aim was to investigate whether liraglutide could improve myofibril and mitochondria injury in skeletal muscle and the mechanisms in diabetic KKAy mice.Method. We divided the male KKAy mice into 2 groups: liraglutide group (250 μg/kg/day liraglutide subcutaneous injection) and model group; meanwhile, the male C57BL/6J mice were considered as the control. After 6 weeks, the ultrastructure of skeletal muscle was observed by electron microscope. The gene expressions of protein tyrosine phosphatase 1B (PTP1B), phosphatidylinositol 3-kinase (PI3K), and glucose transporter type 4 (GLUT4) were determined by real-time PCR. The protein levels of the above molecules and phospho-Akt2 (p-Akt2) were measured by Western blot.Results. Liraglutide significantly ameliorated the injury of mitochondria by increasing the number (+441%) and the area (+113%) of mitochondria and mitochondrial area/100 µm2(+396%) in skeletal muscle of KKAy mice. The results of real-time PCR and Western blot showed that liraglutide downregulated PTP1B while it upregulated PI3K and GLUT4 (P<0.01). The protein level of p-Akt2/Akt2 was also increased (P<0.01).Conclusion. These results revealed that liraglutide could improve myofibril and mitochondria injury in skeletal muscle against T2DM via PTP1B and PI3K/Akt2 signaling pathway.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Bing Jing ◽  
Hongjuan Ji ◽  
Rui Jiang ◽  
Jinlong Wang

Abstract Background Osteoporosis is a widespread chronic disease characterized by low bone density. There is currently no gold standard treatment for osteoporosis. The aim of this study was to explore the role and mechanism of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. Methods MC3T3-E1 cells were divided into control and different dose of Astragaloside (10, 20, 40, 50, and 60 μg/ml). Then, ALP and ARS staining were performed to identify the effects of Astragaloside for early and late osteogenic capacity of MC3T3-E1 cells, respectively. Real-time PCR and western blot were performed to assess the ALP, OCN, and OSX expression. PI3K/Akt signaling pathway molecules were then assessed by Western blot. Finally, PI3K inhibitor, LY294002, was implemented to assess the mechanism of Astragaloside in promoting osteogenic differentiation of MC3T3-E1 cells. Results Astragaloside significantly increased the cell viability than the control group. Moreover, Astragaloside enhanced the ALP activity and calcium deposition than the control groups. Compared with the control group, Astragaloside increased the ALP, OCN, and OSX expression in a dose-response manner. Western blot assay further confirmed the real-time PCR results. Astragaloside could significantly increase the p-PI3K and p-Akt expression than the control group. LY294002 partially reversed the promotion effects of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. LY294002 partially reversed the promotion effects of Astragaloside on ALP, OCN, and OSX of MC3T3-E1 cells. Conclusion The present study suggested that Astragaloside promoted osteogenic differentiation of MC3T3-E1 cells through regulating PI3K/Akt signaling pathway.


2020 ◽  
Vol 10 (4) ◽  
pp. 569-575
Author(s):  
Jiang Wu ◽  
Shixiong Yang ◽  
Jin Shi ◽  
Yibing Shi

Neonatal purulent meningitis (NPM) leads to higher mortality and neurological sequelae rates. miR184 involves in inflammation and tumor, but the role of miR-184 in NPM remains unclear. NPM patients and non-intracranial infected neonates were collected and miR-184 expression in cerebrospinal fluid was assessed by real-time PCR. The Neuro-2a cell line was cultured and divided into control group, inflammation group (treated with LPS), and miR-184 inhibitor group, which was transfected with miR-184 inhibitor on the basis of inflammation followed by analysis of miR-184 and TLR4 expression by Real time PCR, Caspase 3 activity, cell proliferation by MTT assay, secretion of IL-1β and IL-6 by ELISA, NLRP3 expression by real time PCR and western blot, and Caspase-1 p20 and NF- B level by western blot. miR-184 expression level was significantly increased in cerebrospinal fluid of NPM group (P < 0 05) and also elevated in inflammation group along with significantly inhibited cell proliferation was inhibited, increased Caspase 3 activity, IL-1β and IL-6 secretion, and decreased TLR4, NLRP3, Caspase-1 p20 and NFκ- B expression (P < 0 05). miR-184 inhibitor significantly down-regulated miR-184 expression in the inflammation group, promoted cell proliferation, decreased Caspase 3 activity, IL-1β and IL-6 secretion, and increased TLR4, NLRP3, Caspase1 p20 and NF- κB expression (P < 0 05). miR-184 expression is increased in neonatal purulent meningitis and it can inhibit inflammation by targeting TLR4/NLRP3 signaling pathway, leading to amelioration of the progression of neonatal purulent meningitis.


2020 ◽  
Vol 10 (1) ◽  
pp. 133-138
Author(s):  
Peng Zhao ◽  
Junxia Qin ◽  
Lili Liang ◽  
Xinzhong Zhang

Hypertrophic scar (HS) is a process of tissue repair and healing, and excessive fibrosis of local tissue leads to scar formation. During HS formation, fibroblasts (Fb) proliferate, synthesize and secrete and promote HS development. miR-184 regulates skin formation and tissue development. However, miR-184’s role in HS remains unclear. miR-184 expression in HS patients and normal healthy (Control) tissues was measured by real-time PCR. pAKT expression was analyzed by Western blot. Fb cells from human HS were cultured and divided into 2 groups, siRNA NC group and miR-184 siRNA group followed by analysis of miR-184 expression by real time PCR, cell proliferation by MTT assay, secretion of inflammatory factors IL-1β and IL-6 by ELISA, as well as expression of pAKT and AKT by western blot. Compared with control group, miR-184 and pAKT expression was significantly increased in the HS group. Transfection of miR-184 siRNA into Fb significantly downregulated miR-184 expression, inhibited cell proliferation, promoted Caspase 3 activity, decreased IL-1β and IL-6 secretion, and reduced pAKT level (P < 0.05). miR-184 expression is increased in hypertrophic scar tissue. Down-regulation of miR-184 expression in proliferative scar tissue fibroblasts can down-regulate PI3K/AKT signaling pathway, inhibit inflammation, promote apoptosis, inhibit fibroblast proliferation, and regulate hypertrophic scar formation.


2018 ◽  
Author(s):  
Zhenghong Li ◽  
Yun Feng ◽  
Ruling Zhang ◽  
Peiwen Wang ◽  
Lungen Lu ◽  
...  

AbstractMigration and contraction of activated hepatic stellate cell (HSC) are essential factors for cirrhosis formation and development. It has been demonstrated that blebbistatin, a nonmuscle myosin II (NMMII) inhibitor, can inhibit the migration and contraction of HSC, whereas the main cell signaling pathway is still unknown. Mammalian target of rapamycin (mTOR) signaling pathway may be involved in many cells migration and contraction, whether NMMII and mTOR have any crosslinks draw our attention. In the currently study, we used LV-RNAi to specifically attenuate mTOR and NMMII in rat HSC. We aimed to examine the effect of mTOR LV-RNAi on the migration and contraction of HSC and explore the crosslink between mTOR cell signal and NMMII. Using real-time PCR and western blot, we found that mTOR and the downstream factors including S6K and 4EBP1 all up-regulated with the activation of HSC, mTOR and NMMII LV-RNAi was transfected into activated HSC using lipofectamine 2000. The levels of mRNA and proteins were also examined using real-time PCR and western blot respectively. The expression of mTOR can be down-regulated by NMMII LV-RNAi significantly, as well as the expression of S6K, 4EBP1, α-SMA and collagen I, but the level of AKT was up-regulated. Then we used Transwell system and collagen lattices to examine the NMMII and mTOR LV-RNAi efficiency on HSC migration and contraction, as we hypothesized, both of the LV-RNAi could inhibit HSC migration and contraction significantly. These results indicated that nonmuscle myosin II shRNA inhibit migration and contraction in rat hepatic stellate cells through the regulation of mTOR/S6K/4EBP1 signaling pathway


2015 ◽  
Author(s):  
Περσεφόνη Φραγκιαδάκη

Η προεκλαμψία αποτελεί μια από τις κυριότερες αιτίες μητρικής και εμβρυικής/νεογνικής νοσηρότητας και θνητότητας και επιπλέκει το 3-5% των κυήσεων. Προηγούμενες μελέτες έδειξαν ότι μέλη του σηματοδοτικού μονοπατιού Notch (Notch signaling pathway) εκφράζονται στον πλακούντα και παίζουν σημαντικό ρόλο στην ομαλή ανάπτυξη του ενεργοποιώντας μεταγραφικούς παράγοντες οι οποίοι αλλάζουν την έκφραση γονιδίων στόχων. Διαταραχές στη λειτουργία του μονοπατίου Notch σχετίζονται με παθολογική πλακουντοποίηση. Σκοπός της μελέτης αυτής είναι να εξετάσει την έκφραση των υποδοχέων (receptors) NOTCH1,-2,-3,-4, των συνδετών (ligands) DLL1,-3,-4, JAG1,-2 και των γονιδίων στόχων (target genes) HEY1,-2 σε πλακούντες κυήσεων με προεκλαμψία. Εξετάστηκαν δείγματα πλακουντιακού ιστού από 20 προεκλαμπτικές και από 20 φυσιολογικές κυήσεις. Τα επίπεδα mRNA των υπό εξέταση μορίων μετρήθηκαν με ποσοτική (quantitative) Real-Time PCR (qRT-PCR) ενώ η πρωτεϊνική έκφραση της ενδοκυττάριας περιοχής (intracellular domain) των NOTCH2 (NICD2) και NOTCH3 (NICD3) εκτιμήθηκαν με Western Blot (WB). Τα αποτελέσματα μας έδειξαν ότι οι υποδοχείς Notch-1 και Notch-4 αλλά και ο συνδέτης Dll-1 δεν εκφράζονται στους πλακούντες γυναικών με προεκλαμψία ή με φυσιολογική εγκυμοσύνη. Ωστόσο, τα επίπεδα έκφρασης mRNA των NOTCH2, NOTCH3, DLL3, DLL4, JAG1, JAG2, HEY1 and HEY2 ήταν μειωμένα στα παθολογικά δείγματα σε σχέση με τα φυσιολογικά (p<0.01). Η ανάλυση με WB επιβεβαίωσε ότι τα επίπεδα πρωτεϊνικής έκφρασης των NICD2 και NICD3 ήταν επίσης ελαττωμένα στα δείγματα της προεκλαμψίας (p=0.014 και p<0.001, αντίστοιχα). Περαιτέρω στατιστική ανάλυση έδειξε α) μη έκφραση σε γονιδιακό επίπεδο του υποδοχέα NOTCH3 στις εγκύους εκείνες που κάπνιζαν και στη διάρκεια της εγκυμοσύνης σε σχέση με εκείνες που το έκοψαν (p=0.029) και β) στις περιπτώσεις με προεκλαμψία και βάρος νεογνού μικρότερο από την 5η εκατοστιαία θέση παρατηρήσαμε υψηλότερα επίπεδα πρωτεΐνης του NICD-3 (p=0.028) και υψηλότερα επίπεδα mRNA του Dll-3 (p=0.041). Τα αποτελέσματα της μελέτης μας δείχνουν ότι το σηματοδοτικό μονοπάτι Notch αποτελεί σημαντικό μέρος της παθογένειας αυτής της επιπλοκής της εγκυμοσύνης. Περαιτέρω μελέτες απαιτούνται με σκοπό να διερευνηθεί βαθύτερα και να καθοριστεί ο ρόλος των εξετασθέντων μορίων στην προεκλαμψία και να μελετηθεί η δυνητική τους χρήση στην πρόβλεψη και τη διαγνωστική και θεραπευτική προσέγγιση της νόσου.


2021 ◽  
Author(s):  
Yaru Fan ◽  
Yingbin Yan ◽  
Han Liu ◽  
Rui Luo ◽  
Hao Liu ◽  
...  

Abstract Objectives: To study the effect of mechanical overload stimulation on proliferation, differentiation and mineralization of osteoblast and the underlying mechanisms.Methods: MC3T3-E1 cells were divided into overload group and control group. Four-point bending loading device was used to exert mechanical overload stimulation on MC3T3-E1 cells for a certain time. The proliferation of osteoblasts was detected by MTT colorimetric assay. Real-time PCR and Western Blot were used to detect the transcription and expression of osteoblast marker genes and proteins. The specific fluorescent dyes were used to label the actin filament and the nucleus, and the changes of cytoskeleton were observed under laser scanning confocal microscope. The mineralization of osteoblasts was evaluated by the number of calcium nodules formed by alizarin red staining. Results: Compared with the control group, the mechanical overload group significantly inhibited the proliferation of osteoblasts (p <0.05). Real-time PCR and Western Blot showed that the expression of osteoblast differentiation marker gene and protein was inhibited by mechanical overload stimulation. Under laser confocal microscopy, the overload group cell shrinkage deformation was observed, also the microfilament arrangement disorder, the skeleton arrangement loose, the direction difference and the skeleton breakage, but the nucleus does not have obvious change. Alizarin red staining showed that mechanical overload inhibited the formation of calcium nodules in osteoblasts. The expression of β-catenin protein in Wnt signaling pathway was inhibited by overload mechanical stimulation under immunofluorescence microscopy.Conclusion: Mechanical overload stimulation reduces the expression of Runx 2 by affecting the classical Wnt/β-catenin signaling pathway, thus it was inhibited osteoblast proliferation, differentiation and mineralization.


Author(s):  
Xinnan Wu ◽  
Ruixiao Li ◽  
Qing Song ◽  
Chengcheng Zhang ◽  
Ru Jia ◽  
...  

Abstract Background Our previous work demonstrated that lncRNA-MALAT1 was overexpressed in recurrent colorectal cancer (CRC) and metastatic sites in post-surgical patients. However, the upstream regulatory mechanism of MALAT1 is not well-defined. Histone demethylase JMJD2C holds great potential of epigenetic regulating mechanism in tumor diseases, especially the moderating effect on the promoter activity of targeted genes associated closely with tumor development. Therefore, we herein investigated whether JMJD2C could epigeneticly regulate the promoter activity of MALAT1 and the downstream β-catenin signaling pathway, thereby affecting the metastatic abilities of CRC cells. Methods JMJD2C expressions in human CRC samples were detected by real-time PCR and immunohistochemistry staining. Gene silencing and overexpressing efficiencies of JMJD2C were confirmed by real-time PCR and western blot. The migration of CRC cells in vitro were tested by transwell and wound healing assays. The protein expression and cellular localization of JMJD2C and β-catenin were characterized by immunofluorescence staining and western blot. The histone methylation level of MALAT1 promoter region (H3K9me3 and H3K36me3) was tested by ChIP-PCR assays. The promoter activity of MALAT1 was detected by luciferase reporter assay. The expressions of MALAT1 and the downstream β-catenin signaling pathway related genes in CRC cells were detected by real-time PCR and western blot, respectively. The nude mice tail vein metastasis model was established to observe the effect of JMJD2C on the lung metastasis of CRC cells in vivo. Results Our present results indicated that histone demethylase JMJD2C was overexpressed in matched CRC tumor tissues of primary and metastatic foci, and CRC patients with lower JMJD2C expression in primary tumors had better prognosis with longer OS (Overall Survival). The following biological function observation suggested that JMJD2C promoted CRC metastasis in vitro and in vivo. Further molecular mechanism investigation demonstrated that JMJD2C protein translocated into the nuclear, lowered the histone methylation level of MALAT1 promoter in the sites of H3K9me3 and H3K36me3, up-regulated the expression of MALAT1, and enhanced the β-catenin signaling pathway in CRC cells. Conclusion Our data demonstrated that JMJD2C could enhance the metastatic abilities of CRC cells in vitro and in vivo by regulating the histone methylation level of MALAT1 promoter, thereby up-regulating the expression of MALAT1 and enhancing the activity of β-catenin signaling pathway, providing that JMJD2C might be a novel therapeutic target for CRC metastasis.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Sai-Sai Li ◽  
Nan Kang ◽  
Xiang-Lei Li ◽  
Jing Yuan ◽  
Ruby Ling ◽  
...  

Sympathetic remodeling may cause severe arrhythmia after myocardial infarction (MI). Thus, targeting this process may be an effective strategy for clinical prevention of arrhythmias. LianXia Formula Granule (LXFG) can effectively improve the symptoms of patients with arrhythmia after MI, and modern pharmacological studies have shown that Coptidis Rhizoma and Rhizoma Pinelliae Preparata, the components of LXFG, have antiarrhythmia effects. Here, we investigated whether LXFG can mitigate sympathetic remodeling and suppress arrhythmia and then elucidated its underlying mechanism of action in rats after MI. Sprague-Dawley (SD) rats that had undergone a myocardial infarction model were randomly divided into 6 groups, namely, sham, model, metoprolol, and LXFG groups, with high, medium, and low dosages. We exposed the animals to 30 days of treatment and then evaluated incidence of arrhythmia and arrhythmia scores in vivo using programmed electrical stimulation. Moreover, we determined plasma catecholamines contents via enzyme-linked immunosorbent assay and detected expression of tyrosine hydroxylase (TH) at infarcted border zones via western blot, real-time PCR, and immunohistochemical analyses to assess sympathetic remodeling. Finally, we measured key molecules involved in the NGF/TrKA/PI3K/AKT pathways via western blot and real-time PCR. Compared with the model group, treatment with high dose of LXFG suppressed arrhythmia incidence and arrhythmia scores. In addition, all the LXFG groups significantly decreased protein and mRNA levels of TH, improved the average optical density of TH-positive nerve fibers, and reduced the levels of plasma catecholamines relative to the model group. Meanwhile, expression analysis revealed that key molecules in the NGF/TrKA/PI3K/AKT pathways were downregulated in the LXFG group when compared with model group. Overall, these findings indicate that LXFG suppresses arrhythmia and attenuates sympathetic remodeling in rats after MI. The mechanism is probably regulated by suppression of the NGF/TrKA/PI3K/AKT signaling pathway.


2019 ◽  
Vol 20 (10) ◽  
pp. 799-803 ◽  
Author(s):  
Meizhen Zhao ◽  
Yu-Pei Li ◽  
Xiao-Rui Geng ◽  
Miao Zhao ◽  
Shi-Bo Ma ◽  
...  

Background: To investigate MiRNA-126 amounts in serum exosomes from allergic asthma patients as well as lung tissues of asthmatic mice, evaluating the expression of its target gene DNMT1 in mouse specimens. Methods: MiRNA-126 amounts in serum exosomes from asthmatic patients were detected by real-time PCR. The mouse model of allergic asthma was established by OVA-sensitization, and allergic symptoms were recorded; serum IL-4 and sIgE level evaluation (ELISA), broncho alveolar lavage fluid (BALF) cell count and H&E staining were performed to assess airway inflammation. MiRNA-126 and DNMT1 levels in the lung of asthmatic and control mice were detected by real-time PCR; DNMT1 protein levels were detected by immunoblot. Results: MiRNA-126 amounts in peripheral blood exosomes from patients with allergic asthma were significantly higher than that of healthy volunteers (P<0.05). The frequencies of scratching of both sides of the nose and sneezing were elevated within 10 min of excitation in asthmatic rats compared with controls. Meanwhile, OVA-sIgE and IL-4 levels were significantly higher in asthmatic animals than controls (P<0.05). In the asthma group, narrowed bronchial lumen and thickened wall were observed, and bronchial and peripheral vessels showed overt inflammatory cell infiltration. Eosinophil, neutrophil and mast cell amounts in the BALF of asthmatic mice were significantly higher than control values. Furthermore, lung miRNA-126 expression in asthmatic mice was significantly higher than that of controls. Finally, DNMT1 mRNA and protein levels were significantly lower in asthmatic animals compared with controls (P < 0.01). Conclusion: MiRNA-126 is highly expressed in serum exosomes from allergic asthma patients and lung tissues of asthmatic mice, suggesting that it may be involved in the pathogenesis of bronchial asthma.


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