Semicarbazide-sensitive amine oxidase activation promotes adipose conversion of 3T3-L1 cells

2001 ◽  
Vol 358 (2) ◽  
pp. 335-342 ◽  
Author(s):  
Nathalie MERCIER ◽  
Marthe MOLDES ◽  
Khadija EL HADRI ◽  
Bruno FÈVE
Keyword(s):  
Potential Role ◽  
Adipocyte Differentiation ◽  
Amine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Dependent Manner ◽  
Adipose Conversion ◽  
Adipose Tissue Development ◽  
Dose Dependent

Semicarbazide-sensitive amine oxidase (SSAO) is an amine oxidase related to the copper-containing amine oxidase family. The tissular form of SSAO is located at the plasma membrane, and is mainly expressed in vascular smooth muscle cells and adipocytes. Recent studies have suggested that SSAO could activate glucose transport in fat cells. In the present work, we investigated the potential role of a chronic SSAO activation on adipocyte maturation of the 3T3-L1 pre-adipose cell line. Exposure of post-confluent 3T3-L1 pre-adipocytes to methylamine, a physiological substrate of SSAO, promoted adipocyte differentiation in a time- and dose-dependent manner. This effect could be related to SSAO activation, since it was antagonized in the presence of the SSAO inhibitor semicarbazide, but not in the presence of the monoamine oxidase inhibitor pargyline. In addition, methylamine-induced adipocyte maturation was mimicked by 3T3-L1 cell treatment with other SSAO substrates. Finally, the large reversion of methylamine action by catalase indicated that hydrogen peroxide generated by SSAO was involved, at least in part, in the modulation of adipocyte maturation. Taken together, our results suggest that SSAO may contribute to the control of adipose tissue development.

Enhancement of differentiation of cultured adipogenic cells (TA1) by pertussis toxin

1992 ◽  
Vol 70 (8) ◽  
pp. 650-655 ◽  
Author(s):  
Osamu Shinohara ◽  
Yoh-Ichi Murata ◽  
Makoto Shimizu
Keyword(s):  
G Proteins ◽  
Pertussis Toxin ◽  
Adipocyte Differentiation ◽  
Dibutyryl Camp ◽  
Gtp Binding ◽  
Dose Dependent Fashion ◽  
Adipose Conversion ◽  
Adipocyte Cell ◽  
Dose Dependent

Differentiation of adipocytes is controlled by a variety of hormones and growth factors. To investigate the possible role of GTP-binding proteins (G proteins) in the process of adipose conversion, we studied the effect of pertussis toxin on differentiation of the fibroblast/adipocyte cell line (TA1). Pertussis toxin potentiated dexamethasone- and indomethacin-induced adipocyte differentiation in a time- and dose-dependent fashion. Addition of dibutyryl cAMP or forskolin inhibited adipose conversion, indicating that an abolishment of inhibitory control of adenylate cyclase is not responsible for the action of pertussis toxin. The B oligomer of the toxin did not mimic the effect of the holotoxin. Pertussis toxin catalyzed ADP-ribosylation of 40 000 molecular mass protein of the membrane fraction was dose-dependently inhibited by the pretreatment of the cells with the toxin. These results indicate the possible involvement of pertussis toxin-sensitive G proteins in adipogenesis.Key words: adipose tissue, pertussis toxin, GTP-binding protein.

scholarly journals Isatin inhibits LSD1 regulated autophagy through SESN2-mTOR signaling pathway in neuroblastoma

2020 ◽  
Author(s):  
Xue Li ◽  
Li Zhang ◽  
Yiming Nai ◽  
Fangling Wang ◽  
Yanan Hua ◽  
...  
Keyword(s):  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor ◽  
Enzyme Activation ◽  
Experimental Result ◽  
Dependent Manner ◽  
Promoter Regions ◽  
Lysine Specific Demethylase ◽  
Dependent Signal ◽  
Dose Dependent ◽  
Transcriptional Induction

Abstract Neuroblastoma (NB) is common in the pediatric tumors with low cure rate and high mortality, drug resistance makes chemotherapy more difficult, it threaten to children's health seriously. 1H-indole-2, 3-dione (isatin) is a second-hand of derivative of anticarcinogen indirubin which had been shown to be a monoamine oxidase inhibitor and have antitumor activity, in this study, we explained that SH-SY5Y cells was add to isatin at a dose-dependent level ranging from 50 to 200 µmol/L were capable of inhibiting tumor cell growth, included triggering apoptosis and inhibiting proliferation, invasion and metastasis, and assess ed the potential anticancer capability of isatin on the induction of autophagy. The experimental result showed that cell SH-SY5Y disposed with isatin could induce autophagy effectively, at the same time, it also help suppress the growth of tumor cells. Furthermore , the article indicated that the induction of autophagy of isatin-mediated occurred in inhibition- lysine-specific demethylase 1(LSD1) and sestrin2 (SESN2) - dependent manner. Furthermore, we identified that SH-SY5Y cells after treating with isatin induced SESN2 expression via a mTOR-dependent signal pathway, which mechanism is that isatin inhibit LSD1-enzyme activation and combine the promoter regions of SESN2, so that given rise to a significant transcriptional induction of SESN2. In addition , western blot analysis indicated that SH-SY5Y cells with isatin-exposed can regulated activity of LC-3, Beclin1 and p62 which are correlated with autophagy. Collectively, all the results from this study illistrated that adding to isatin could occur to induce autophagy and restrain NB cell SH-SY5Y growth through mTOR-dependent transcriptional induction of SESN2, this supplied a new mechanism for understanding the anti-tumor ability of isatin on NB. Taken together, this paper demonstrate that isatin is a promising candidate for treating NB.

Abstract P210: (Pro)Renin Receptor Regulates Potassium Homeostasis via Intrarenal Aldosterone

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Chuanming Xu ◽  
Aihua Lu ◽  
Hong Wang ◽  
Hui Fang ◽  
Li Zhou ◽  
...  
Keyword(s):  
Protein Expression ◽  
Potential Role ◽  
Fold Increase ◽  
Dependent Manner ◽  
Sd Rats ◽  
High K ◽  
Functional Implications ◽  
Calcium Activated Potassium Channel ◽  
Dose Dependent

It has been shown that transgenic overexpression of human (pro)renin receptor (PRR) results in elevated aldosterone (Aldo) level with unclear functional implications. The present study examined a potential role of renal PRR during high K + (HK) loading. In normal SD rats, a 1-week HK intake (5% KCl in diet) induced a 3.4-fold increase in renal protein expression of full-length PRR and 4.2-fold increase in urinary excretion of soluble PRR (sPRR). Administration of PRO20, a decoy peptide antagonist of PRR, at 700 μg/kg/d via i.p. injections, to K + -loaded animals elevated plasma K + level (5.72+0.08 vs. 4.84±0.18 mM, p<0.05) and decreased urinary K + excretion (2.52+0.11 vs. 3.43+0.19 mmol/24h, p<0.05), accompanied with a 26.2% reduction of urinary aldosterone (Aldo) excretion. HK downregulated NCC protein expression (57.8%) and upregulated renal protein expression of aldosterone synthase CYP11B2 (229%), ROMK (156%), calcium-activated potassium channel subunit alpha-1 (α-BK) (367%), α-Na + -K + -ATPase (596%), and β-ENaC (155%), all of which were significantly blunted by PRO20 (by 50 - 70%). The same maneuvers were applied to adrenalectomized (ADX) rats. Although plasma Aldo was extremely low and also unresponsive to HK loading, urinary Aldo excretion was elevated by 274% with this treatment, which was abolished by PRO20. The HK-induced responses of the above K + and Na + transporting proteins in ADX rats all persisted and also remained sensitive to PRO20. Additionally, spironolactone treatment in ADX rats was still effective in inhibiting kaliuresis induced by HK loading, resulting in hyperkalemia (Plasma K+: 5.13±0.07 vs. 4.19±0.27 mM, p<0.05). In primary rat IMCD cells, exposure to 10 mM KCl for 24 h augmented PRR protein expression and sPRR release in a time- and dose-dependent manner. HK upregulated Aldo release in parallel with increased CYP11B2 protein expression, which were both attenuated by PRO20 or PRR siRNA. A recombinant sPRR, sPRR-His, stimulated Aldo release and CYP11B2 expression. Taken together, we conclude that HK increased renal PRR expression that stimulates renal synthesis of Aldo that coordinates the response of renal membrane Na + and K + transporting proteins to facilitate K + secretion.

Amelioration of Carbon Tetrachloride-Induced Liver Injury by Citrus Leaf Extract

2019 ◽  
Vol 17 (4) ◽  
pp. 426-431
Author(s):  
Jin Xuezhu ◽  
Li Jitong ◽  
Nie Leigang ◽  
Xue Junlai
Keyword(s):  
Carbon Tetrachloride ◽  
Leaf Extract ◽  
Hepatic Injury ◽  
The Body ◽  
Dependent Manner ◽  
Weight Changes ◽  
Citrus Leaf ◽  
Dose Dependent ◽  
And Oxidative Stress

The main purpose of this study is to investigate the role of citrus leaf extract in carbon tetrachloride-induced hepatic injury and its potential molecular mechanism. Carbon tetrachloride was used to construct hepatic injury animal model. To this end, rats were randomly divided into 4 groups: control, carbon tetrachloride-treated, and two carbon tetrachloride + citrus leaf extract-treated groups. The results show that citrus leaf extract treatment significantly reversed the effects of carbon tetrachloride on the body weight changes and liver index. Besides, treatment with citrus leaf extract also reduced the levels of serum liver enzymes and oxidative stress in a dose-dependent manner. H&E staining and western blotting suggested that citrus leaf extract could repair liver histological damage by regulating AMPK and Nrf-2.

scholarly journals Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Map Kinases ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Dual Action ◽  
Dose Dependent ◽  
Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

Role of extracellular calcium and calmodulin in prolactin secretion induced by hyposmolarity, thyrotropin-releasing hormone, and high K+ in GH4C1 cells

1990 ◽  
Vol 123 (2) ◽  
pp. 218-224 ◽  
Author(s):  
Xiangbing Wang ◽  
Noriyuki Sato ◽  
Monte A. Greer ◽  
Susan E. Greer ◽  
Staci McAdams
Keyword(s):  
Smooth Muscle ◽  
Muscle Relaxant ◽  
Prolactin Secretion ◽  
Thyrotropin Releasing Hormone ◽  
Dependent Manner ◽  
Cell Toxicity ◽  
High K ◽  
Dose Dependent ◽  
Smooth Muscle Relaxant

Abstract. The mechanism by which 30% medium hyposmolarity induces PRL secretion by GH4C1 cells was compared with that induced by 100 nmol/l TRH or 30 mmol/l K+. Removing medium Ca2+, blocking Ca2+ channels with 50 μmol/l verapamil, or inhibiting calmodulin activation with 20 μmol/l trifluoperazine, 10 μmol/l chlorpromazine or 10 μmol/l pimozide almost completely blocked hyposmolarity-induced secretion. The smooth muscle relaxant, W-7, which is believed relatively specific in inhibiting the Ca2+-calmodulin interaction, depressed hyposmolarity-induced PRL secretion in a dose-dependent manner (r = −0.991, p<0.01 ). The above drugs also blocked or decreased high K+-induced secretion, but had much less effect on TRH-induced secretion. Secretion induced by TRH, hyposmolarity, or high K+ was optimal at pH 7.3-7.65 and was significantly depressed at pH 6.0 or 8.0, indicating that release of hormone induced by all 3 stimuli is due to an active cell process requiring a physiologic extracellular pH and is not produced by nonspecific cell toxicity. The data suggest hyposmolarity and high K+ may share some similarities in their mechanism of stimulating secretion, which is different from that of TRH.

ROLE OF AN ENDOGENOUS MONOAMINE OXIDASE INHIBITOR, ISATIN, IN SHRSP BRAIN

1995 ◽  
Vol 22 (s1) ◽  
pp. S86-S87 ◽  
Author(s):  
N. Hamaue ◽  
T. Endo ◽  
M. Hirafuji ◽  
N. Yamazaki ◽  
H. Togashi ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Monoamine Oxidase Inhibitor ◽  
Oxidase Inhibitor

The P-element-induced silencing effect of KP transposons is dose dependent in Drosophila melanogaster

Genome ◽  
2011 ◽  
Vol 54 (9) ◽  
pp. 752-762 ◽  
Author(s):  
Alireza Sameny ◽  
John Locke
Keyword(s):  
Drosophila Melanogaster ◽  
Critical Role ◽  
Mutagenic Effect ◽  
P Element ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
P Elements ◽  
Single Well ◽  
Dose Dependent

Transposable elements are found in the genomes of all eukaryotes and play a critical role in altering gene expression and genome organization. In Drosophila melanogaster, transposable P elements are responsible for the phenomenon of hybrid dysgenesis. KP elements, a deletion-derivative of the complete P element, can suppress this mutagenic effect. KP elements can also silence the expression of certain other P-element-mediated transgenes in a process called P-element-dependent silencing (PDS), which is thought to involve the recruitment of heterochromatin proteins. To explore the mechanism of this silencing, we have mobilized KP elements to create a series of strains that contain single, well-defined KP insertions that show PDS. To understand the quantitative role of KP elements in PDS, these single inserts were combined in a series of crosses to obtain genotypes with zero, one, or two KP elements, from which we could examine the effect of KP gene dose. The extent of PDS in these genotypes was shown to be dose dependent in a logarithmic rather than linear fashion. A logarithmic dose dependency is consistent with the KP products interacting with heterochromatic proteins in a concentration-dependent manner such that two molecules are needed to induce gene silencing.

VCAM-1 is a CS1 peptide-inhibitable adhesion molecule expressed by lymph node high endothelium

1993 ◽  
Vol 106 (1) ◽  
pp. 109-119 ◽  
Author(s):  
M.J. May ◽  
G. Entwistle ◽  
M.J. Humphries ◽  
A. Ager
Keyword(s):  
Lymph Node ◽  
Cell Interaction ◽  
Tnf Alpha ◽  
Dependent Manner ◽  
Ifn Gamma ◽  
Lymphocyte Adhesion ◽  
Peripheral Lymph ◽  
Endothelial Surface ◽  
Dose Dependent

Previous studies have shown that unactivated lymphocytes bind to CS1 peptide and that the adhesion of these cells to high endothelium is inhibited by CS1 peptide. These results suggest that lymphocyte binding occurs via recognition of the CS1-containing splice variant of fibronectin expressed on the high endothelial surface. We have now extended these studies by determining the role of the CS1 receptor, alpha 4 beta 1 (VLA-4) and the alternative VLA-4 ligand, VCAM-1 in a rat model of lymphocyte-high endothelial cell interaction. Anti-VLA-4 antibody, HP2/1, blocked lymphocyte adhesion to resting and IFN-gamma (interferon-gamma) pretreated cultured high endothelial cells (HEC) in a dose-dependent manner with maximal inhibition of 60%. HP2/1 completely blocked the adhesion of rat lymphocytes to immobilized CS1 peptide and to a recombinant soluble (rs) form of human VCAM-1. Lymphocyte binding to rsVCAM-1 was also completely blocked by CS1 peptide. Anti-rat VCAM-1 monoclonal antibody 5F10 inhibited adhesion to untreated and IFN-gamma-treated HEC equally and its effect at 50% inhibition was slightly less than that of HP2/1. These findings suggest that a CS1 peptide-inhibitable ligand expressed by high endothelium is VCAM-1. The majority of cultured HEC expressed significant levels of VCAM-1 under basal conditions, as did HEV in peripheral lymph nodes. VCAM-1 expression by HEC was upregulated by cytokine pretreatment and the effects were ordered: IFN-gamma &gt; TNF-alpha &gt; IL-1 beta. The results described here demonstrate that rat peripheral lymph node HEC express VCAM-1, its expression is upregulated by cytokines, in particular IFN-gamma, and it supports the adhesion of unactivated lymphocytes. They also suggest that the VLA-4/VCAM-1 adhesion pathway may operate during the constitutive migration of lymphocytes into lymphoid organs. Although the mechanism of CS1 peptide inhibition was not determined, these results show that VCAM-1 is a CS1 peptide-inhibitable ligand and therefore CS1, on its own, cannot be used as a specific indicator of fibronectin activity.

PROTECTIVE ROLE OF FICUS RACEMOSA IN DIABETES INDUCED NEUROPATHY: STRUCTURAL AND FUNCTIONAL EVIDENCES

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (11) ◽  
pp. 58-60
Author(s):  
N Solanki ◽  
◽  
S. K Bhavsar
Keyword(s):  
Sciatic Nerve ◽  
Diabetic Neuropathy ◽  
Ethanolic Extract ◽  
Protective Role ◽  
Diabetic Rats ◽  
Dependent Manner ◽  
Traditional System ◽  
Ficus Racemosa ◽  
Dose Dependent

Ficus racemosa is used in traditional system of medicine for various health problems and diseases, and is commonly known as Gular fig. The main objective was to study its effects against streptozotocin induced diabetic neuropathy by structural and functional marker. Investigation of diabetic neuropathy was carried out through functional and structural assessment in streptozotocin induced in diabetic rats. Diabetic rats were treated for 28 days in dose dependent manner of Ficus racemosa aqueous extract (250 mg/kg and 500 mg/kg) and ethanolic extract (200 mg/kg and 400 mg/kg). Study showed marked protection observed by Ficus racemosa in hippocampus region of brain and sciatic nerve tissues. Ficus racemosa treatment showed improvement in functional and structural markers, which strongly suggest its protective role in diabetic neuropathy.

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