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Sample records for reversible hepatocyte hypertrophy

  1. Reversible compensatory hypertrophy in rat kidneys: morphometric characterization.

    PubMed

    Schwartz, M M; Churchill, M; Bidani, A; Churchill, P C

    1993-03-01

    Functional renal compensatory hypertrophy (RCH) in the uninephrectomized rat is completely reversible by transplantation in Brown Norway (BN) rats, while anatomic RCH is not. To determine the nephron element(s) responsible for persistent anatomic RCH, we performed morphometric analysis on perfusion fixed rat kidneys following renal function studies. In this model the function of renal transplants is not different from contralateral and unmanipulated control kidneys, and there is no histological evidence of rejection. Rats uninephrectomized for three or six weeks had larger glomeruli than controls, and after transplantation of a previously hypertrophied kidney into a rat with a normal or a solitary hypertrophied kidney, glomerular size returned to control levels. Increased glomerular capillary volume (CVCP) in kidneys with RCH was due to increased capillary length (LCP; 13.1 +/- 1.0 mm cf. 10.3 +/- 0.9, P < 0.01) without increase in capillary radius (RCP; 3.26 +/- 0.33 microM cf. 3.28 +/- 0.24). In contrast, return of CVCP to control levels in kidneys undergoing regression was associated with persistently elevated LCP (13.0 +2- 2.9 mm; native previously hypertrophied kidney; 12.2 +/- 0.9; transplanted previously hypertrophied kidney vs. 10.3 +/- 0.9, P < 0.01) and decreased RCP (2.79 +/- 0.10 microM and 2.73 +/- 0.09, cf 3.28 +/- 0.24, P < 0.01). RCH was associated with proportional increases in glomerular, tubular, and vascular-interstitial volumes while only elevated tubular volume persisted during regression. Altered glomerular capillary dimensions and increased tubular volumes acquired during renal RCH induced by unilateral nephrectomy persisted during complete functional regression.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Copper reverses cardiomyocyte hypertrophy through vascular endothelial growth factor-mediated reduction in the cell size.

    PubMed

    Zhou, Yang; Jiang, Youchun; Kang, Y James

    2008-07-01

    Previous studies have shown that dietary copper supplementation reversed heart hypertrophy induced by pressure overload in a mouse model. The present study was undertaken to understand the cellular basis of copper-induced regression of cardiac hypertrophy. Primary cultures of neonatal rat cardiomyocytes were treated with phenylephrine (PE) at a final concentration of 100 microM in cultures for 48 h to induce cellular hypertrophy. The hypertrophied cardiomyocytes were exposed to copper sulfate at a final concentration of 5 microM in cultures for additional 24 h. This copper treatment reduced the size of the hypertrophied cardiomyocytes, as measured by flow cytometry, protein content in cells, cell volume and cardiomyocyte hypertrophy markers including beta-myosin heavy chain protein, skeletal alpha-actin, and atrial natriuretic peptide. Cell cycle analysis and cell sorting of p-histone-3 labeled cardiomyocytes indicated that cell division was not involved in the copper-induced regression of cardiomyocyte hypertrophy. Copper also inhibited PE-induced apoptosis, determined by a TUNEL assay. Because copper stimulates vascular endothelial growth factor (VEGF) production through activation of hypoxia-inducible transcription factor, an anti-VEGF antibody at a final concentration of 2 ng/ml in cultures was used and shown to blunt copper-induced regression of cell hypertrophy. Conversely, VEGF alone at a final concentration of 0.2 microg/ml reversed cell hypertrophy as the same as copper did. This study demonstrates that both copper and VEGF reduce the size of hypertrophied cardiomyocytes, and copper regression of cardiac hypertrophy is VEGF-dependent. PMID:18495151

  3. Reversible compensatory hypertrophy in transplanted brown Norway rat kidneys.

    PubMed

    Churchill, M; Churchill, P C; Schwartz, M; Bidani, A; McDonald, F

    1991-07-01

    Recently we described methods for optimizing the function of transplanted rat kidneys. In unilaterally nephrectomized recipients, one week after surgery, the left transplanted kidney was identical to the right native kidney with respect to wet weight and the clearances of inulin and para-aminohippuric acid (PAH). The goals of the present experiments were first, to extend the post-surgery period to three weeks (sufficient to allow hypertrophic changes), and second, to study function of transplanted hypertrophied kidneys. Genetically identical Brown Norway rats were used as donor and recipients. Three weeks after transplanting a normal kidney into a unilaterally-nephrectomized recipient, the transplanted kidney had a normal plasma flow and was identical to the contralateral native kidney with respect to wet weight and the clearances of inulin and PAH. Three weeks after transplanting a normal kidney into a bilaterally-nephrectomized recipient, the wet weight, inulin and PAH clearances, and plasma flow of the transplanted kidney were all higher than control, and not significantly different from those observed in unilaterally-nephrectomized control rats. Thus, transplanted and native kidneys exhibited the same degree of compensatory hypertrophy. Hypertrophied donor kidneys (that is, the donor rat had been unilaterally-nephrectomized three weeks previously) remained hypertrophied in bilaterally-nephrectomized recipients, but in unilaterally-nephrectomized recipients, they regressed towards normal (that is, the values of wet weight, inulin and PAH clearances and plasma flow were significantly less than those in rats with only one kidney) while the contralateral native kidney remained normal (values of wet weight and inulin and PAH clearances were not different from control).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Reversal of acetaminophen toxicity in isolated hamster hepatocytes by dithiothreitol

    SciTech Connect

    Tee, L.B.; Boobis, A.R.; Huggett, A.C.; Davies, D.S.

    1986-04-01

    The toxicity of acetaminophen in freshly isolated hamster hepatocytes was investigated. Cells exposed to 2.5 mM acetaminophen for 90 min, followed by washing to completely remove unbound acetaminophen, and resuspension in fresh buffer, showed a dramatic decrease in viability over the ensuing 4.5 hr by which time only 4% of the cells could still exclude trypan blue. During the initial 90-min incubation, there was a substantial depletion of glutathione, to 19% of control values, covalent binding of (/sup 14/C)acetaminophen to cellular proteins, and evidence of morphological changes consistent with some disturbance of the plasma membrane. During subsequent incubation of these cells, covalent binding did not change nor did lipid peroxidation, despite the decrease in viability that occurred. Subsequent incubation of cells exposed to acetaminophen for 90 min in buffer containing 1.5 mM dithiothreitol (DTT), a disulfide-reducing agent, largely prevented the decrease in cell viability and reversed the morphological changes that occurred during the first 90-min incubation. However, there was no change in lipid peroxidation, glutathione content, or covalent binding. It is concluded that acetaminophen interacted with some critical target in the cell, and that this left unchecked, led eventually to the death of the cell. DTT prevented and reversed this effect. The toxicity of acetaminophen, and its reversal by DTT, appear independent of either covalent binding of acetaminophen or lipid peroxidation. In addition, the effect of DTT was independent of the concentration of glutathione, most probably acting by directly reducing oxidized SH-groups in critical enzymes, possibly membrane-bound ATP-dependent Ca2+ translocases.

  5. Metabolic scaling predicts posthepatectomy liver regeneration after accounting for hepatocyte hypertrophy.

    PubMed

    Young, LeAnne H; Periwal, Vipul

    2016-04-01

    We adapted a mathematical model of posthepatectomy liver regeneration using data from a subset of patients in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study. The original model addressed changes in the number of quiescent, primed, and proliferating cells. Our adapted model takes into account hypertrophy of primed and replicating cells, and it is better able to predict liver volume. In addition, by building off the hypothesis that cell cycle parameters are approximately the same across all mammals, we found that changing only a single parameter characterizing metabolic load could model liver regeneration in 5 species of mammals. In conclusion, we improved a mathematical model of liver regeneration, predicted mammalian liver regeneration based on metabolism, and found correlations between model parameters and physiological measurements from liver donors.

  6. Comparison of mutagenicities in a Salmonella reversion assay mediated by uninduced hepatocytes and hepatocytes from rats pretreated for 1 or 5 days with Aroclor 1254.

    PubMed

    Hass, B S; Heflich, R H; Shaddock, J G; Casciano, D A

    1985-01-01

    Hepatocytes prepared from rats pretreated for 5 days with 500 mg/kg Aroclor 1254 were found to be unsuitable for use in a modified Salmonella mutagenicity assay. These hepatocytes exhibited low viability, did not readily attach to plastic culture dishes, and produced mutagenicity responses with benzo[a]pyrene (B[a]P) and 2-aminofluorene (2AF) that were greatly enhanced by the addition of an NADPH-regenerating system (NADPH-RS). Shortening the Aroclor pretreatment time to 1 day resulted in hepatocytes that exhibited high viability and readily attached to plastic culture dishes. These hepatocytes produced higher numbers of revertants when used to assay the mutagenicities of B[a]P and 2AF than were produced using hepatocytes from animals that were pretreated for 5 days. These reversion frequencies were also higher than those produced using uninduced hepatocytes and were much less affected by the addition of NADPH-RS than were the reversions mediated by the 5-day preinduced hepatocytes. Liver homogenate postmitochondrial fractions (S9s), which were prepared from rats pretreated with Aroclor for 1 or 5 days, were nearly equal in their ability to mediate the mutagenicity of B[a]P and 2AF in the Salmonella/microsome reversion assay. Qualitative differences between the S9- and hepatocyte-mediated mutagenicity of 2AF were found, however. These results indicate that employing hepatocytes from rats pretreated with Aroclor for 1 day, rather than 5 days, results in an enzymatically induced, more-intact cell population that is capable of detecting the mutagenicity of B[a]P and 2AF in a modified Salmonella reversion assay.

  7. Simvastatin reverses cardiomyocyte hypertrophy via the upregulation of phosphatase and tensin homolog expression

    PubMed Central

    CHEN, YONG-QING; ZHAO, LIAN-YOU; ZHANG, WEI-ZE; LI, TAO

    2015-01-01

    The aim of the present study was to investigate the effects of simvastatin on the protein kinase B (PKB) signaling pathway and the expression of phosphatase and tensin homolog (PTEN). The effects of simvastatin were analyzed by administering the drug orally to male spontaneously hypertensive rats (SHRs) at a dose of 10 mg/kg/day, while the control animals received an equal volume of saline. The systolic pressure (mmHg) of the rat tail artery was measured prior to the initiation of the experiment, and once a week until the end of the experiment. At the end of the experiment, the animals were euthanized and the hearts were removed. The left ventricular and interventricular septum were weighed, after which the left ventricular mass/body mass ratio was calculated. In addition, cardiomyocytes isolated from Sprague Dawley rats were cultured with 15% fetal bovine serum to induce hypertrophy, following which the cells were treated with different doses of simvastatin. The in vitro effects were assessed by measuring the surface area of the cardiomyocytes, while the rate of protein synthesis was measured using a 3H-leucine incorporation assay and western blot analyses. Simvastatin was demonstrated to inhibit cardiomyocyte hypertrophy in the in vivo and in vitro experiments. Notably, simvastatin increased PTEN expression and inhibited PKB expression in the SHR model, as well as in the cardiomyocytes in culture. In addition, the use of PTEN antisense oligodeoxynucleotides was revealed to inhibit the effects of simvastatin on cardiomyocytes. Therefore, these results indicated that simvastatin was able to reverse cardiomyocyte hypertrophy in vivo and in vitro, possibly by increasing the expression of PTEN. PMID:26622396

  8. Short environmental enrichment in adulthood reverses anxiety and basolateral amygdala hypertrophy induced by maternal separation

    PubMed Central

    Koe, A S; Ashokan, A; Mitra, R

    2016-01-01

    Maternal separation during early childhood results in greater sensitivity to stressors later in adult life. This is reflected as greater propensity to develop stress-related disorders in humans and animal models, including anxiety and depression. Environmental enrichment (EE) reverses some of the damaging effects of maternal separation in rodent models when provided during peripubescent life, temporally proximal to the separation. It is presently unknown if EE provided outside this critical window can still rescue separation-induced anxiety and neural plasticity. In this report we use a rat model to demonstrate that a single short episode of EE in adulthood reduced anxiety-like behaviour in maternally separated rats. We further show that maternal separation resulted in hypertrophy of dendrites and increase in spine density of basolateral amygdala neurons in adulthood, long after initial stress treatment. This is congruent with prior observations showing centrality of basolateral amygdala hypertrophy in anxiety induced by stress during adulthood. In line with the ability of the adult enrichment to rescue stress-induced anxiety, we show that enrichment renormalized stress-induced structural expansion of the amygdala neurons. These observations argue that behavioural plasticity induced by early adversity can be rescued by environmental interventions much later in life, likely mediated by ameliorating effects of enrichment on basolateral amygdala plasticity. PMID:26836417

  9. Short environmental enrichment in adulthood reverses anxiety and basolateral amygdala hypertrophy induced by maternal separation.

    PubMed

    Koe, A S; Ashokan, A; Mitra, R

    2016-02-02

    Maternal separation during early childhood results in greater sensitivity to stressors later in adult life. This is reflected as greater propensity to develop stress-related disorders in humans and animal models, including anxiety and depression. Environmental enrichment (EE) reverses some of the damaging effects of maternal separation in rodent models when provided during peripubescent life, temporally proximal to the separation. It is presently unknown if EE provided outside this critical window can still rescue separation-induced anxiety and neural plasticity. In this report we use a rat model to demonstrate that a single short episode of EE in adulthood reduced anxiety-like behaviour in maternally separated rats. We further show that maternal separation resulted in hypertrophy of dendrites and increase in spine density of basolateral amygdala neurons in adulthood, long after initial stress treatment. This is congruent with prior observations showing centrality of basolateral amygdala hypertrophy in anxiety induced by stress during adulthood. In line with the ability of the adult enrichment to rescue stress-induced anxiety, we show that enrichment renormalized stress-induced structural expansion of the amygdala neurons. These observations argue that behavioural plasticity induced by early adversity can be rescued by environmental interventions much later in life, likely mediated by ameliorating effects of enrichment on basolateral amygdala plasticity.

  10. Carbon Tetrachloride at Hepatotoxic Levels Blocks Reversibly Gap Junctions between Rat Hepatocytes

    NASA Astrophysics Data System (ADS)

    Saez, J. C.; Bennett, M. V. L.; Spray, D. C.

    1987-05-01

    Electrical coupling and dye coupling between pairs of rat hepatocytes were reversibly reduced by brief exposure to halogenated methanes (CBrCl3, CCl4, and CHCl3). The potency of different halomethanes in uncoupling hepatocytes was comparable to their hepatotoxicity in vivo, and the rank order was the same as that of their tendency to form free radicals. The effect of carbon tetrachloride (CCl4) on hepatocytes was substantially reduced by prior treatment with SKF 525A, an inhibitor of cytochrome P-450, and by exposure to the reducing reagent β -mercaptoethanol. Halomethane uncoupling occurred with or without extracellular calcium and did not change intracellular concentrations of calcium and hydrogen ions or the phosphorylation state of the main gap-junctional protein. Thus the uncoupling appears to depend on cytochrome P-450 oxidative metabolism in which free radicals are generated and may result from oxidation of the gap-junctional protein or of a regulatory molecule that leads to closure of gap-junctional channels. Decreases in junctional conductance may be a rapid cellular response to injury that protects healthy cells by uncoupling them from unhealthy ones.

  11. Honokiol blocks and reverses cardiac hypertrophy in mice by activating mitochondrial SIRT3

    PubMed Central

    Pillai, Vinodkumar B.; Samant, Sadhana; Sundaresan, Nagalingam R.; Raghuraman, Hariharasundaram; Kim, Gene; Bonner, Michael Y.; Arbiser, Jack L.; Walker, Douglas I.; Jones, Dean P.; Gius, David; Gupta, Mahesh P.

    2015-01-01

    Honokiol (HKL) is a natural biphenolic compound derived from the bark of magnolia trees with anti-inflammatory, anti-oxidative, anti-tumor and neuroprotective properties. Here we show that HKL blocks agonist-induced and pressure overload-mediated, cardiac hypertrophic responses, and ameliorates pre-existing cardiac hypertrophy, in mice. Our data suggest that the anti-hypertrophic effects of HKL depend on activation of the deacetylase SIRT3. We demonstrate that HKL is present in mitochondria, enhances SIRT3 expression nearly two-fold and suggest that HKL may bind to SIRT3 to further increase its activity. Increased SIRT3 activity is associated with reduced acetylation of mitochondrial SIRT3 substrates, MnSOD and OSCP. HKL-treatment increases mitochondrial rate of oxygen consumption and reduces ROS synthesis in wild-type, but not in SIRT3-KO cells. Moreover, HKL-treatment blocks cardiac fibroblast proliferation and differentiation to myofibroblasts in SIRT3-dependent manner. These results suggest that HKL is a pharmacological activator of SIRT3 capable of blocking, and even reversing, the cardiac hypertrophic response. PMID:25871545

  12. Reversible cardiac hypertrophy induced by PEG-coated gold nanoparticles in mice

    PubMed Central

    Yang, Chengzhi; Tian, Aiju; Li, Zijian

    2016-01-01

    Gold nanoparticles (GNPs) are attracting more and more attention for their great potential value in biomedical application. Currently, no study has been reported on the chronic cardiac toxicity of GNPs after repeated administration. Here we carried out a comprehensive evaluation of the chronic cardiac toxicity of GNPs to the heart. Polyethylene glycol (PEG) -coated GNPs at three different sizes (10, 30 and 50 nm) or PBS was administrated to mice via tail vein for 14 consecutive days. Then the mice were euthanized at 2 weeks, 4 weeks or 12 weeks after the first injection. The accumulation of GNPs in the mouse heart and their effects on cardiac function, structure, fibrosis and inflammation were analysized. GNPs with smaller size showed higher accumulation and faster elimination. None of the three sizes of GNPs affected cardiac systolic function. The LVIDd (left ventricular end-diastolicinner-dimension), LVMass (left ventricular mass) and HW/BW (heart weight/body weight) were significantly increased in the mice receiving 10 nm PEG-GNPs for 2 weeks, but not for 4 weeks or 12 weeks. These results indicated that the accumulation of small size GNPs can induce reversible cardiac hypertrophy. Our results provide the basis for the further biomedical applications of GNPs in cardiac diseases. PMID:26830764

  13. Complete reversibility of physiological coronary vascular abnormalities in hypertrophied hearts produced by pressure overload in the rat.

    PubMed Central

    Isoyama, S; Ito, N; Kuroha, M; Takishima, T

    1989-01-01

    Using an experimental model of ascending aortic banding in the rat, we examined whether coronary circulation abnormalities in hypertrophied hearts are reversible after debanding. 4-wk banding produced significant increases in in vivo left ventricular (LV) pressure (194 +/- 13 vs. 114 +/- 9 mmHg in shamoperated controls) and LV dry wt/body wt (48 +/- 5% above controls). In isolated hearts perfused with Krebs-Henseleit buffer, coronary flow rate (CFR) was estimated under nonworking conditions. During maximal vasodilation after 1 min-ischemia, CFR at a coronary perfusion pressure (CPP) of 100 mmHg and CFR/myocardidial mass at CPPs of 100 and 150 mmHg decreased significantly (72 +/- 5%; 53 +/- 4 and 61 +/- 4% of controls). 1 or 4 wk after debanding, LV systolic pressures were similar to control values, and the degree of myocardial hypertrophy decreased to levels 23 +/- 6 (P less than 0.01) and 11 +/- 6% (P less than 0.01) above their control values, respectively. At 1 wk there was no significant increase in CFR/myocardial mass, compared to values in the banded group (67 +/- 8 vs. 53 +/- 4% of controls at 100 mmHg and 67 +/- 9 vs. 61 +/- 4% at 150 mmHg of CPP). At 4 wk, CFR and the ratio had increased toward normal. Thus, decreased coronary perfusion in hypertrophied hearts is completely reversible. Images PMID:2525568

  14. Rat hepatocyte culture model of macrosteatosis: Effect of macrosteatosis induction and reversal on viability and liver-specific function

    PubMed Central

    Nativ, Nir I.; Yarmush, Gabriel; Chen, Alvin; Dong, David; Henry, Scot D.; Guarrera, James V.; Klein, Kenneth M.; Maguire, Tim; Schloss, Rene; Berthiaume, Francois; Yarmush, Martin L.

    2013-01-01

    Background & Aims A common cause of liver donor ineligibility is macrosteatosis. Recovery of such livers could enhance donor availability. Living donor studies have shown diet-induced reduction of macrosteatosis enables transplantation. However, cadaveric liver macrosteatotic reduction must be performed ex vivo within hours. Towards this goal, we investigated the effect of accelerated macrosteatosis reduction on hepatocyte viability and function using a novel system of macrosteatotic hepatocytes. Methods Hepatocytes isolated from lean Zucker rats were cultured in a collagen sandwich, incubated for 6 days in fatty acid-supplemented medium to induce steatosis, and then switched for 2 days to medium supplemented with lipid metabolism promoting agents. Intracellular lipid droplet size distribution and triglyceride, viability, albumin and urea secretion, and bile canalicular function were measured. Results Fatty acid-supplemented medium induced microsteatosis in 3 days and macrosteatosis in 6 days, the latter evidenced by large lipid droplets dislocating the nucleus to the cell periphery. Macrosteatosis significantly impaired all functions tested. Macrosteatosis decreased upon returning hepatocytes to standard medium, and the rate of decrease was 4-fold faster with supplemented agents, yielding 80% reduction in 2 days. Viability of macrosteatosis reduced hepatocytes was similar to control lean cells. Accelerated macrosteatotic reduction led to faster recovery of urea secretion and bile canalicular function, but not of albumin secretion. Conclusions Macrosteatosis reversibly decreases hepatocyte function and supplementary agents accelerate macrosteatosis reduction and some functional restoration with no effect on viability. This in vitro model may be useful to screen agents for macrosteatotic reduction in livers before transplantation. PMID:23872604

  15. AMPK Activation Prevents and Reverses Drug-Induced Mitochondrial and Hepatocyte Injury by Promoting Mitochondrial Fusion and Function

    PubMed Central

    Taniane, Caitlin; Farrell, Geoffrey; Arias, Irwin M.; Lippincott-Schwartz, Jennifer; Fu, Dong

    2016-01-01

    Mitochondrial damage is the major factor underlying drug-induced liver disease but whether conditions that thwart mitochondrial injury can prevent or reverse drug-induced liver damage is unclear. A key molecule regulating mitochondria quality control is AMP activated kinase (AMPK). When activated, AMPK causes mitochondria to elongate/fuse and proliferate, with mitochondria now producing more ATP and less reactive oxygen species. Autophagy is also triggered, a process capable of removing damaged/defective mitochondria. To explore whether AMPK activation could potentially prevent or reverse the effects of drug-induced mitochondrial and hepatocellular damage, we added an AMPK activator to collagen sandwich cultures of rat and human hepatocytes exposed to the hepatotoxic drugs, acetaminophen or diclofenac. In the absence of AMPK activation, the drugs caused hepatocytes to lose polarized morphology and have significantly decreased ATP levels and viability. At the subcellular level, mitochondria underwent fragmentation and had decreased membrane potential due to decreased expression of the mitochondrial fusion proteins Mfn1, 2 and/or Opa1. Adding AICAR, a specific AMPK activator, at the time of drug exposure prevented and reversed these effects. The mitochondria became highly fused and ATP production increased, and hepatocytes maintained polarized morphology. In exploring the mechanism responsible for this preventive and reversal effect, we found that AMPK activation prevented drug-mediated decreases in Mfn1, 2 and Opa1. AMPK activation also stimulated autophagy/mitophagy, most significantly in acetaminophen-treated cells. These results suggest that activation of AMPK prevents/reverses drug-induced mitochondrial and hepatocellular damage through regulation of mitochondrial fusion and autophagy, making it a potentially valuable approach for treatment of drug-induced liver injury. PMID:27792760

  16. Autophagic sequestration of (/sup 14/C)sucrose, introduced into rat hepatocytes by reversible electro-permeabilization

    SciTech Connect

    Gordon, P.B.; Seglen, P.O.

    1982-11-01

    Isolated rat hepatocytes could be made permeable to small molecules such as (/sup 14/C)sucrose (but not to proteins) but subjecting the cells to repeated discharges in a high-voltage field. During subsequent incubation at 37/sup 0/C, the permeability changes were reversed within 15 min, the electron-injected (/sup 14/C)sucros remaining trapped inside the re-sealed plasma membrane. Autophagic sequestration of (/sup 14/C)sucrose, i.e., the transfer of radioactivity from cytosol to sedimentable vesicles (autophagosomes and lysosomes), could be followed by incubating the (/sup 14/C)sucrose-loaded hepatocytes for up to 2 h at 37/sup 0/C. After incubation, the cells were disrupted by a single high-voltage discharge in electrolyte-free medium (sucrose), and sedimentable cell components were separated from the cytosol by centrifugation through metrizamide. By the use of these methods, which are particularly suitable for the analysis of many small cell samples, it could be shown that (/sup 14/C)sucros was autophagically sequestered in the hepatocytes at a rate of 4-5%/h. The sequestration was nearly completely inhibited by the specific autophagy inhibitor 3-methyladenine.

  17. Deficiency of cardiac Acyl-CoA synthetase-1 induces diastolic dysfunction, but pathologic hypertrophy is reversed by rapamycin.

    PubMed

    Paul, David S; Grevengoed, Trisha J; Pascual, Florencia; Ellis, Jessica M; Willis, Monte S; Coleman, Rosalind A

    2014-06-01

    In mice with temporally-induced cardiac-specific deficiency of acyl-CoA synthetase-1 (Acsl1(H-/-)), the heart is unable to oxidize long-chain fatty acids and relies primarily on glucose for energy. These metabolic changes result in the development of both a spontaneous cardiac hypertrophy and increased phosphorylated S6 kinase (S6K), a substrate of the mechanistic target of rapamycin, mTOR. Doppler echocardiography revealed evidence of significant diastolic dysfunction, indicated by a reduced E/A ratio and increased mean performance index, although the deceleration time and the expression of sarco/endoplasmic reticulum calcium ATPase and phospholamban showed no difference between genotypes. To determine the role of mTOR in the development of cardiac hypertrophy, we treated Acsl1(H-/-) mice with rapamycin. Six to eight week old Acsl1(H-/-) mice and their littermate controls were given i.p. tamoxifen to eliminate cardiac Acsl1, then concomitantly treated for 10weeks with i.p. rapamycin or vehicle alone. Rapamycin completely blocked the enhanced ventricular S6K phosphorylation and cardiac hypertrophy and attenuated the expression of hypertrophy-associated fetal genes, including α-skeletal actin and B-type natriuretic peptide. mTOR activation of the related Acsl3 gene, usually associated with pathologic hypertrophy, was also attenuated in the Acsl1(H-/-) hearts, indicating that alternative pathways of fatty acid activation did not compensate for the loss of Acsl1. Compared to controls, Acsl1(H-/-) hearts exhibited an 8-fold higher uptake of 2-deoxy[1-(14)C]glucose and a 35% lower uptake of the fatty acid analog 2-bromo[1-(14)C]palmitate. These data indicate that Acsl1-deficiency causes diastolic dysfunction and that mTOR activation is linked to the development of cardiac hypertrophy in Acsl1(H-/-) mice. PMID:24631848

  18. Controlled and reversible induction of differentiation and activation of adult human hepatocytes by a biphasic culture technique

    PubMed Central

    Auth, Marcus K.H.; Boost, Kim A.; Leckel, Kerstin; Beecken, Wolf-Dietrich; Engl, Tobias; Jonas, Dietger; Oppermann, Elsie; Hilgard, Philip; Markus, Bernd H.; Bechstein, Wolf-Otto; Blaheta, Roman A.

    2005-01-01

    AIM: Clinical application of human hepatocytes (HC) is hampered by the progressive loss of growth and differentiation in vitro. The object of the study was to evaluate the effect of a biphasic culture technique on expression and activation of growth factor receptors and differentiation of human adult HC. METHODS: Isolated HC were sequentially cultured in a hormone enriched differentiation medium (DM) containing nicotinamide, insulin, transferrin, selenium, and dexame-thasone or activation medium (AM) containing hepatocyte growth factor (HGF), epidermal growth factor (EGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF). Expression, distribution and activation of the HC receptors (MET and EGFR) and the pattern of characteristic cytokeratin (CK) filaments were measured by fluorometry, confocal microscopy and Western blotting. RESULTS: In the biphasic culture system, HC underwent repeated cycles of activation (characterized by expression and activation of growth factor receptors) and re-differentiation (illustrated by distribution of typical filaments CK-18 but low or absent expression of CK-19). In AM increased expression of MET and EGFR was associated with receptor translocation into the cytoplasm and induction of atypical CK-19. In DM low expression of MET and EGFR was localized on the cell membrane and CK-19 was reduced. Receptor phosphorylation required embedding of HC in collagen type I gel. CONCLUSION: Control and reversible modulation of growth factor receptor activation of mature human HC can be accomplished in vitro, when defined signals from the extracellular matrix and sequential growth stimuli are provided. The biphasic technique helps overcome de-differentiation, which occurs during continuous stimulation by means of growth factors. PMID:15810072

  19. Elevated Sensitivity of Macrosteatotic Hepatocytes to Hypoxia-Reoxygenation Stress Is Reversed by a Novel Defatting Protocol

    PubMed Central

    Nativ, Nir I.; Yarmush, Gabriel; So, Ashley; Barminko, Jeffery; Maguire, Timothy J.; Schloss, Rene; Berthiaume, Francois; Yarmush, Martin L.

    2014-01-01

    Macrosteatotic livers exhibit elevated intrahepatic triglyceride (TG) content in the form of large lipid droplets (LDs), reduced ATP, and elevated reactive oxygen species (ROS), contributing to their elevated sensitivity to ischemia-reperfusion injury during transplantation. Decreasing macrosteatosis in living donors through dieting has been shown to improve transplantation outcome. Accomplishing the same feat in deceased donor grafts would require ex-vivo exposure to potent defatting agents. Herein, we used a rat hepatocyte culture system exhibiting macrosteatotic LD morphology, elevated TG levels, and elevated sensitivity to hypoxia and reoxygenation (H/R), to test for such agents and ameliorate H/R sensitivity. Macrosteatotic hepatocyte preconditioning for 48h with a defatting cocktail, previously developed to promote TG catabolism, reduced the number of macrosteatotic LDs and intracellular TG levels by 82% and 27%, respectively, but did not ameliorate sensitivity to H/R. L-carnitine supplementation to this cocktail, together with hyperoxic exposure, yielded a similar reduction in macrosteatotic LD numbers, and to a 57% reduction in intrahepatic TG storage, likely by increasing the supply of acetyl-CoA to mitochondria, as indicated by a 70% increase in ketone body secretion. Furthermore, this treatment reduced ROS levels by 32%, increased ATP levels by 27%, nearing ATP levels of lean controls, and completely abolished H/R sensitivity as indicated by ~85% viability post H/R and return of cytosolic lactate dehydrogenase release down to levels seen in lean controls. Cultures maintained for 48h post H/R were ~83% viable and exhibited superior urea secretion and bile canalicular transport compared to untreated macrosteatotic cultures. These findings show that the elevated sensitivity of macrosteatotic hepatocytes to H/R can be overcome by defatting agents, suggesting a possible route for the recovery of discarded macrosteatotic grafts. PMID:24802973

  20. Immortalization of Human Fetal Hepatocyte by Ectopic Expression of Human Telomerase Reverse Transcriptase, Human Papilloma Virus (E7) and Simian Virus 40 Large T (SV40 T) Antigen Towards Bioartificial Liver Support

    PubMed Central

    Giri, Shibashish; Bader, Augustinus

    2014-01-01

    Background Generation of genetically stable and non-tumoric immortalization cell line from primary cells would be enormously useful for research and therapeutic purposes, but progress towards this goal has so far been limited. It is now universal acceptance that immortalization of human fetal hepatocytes based on recent advances of telomerase biology and oncogene, lead to unlimited population doubling could be the possible source for bioartificial liver device. Methods Immortalization of human fetal hepatocytes cell line by ectopic expression of human telomerase reverse transcriptase (hTERT), human papilloma virus gene (E7) and simian virus 40 large T (SV40 T) antigens is main goal of present study. We used an inducible system containing human telomerase and E7, both of which are cloned into responder constructs controlled by doxycycline transactivator. We characterized the immortalized human fetal hepatocyte cells by analysis of green fluorescent cells (GFP) positive cells using flow cytometry (FACs) cell sorting and morphology, proliferative rate and antigen expression by immunohistochemical analysis. In addition to we analysized lactate formation, glucose consumption, albumin secretion and urea production of immortalized human fetal hepatocyte cells. Results After 25 attempts for transfection of adult primary hepatocytes by human telomerase and E7 to immortalize them, none of the transfection systems resulted in the production of a stable, proliferating cell line. Although the transfection efficiency was more than 70% on the first day, the vast majority of the transfected hepatocytes lost their signal within the first 5–7 days. The remaining transfected hepatocytes persisted for 2–4 weeks and divided one or two times without forming a clone. After 10 attempts of transfection human fetal hepatocytes using the same transfection system, we obtained one stable human fetal hepatocytes cell line which was able albumin secretion urea production and glucose

  1. Apolipoprotein A-I Mimetic Peptide D-4F Reduces Cardiac Hypertrophy and Improves Apolipoprotein A-I-Mediated Reverse Cholesterol Transport From Cardiac Tissue in LDL Receptor-null Mice Fed a Western Diet.

    PubMed

    Han, Jie; Zhang, Song; Ye, Ping; Liu, Yong-Xue; Qin, Yan-Wen; Miao, Dong-Mei

    2016-05-01

    Epidemiological studies have suggested that hypercholesterolemia is an independent determinant of increased left ventricular (LV) mass. Because high-density lipoprotein and its major protein apolipoprotein A-I (apoA-I) mediate reverse cholesterol transport (RCT) and have cardiac protective effects, we hypothesized that the apoA-I mimetic peptide D-4F could promote RCT in cardiac tissue and decrease cardiac hypertrophy induced by hypercholesterolemia. Low-density lipoprotein receptor-null mice were fed by a Western diet for 18 weeks and then randomized to receive water, or D-4F 0.3 mg/mL, or D-4F 0.5 mg/mL added to drinking water for 6 weeks. After D-4F administration, an increase in high-density lipoprotein cholesterol and a decrease in low-density lipoprotein cholesterol, total cholesterol, and triglyceride in a trend toward dose-responsivity were found in cardiac tissue. Ultrasound biomicroscopy revealed a reduction in LV posterior wall end-diastolic dimension, and an increase in mitral valve E/A ratio and LV ejection fraction. Hematoxylin-eosin staining showed reduced LV wall thickness and myocardial cell diameter. The protein levels of ABCA1 and LXRα were elevated in cardiac tissue of D-4F treated mice compared with the controls (P < 0.05). These results demonstrated that D-4F treatment reduced cardiac hypertrophy, and improved cardiac performance in low-density lipoprotein receptor-null mice fed a Western diet, presumably through the LXRα-ABCA1 pathway associated with enhanced myocardial RCT.

  2. Recovery of mature hepatocytic phenotype following bile ductular transdifferentiation of rat hepatocytes in vitro.

    PubMed

    Sone, Masayuki; Nishikawa, Yuji; Nagahama, Yasuharu; Kumagai, Eriko; Doi, Yuko; Omori, Yasufumi; Yoshioka, Toshiaki; Tokairin, Takuo; Yoshida, Masayuki; Sugiyama, Toshihiro; Enomoto, Katsuhiko

    2012-12-01

    We previously demonstrated that mature rat hepatocytes transdifferentiate to bile ductular cells when cultured in a three-dimensional collagen-rich matrix. Here, we show that the phenotype of transdifferentiated hepatocytes can be reversed by modulating culture conditions. Spheroidal aggregates of hepatocytes were cultured within a collagen gel matrix in the presence of serum and tumor necrosis factor-α. Spheroids transformed into ductular structures composed of small cuboidal cells, lost the expression of hepatocytic markers, whereas aberrantly expressed bile ductular markers. The transdifferentiated cells were then retrieved from the gels, plated on surfaces coated with a basement membrane-like material, and cultured in serum-free media. Cells spontaneously formed spheroidal aggregates and recovered hepatocytic phenotype. Dexamethasone (Dex), which suppressed the phosphorylation of ERK and Jun N-terminal kinase, facilitated the recovery, and the combination with interleukin-6 or oncostatin M resulted in the recovery of hepatocyte nuclear factor 4 α protein expression and the typical hepatocytic morphology, and a decrease in the expression of bile ductular markers. A cDNA microarray analysis revealed that the hepatocyte-specific mRNA expression profile was recovered in these cells. Our results demonstrate that hepatocytes are able to recover their phenotypes following bile ductular transdifferentiation, suggesting that hepatocytic and bile ductular phenotypes may be mutually reversible.

  3. Reconstitution of liver mass via cellular hypertrophy in the rat.

    PubMed

    Nagy, P; Teramoto, T; Factor, V M; Sanchez, A; Schnur, J; Paku, S; Thorgeirsson, S S

    2001-02-01

    The liver has an extremely effective regenerative capacity. When 70% of a rat liver is removed by surgery, the liver mass regrows in 7 to 10 days by the compensatory hyperplasia of the remnant part. In case of damage to the surviving hepatocytes, the facultative stem-cell compartment is activated and the liver regenerates by means of oval-cell proliferation/differentiation. In the present study, we demonstrate that when both hepatocyte proliferation and stem-cell activation were prevented by dexamethasone (Dex) administration, the liver mass was restored in the absence of DNA synthesis. The restoration of the liver was accomplished by the preferential enlargement/hypertrophy of the periportal hepatocytes. A similar response was observed when cell proliferation was arrested by 5-fluorouracil (FU) following partial hepatectomy. Therefore, the hepatocytic hypertrophy appears to provide an alternative mechanism of liver-mass restoration. This hypertrophic condition of the liver is not stable, because following the withdrawal of Dex, the enlarged hepatocytes entered in the cell cycle and the normal liver structure and DNA content was re-established. PMID:11172335

  4. 2',3'-dideoxy-beta-L-5-fluorocytidine inhibits duck hepatitis B virus reverse transcription and suppresses viral DNA synthesis in hepatocytes, both in vitro and in vivo.

    PubMed Central

    Zoulim, F; Dannaoui, E; Borel, C; Hantz, O; Lin, T S; Liu, S H; Trépo, C; Cheng, Y C

    1996-01-01

    beta-L-Nucleoside analogs represent a new class of potent antiviral agents with low cytotoxicity which provide new hope in the therapy of chronic hepatitis B virus (HBV) infections. We evaluated the anti-HBV activity of 2',3'-dideoxy-beta-L-5-fluorocytidine (beta-L-F-ddC), a beta-L-nucleoside analog derived from 2',3'-dideoxycytidine (ddC), in the duck HBV (DHBV) model. This compound was previously shown to inhibit HBV DNA synthesis in a stably transfected hepatoma cell line (F2215). Using a cell-free system for the expression of an enzymatically active DHBV polymerase, we could demonstrate that the triphosphate form of beta-L-F-ddC does inhibit hepadnavirus reverse transcription. In primary duck hepatocyte culture, beta-L-F-ddC showed a potent inhibitory effect on DHBV DNA synthesis which was concentration dependent. Although beta-L-F-ddC was shown to be less active than ddC against the DHBV reverse transcriptase in vitro, beta-L-F-ddC was a stronger inhibitor in hepatocytes. The oral administration of beta-L-F-ddC in experimentally infected ducklings showed that beta-L-F-ddC is a potent inhibitor of viral replication in vivo. Short-term therapy could not prevent a rebound of viral replication after the drug was withdrawn. Preventive therapy with beta-L-F-ddC could delay the onset of viremia by only 1 day compared with the time to the onset of viremia in the control group. The in vivo inhibitory effect of beta-L-F-ddC was much stronger than that of ddC and was not associated with signs of toxicity. Our data show that beta-L-F-ddC inhibits hepadnavirus reverse transcription and is a strong inhibitor of viral replication both in vitro and in vivo. PMID:8834896

  5. Benign masseter muscle hypertrophy.

    PubMed

    Rispoli, Daniel Zeni; Camargo, Paulo M; Pires, José L; Fonseca, Vinicius R; Mandelli, Karina K; Pereira, Marcela A C

    2008-01-01

    Idiopathic hypertrophy of the masseter muscle is a rare disorder of unknown cause. Some authors associate it with the habit of chewing gum, temporo-mandibular joint disorder, congenital and functional hypertrophies, and emotional disorders (stress and nervousness). Most patients complain of the cosmetic change caused by facial asymmetry, also called square face, however, symptoms such as trismus, protrusion and bruxism may also occur. The goals of the present investigation were: to report a case of idiopathic masseter hypertrophy, describe its symptoms and treatment. The patient reported bilateral bulging in the region of the mandible angle, of slow and progressive evolution. He did not complain of pain or discomfort, however there was bilateral otalgia, nighttime trismus and stress. In his physical exam we noticed bilateral masseter hypertrophy without local inflammatory alterations. We indicated surgical treatment with an extraoral approach. Complementary tests are indicated when there is diagnostic doubts. Treatment varies from conservative to surgical, and the later depends on surgeon skill and experience.

  6. Regression of Pathological Cardiac Hypertrophy: Signaling Pathways and Therapeutic Targets

    PubMed Central

    Hou, Jianglong; Kang, Y. James

    2012-01-01

    Pathological cardiac hypertrophy is a key risk factor for heart failure. It is associated with increased interstitial fibrosis, cell death and cardiac dysfunction. The progression of pathological cardiac hypertrophy has long been considered as irreversible. However, recent clinical observations and experimental studies have produced evidence showing the reversal of pathological cardiac hypertrophy. Left ventricle assist devices used in heart failure patients for bridging to transplantation not only improve peripheral circulation but also often cause reverse remodeling of the geometry and recovery of the function of the heart. Dietary supplementation with physiologically relevant levels of copper can reverse pathological cardiac hypertrophy in mice. Angiogenesis is essential and vascular endothelial growth factor (VEGF) is a constitutive factor for the regression. The action of VEGF is mediated by VEGF receptor-1, whose activation is linked to cyclic GMP-dependent protein kinase-1 (PKG-1) signaling pathways, and inhibition of cyclic GMP degradation leads to regression of pathological cardiac hypertrophy. Most of these pathways are regulated by hypoxia-inducible factor. Potential therapeutic targets for promoting the regression include: promotion of angiogenesis, selective enhancement of VEGF receptor-1 signaling pathways, stimulation of PKG-1 pathways, and sustention of hypoxia-inducible factor transcriptional activity. More exciting insights into the regression of pathological cardiac hypertrophy are emerging. The time of translating the concept of regression of pathological cardiac hypertrophy to clinical practice is coming. PMID:22750195

  7. Reversals.

    ERIC Educational Resources Information Center

    National Center on Educational Media and Materials for the Handicapped, Columbus, OH.

    Selected from the National Instructional Materials Information System (NIMIS)--a computer based on-line interactive retrieval system on special education materials--the bibliography covers nine materials for remediating reversals in handicapped students at the early childhood and elementary levels. Entries are presented in order of NIMIS accession…

  8. Fatty acids increase neuronal hypertrophy of Pten knockdown neurons

    PubMed Central

    Fricano, Catherine J.; DeSpenza, Tyrone; Frazel, Paul W.; Li, Meijie; O'Malley, A. James; Westbrook, Gary L.; Luikart, Bryan W.

    2014-01-01

    Phosphatase and tensin homolog (Pten) catalyzes the reverse reaction of PI3K by dephosphorylating PIP3 to PIP2. This negatively regulates downstream Akt/mTOR/S6 signaling resulting in decreased cellular growth and proliferation. Co-injection of a lentivirus knocking Pten down with a control lentivirus allows us to compare the effects of Pten knockdown between individual neurons within the same animal. We find that knockdown of Pten results in neuronal hypertrophy by 21 days post-injection. This neuronal hypertrophy is correlated with increased p-S6 and p-mTOR in individual neurons. We used this system to test whether an environmental factor that has been implicated in cellular hypertrophy could influence the severity of the Pten knockdown-induced hypertrophy. Implantation of mini-osmotic pumps delivering fatty acids results in increased neuronal hypertrophy and p-S6/p-mTOR staining. These hypertrophic effects were reversed in response to rapamycin treatment. However, we did not observe a similar increase in hypertrophy in response to dietary manipulations of fatty acids. Thus, we conclude that by driving growth signaling with fatty acids and knocking down a critical regulator of growth, Pten, we are able to observe an additive morphological phenotype of increased soma size mediated by the mTOR pathway. PMID:24795563

  9. O-GlcNAc signaling is essential for NFAT-mediated transcriptional reprogramming during cardiomyocyte hypertrophy.

    PubMed

    Facundo, Heberty T; Brainard, Robert E; Watson, Lewis J; Ngoh, Gladys A; Hamid, Tariq; Prabhu, Sumanth D; Jones, Steven P

    2012-05-15

    The regulation of cardiomyocyte hypertrophy is a complex interplay among many known and unknown processes. One specific pathway involves the phosphatase calcineurin, which regulates nuclear translocation of the essential cardiac hypertrophy transcription factor, nuclear factor of activated T-cells (NFAT). Although metabolic dysregulation is frequently described during cardiac hypertrophy, limited insights exist regarding various accessory pathways. One metabolically derived signal, beta-O-linked N-acetylglucosamine (O-GlcNAc), has emerged as a highly dynamic posttranslational modification of serine and threonine residues regulating physiological and stress processes. Given the metabolic dysregulation during hypertrophy, we hypothesized that NFAT activation is dependent on O-GlcNAc signaling. Pressure overload-induced hypertrophy (via transverse aortic constriction) in mice or treatment of neonatal rat cardiac myocytes with phenylephrine significantly enhanced global O-GlcNAc signaling. NFAT-luciferase reporter activity revealed O-GlcNAc-dependent NFAT activation during hypertrophy. Reversal of enhanced O-GlcNAc signaling blunted cardiomyocyte NFAT-induced changes during hypertrophy. Taken together, these results demonstrate a critical role of O-GlcNAc signaling in NFAT activation during hypertrophy and provide evidence that O-GlcNAc signaling is coordinated with the onset and progression of cardiac hypertrophy. This represents a potentially significant and novel mechanism of cardiac hypertrophy, which may be of particular interest in future in vivo studies of hypertrophy.

  10. Preferential Glutathione Conjugation of a Reverse Diol Epoxide Compared to a Bay Region Diol Epoxide of Phenanthrene in Human Hepatocytes: Relevance to Molecular Epidemiology Studies of Glutathione-S-Transferase Polymorphisms and Cancer

    PubMed Central

    Hecht, Stephen S.; Berg, Jeannette Zinggeler; Hochalter, J. Bradley

    2009-01-01

    Bay region diol epoxides are recognized ultimate carcinogens of polycyclic aromatic hydrocarbons (PAH), and in vitro studies have demonstrated that they can be detoxified by conjugation with glutathione, leading to the widely investigated hypothesis that individuals with low activity forms of glutathione-S-transferases are at higher risk of PAH induced cancer, a hypothesis that has found at most weak support in molecular epidemiology studies. A weakness in this hypothesis was that the mercapturic acids resulting from conjugation of PAH bay region diol epoxides had never been identified in human urine. We recently analyzed smokers’ urine for mercapturic acids derived from phenanthrene, the simplest PAH with a bay region. The only phenanthrene diol epoxide-derived mercapturic acid in smokers’ urine was produced from the reverse diol epoxide, anti-phenanthrene-3,4-diol-1,2-epoxide (11), not the bay region diol epoxide, anti-phenanthrene-1,2-diol-3,4-epoxide (10), which does not support the hypothesis noted above. In this study, we extended these results by examining the conjugation of phenanthrene metabolites with glutathione in human hepatocytes. We identified the mercapturic acid N-acetyl-S-(r-4,t-2,3-trihydroxy-1,2,3,4-tetrahydro-c-1-phenanthryl)-L-cysteine (14a), (0.33–35.9 pmol/mL at 10 µM 8, 24h incubation, N = 10) in all incubations with phenanthrene-3,4-diol (8) and the corresponding diol epoxide 11, but no mercapturic acids were detected in incubations with phenanthrene-1,2-diol (7) and only trace amounts were observed in incubations with the corresponding bay region diol epoxide 10. Taken together with our previous results, these studies clearly demonstrate that glutathione conjugation of a reverse diol epoxide of phenanthrene is favored over conjugation of a bay region diol epoxide. Since reverse diol epoxides of PAH are generally weakly or non-mutagenic/carcinogenic, these results, if generalizable to other PAH, do not support the widely held

  11. Bipotential adult liver progenitors are derived from chronically injured mature hepatocytes

    PubMed Central

    Tarlow, Branden D.; Pelz, Carl; Naugler, Willscott E.; Wakefield, Leslie; Wilson, Elizabeth M.; Finegold, Milton J.; Grompe, Markus

    2014-01-01

    Summary Adult liver progenitor cells are biliary-like epithelial cells that emerge only under injury conditions in the periportal region of the liver. They exhibit phenotypes of both hepatocytes and bile ducts. However, their origin and their significance to injury repair remain unclear. Here, we used a chimeric lineage tracing system to demonstrate that hepatocytes contribute to the progenitor pool. RNA-sequencing, ultrastructural analysis, and in vitro progenitor assays revealed that hepatocyte-derived progenitors were distinct from their biliary-derived counterparts. In vivo lineage tracing and serial transplantation assays showed that hepatocyte-derived proliferative ducts retained a memory of their origin and differentiated back into hepatocytes upon cessation of injury. Similarly, human hepatocytes in chimeric mice also gave rise to biliary progenitors in vivo. We conclude that human and mouse hepatocytes can undergo reversible ductal metaplasia in response to injury, expand as ducts and subsequently contribute to restoration of the hepatocyte mass. PMID:25312494

  12. Ventricular hypertrophy--physiological mechanisms.

    PubMed

    Vaughan Williams, E M

    1986-01-01

    Adult cardiac myocytes are incapable of mitosis. Dead cells are replaced by connective tissue so that after myocardial infarction (MI), function can only be restored by compensatory hypertrophy of the surviving myocardium. In physiological hypertrophy in response to exercise, high altitude, or mild hypertension, additional myoplasm expands cell diameter in an orderly fashion; Z-lines are in register and the normal ratio of volume densities of contractile elements, mitochondria, and capillaries is conserved. In hypertrophy induced by aortic or pulmonary artery banding or by experimental or congenital hypertension, the borderline between physiological and pathological hypertrophy may be crossed, causing disorganization of fibers and an unfavourable contractile element to capillary ratio. There was, therefore, a need for a graded model of hypertrophy, which involves simulating an altitude of 6,000 m at sea level by supplying rabbits with appropriate nitrogen/oxygen mixtures. In this environment, 50% right ventricular hypertrophy can be achieved without alteration of left ventricular weight or hematocrit. Longer exposures produced 100% right ventricular hypertrophy, with only moderate increases in hematocrit and left ventricular weight. It is well known that adrenergic stimulation causes cardiac hypertrophy, and it has been suggested that release of a trophic factor from sympathetic nerves, either noradrenaline or a protein, might be a necessary stimulus for growth. If so, long-term treatment of post-MI patients with beta-adrenergic blocking agents could inhibit a desirable compensatory hypertrophy of the surviving myocardium. In the above model it has been found, however, that neither beta-blockade nor chemical sympathectomy with guanethidine or 6-hydroxydopamine had any effect on the hypertrophy, nor did treatment with verapamil or nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Hepatocyte transplantation for inherited metabolic diseases of the liver.

    PubMed

    Jorns, C; Ellis, E C; Nowak, G; Fischler, B; Nemeth, A; Strom, S C; Ericzon, B G

    2012-09-01

    Inherited metabolic diseases of the liver are characterized by deficiency of a hepatic enzyme or protein often resulting in life-threatening disease. The remaining liver function is usually normal. For most patients, treatment consists of supportive therapy, and the only curative option is liver transplantation. Hepatocyte transplantation is a promising therapy for patients with inherited metabolic liver diseases, which offers a less invasive and fully reversible approach. Procedure-related complications are rare. Here, we review the experience of hepatocyte transplantation for metabolic liver diseases and discuss the major obstacles that need to be overcome to establish hepatocyte transplantation as a reliable treatment option in the clinic.

  14. Inhibition of heme oxygenase-1 partially reverses the arsenite-mediated decrease of CYP1A1, CYP1A2, CYP3A23, and CYP3A2 catalytic activity in isolated rat hepatocytes.

    PubMed

    Anwar-Mohamed, Anwar; Klotz, Lars-Oliver; El-Kadi, Ayman O S

    2012-03-01

    Heme oxygenase (HO-1), the rate-limiting enzyme in the physiological breakdown of heme, is ubiquitous, and its expression can be increased by arsenite [As(III)], and similar other stimuli that induce cellular oxidative stress. Interestingly, it has been shown that the As(III)-induced HO-1 is inversely correlated with a decrease in cytochromes P450 (P450s) activity; however, the direct role for HO-1 in the inhibition of P450 enzymes remains unknown. Our results showed that As(III) at a concentration of 5 μM decreased the constitutive and inducible expression of CYP1A1, CYP1A2, CYP3A23, and CYP3A2 at the mRNA, protein, and catalytic activity levels. Moreover, As(III) decreased the nuclear accumulation of aryl hydrocarbon receptor (AhR) and pregnane X receptor without increasing their degradation. As(III) also increased the binding of cytosolic AhR to heat shock protein 90 and hepatitis B virus X-associated protein 2. In the presence of 2,3,7,8-tetrachlorodibenzo-p-dioxin as an inducer for CYP1A and rifampin as an inducer for CYP3A, As(III) decreased the enzymatic activity of the four P450s more than it decreased their mRNA or protein expression levels. It is noteworthy that treatment with the competitive HO-1 inhibitor, tin-mesoporphyrin, or supplementing external heme partially reversed the As(III)-mediated decrease in activities of the four P450s. In conclusion, the current study provides the first evidence that As(III) decreases CYP1A1, CYP1A2, CYP3A23, and CYP3A2 expression in freshly isolated rat primary hepatocytes. Furthermore, inhibiting the As(III)-mediated induction of HO-1 partially restores the enzymatic activity of these P450s that was initially decreased by As(III), confirming the direct role of HO-1 in the inhibition of P450s.

  15. MicroRNA-561 promotes acetaminophen-induced hepatotoxicity in HepG2 cells and primary human hepatocytes through downregulation of the nuclear receptor corepressor dosage-sensitive sex-reversal adrenal hypoplasia congenital critical region on the X chromosome, gene 1 (DAX-1).

    PubMed

    Li, Minghua; Yang, Yinxue; He, Zhi-Xu; Zhou, Zhi-Wei; Yang, Tianxin; Guo, Peixuan; Zhang, Xueji; Zhou, Shu-Feng

    2014-01-01

    One of the major mechanisms involved in acetaminophen (APAP)-induced hepatotoxicity is hepatocyte nuclear factor 4α (HNF4α)-mediated activation of pregnane X receptor (PXR) and constitutive androstane receptor (CAR). In the present study, we investigated the role of miR-561 and its target gene DAX-1 encoding a corepressor of HNF4α in the process of APAP-induced hepatotoxicity. We used both human hepatocellular liver carcinoma cell line (HepG2) cells and primary human hepatocytes in this study and monitored the levels of reactive oxygen species, lactate dehydrogenase, and glutathione. Our bioinformatics study suggests an association between miR-561 and DAX-1, but not HNF4α. Treatment of HepG2 cells with APAP significantly reduced the expression of DAX-1 in a concentration-dependent manner. miR-561 was induced by APAP treatment in HepG2 cells. Transfection of HepG2 cells with an miR-561 mimic exacerbated APAP-induced hepatotoxicity. HNF4α is physically associated with DAX-1 in HepG2 cells. A decreased protein level of DAX-1 by APAP treatment was also enhanced by miR-561 mimic transfection in HepG2 cells and primary human hepatocytes. The basal and APAP-induced expression of PXR and CAR was enhanced by miR-561 mimic transfection; however, transfection of HepG2 cells or primary human hepatocytes with a miR-561 inhibitor or DAX-1 small interfering RNA reversed these effects. Additionally, the chromatin immunoprecipitation assay revealed that recruitment of DAX-1 onto the PXR promoter was inversely correlated with the recruitment of peroxisome proliferator-activated receptor-α coactivator-1α and HNF4α on APAP treatment. These results indicate that miR-561 worsens APAP-induced hepatotoxicity via inhibition of DAX-1 and consequent transactivation of nuclear receptors.

  16. Kshara application for turbinate hypertrophy

    PubMed Central

    Kotrannavar, Vijay Kumar S.; Angadi, Savita S.

    2013-01-01

    Nasapratinaha (nasal obstruction) is a commonly encountered disease in clinical practice. It is one of the nasal disorders, explained in Ayurveda, having nasal obstruction leading to difficulty in breathing as the main cardinal feature. In contemporary science, this condition can be correlated with various diseases such as turbinate hypertrophy, deviated nasal septum, nasal mass, mucosal congestion, allergic rhinitis, and others; among which turbinate hypertrophy is a common cause. Turbinate hypertrophy can be treated with surgical and medical methods. The medical treatment has limitation for prolonged use because of health purpose, surgical approaches too have failed to achieve desired results in turbinate hypertrophy due to complications and high recurrence rate. The medical and surgical managements have their own limitations, merits, and demerits like synechiae formation, rhinitis sicca, severe bleeding, or osteonecrosis of the turbinate bone A parasurgical treatment explained in Ayurveda, known as kshara pratisarana, which is a minimal invasive and precise procedure for this ailment, tried to overcome this problem. ‘Kshara Karma’ is a popular treatment modality in Ayurveda, which has been advocated in disorders of nose like arbuda (tumor) and adhimamsa (muscular growth). Clinical observation has shown its effectiveness in the management of turbinate hypertrophy. A case report of 45-year-old male who presented with complaints of frequent nasal obstruction, nasal discharge, discomfort in nose, and headache; and diagnosed as turbinate hypertrophy has been presented here. The patient was treated with one application of Kshara over the turbinates. The treatment was effective and no recurrence was noticed in the follow up. PMID:24459392

  17. Idiopathic left ventricular hypertrophy in an infant.

    PubMed

    Bhardwaj, Rajeev; Bhardwaj, Praveen

    2011-01-01

    Cardiac hypertrophy in infancy has been a subject of considerable interest. We present a case of significant left ventricular hypertrophy without any associated cause, presenting in infancy. PMID:23550435

  18. Compensatory Hypertrophy of Skeletal Muscle: Contractile Characteristics

    ERIC Educational Resources Information Center

    Ianuzzo, C. D.; Chen, V.

    1977-01-01

    Describes an experiment using rats that demonstrates contractile characteristics of normal and hypertrophied muscle. Compensatory hypertrophy of the plantaris muscle is induced by surgical removal of the synergistic gastrocnemium muscle. Includes methods for determination of contractile properties of normal and hypertrophied muscle and…

  19. Glucose metabolism and cardiac hypertrophy

    PubMed Central

    Kolwicz, Stephen C.; Tian, Rong

    2011-01-01

    The most notable change in the metabolic profile of hypertrophied hearts is an increased reliance on glucose with an overall reduced oxidative metabolism, i.e. a reappearance of the foetal metabolic pattern. In animal models, this change is attributed to the down-regulation of the transcriptional cascades promoting gene expression for fatty acid oxidation and mitochondrial oxidative phosphorylation in adult hearts. Impaired myocardial energetics in cardiac hypertrophy also triggers AMP-activated protein kinase (AMPK), leading to increased glucose uptake and glycolysis. Aside from increased reliance on glucose as an energy source, changes in other glucose metabolism pathways, e.g. the pentose phosphate pathway, the glucosamine biosynthesis pathway, and anaplerosis, are also noted in the hypertrophied hearts. Studies using transgenic mouse models and pharmacological compounds to mimic or counter the switch of substrate preference in cardiac hypertrophy have demonstrated that increased glucose metabolism in adult heart is not harmful and can be beneficial when it provides sufficient fuel for oxidative metabolism. However, improvement in the oxidative capacity and efficiency rather than the selection of the substrate is likely the ultimate goal for metabolic therapies. PMID:21502371

  20. Kallikrein-related peptidase 8 is expressed in myocardium and induces cardiac hypertrophy

    PubMed Central

    Cao, Buqing; Yu, Qing; Zhao, Wei; Tang, Zhiping; Cong, Binghai; Du, Jiankui; Lu, Jianqiang; Zhu, Xiaoyan; Ni, Xin

    2016-01-01

    The tissue kallikrein-related peptidase family (KLK) is a group of trypsin- and chymotrypsin-like serine proteases that share a similar homology to parent tissue kallikrein (KLK1). KLK1 is identified in heart and has anti-hypertrophic effects. However, whether other KLK family members play a role in regulating cardiac function remains unknown. In the present study, we demonstrated for the first time that KLK8 was expressed in myocardium. KLK8 expression was upregulated in left ventricle of cardiac hypertrophy models. Both intra-cardiac adenovirus-mediated and transgenic-mediated KLK8 overexpression led to cardiac hypertrophy in vivo. In primary neonatal rat cardiomyocytes, KLK8 knockdown inhibited phenylephrine (PE)-induced cardiomyocyte hypertrophy, whereas KLK8 overexpression promoted cardiomyocyte hypertrophy via a serine protease activity-dependent but kinin receptor-independent pathway. KLK8 overexpression increased epidermal growth factor (EGF) production, which was blocked by the inhibitors of serine protease. EGF receptor (EGFR) antagonist and EGFR knockdown reversed the hypertrophy induced by KLK8 overexpression. KLK8-induced cardiomyocyte hypertrophy was also significantly decreased by blocking the protease-activated receptor 1 (PAR1) or PAR2 pathway. Our data suggest that KLK8 may promote cardiomyocyte hypertrophy through EGF signaling- and PARs-dependent but a kinin receptor-independent pathway. It is implied that different KLK family members can subtly regulate cardiac function and remodeling. PMID:26823023

  1. Neurogenic muscle hypertrophy: a case report

    PubMed Central

    Shin, Hyun Ho; Jeon, Young Hoon; Jang, Seung Won

    2016-01-01

    Muscular hypertrophy is caused mainly due to myopathic disorder. But, it is also rarely produced by neurogenic disorder. A 74-year-old woman complained of right calf pain with hypertrophy for several years. Recent lumbar spine magnetic resonance imaging (MRI) showed central and lateral canal narrowing at the L4-L5 intervertebral space. Lower extremity MRI revealed fatty change of right medial head of the gastrocnemius and soleus, causing right calf hypertrophy. Electrodiagnostic examinations including electromyography and nerve conduction velocity testing demonstrated 5th lumbar and 1st sacral polyradiculopathy. Integrating all the results, the diagnosis was neurogenic muscle hypertrophy. Neurogenic muscle hypertrophy is very rare, but we recommend that clinicians consider this problem when a patient complains of lower limb hypertrophy and pain. PMID:27738507

  2. Hepatocyte innervation in primates

    PubMed Central

    1977-01-01

    The efferent innervation and some characteristics of nerve fibers of the liver lobule in the tree shrew, a primate, are described. Nerve endings on hepatocytes were encountered regularly and were determined to be efferent adrenergic nerves. Transmission electron microscopy revealed nerve endings and varicosities in close apposition to the hepatocytes adjacent to the connective tissue of the triads as well as within the liver lobule in the space of Disse. Fluorescence microscopy indicated the existence of adrenergic nerves with a similar distribution. Autoradiography of the avid uptake of exogenous [3H]norepinephrine indicated that all intralobular nerves are potentially norepinephrinergic (adrenergic). Chemical sympathectomy with 6-OH-dopamine resulted in the degeneration of all intralobular liver nerve fibers as revealed by fluorescence microscopy and electron microscopy. Substantial regeneration occurred after 60-90 days but was not completed by that time. Some nerves were also observed in close association with von Kupffer cells and endothelial cells. The functional significance of the efferent liver innervation is discussed. PMID:406265

  3. Lab on a chip-based hepatic sinusoidal system simulator for optimal primary hepatocyte culture.

    PubMed

    Choi, Yoon Young; Kim, Jaehyung; Lee, Sang-Hoon; Kim, Dong-Sik

    2016-08-01

    Primary hepatocyte cultures have been used in studies on liver disease, physiology, and pharmacology. While they are an important tool for in vitro liver studies, maintaining liver-specific characteristics of hepatocytes in vitro is difficult, as these cells rapidly lose their unique characteristics and functions. Portal flow is an important condition to preserve primary hepatocyte functions and liver regeneration in vivo. We have developed a microfluidic chip that does not require bulky peripheral devices or an external power source to investigate the relationship between hepatocyte functional maintenance and flow rates. In our culture system, two types of microfluidic devices were used as scaffolds: a monolayer- and a concave chamber-based device. Under flow conditions, our chips improved albumin and urea secretion rates after 13 days compared to that of the static chips. Reverse transcription polymerase chain reaction demonstrated that hepatocyte-specific gene expression was significantly higher at 13 days under flow conditions than when using static chips. For both two-dimensional and three-dimensional culture on the chips, flow resulted in the best performance of the hepatocyte culture in vitro. We demonstrated that flow improves the viability and efficiency of long-term culture of primary hepatocytes and plays a key role in hepatocyte function. These results suggest that this flow system has the potential for long-term hepatocyte cultures as well as a technique for three-dimensional culture. PMID:27334878

  4. MicroRNA-194 Regulates Hepatocytic Differentiation of Progenitor Cells by Targeting YAP1

    PubMed Central

    Jung, Kwang Hwa; McCarthy, Ryan L.; Zhou, Chong; Uprety, Nadima; Barton, Michelle Craig; Beretta, Laura

    2015-01-01

    MicroRNA expression profiling in human liver progenitor cells following hepatocytic differentiation identified miR-122 and miR-194 as the microRNAs most strongly upregulated during hepatocytic differentiation of progenitor cells. MiR-194 was also highly upregulated following hepatocytic differentiation of human embryonic stem cells (hESCs). Overexpression of miR-194 in progenitor cells accelerated their differentiation into hepatocytes, as measured by morphological features such as canaliculi and expression of hepatocytic markers. Overexpression of miR-194 in hESCs induced their spontaneous differentiation, a phenotype accompanied with accelerated loss of the pluripotent factors OCT4 and NANOG and decrease in mesoderm marker HAND1 expression. We then identified YAP1 as a direct target of miR-194. Inhibition of YAP1 strongly induced hepatocytic differentiation of progenitor cells and YAP1 over expression reversed the miR-194-induced hepatocytic differentiation of progenitor cells. In conclusion, we identified miR-194 as a potent inducer of hepatocytic differentiation of progenitor cells and further identified YAP1 as a mediator of miR-194's effects on hepatocytic differentiation and liver progenitor cell fate. PMID:26731713

  5. MicroRNA Regulates Hepatocytic Differentiation of Progenitor Cells by Targeting YAP1.

    PubMed

    Jung, Kwang Hwa; McCarthy, Ryan L; Zhou, Chong; Uprety, Nadima; Barton, Michelle Craig; Beretta, Laura

    2016-05-01

    MicroRNA expression profiling in human liver progenitor cells following hepatocytic differentiation identified miR-122 and miR-194 as the microRNAs most strongly upregulated during hepatocytic differentiation of progenitor cells. MiR-194 was also highly upregulated following hepatocytic differentiation of human embryonic stem cells (hESCs). Overexpression of miR-194 in progenitor cells accelerated their differentiation into hepatocytes, as measured by morphological features such as canaliculi and expression of hepatocytic markers. Overexpression of miR-194 in hESCs induced their spontaneous differentiation, a phenotype accompanied with accelerated loss of the pluripotent factors OCT4 and NANOG and decrease in mesoderm marker HAND1 expression. We then identified YAP1 as a direct target of miR-194. Inhibition of YAP1 strongly induced hepatocytic differentiation of progenitor cells and YAP1 overexpression reversed the miR-194-induced hepatocytic differentiation of progenitor cells. In conclusion, we identified miR-194 as a potent inducer of hepatocytic differentiation of progenitor cells and further identified YAP1 as a mediator of miR-194's effects on hepatocytic differentiation and liver progenitor cell fate. Stem Cells 2016;34:1284-1296.

  6. [Effect of Bacillus cereus hemolysin II on hepatocyte cells].

    PubMed

    Kholodkov, O A; Budarina, Zh; Kovalevskaya, J I; Si'unov, A V; Solonin, A

    2015-01-01

    We investigated the efficiency of increasing the permeability (permeabilization) of cell membranes in primary liver cells by Bacillus cereus hemolysin II. An assessment of the degree of permeabilization was car ried out by measuring the fluorescence intensity of various low molecular weight dyes, which enter through pores into hepatocyte cells cultivated with hemolysin. We uncovered a high efficacy of hemolysin HlyII action on hepatocyte cell walls, which exceeded the effect of nonionic detergent, digitonin, which is commonly employed for pore formation in various cell membranes. Our results also point to the reversibility of membrane permeabilization in primary hepatocytes. The data obtained in this study can be utilized for assessments of pore-forming activity, in studies of hepatic mechanisms of action, and also the determination of the liver toxicity for different low molecular weight drugs. PMID:26027363

  7. [Effect of Bacillus cereus hemolysin II on hepatocyte cells].

    PubMed

    Kholodkov, O A; Budarina, Zh; Kovalevskaya, J I; Si'unov, A V; Solonin, A

    2015-01-01

    We investigated the efficiency of increasing the permeability (permeabilization) of cell membranes in primary liver cells by Bacillus cereus hemolysin II. An assessment of the degree of permeabilization was car ried out by measuring the fluorescence intensity of various low molecular weight dyes, which enter through pores into hepatocyte cells cultivated with hemolysin. We uncovered a high efficacy of hemolysin HlyII action on hepatocyte cell walls, which exceeded the effect of nonionic detergent, digitonin, which is commonly employed for pore formation in various cell membranes. Our results also point to the reversibility of membrane permeabilization in primary hepatocytes. The data obtained in this study can be utilized for assessments of pore-forming activity, in studies of hepatic mechanisms of action, and also the determination of the liver toxicity for different low molecular weight drugs.

  8. Genetics Home Reference: myostatin-related muscle hypertrophy

    MedlinePlus

    ... Conditions myostatin-related muscle hypertrophy myostatin-related muscle hypertrophy Enable Javascript to view the expand/collapse boxes. ... Open All Close All Description Myostatin-related muscle hypertrophy is a rare condition characterized by reduced body ...

  9. Acute Targeting of General Transcription Factor IIB Restricts Cardiac Hypertrophy via Selective Inhibition of Gene Transcription

    PubMed Central

    Sayed, Danish; Yang, Zhi; He, Minzhen; Pfleger, Jessica M.; Abdellatif, Maha

    2014-01-01

    Background We previously reported that specialized and housekeeping genes are differentially regulated via de novo recruitment and pause-release of RNA polymerase II (pol II), respectively, during cardiac hypertrophy. However, the significance of this finding remains to be examined. Therefore, the purpose of this study was to determine the mechanisms that differentially regulate these gene groups and exploit them for therapeutic targeting. Methods and Results Here we show that general transcription factor IIB (TFIIB) and cyclin-dependent kinase 9 are upregulated during hypertrophy, both targeted by miR-1, and play preferential roles in regulating those two groups of genes. Chromatin immunoprecipitation-sequencing reveals that TFIIB is constitutively bound to all paused, housekeeping, promoters, whereas, de novo recruitment of TFIIB and pol II is required for specialized genes that are induced during hypertrophy. We exploited this dichotomy to acutely inhibit induction of the latter set, which encompasses cardiomyopathy, immune reaction, and extracellular matrix genes, using locked nucleic acid (LNA)-modified antisense TFIIB oligonucleotide treatment. This resulted in suppression of all specialized genes, while sparing the housekeeping ones, and, thus, attenuated pathological hypertrophy. Conclusions The data for the first time reveal distinct general transcription factor IIB dynamics that regulate specialized vs. housekeeping genes during cardiac hypertrophy. Thus, by acutely targeting TFIIB we were able to selectively inhibit the former set of genes and ameliorate pressure overload hypertrophy. We also demonstrate the feasibility of acutely and reversibly targeting cardiac mRNA for therapeutic purposes using LNA-modified antisense oligonucleotides. PMID:25398966

  10. Mammary hypertrophy in an ovariohysterectomized cat.

    PubMed

    Pukay, B P; Stevenson, D A

    1983-05-01

    A four year old ovariohysterectomized domestic short-haired cat under treatment for behavioral urine spraying and idiopathic alopecia developed mammary gland hypertrophy following treatment with megestrol acetate. Withdrawal of the progestin and treatment with androgen failed to cause regression of the hypertrophy. The affected mammary gland was surgically excised and recovery was uneventful.

  11. Telomere dynamics during aging in polygenic left ventricular hypertrophy.

    PubMed

    Marques, Francine Z; Booth, Scott A; Prestes, Priscilla R; Curl, Claire L; Delbridge, Lea M D; Lewandowski, Paul; Harrap, Stephen B; Charchar, Fadi J

    2016-01-01

    Short telomeres are associated with increased risk of cardiovascular disease. Here we studied cardiomyocyte telomere length at key ages during the ontogeny of cardiac hypertrophy and failure in the hypertrophic heart rat (HHR) and compared these with the normal heart rat (NHR) control strain. Key ages corresponded with the pathophysiological sequence beginning with fewer cardiomyocytes (2 days), leading to left ventricular hypertrophy (LVH) (13 wk) and subsequently progression to heart failure (38 wk). We measured telomere length, tissue activity of telomerase, mRNA levels of telomerase reverse transcriptase (Tert) and telomerase RNA component (Terc), and expression of the telomeric regulator microRNA miR-34a. Cardiac telomere length was longer in the HHR compared with the control strain at 2 days and 38 wk, but shorter at 13 wk. Neonatal HHR had higher cardiac telomerase activity and expression of Tert and miR-34a. Telomerase activity was not different at 13 or 38 wk. Tert mRNA and Terc RNA were overexpressed at 38 wk, while miR-34a was overexpressed at 13 wk but downregulated at 38 wk. Circulating leukocytes were strongly correlated with cardiac telomere length in the HHR only. The longer neonatal telomeres in HHR are likely to reflect fewer fetal and early postnatal cardiomyocyte cell divisions and explain the reduced total cardiomyocyte complement that predisposes to later hypertrophy and failure. Although shorter telomeres were a feature of cardiac hypertrophy at 13 wk, they were not present at the progression to heart failure at 38 wk.

  12. Current status of hepatocyte xenotransplantation.

    PubMed

    Meier, Raphael P H; Navarro-Alvarez, Nalu; Morel, Philippe; Schuurman, Henk-Jan; Strom, Stephen; Bühler, Leo H

    2015-11-01

    The treatment of acute liver failure, a condition with high mortality, comprises optimal clinical care, and in severe cases liver transplantation. However, there are limitations in availability of organ donors. Hepatocyte transplantation is a promising alternative that could fill the medical need, in particular as the bridge to liver transplantation. Encapsulated porcine hepatocytes represent an unlimited source that could function as a bioreactor requiring minimal immunosuppression. Besides patients with acute liver failure, patients with alcoholic hepatitis who are unresponsive to a short course of corticosteroids are a target for hepatocyte transplantation. In this review we present an overview of the innate immune barriers in hepatocyte xenotransplantation, including the role of complement and natural antibodies; the role of phagocytic cells and ligands like CD47 in the regulation of phagocytic cells; and the role of Natural Killer cells. We present also some illustrations of physiological species incompatibilities in hepatocyte xenotransplantation, such as incompatibilities in the coagulation system. An overview of the methodology for cell microencapsulation is presented, followed by proof-of-concept studies in rodent and nonhuman primate models of fulminant liver failure: these studies document the efficacy of microencapsulated porcine hepatocytes which warrants progress towards clinical application. Lastly, we present an outline of a provisional clinical trial, that upon completion of preclinical work could start within the upcoming 2-3 years.

  13. The role of autophagy in cardiac hypertrophy.

    PubMed

    Li, Lanfang; Xu, Jin; He, Lu; Peng, Lijun; Zhong, Qiaoqing; Chen, Linxi; Jiang, Zhisheng

    2016-06-01

    Autophagy is conserved in nature from lower eukaryotes to mammals and is an important self-cannibalizing, degradative process that contributes to the elimination of superfluous materials. Cardiac hypertrophy is primarily characterized by excess protein synthesis, increased cardiomyocyte size, and thickened ventricular walls and is a major risk factor that promotes arrhythmia and heart failure. In recent years, cardiomyocyte autophagy has been considered to play a role in controlling the hypertrophic response. However, the beneficial or aggravating role of cardiomyocyte autophagy in cardiac hypertrophy remains controversial. The exact mechanism of cardiomyocyte autophagy in cardiac hypertrophy requires further study. In this review, we summarize the controversies associated with autophagy in cardiac hypertrophy and provide insights into the role of autophagy in the development of cardiac hypertrophy. We conclude that future studies should emphasize the relationship between autophagy and the different stages of cardiac hypertrophy, as well as the autophagic flux and selective autophagy. Autophagy will be a potential therapeutic target for cardiac hypertrophy. PMID:27084518

  14. Do inflammatory cells influence skeletal muscle hypertrophy?

    PubMed

    Koh, Timothy J; Pizza, Francis X

    2009-06-01

    Most research on muscle hypertrophy has focused on the responses of muscle cells to mechanical loading; however, a number of studies also suggest that inflammatory cells may influence muscle hypertrophy. Neutrophils and macrophages accumulate in skeletal muscle following increased mechanical loading, and we have demonstrated that macrophages are essential for hypertrophy following synergist ablation. Whether neutrophils are required remains to be determined. Non-steroidal anti-inflammatory drugs impair adaptive responses of skeletal muscle in both human and animal experiments suggesting that the routine use of such drugs could impair muscle performance. Much remains to be learned about the role of inflammatory cells in muscle hypertrophy, including the molecular signals involved in calling neutrophils and macrophages to skeletal muscle as well as those that regulate their function in muscle. In addition, although we have demonstrated that macrophages produce growth promoting factors during muscle hypertrophy, the full range of functional activities involved in muscle hypertrophy remains to be determined. Further investigation should provide insight into the intriguing hypothesis that inflammatory cells play integral roles in regulating muscle hypertrophy.

  15. Glycogenotic hepatocellular carcinoma with glycogen-ground-glass hepatocytes: A heuristically highly relevant phenotype

    PubMed Central

    Bannasch, Peter

    2012-01-01

    Glycogenotic hepatocellular carcinoma (HCC) with glycogen-ground-glass hepatocytes has recently been described as an allegedly “novel variant” of HCC, but neither the historical background nor the heuristic relevance of this observation were put in perspective. In the present contribution, the most important findings in animal models and human beings related to the emergence and further evolution of excessively glycogen storing (glycogenotic) hepatocytes with and without ground glass features during neoplastic development have been summarized. Glycogenotic HCCs with glycogen-ground-glass hepatocytes represent highly differentiated neoplasms which contain subpopulations of cells phenotypically resembling those of certain types of preneoplastic hepatic foci and benign hepatocellular neoplasms. It is questionable whether the occurrence of glycogen-ground-glass hepatocytes in a glycogenotic HCC justifies its classification as a specific entity. The typical appearance of ground-glass hepatocytes is due to a hypertrophy of the smooth endoplasmic reticulum, which is usually associated with an excessive storage of glycogen and frequently also with an expression of the hepatitis B surface antigen. Sequential studies in animal models and observations in humans indicate that glycogen-ground-glass hepatocytes are a facultative, integral part of a characteristic cellular sequence commencing with focal hepatic glycogenosis potentially progressing to benign and malignant neoplasms. During this process highly differentiated glycogenotic cells including ground-glass hepatocytes are gradually transformed via various intermediate stages into poorly differentiated glycogen-poor, basophilic (ribosome-rich) cancer cells. Histochemical, microbiochemical, and molecular biochemical studies on focal hepatic glycogenosis and advanced preneoplastic and neoplastic lesions in tissue sections and laser-dissected specimens in rat and mouse models have provided compelling evidence for an early

  16. Regression of altitude-produced cardiac hypertrophy.

    NASA Technical Reports Server (NTRS)

    Sizemore, D. A.; Mcintyre, T. W.; Van Liere, E. J.; Wilson , M. F.

    1973-01-01

    The rate of regression of cardiac hypertrophy with time has been determined in adult male albino rats. The hypertrophy was induced by intermittent exposure to simulated high altitude. The percentage hypertrophy was much greater (46%) in the right ventricle than in the left (16%). The regression could be adequately fitted to a single exponential function with a half-time of 6.73 plus or minus 0.71 days (90% CI). There was no significant difference in the rates of regression for the two ventricles.

  17. Differential effect of interleukin-10 on hepatocyte apoptosis.

    PubMed

    Santiago-Lomelí, Mariana; Gómez-Quiroz, Luis E; Ortíz-Ortega, Víctor M; Kershenobich, David; Gutiérrez-Ruiz, Maria Concepción

    2005-04-15

    Current data suggests that hepatocyte apoptosis is an essential feature contributing to several chronic liver diseases. It has been shown that IL-10 has diverse and potentially pleiotropic actions that suggest that it may have a direct effect on apoptosis. It has been established that NF-kappaB activation is essential to protect hepatocytes from apoptosis. The purpose of the present work is to evaluate the effect of the anti-inflammatory cytokine, IL-10 on the activation of NF-kappaB in primary cultured rat hepatocytes and hepatoblastoma (HepG2) cell line and explore its consequences on apoptosis. Apoptosis was induced by TNF-alpha and cicloheximide in HepG2 hepatoblastoma cells and by ethanol and a glutathione depletor in primary cultured rat hepatocytes. NF-kappaB activation was determined by EMSA. IL-10 increased ethanol induced apoptosis in primary culture rat hepatocytes (28%). These effects were enhanced when the cells were pre-treated with IL-10 under conditions of oxidative stress (glutathione depletion). The effects of IL-10 on primary cultured hepatocytes were independent of NF-kappaB activation. When apoptosis was induced by cicloheximide and TNF-alpha in hepatoblastoma cells, pretreatment with IL-10 was accompanied by a decrease of 38% in apoptosis. IL-10 did not have any effect on the signaling cascade of apoptosis but caused a significant increase in NF-kappaB activation. When NF-kappaB activation was inhibited by sulfazalazine the decrease in apoptosis was reversed. The present study demonstrates the importance of differential cell marking when trying to characterize the effects of cytokines in their contribution to liver cell apoptosis. The study provides insight into the mechanisms by which IL-10 affects apoptosis through a differential effect on NF-kappaB activation.

  18. Three Dimensional Primary Hepatocyte Culture

    NASA Technical Reports Server (NTRS)

    Yoffe, Boris

    1998-01-01

    Our results demonstrated for the first time the feasibility of culturing PHH in microgravity bioreactors that exceeded the longest period obtained using other methods. Within the first week of culture, isolated hepatocytes started to form aggregates, which continuously increased in size (up to 1 cm) and macroscopically appeared as a multidimensional tissue-like assembly. To improve oxygenation and nutrition within the spheroids we performed experiments with the biodegradable nonwoven fiber-based polymers made from PolyGlycolic Acid (PGA). It has been shown that PGA scaffolds stimulate isolated cells to regenerate tissue with defined sizes and shapes and are currently being studied for various tissue-engineering applications. Our data demonstrated that culturing hepatocytes in the presence of PGA scaffolds resulted in more efficient cell assembly and formations of larger cell spheroids (up to 3 cm in length, see figure). The histology of cell aggregates cultured with PGA showed polymer fibers with attached hepatocytes. We initiated experiments to co-culture primary human hepatocytes with human microvascular endothelial cells in the bioreactor. The presence of endothelial cells in co-cultures were established by immunohistochemistry using anti-CD34 monoclonal Ab. Our preliminary data demonstrated that cultures of purified hepatocytes with human microvascular endothelial cells exhibited better growth and expressed higher levels of albumin MRNA for a longer period of time than cultures of ppfified, primary human hepatocytes cultured alone. We also evaluated microsomal deethylation activity of hepatocytes cultured in the presence of endothelial cells.In summary, we have established liver cell culture, which mimicked the structure and function of the parent tissue.

  19. The pathological role of advanced glycation end products-downregulated heat shock protein 60 in islet β-cell hypertrophy and dysfunction

    PubMed Central

    Wu, Cheng-Tien; Yang, Ting-Hua; Chiang, Chih-Kang; Liu, Shing-Hwa

    2016-01-01

    Heat shock protein 60 (HSP60) is a mitochondrial chaperone. Advanced glycation end products (AGEs) have been shown to interfere with the β-cell function. We hypothesized that AGEs induced β-cell hypertrophy and dysfunction through a HSP60 dysregulation pathway during the stage of islet/β-cell hypertrophy of type-2-diabetes. We investigated the role of HSP60 in AGEs-induced β-cell hypertrophy and dysfunction using the models of diabetic mice and cultured β-cells. Hypertrophy, increased levels of p27Kip1, AGEs, and receptor for AGEs (RAGE), and decreased levels of HSP60, insulin, and ATP content were obviously observed in pancreatic islets of 12-week-old db/db diabetic mice. Low-concentration AGEs significantly induced the cell hypertrophy, increased the p27Kip1 expression, and decreased the HSP60 expression, insulin secretion, and ATP content in cultured β-cells, which could be reversed by RAGE neutralizing antibody. HSP60 overexpression significantly reversed AGEs-induced hypertrophy, dysfunction, and ATP reduction in β-cells. Oxidative stress was also involved in the AGEs-decreased HSP60 expression in β-cells. Pancreatic sections from diabetic patient showed islet hypertrophy, increased AGEs level, and decreased HSP60 level as compared with normal subject. These findings highlight a novel mechanism by which a HSP60-correlated signaling pathway contributes to the AGEs-RAGE axis-induced β-cell hypertrophy and dysfunction under diabetic hyperglycemia. PMID:27056903

  20. Reactivation of peroxisome proliferator-activated receptor alpha is associated with contractile dysfunction in hypertrophied rat heart.

    PubMed

    Young, M E; Laws, F A; Goodwin, G W; Taegtmeyer, H

    2001-11-30

    In pressure overload-induced hypertrophy, the heart increases its reliance on glucose as a fuel while decreasing fatty acid oxidation. A key regulator of this substrate switching in the hypertrophied heart is peroxisome proliferator-activated receptor alpha (PPARalpha). We tested the hypothesis that down-regulation of PPARalpha is an essential component of cardiac hypertrophy at the levels of increased mass, gene expression, and metabolism by pharmacologically reactivating PPARalpha. Pressure overload (induced by constriction of the ascending aorta for 7 days in rats) resulted in cardiac hypertrophy, increased expression of fetal genes (atrial natriuretic factor and skeletal alpha-actin), decreased expression of PPARalpha and PPARalpha-regulated genes (medium chain acyl-CoA dehydrogenase and pyruvate dehydrogenase kinase 4), and caused substrate switching (measured ex vivo in the isolated working heart preparation). Treatment of rats with the specific PPARalpha agonist WY-14,643 (8 days) did not affect the trophic response or atrial natriuretic factor induction to pressure overload. However, PPARalpha activation blocked skeletal alpha-actin induction, reversed the down-regulation of measured PPARalpha-regulated genes in the hypertrophied heart, and prevented substrate switching. This PPARalpha reactivation concomitantly resulted in severe depression of cardiac power and efficiency in the hypertrophied heart (measured ex vivo). Thus, PPARalpha down-regulation is essential for the maintenance of contractile function of the hypertrophied heart. PMID:11574533

  1. The plasma membrane calcium ATPase 4 signalling in cardiac fibroblasts mediates cardiomyocyte hypertrophy

    PubMed Central

    Mohamed, Tamer M. A.; Abou-Leisa, Riham; Stafford, Nicholas; Maqsood, Arfa; Zi, Min; Prehar, Sukhpal; Baudoin-Stanley, Florence; Wang, Xin; Neyses, Ludwig; Cartwright, Elizabeth J.; Oceandy, Delvac

    2016-01-01

    The heart responds to pathological overload through myocyte hypertrophy. Here we show that this response is regulated by cardiac fibroblasts via a paracrine mechanism involving plasma membrane calcium ATPase 4 (PMCA4). Pmca4 deletion in mice, both systemically and specifically in fibroblasts, reduces the hypertrophic response to pressure overload; however, knocking out Pmca4 specifically in cardiomyocytes does not produce this effect. Mechanistically, cardiac fibroblasts lacking PMCA4 produce higher levels of secreted frizzled related protein 2 (sFRP2), which inhibits the hypertrophic response in neighbouring cardiomyocytes. Furthermore, we show that treatment with the PMCA4 inhibitor aurintricarboxylic acid (ATA) inhibits and reverses cardiac hypertrophy induced by pressure overload in mice. Our results reveal that PMCA4 regulates the development of cardiac hypertrophy and provide proof of principle for a therapeutic approach to treat this condition. PMID:27020607

  2. Teres Minor Hypertrophy is a Common and Negative Predictor of Outcomes after Rotator Cuff Repair

    PubMed Central

    Tokish, John M.; Thigpen, Charles A.; Kissenberth, Michael J.; Hunt, Quinn; Tolan, Stefan John; Swinehart, S. Dane; Shelley, Christina; Hawkins, Richard J.

    2016-01-01

    Objectives: The teres minor has received increased attention in its role as a rotator cuff muscle, particularly in the setting of large infraspinatus tears. Studies have shown that it plays an important beneficial role after total (TSA) and reverse (RSA) shoulder arthroplasty, as well as in maintenance of function in the setting of infraspinatus wasting in patients with large rotator cuff tears. No study, however, has investigated how often teres minor hypertrophy occurs in a population of rotator cuff tears, whether it occurs in the absence of infraspinatus tearing, or whether it is a positive or negative prognostic indicator on outcomes after rotator cuff repair. The purpose of this study was to determine the prevalence of teres minor hypertrophy in a cohort of patients undergoing rotator cuff repair, and to determine its prognostic effect, if any, on outcomes after surgical repair. Methods: Over a 3 year period, all rotator cuff repairs performed in a single practice by 3 American Shoulder and Elbow Society (ASES) member surgeons were collected. One hundered forty-four patients who had preoperative and postoperative (ASES) outcomes (minimum 2 year), and preoperative Magnetic Resonance Imaging (MRI) were included in the study. All MRIs were evaluated for rotator cuff tear tendon involvement, tear size, and Goutallier changes of each muscle. In addition, occupational ratios were determined for the supraspinatus, infraspinatus, and teres minor muscles. Patients were divided into 2 groups, based upon whether they had teres minor hypertrophy or not, based on a previously established definition. A 2 way univariate ANOVA was used to determine the effect of teres minor hypertrophy(tear size by hypertrophy) and Goutallier changes(tear size by fatty infiltration) on ASES change scores(α=0.05) Results: Teres minor hypertrophy was a relatively common finding in this cohort of rotator cuff patients, with 51% of all shoulders demonstrating hypertrophy. Interestingly, in

  3. An unusual case of lingual tonsillar hypertrophy.

    PubMed

    Hope, Nicholas; Patricia Smith, Caroline; Moran, Michael; Primrose, William

    2016-05-01

    Lingual tonsillar hypertrophy is an unusual presentation of voice change. If managed incorrectly this group of patients has the potential to deteriorate significantly causing airway obstruction and potentially death.

  4. A Rare Case of Lipomatous Hypertrophy of the Interventricular Septum

    PubMed Central

    Matsiras, Sotirios; Vassilikos, Vassilios

    2016-01-01

    Asymmetrical left ventricular hypertrophy secondary to interventricular septum hypertrophy is usually considered a typical phenotype of hypertrophic cardiomyopathy. In rare cases other conditions such as tumors or lipomatous hypertrophy of the interventricular septum may have a similar presentation. We present a case of a male patient who presented for routine cardiology work up and was diagnosed of having ventricular septal hypertrophy secondary to localized lipomatous hypertrophy. PMID:27358712

  5. Rapamycin Inhibits Cardiac Hypertrophy by Promoting Autophagy via the MEK/ERK/Beclin-1 Pathway

    PubMed Central

    Gu, Jun; Hu, Wei; Song, Zhi-Ping; Chen, Yue-Guang; Zhang, Da-Dong; Wang, Chang-Qian

    2016-01-01

    Rapamycin, also known as sirolimus, is an antifungal agent and immunosuppressant drug used to prevent organ rejection in transplantation. However, little is known about the role of rapamycin in cardiac hypertrophy and the signaling pathways involved. Here, the effect of rapamycin was examined using phenylephrine (PE) induced cardiomyocyte hypertrophy in vitro and in a rat model of aortic banding (AB) - induced hypertrophy in vivo. Inhibition of MEK/ERK signaling reversed the effect of rapamycin on the up-regulation of LC3-II, Beclin-1 and Noxa, and the down-regulation of Mcl-1 and p62. Silencing of Noxa or Beclin-1 suppressed rapamycin-induced autophagy, and co-immunoprecipitation experiments showed that Noxa abolishes the inhibitory effect of Mcl-1 on Beclin-1, promoting autophagy. In vivo experiments showed that rapamycin decreased AB-induced cardiac hypertrophy in a MEK/ERK dependent manner. Taken together, our results indicate that rapamycin attenuates cardiac hypertrophy by promoting autophagy through a mechanism involving the modulation of Noxa and Beclin-1 expression by the MEK/ERK signaling pathway. PMID:27047390

  6. Reduction of blood oxygen levels enhances postprandial cardiac hypertrophy in Burmese python (Python bivittatus).

    PubMed

    Slay, Christopher E; Enok, Sanne; Hicks, James W; Wang, Tobias

    2014-05-15

    Physiological cardiac hypertrophy is characterized by reversible enlargement of cardiomyocytes and changes in chamber architecture, which increase stroke volume and via augmented convective oxygen transport. Cardiac hypertrophy is known to occur in response to repeated elevations of O2 demand and/or reduced O2 supply in several species of vertebrate ectotherms, including postprandial Burmese pythons (Python bivittatus). Recent data suggest postprandial cardiac hypertrophy in P. bivittatus is a facultative rather than obligatory response to digestion, though the triggers of this response are unknown. Here, we hypothesized that an O2 supply-demand mismatch stimulates postprandial cardiac enlargement in Burmese pythons. To test this hypothesis, we rendered animals anemic prior to feeding, essentially halving blood oxygen content during the postprandial period. Fed anemic animals had heart rates 126% higher than those of fasted controls, which, coupled with a 71% increase in mean arterial pressure, suggests fed anemic animals were experiencing significantly elevated cardiac work. We found significant cardiac hypertrophy in fed anemic animals, which exhibited ventricles 39% larger than those of fasted controls and 28% larger than in fed controls. These findings support our hypothesis that those animals with a greater magnitude of O2 supply-demand mismatch exhibit the largest hearts. The 'low O2 signal' stimulating postprandial cardiac hypertrophy is likely mediated by elevated ventricular wall stress associated with postprandial hemodynamics.

  7. Mechanotransduction pathways in skeletal muscle hypertrophy.

    PubMed

    Yamada, André Katayama; Verlengia, Rozangela; Bueno Junior, Carlos Roberto

    2012-02-01

    In the last decade, molecular biology has contributed to define some of the cellular events that trigger skeletal muscle hypertrophy. Recent evidence shows that insulin like growth factor 1/phosphatidyl inositol 3-kinase/protein kinase B (IGF-1/PI3K/Akt) signaling is not the main pathway towards load-induced skeletal muscle hypertrophy. During load-induced skeletal muscle hypertrophy process, activation of mTORC1 does not require classical growth factor signaling. One potential mechanism that would activate mTORC1 is increased synthesis of phosphatidic acid (PA). Despite the huge progress in this field, it is still early to affirm which molecular event induces hypertrophy in response to mechanical overload. Until now, it seems that mTORC1 is the key regulator of load-induced skeletal muscle hypertrophy. On the other hand, how mTORC1 is activated by PA is unclear, and therefore these mechanisms have to be determined in the following years. The understanding of these molecular events may result in promising therapies for the treatment of muscle-wasting diseases. For now, the best approach is a good regime of resistance exercise training. The objective of this point-of-view paper is to highlight mechanotransduction events, with focus on the mechanisms of mTORC1 and PA activation, and the role of IGF-1 on hypertrophy process. PMID:22171534

  8. Mechanotransduction pathways in skeletal muscle hypertrophy.

    PubMed

    Yamada, André Katayama; Verlengia, Rozangela; Bueno Junior, Carlos Roberto

    2012-02-01

    In the last decade, molecular biology has contributed to define some of the cellular events that trigger skeletal muscle hypertrophy. Recent evidence shows that insulin like growth factor 1/phosphatidyl inositol 3-kinase/protein kinase B (IGF-1/PI3K/Akt) signaling is not the main pathway towards load-induced skeletal muscle hypertrophy. During load-induced skeletal muscle hypertrophy process, activation of mTORC1 does not require classical growth factor signaling. One potential mechanism that would activate mTORC1 is increased synthesis of phosphatidic acid (PA). Despite the huge progress in this field, it is still early to affirm which molecular event induces hypertrophy in response to mechanical overload. Until now, it seems that mTORC1 is the key regulator of load-induced skeletal muscle hypertrophy. On the other hand, how mTORC1 is activated by PA is unclear, and therefore these mechanisms have to be determined in the following years. The understanding of these molecular events may result in promising therapies for the treatment of muscle-wasting diseases. For now, the best approach is a good regime of resistance exercise training. The objective of this point-of-view paper is to highlight mechanotransduction events, with focus on the mechanisms of mTORC1 and PA activation, and the role of IGF-1 on hypertrophy process.

  9. Hepatocyte cell therapy in liver disease.

    PubMed

    Bartlett, David Christopher; Newsome, Philip N

    2015-01-01

    Liver disease is a leading cause of morbidity and mortality. Liver transplantation remains the only proven treatment for end-stage liver failure but is limited by the availability of donor organs. Hepatocyte cell therapy, either with bioartificial liver devices or hepatocyte transplantation, may help address this by delaying or preventing liver transplantation. Early clinical studies have shown promising results, however in most cases, the benefit has been short lived and so further research into these therapies is required. Alternative sources of hepatocytes, including stem cell-derived hepatocytes, are being investigated as the isolation of primary human hepatocytes is limited by the same shortage of donor organs. This review summarises the current clinical experience of hepatocyte cell therapy together with an overview of possible alternative sources of hepatocytes. Current and future areas for research that might lead towards the realisation of the full potential of hepatocyte cell therapy are discussed. PMID:26212798

  10. The current status of primary hepatocyte culture

    PubMed Central

    Mitaka, Toshihiro

    1998-01-01

    Recently, there have been significant advances toward the development of culture conditions that promote proliferation of primary rodent hepatocytes. There are two major methods for the multiplication of hepatocytes in vitro: one is the use of nicotinamide, the other is the use of a nutrient-rich medium. In the medium containing a high concentration of nicotinamide and a growth factor, primary hepatocytes can proliferate well. In this culture condition small mononucleate cells, which are named small hepatocytes, appear and form colonies. Small hepatocytes have a high potential to proliferate while maintaining hepatic characteristics, and can differentiate into mature ones. On the other hand, combining the nutrient-rich medium with 2% DMSO, the proliferated hepatocytes can recover the hepatic differentiated functions and maintain them for a long time. In this review I describe the culture conditions for the proliferation and differentiation of primary hepatocytes and discuss the small hepatocytes, especially their roles in liver growth. PMID:10319020

  11. Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling.

    PubMed

    Gitau, Samuel Chege; Li, Xuelian; Zhao, Dandan; Guo, Zhenfeng; Liang, Haihai; Qian, Ming; Lv, Lifang; Li, Tianshi; Xu, Bozhi; Wang, Zhiguo; Zhang, Yong; Xu, Chaoqian; Lu, Yanjie; Du, Zhiming; Shan, Hongli; Yang, Baofeng

    2015-12-01

    Ventricular hypertrophy is a powerful and independent predictor of cardiovascular morbid events. The vascular properties of low-dose acetyl salicylic acid (aspirin) provide cardiovascular benefits through the irreversible inhibition of platelet cyclooxygenase 1; however, the possible anti-hypertrophic properties and potential mechanism of aspirin have not been investigated in detail. In this study, healthy wild-type male mice were randomly divided into three groups and subjected to transverse aortic constriction (TAC) or sham operation. The TAC-operated mice were treated with the human equivalent of low-dose aspirin (10 mg·kg(-1)·d(-1)); the remaining mice received an equal amount of phosphate buffered saline with 0.65% ethanol, which was used as a vehicle. A cardiomyocyte hypertrophy model induced by angiotensin II (10 nmol·L(-1)) was treated with the human equivalent of low (10 or 100 μmol·L(-1)) and high (1000 μmol·L(-1)) aspirin concentrations in plasma. Changes in the cardiac structure and function were assessed through echocardiography and transmission electron microscopy. Gene expression was determined through RT-PCR and western blot analysis. Results indicated that aspirin treatment abrogated the increased thickness of the left ventricular anterior and posterior walls, the swelling of mitochondria, and the increased surface area in in vivo and in vitro hypertrophy models. Aspirin also normalized the upregulated hypertrophic biomarkers, β-myosin heavy chain (β-MHC), atrial natriuretic peptide (ANP), and b-type natriuretic peptide (BNP). Aspirin efficiently reversed the upregulation of β-catenin and P-Akt expression and the TAC- or ANG II-induced downregulation of GSK-3β. Therefore, low-dose aspirin possesses significant anti-hypertrophic properties at clinically relevant concentrations for anti-thrombotic therapy. The downregulation of β-catenin and Akt may be the underlying signaling mechanism of the effects of aspirin. PMID:26626190

  12. Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling.

    PubMed

    Gitau, Samuel Chege; Li, Xuelian; Zhao, Dandan; Guo, Zhenfeng; Liang, Haihai; Qian, Ming; Lv, Lifang; Li, Tianshi; Xu, Bozhi; Wang, Zhiguo; Zhang, Yong; Xu, Chaoqian; Lu, Yanjie; Du, Zhiming; Shan, Hongli; Yang, Baofeng

    2015-12-01

    Ventricular hypertrophy is a powerful and independent predictor of cardiovascular morbid events. The vascular properties of low-dose acetyl salicylic acid (aspirin) provide cardiovascular benefits through the irreversible inhibition of platelet cyclooxygenase 1; however, the possible anti-hypertrophic properties and potential mechanism of aspirin have not been investigated in detail. In this study, healthy wild-type male mice were randomly divided into three groups and subjected to transverse aortic constriction (TAC) or sham operation. The TAC-operated mice were treated with the human equivalent of low-dose aspirin (10 mg·kg(-1)·d(-1)); the remaining mice received an equal amount of phosphate buffered saline with 0.65% ethanol, which was used as a vehicle. A cardiomyocyte hypertrophy model induced by angiotensin II (10 nmol·L(-1)) was treated with the human equivalent of low (10 or 100 μmol·L(-1)) and high (1000 μmol·L(-1)) aspirin concentrations in plasma. Changes in the cardiac structure and function were assessed through echocardiography and transmission electron microscopy. Gene expression was determined through RT-PCR and western blot analysis. Results indicated that aspirin treatment abrogated the increased thickness of the left ventricular anterior and posterior walls, the swelling of mitochondria, and the increased surface area in in vivo and in vitro hypertrophy models. Aspirin also normalized the upregulated hypertrophic biomarkers, β-myosin heavy chain (β-MHC), atrial natriuretic peptide (ANP), and b-type natriuretic peptide (BNP). Aspirin efficiently reversed the upregulation of β-catenin and P-Akt expression and the TAC- or ANG II-induced downregulation of GSK-3β. Therefore, low-dose aspirin possesses significant anti-hypertrophic properties at clinically relevant concentrations for anti-thrombotic therapy. The downregulation of β-catenin and Akt may be the underlying signaling mechanism of the effects of aspirin.

  13. Asialoglycoprotein Receptor-Mediated Gene Delivery to Hepatocytes Using Galactosylated Polymers.

    PubMed

    Thapa, Bindu; Kumar, Piyush; Zeng, Hongbo; Narain, Ravin

    2015-09-14

    Highly efficient, specific, and nontoxic gene delivery vector is required for gene therapy to the liver. Hepatocytes exclusively express asialoglycoprotein receptor (ASGPR), which can recognize and bind to galactose or N-acetylgalactosamine. Galactosylated polymers are therefore explored for targeted gene delivery to the liver. A library of safe and stable galactose-based glycopolymers that can specifically deliver genes to hepatocytes were synthesized having different architectures, compositions, and molecular weights via the reversible addition-fragmentation chain transfer process. The physical and chemical properties of these polymers have a great impact on gene delivery efficacy into hepatocytes, as such block copolymers are found to form more stable complexes with plasmid and have high gene delivery efficiency into ASGPR expressing hepatocytes. Transfection efficiency and uptake of polyplexes with these polymers decreased significantly by preincubation of hepatocytes with free asialofetuin or by adding free asialofetuin together with polyplexes into hepatocytes. The results confirmed that polyplexes with these polymers were taken up specifically by hepatocytes via ASGPR-mediated endocytosis. The results from transfection efficiency and uptake of these polymers in cells without ASGPR, such as SK Hep1 and HeLa cells, further support this mechanism. Since in vitro cytotoxicity assays prove these glycopolymers to be nontoxic, they may be useful for delivery of clinically important genes specifically to the liver.

  14. A20 is up-regulated in primary mouse hepatocytes subjected to hypoxia and reperfusion.

    PubMed

    Sun, Jiao; Sun, Luning; Zhang, Ning; Lu, Xiaomei; Zhang, Haipeng

    2012-12-01

    Hepatic ischemia reperfusion-induced injury is a major medical concern, and it is important to characterize the adaptive mechanisms of hepatocytes to hypoxia and reoxygenation to sustain liver function. In this study, we reported a proteomic analysis of ischemia reperfusion-induced global responses in primary hepatocytes. The primary hepatocytes were isolated from mice and exposed to oxygen to mimic ischemia reperfusion. Total proteins were extracted from the cells and analyzed by two-dimensional gel electrophoresis followed by matrix-assisted laser desorption time-of-flight mass spectrometry. Zinc finger protein A20, mercaptopyruvate sulfur transferase, apolipoprotein E precursor and carbamoyl-phosphate synthase mitochondrial precursor were identified as differentially expressed in differently exposed groups. Reverse transcriptase polymerase chain reaction and Western blot analysis validated that A20 was significantly up-regulated in the hepatocytes subjected to hypoxia and reperfusion. In addition, the expression of peroxisome proliferator-activated receptor α, an A20 target, was up-regulated in the hepatocytes subjected to hypoxia and reperfusion. Our results on A20 provide new insight into the mechanism underlying the adaptation of hepatocytes to hypoxia and reperfusion. Because of its role in the up-regulation of peroxisome proliferator-activated receptor α expression to protect hepatocytes from reperfusion-induced apoptosis, A20 is a potential target for the prevention and therapy of liver injury after ischemia reperfusion.

  15. Efficient amelioration of carbon tetrachloride induced toxicity in isolated rat hepatocytes by Syzygium cumini Skeels extract.

    PubMed

    Veigas, Jyothi M; Shrivasthava, Richa; Neelwarne, Bhagyalakshmi

    2008-09-01

    Syzygium cumini, Indian black plum or Java plum, is a rich source for anthocyanins (230 mg/100g DW) showing high antioxidant activity in vitro. In the following study it is further demonstrated that S. cumini peel extract rich in anthocyanins (SCA) offers considerable protection against carbon tetrachloride (CCl(4))-induced damage in rat hepatocytes. SCA itself being non-toxic to primary rat hepatocytes at concentrations ranging from 50 to 500 ppm, was found to suppress CCl(4)-induced LDH leakage by 54% at 50ppm, thereby improving the cell viability by 39%. The SCA significantly reversed the CCl(4) induced changes in cellular glutathione (GSH) level, lipid peroxidation and activity of the antioxidant enzyme glutathione peroxidase. Exposure of hepatocytes to SCA after CCl(4) treatment was found to elevate GSH and GPx activities by 2-folds, whereas the activities of catalase and superoxide dismutase were not significantly affected. The fruit pulp extract (SPE) was less effective in offering protection to rat hepatocytes, particularly in terms of total GSH content and a consequent increase in lipid peroxidation although the higher GPx activity suggests the probable involvement of GSH as a substrate for GPx. These observations suggest that the fruit peel extract of S. cumini, is largely responsible for the reversal of CCl(4)-induced oxidative damage in rat hepatocytes. Both peel and pulp extract appear to offer protection to rat hepatocytes through GPx along with other biological pathways independent of catalase and superoxide dismutase. PMID:18538978

  16. MRI of nasopharyngeal adenoid hypertrophy.

    PubMed

    Surov, Alexey; Ryl, Ina; Bartel-Friedrich, Sylvia; Wienke, Andreas; Kösling, Sabrina

    2016-10-01

    Nasopharyngeal adenoid hypertrophy (NAH) is a typical benign lesion. Due to involution, nasopharyngeal lymphatic tissue usually is not found in adults beyond the 30th to 40th year of life. However, occasionally NAH has been recognized after the 50th or 60th year. The aim of this study is to identify the frequency of NAH and to analyze its MRI findings in different age groups. From 2007 to 2011, 6693 MR investigations of the head were performed at our institution. MRI was obtained with a 1.5 T MRI device. NAH was identified in 18.0% of the patients. The frequency of NAH varied from 60.3% to 1.0% in the different age groups. The mean size of NAH was 23.2 ± 4.5 mm in cranio-caudal, 31.1 ± 5.2 mm in left-right, and 14.2 ± 4.1 mm in the anterior-posterior direction. The left-right and cranio-caudal sizes of NAH were largest in the 0-9 age group and decreased with age. On T1-w images most lesions (95.4%) were hypointense in comparison to the adjacent musculature. On T2-w fat-saturated images 82.4% of the lesions were hyperintense. After intravenous administration of contrast medium most lesions showed a slight enhancement (58.6%). Moderate enhancement was seen in 32.4% and a marked enhancement was identified in 9.0%. In the 0-9 age group most lesions showed a slight enhancement. Cysts within NAH were identified in 433 cases (35.9%). The frequency of cysts increased continuously with age, namely from 10.9% to 65.2%.

  17. Metabolism of 2-acetylaminofluorene by hepatocytes isolated from rainbow trout.

    PubMed

    Steward, A R; Elmarakby, S A; Stuart, K G; Kumar, S; Sikka, H C

    1995-02-01

    The metabolism of 2-acetyl-[9-14C]aminofluorene (AAF) by hepatocytes isolated from rainbow trout (Oncorhynchus mykiss), Shasta strain, was investigated in order to assess the competing activation and detoxification pathways which may explain the resistance of this species and strain to the initiation of carcinogenesis by this model carcinogenic aromatic amide. Freshly isolated hepatocytes (per milliliter: 1.0 mg dry wt; 1.5 (10(6)) hepatocytes) incubated with 65 microM AAF for 4 hr converted 15.4 nmol AAF to metabolites, including 7.8 nmol of water-soluble compounds. AAF-derived radioactivity extracted from the incubation mixtures, before and after hydrolysis by beta-glucuronidase and arylsulfatase, was analyzed by reversed-phase HPLC. The metabolite profile following incubation of hepatocytes with 6.5 microM AAF for 4 hr included (as percentage of total metabolites); 7-OH-AAF, 5-/8-/9-OH-AAF and 2-aminofluorene (AF) (17, 2.4, and 2.7%, respectively); conjugates of these respective primary metabolites (39, 9, and 4%, respectively). Glucuronides amounted to 49% of the total metabolites. N-OH-AAF and its conjugates always amounted to < 1% of total metabolites. The relative amount of (unconjugated) AF increased considerably (to 26%) following incubation of hepatocytes with 65 microM AAF, with a corresponding decrease in the total amount of glucuronides formed. Following incubation with 65 microM AAF, 1.6% of AAF metabolites was covalently bound to macromolecules, giving a ratio of covalently bound derivatives to detoxification products of 0.028. These data are consistent with the hypothesis that rainbow trout are resistant to AAF-induced hepatocarcinogenesis, in part, because trout liver efficiently detoxifies AAF and forms only relatively small amounts of active intermediates capable of binding to macromolecules, including DNA.

  18. Coronary haemodynamics in left ventricular hypertrophy.

    PubMed Central

    Wallbridge, D. R.; Cobbe, S. M.

    1996-01-01

    BACKGROUND: Left ventricular hypertrophy is associated with an increased risk of cardiovascular morbidity and mortality. Previous studies have shown that patients with left ventricular hypertrophy develop electrocardiographic changes and left ventricular dysfunction during acute hypotension, and suggest that the lower end of autoregulation may be shifted upwards. AIM: To measure coronary blood flow (velocity) and flow reserve during acute hypotension in patients with left ventricular hypertrophy. PATIENTS: Eight patients with atypical chest pain and seven with hypertensive left ventricular hypertrophy; all with angiographically normal epicardial vessels. SETTING: Tertiary referral centre. METHODS: The physiological range of blood pressure was determined by previous ambulatory monitoring. Left ventricular mass was determined by echocardiography. At cardiac catheterisation, left coronary blood flow velocity was measured using a Judkins style Doppler tipped catheter. During acute hypotension with sodium nitroprusside, coronary blood flow velocity was recorded at rest and during maximal hyperaemia induced by intracoronary injection of adenosine. Quantitative coronary angiography was performed manually. RESULTS: For both groups coronary blood flow velocity remained relatively constant over a range of physiological diastolic blood pressures and showed a steep relation with diastolic blood pressure during maximal hyperaemia with intracoronary adenosine. Absolute coronary blood flow (calculated from quantitative angiographic data), standardised for left ventricular mass, showed reduced flow in the hypertensive group at rest and during maximal vasodilatation. CONCLUSION: The results are consistent with an inadequate blood supply to the hypertrophied heart, but no upward shift of the lower end of the autoregulatory range was observed. PMID:8705764

  19. Tumor necrosis factor: receptor binding and expression of receptors in cultured mouse hepatocytes.

    PubMed

    Adamson, G M; Billings, R E

    1994-04-01

    Recombinant murine tumor necrosis factor (TNF-alpha) was labeled with 125I and used to determine the binding characteristics, internalization and intracellular degradation in cultured mouse hepatocytes. [125I]TNF-alpha bound specifically to hepatocytes and Scatchard analysis of the data indicated binding to both a low-affinity (Kd = 20 nM) high capacity (51225 sites/cell) component and high-affinity component (Kd = 4 pM), with low capacity (290 sites/cell). The extent of TNF-alpha binding to hepatocytes correlated closely with its biological activity in hepatocytes, as indexed by depletion of intracellular ATP. At concentrations lower than 0.06 nM there was minimal binding and no effect on cellular ATP, whereas maximal binding at concentrations greater than 45 nM caused 80% depletion (in comparison to controls) of hepatocyte ATP. Incubation at 37 degrees C resulted in rapid uptake, internalization and degradation of [125I]TNF-alpha. This was followed by release of degraded material from hepatocytes. Examination, by reverse transcriptase/polymerase chain reaction technology, of hepatocyte RNA extracted after the 4-hr adherence period revealed that mouse hepatocytes expressed mRNA for both TNF-alpha receptor 1 and TNF-alpha receptor 2, and that the relative abundance of TNF-alpha receptor 1 was approximately 7-fold greater than that for TNF-alpha receptor 2. Because it has been shown that these receptors have different affinities for TNF-alpha, this may explain the high- and low-affinity binding sites present on cultured mouse hepatocytes.

  20. UCR1C is a novel activator of phosphodiesterase 4 (PDE4) long isoforms and attenuates cardiomyocyte hypertrophy

    PubMed Central

    Wang, Li; Burmeister, Brian T.; Johnson, Keven R.; Baillie, George S.; Karginov, Andrei V.; Skidgel, Randal A.; O’Bryan, John P.; Carnegie, Graeme K.

    2015-01-01

    Hypertrophy increases the risk of heart failure and arrhythmia. Prevention or reversal of the maladaptive hypertrophic phenotype has thus been proposed to treat heart failure. Chronic β-adrenergic receptor (β-AR) stimulation induces cardiomyocyte hypertrophy by elevating 3′, 5′-cyclic adenosine monophosphate (cAMP) levels and activating downstream effectors such protein kinase A (PKA). Conversely, hydrolysis of cAMP by phosphodiesterases (PDEs) spatiotemporally restricts cAMP signaling. Here, we demonstrate that PDE4, but not PDE3, is critical in regulating cardiomyocyte hypertrophy, and may represent a potential target for preventing maladaptive hypertrophy. We identify a sequence within the upstream conserved region 1 of PDE4D, termed UCR1C, as a novel activator of PDE4 long isoforms. UCR1C activates PDE4 in complex with A-Kinase anchoring protein (AKAP)-Lbc resulting in decreased PKA signaling facilitated by AKAP-Lbc. Expression of UCR1C in cardiomyocytes inhibits hypertrophy in response to chronic β-AR stimulation. This effect is partially due to inhibition of nuclear PKA activity, which decreases phosphorylation of the transcription factor cAMP response element-binding protein (CREB). In conclusion, PDE4 activation by UCR1C attenuates cardiomyocyte hypertrophy by specifically inhibiting nuclear PKA activity. PMID:25683917

  1. Na+/H+ exchanger isoform 1 induced cardiomyocyte hypertrophy involves activation of p90 ribosomal s6 kinase.

    PubMed

    Jaballah, Maiy; Mohamed, Iman A; Alemrayat, Bayan; Al-Sulaiti, Fatima; Mlih, Mohamed; Mraiche, Fatima

    2015-01-01

    Studies using pharmacological and genetic approaches have shown that increased activity/expression of the Na+/H+ exchanger isoform 1 (NHE1) play a critical role in the pathogenesis of cardiac hypertrophy. Despite the importance of NHE1 in cardiac hypertrophy, severe cerebrovascular side effects were associated with the use of NHE1 inhibitors when administered to patients with myocardial infarctions. p90 ribosomal S6 Kinase (RSK), a downstream regulator of the mitogen-activated protein kinase pathway, has also been implicated in cardiac hypertrophy. We hypothesized that RSK plays a role in the NHE1 induced cardiomyocyte hypertrophic response. Infection of H9c2 cardiomyoblasts with the active form of the NHE1 adenovirus induced hypertrophy and was associated with an increase in the phosphorylation of RSK (P<0.05). Parameters of hypertrophy such as cell area, protein content and atrial natriuretic mRNA expression were significantly reduced in H9c2 cardiomyoblasts infected with active NHE1 in the presence of dominant negative RSK (DN-RSK) (P<0.05). These results confirm that NHE1 lies upstream of RSK. Increased phosphorylation and activation of GATA4 at Ser261 was correlated with increased RSK phosphorylation. This increase was reversed upon inhibition of RSK or NHE1. These findings demonstrate for the first time that the NHE1 mediated hypertrophy is accounted for by increased activation and phosphorylation of RSK, which subsequently increased the phosphorylation of GATA4; eventually activating fetal gene transcriptional machinery. PMID:25830299

  2. Left Ventricular Hypertrophy Phenotype in Childhood-Onset Essential Hypertension.

    PubMed

    Gupta-Malhotra, Monesha; Hashmi, Syed Shahrukh; Poffenbarger, Tim; McNiece-Redwine, Karen

    2016-05-01

    The aim of this study was to determine the risk factors associated with left ventricular (LV) hypertrophy (LVH) among 89 untreated children with primary hypertension. Clinic hypertension was confirmed by 24-hour ambulatory blood pressure (BP) monitoring. LV mass (LVM) index was calculated as LVM (g)/height (m)(2.7) and LVH was defined as LVM index >95th percentile. Children with (n=32) and without (n=57) LVH were compared. Both obesity and systolic BP were independently associated with LVH, with a higher contribution by body mass index. Obesity contributed significantly, with a nearly nine-fold increased risk of LVH. There was evidence of effect modification by the presence or absence of obesity on the relationship between systolic BP and LVH, whereby the relationship existed mainly in nonobese rather than obese children. Hence, to achieve reversal of LVH, clinicians should take into account both BP control and weight management.

  3. Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

    SciTech Connect

    Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra; De Ridder, Mark

    2013-03-01

    Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes.

  4. The mitochondrial import gene tomm22 is specifically required for hepatocyte survival and provides a liver regeneration model

    PubMed Central

    Curado, Silvia; Ober, Elke A.; Walsh, Susan; Cortes-Hernandez, Paulina; Verkade, Heather; Koehler, Carla M.; Stainier, Didier Y. R.

    2010-01-01

    SUMMARY Understanding liver development should lead to greater insights into liver diseases and improve therapeutic strategies. In a forward genetic screen for genes regulating liver development in zebrafish, we identified a mutant – oliver – that exhibits liver-specific defects. In oliver mutants, the liver is specified, bile ducts form and hepatocytes differentiate. However, the hepatocytes die shortly after their differentiation, and thus the resulting mutant liver consists mainly of biliary tissue. We identified a mutation in the gene encoding translocase of the outer mitochondrial membrane 22 (Tomm22) as responsible for this phenotype. Mutations in tomm genes have been associated with mitochondrial dysfunction, but most studies on the effect of defective mitochondrial protein translocation have been carried out in cultured cells or unicellular organisms. Therefore, the tomm22 mutant represents an important vertebrate genetic model to study mitochondrial biology and hepatic mitochondrial diseases. We further found that the temporary knockdown of Tomm22 levels by morpholino antisense oligonucleotides causes a specific hepatocyte degeneration phenotype that is reversible: new hepatocytes repopulate the liver as Tomm22 recovers to wild-type levels. The specificity and reversibility of hepatocyte ablation after temporary knockdown of Tomm22 provides an additional model to study liver regeneration, under conditions where most hepatocytes have died. We used this regeneration model to analyze the signaling commonalities between hepatocyte development and regeneration. PMID:20483998

  5. Association between miR-181b and PKG 1 in myocardial hypertrophy and its clinical implications

    PubMed Central

    ZHONG, WEI; YANG, JUN; CAO, QIAN; HUAN, XIAODONG

    2015-01-01

    The aim of this study was to explore the microRNA (miR)-181b expression in myocardial hypertrophy and to investigate its association with cGMP-dependent protein kinase type I (PKG 1) in an in vitro model. The miR-181b level in the peripheral blood was determined in patients with myocardial hypertrophy, and an in vitro model was established via phenylephrine (PE) treatment. Reverse transcription-quantitative polymerase chain reaction analysis and western blotting were performed to detect the expression levels of miR-181b, PKG 1 and hypertrophy-related genes. The results revealed that the expression of miR-181b was elevated in the peripheral blood of patients with myocardial hypertrophy, and this may have contributed to the pathology and progression of the disease. When the primary myocardial cells were treated with PE, microscopic observation and flow cytometry revealed significant hypertrophy. Furthermore, upregulation of myocardial hypertrophy-related genes, including β-myosin heavy chain, α-sarcomeric actinin and atrial natriuretic peptide, was observed. The miR-181b expression level in the PE-treated cells was elevated, while the mRNA and protein expression levels of PKG 1 were decreased, indicating a negative correlation between miR-181b and PKG 1 in myocardial hypertrophy. In addition, when the PE-treated primary myocardial cells were transfected with miR-181b inhibitor, the reduced PKG 1 expression was restored and the myocardial hypertrophy alleviated, as indicated by the reduced cellular sizes and decreased expression levels of the myocardial hypertrophy-related genes. In conclusion, miR-181b expression has been shown to be upregulated in myocardial hypertrophy, and this may play a role in the pathogenesis of the disease by regulating the expression of PKG 1. The present findings suggest that miR-181b is a promising molecular indicator for the clinical diagnosis and treatment of cardiac hypertrophy. PMID:26622405

  6. Tripartite motif 32 prevents pathological cardiac hypertrophy

    PubMed Central

    Huang, Jia; Ji, Yanxiao; Zhang, Xiaojing; Wang, Pixiao; Deng, Keqiong; Jiang, Xi; Ma, Genshan

    2016-01-01

    TRIM32 (tripartite motif 32) is widely accepted to be an E3 ligase that interacts with and eventually ubiquitylates multiple substrates. TRIM32 mutants have been associated with LGMD-2H (limb girdle muscular dystrophy 2H). However, whether TRIM32 is involved in cardiac hypertrophy induced by biomechanical stresses and neurohumoral mediators remains unclear. We generated mice and isolated NRCMs (neonatal rat cardiomyocytes) that overexpressed or were deficient in TRIM32 to investigate the effect of TRIM32 on AB (aortic banding) or AngII (angiotensin II)-mediated cardiac hypertrophy. Echocardiography and both pathological and molecular analyses were used to determine the extent of cardiac hypertrophy and subsequent fibrosis. Our results showed that overexpression of TRIM32 in the heart significantly alleviated the hypertrophic response induced by pressure overload, whereas TRIM32 deficiency dramatically aggravated pathological cardiac remodelling. Similar results were also found in cultured NRCMs incubated with AngII. Mechanistically, the present study suggests that TRIM32 exerts cardioprotective action by interruption of Akt- but not MAPK (mitogen-dependent protein kinase)-dependent signalling pathways. Additionally, inactivation of Akt by LY294002 offset the exacerbated hypertrophic response induced by AB in TRIM32-deficient mice. In conclusion, the present study indicates that TRIM32 plays a protective role in AB-induced pathological cardiac remodelling by blocking Akt-dependent signalling. Therefore TRIM32 could be a novel therapeutic target for the prevention of cardiac hypertrophy and heart failure. PMID:26884348

  7. Skeletal Muscle Hypertrophy after Aerobic Exercise Training

    PubMed Central

    Konopka, Adam R.; Harber, Matthew P.

    2014-01-01

    Current dogma suggests aerobic exercise training has minimal effect on skeletal muscle size. We and others have demonstrated that aerobic exercise acutely and chronically alters protein metabolism and induces skeletal muscle hypertrophy. These findings promote an antithesis to the status quo by providing novel perspective on skeletal muscle mass regulation and insight into exercise-countermeasures for populations prone to muscle loss. PMID:24508740

  8. The immobilization of hepatocytes on 24 nm-sized gold colloid for enhanced hepatocytes proliferation.

    PubMed

    Gu, Hai-Ying; Chen, Zhong; Sa, Rong-Xiao; Yuan, Su-Su; Chen, Hong-Yuan; Ding, Yi-Tao; Yu, Ai-Min

    2004-08-01

    Bioartificial liver and hepatocyte transplantation is anticipated to supply a temporary metabolic support for candidates of liver transplantation or for patients with fulminant liver failure. An essential restriction of this form is the inability to acquire an enough amount of hepatocytes. Enhancement of the proliferation and differentiated function of hepatocytes is becoming a pursued target. Here, porcine hepatocytes were successfully immobilized on nano-sized gold colloid particles to construct a "hepatocyte/gold colloid" interface at which hepatocytes can be quickly proliferated. The properties of this resulting interface were characterized and confirmed by scanning electron microscopy and atomic force microscopy. The proliferative mechanism of hepatocytes was also discussed. The proliferated hepatocytes could be applied to the clinic based on their excellent functions for the synthesis of protein, glucose and urea as well as lower lactate dehydrogenase release. PMID:15020118

  9. Strategies for immortalization of primary hepatocytes

    PubMed Central

    Eva, Ramboer; Bram, De Craene; Joery, De Kock; Tamara, Vanhaecke; Geert, Berx; Vera, Rogiers; Mathieu, Vinken

    2014-01-01

    The liver has the unique capacity to regenerate in response to a damaging event. Liver regeneration is hereby largely driven by hepatocyte proliferation, which in turn relies on cell cycling. The hepatocyte cell cycle is a complex process that is tightly regulated by several well-established mechanisms. In vitro, isolated hepatocytes do not longer retain this proliferative capacity. However, in vitro cell growth can be boosted by immortalization of hepatocytes. Well-defined immortalization genes can be artificially overexpressed in hepatocytes or the cells can be conditionally immortalized leading to controlled cell proliferation. This paper discusses the current immortalization techniques and provides a state-of-the-art overview of the actually available immortalized hepatocyte-derived cell lines and their applications. PMID:24911463

  10. A scientist revisits the atrophy-hypertrophy complex: hepatic apoptosis and regeneration.

    PubMed

    Black, Dalliah M; Behrns, Kevin E

    2002-10-01

    In 1898, Cantlie demonstrated his deep insight into the AHC when he wrote. "It is theoretically possible to tie the vessels of one side at the gate of the liver...leaving the other side to do the work. That one-half of the liver can hypertrophy, so as to perform the function of the whole, is attested by pathological study...I commend this subject to all those who are working on the surgery of the liver; and I believe that if, in the hands of future observers, the statements I have made receive closer investigation, surgery of the liver will be advanced a step." More than 100 years later, his foresight is coming to fruition, but the understanding of the AHC remains rudimentary. Further insight into the cellular and molecular mechanisms that initiate hepatocyte replication after contralateral atrophy may allow the development of novel therapeutic treatments or adjuncts.

  11. Circadian rhythm of dry mass and weight-class-pattern of the rat hepatocytes--effects of light-dark and feeding regimens.

    PubMed

    Tongiani, R; Chieli, E; Malvaldi, G

    1982-01-01

    1. Dry weight has been determined of individual hepatocytes isolated from rats kept at natural or at reversed daily light-dark cycle, and from rats under time-restricted feeding. Behaviours of liver weight, mitotic activity and binuclearity frequency of the hepatocytes and serum corticosterone have been also investigated. 2. At natural light-dark cycle, liver weight, hepatocyte mitotic activity, and serum corticosterone were higher during the day than during the night. In accordance, dry weight and class number of the hepatocytes were both higher by day than by night. 3. By reversal of the light-dark cycle, circadian rhythms of liver weight, hepatocyte mitotic activity and serum corticosterone underwent a reversal. In accordance, circadian rhythm also reversed of both dry mass of the hepatocytes, which became heavier by night than by day, and pattern of the hepatocyte weight-classes, which became sharper, more discrete and more numerous by night, less defined and lower in number by day. 4. Feeding restriction to early morning or to late afternoon did not affect substantially the circadian rhythms of the parameters examined. 5. Binuclear cell frequency did never differ significantly at midnight with respect to midday, irrespectively to the experimental condition. 6. Regulation of the circadian rhythm of both weight-class pattern and dry mass of the hepatocytes appears to be mainly acted by the light-dark regimen likely via modulation of the plasma glucocorticoids (corticosterone) concentration, and increase/decrease of which causes a decrease/increase of the total solid content of hepatocytes, with redistribution of cells in the weight-classes. 7. Feeding rhythm and time elapsed from food intake mainly influence definition of the individual weight-classes and weight range of the hepatocytes.

  12. Tanshinone IIA Prevents Leu27IGF-II-Induced Cardiomyocyte Hypertrophy Mediated by Estrogen Receptor and Subsequent Akt Activation.

    PubMed

    Weng, Yueh-Shan; Wang, Hsueh-Fang; Pai, Pei-Ying; Jong, Gwo-Ping; Lai, Chao-Hung; Chung, Li-Chin; Hsieh, Dennis Jine-Yuan; HsuanDay, Cecilia; Kuo, Wei-Wen; Huang, Chih-Yang

    2015-01-01

    IGF-IIR plays important roles as a key regulator in myocardial pathological hypertrophy and apoptosis, which subsequently lead to heart failure. Salvia miltiorrhiza Bunge (Danshen) is a traditional Chinese medicinal herb used to treat cardiovascular diseases. Tanshinone IIA is an active compound in Danshen and is structurally similar to 17[Formula: see text]-estradiol (E[Formula: see text]. However, whether tanshinone IIA improves cardiomyocyte survival in pathological hypertrophy through estrogen receptor (ER) regulation remains unclear. This study investigates the role of ER signaling in mediating the protective effects of tanshinone IIA on IGF-IIR-induced myocardial hypertrophy. Leu27IGF-II (IGF-II analog) was shown in this study to specifically activate IGF-IIR expression and ICI 182,780 (ICI), an ER antagonist used to investigate tanshinone IIA estrogenic activity. We demonstrated that tanshinone IIA significantly enhanced Akt phosphorylation through ER activation to inhibit Leu27IGF-II-induced calcineurin expression and subsequent NFATc3 nuclear translocation to suppress myocardial hypertrophy. Tanshinone IIA reduced the cell size and suppressed ANP and BNP, inhibiting antihypertrophic effects induced by Leu27IGF-II. The cardioprotective properties of tanshinone IIA that inhibit Leu27IGF-II-induced cell hypertrophy and promote cell survival were reversed by ICI. Furthermore, ICI significantly reduced phospho-Akt, Ly294002 (PI3K inhibitor), and PI3K siRNA significantly reduced the tanshinone IIA-induced protective effect. The above results suggest that tanshinone IIA inhibited cardiomyocyte hypertrophy, which was mediated through ER, by activating the PI3K/Akt pathway and inhibiting Leu27IGF-II-induced calcineurin and NFATC3. Tanshinone IIA exerted strong estrogenic activity and therefore represented a novel selective ER modulator that inhibits IGF-IIR signaling to block cardiac hypertrophy. PMID:26621443

  13. Carbonic anhydrase inhibition prevents and reverts cardiomyocyte hypertrophy

    PubMed Central

    Alvarez, Bernardo V; Johnson, Danielle E; Sowah, Daniel; Soliman, Daniel; Light, Peter E; Xia, Ying; Karmazyn, Morris; Casey, Joseph R

    2007-01-01

    Hypertrophic cardiomyocyte growth contributes substantially to the progression of heart failure. Activation of the plasma membrane Na+–H+ exchanger (NHE1) and Cl−–HCO3− exchanger (AE3) has emerged as a central point in the hypertrophic cascade. Both NHE1 and AE3 bind carbonic anhydrase (CA), which activates their transport flux, by providing H+ and HCO3−, their respective transport substrates. We examined the contribution of CA activity to the hypertrophic response of cultured neonatal and adult rodent cardiomyocytes. Phenylephrine (PE) increased cell size by 37 ± 2% and increased expression of the hypertrophic marker, atrial natriuretic factor mRNA, twofold in cultured neonatal rat cardiomyocytes. Cell size was also increased in adult cardiomyocytes subjected to angiotensin II or PE treatment. These effects were associated with increased expression of cytosolic CAII protein and the membrane-anchored isoform, CAIV. The membrane-permeant CA inhibitor, 6-ethoxyzolamide (ETZ), both prevented and reversed PE-induced hypertrophy in a concentration-dependent manner in neonate cardiomyocytes (IC50 = 18 μm). ETZ and the related CA inhibitor methazolamide prevented hypertrophy in adult cardiomyocytes. In addition, ETZ inhibited transport activity of NHE1 and the AE isoform, AE3, with respective EC50 values of 1.2 ± 0.3 μm and 2.7 ± 0.3 μm. PE significantly increased neonatal cardiomyocyte Ca2+ transient frequency from 0.33 ± 0.4 Hz to 0.77 ± 0.04 Hz following 24 h treatment; these Ca2+-handling abnormalities were completely prevented by ETZ (0.28 ± 0.07 Hz). Our study demonstrates a novel role for CA in mediating the hypertrophic response of cardiac myocytes to PE and suggests that CA inhibition represents an effective therapeutic approach towards mitigation of the hypertrophic phenotype. PMID:17124262

  14. Left ventricular hypertrophy and obesity: only a matter of fat?

    PubMed

    Murdolo, Giuseppe; Angeli, Fabio; Reboldi, Gianpaolo; Di Giacomo, Letizia; Aita, Adolfo; Bartolini, Claudia; Vedecchia, Paolo

    2015-03-01

    Obesity can be regarded as an energy balance disorder in which inappropriate expansion and dys-function of adipose tissue lead to unfavorable outcomes. Even in the absence of hypertension, adiposity induces structural and functional changes in the heart through hemodynamic and non hemodynamic factors. In the "obese" heart, besides the growth of cardiomyocytes, interstitial fat infiltration and triglyceride accumulation in the contractile elements importantly contribute to left-ventricular mass (LVM) accrual, hypertrophy (LVH) and geometric pattern. In harmony with this, the likelihood of LVH is greater in either obese normotensive or hypertensive individuals than in their non-obese counterparts. Interestingly, recent observations highlight the increasing prevalence of the "concentric" (ie, combined remodeling and hypertrophy), rather than "eccentric" pattern of LV geometry in obesity. Nonetheless, obesity is linked with lack of decrease, or even increase, of LVM over time, independently of blood pressure control and hypertensive treatment. Although obesity-related LV changes result in progressive systolic and diastolic heart failure, the assessment of LVM and LVH in obese individuals still remains a difficult task. In this scenario, it is tempting to speculate that therapeutic interventions for reversal of LVH in obesity should either overcome the "non-hemodynamic" factors or reduce the hemodynamic load. Indeed, weight loss, either achieved by lifestyle changes or bariatric procedures, decreases LVM and improves LV function regardless of blood pressure status. These and other mechanistic insights are discussed in this review, which focuses on "adipose dysfunction" as potential instigator of, and putative therapeutic target for, LVH regression in the setting of obesity.

  15. Hepatocyte growth factor induces Mcl-1 in primary human hepatocytes and inhibits CD95-mediated apoptosis via Akt.

    PubMed

    Schulze-Bergkamen, Henning; Brenner, Dirk; Krueger, Andreas; Suess, Dorothee; Fas, Stefanie C; Frey, Christian R; Dax, Andreas; Zink, Dorothea; Büchler, Peter; Müller, Martina; Krammer, Peter H

    2004-03-01

    CD95 (APO-1/Fas)-mediated apoptosis of hepatocytes plays a central role in the pathophysiology of various human liver diseases. Hepatocyte growth factor (HGF) was shown to exert antiapoptotic functions in rodent hepatocytes. We previously showed that primary human hepatocytes (PHH) are a valuable tool for the investigation of apoptotic processes in liver cells. In this study, we analyzed the influence of HGF on CD95-mediated apoptosis of PHH and its molecular determinants. HGF significantly inhibited CD95-mediated apoptosis of PHH as well as cleavage of caspase-8 and poly (ADP-ribose)polymerase. HGF transcriptionally induced the expression of the anti-apoptotic Bcl-2 family member myeloid cell leukemia-1 (Mcl-1). In contrary, HGF did not alter the expression levels of Bcl-2 or Bcl-x(L). HGF activated survival pathways such as the phosphatidylinositol-3 kinase (PI3K)/Akt pathway, the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase/ERK and the signal transducer and activator of transcription 3 (STAT3) pathway. Notably, HGF triggered serine(727)--but not tyrosine(705)--phosphorylation of STAT3. Pretreatment of PHH with the PI3K inhibitor LY294002 as well as adenoviral transduction of dominant negative Akt1 prevented HGF-mediated Mcl-1 induction and reversed the antiapoptotic effects of HGF. In conclusion, HGF confers survival of PHH by activation of the PI3K/Akt pathway. PI3K/Akt activation by HGF results in the induction of antiapoptotic proteins such as Mcl-1. Thus, application of HGF may be a therapeutic approach to prevent CD95-mediated hepatocellular damage in human liver diseases. PMID:14999683

  16. Hepatocyte Death: A Clear and Present Danger

    PubMed Central

    MALHI, HARMEET; GUICCIARDI, MARIA EUGENIA; GORES, GREGORY J.

    2010-01-01

    The hepatocyte is especially vulnerable to injury due to its central role in xenobiotic metabolism including drugs and alcohol, participation in lipid and fatty acid metabolism, its unique role in the enterohepatic circulation of bile acids, the widespread prevalence of hepatotropic viruses, and its existence within a milieu of innate immune responding cells. Apoptosis and necrosis are the most widely recognized forms of hepatocyte cell death. The hepatocyte displays many unique features regarding cell death by apoptosis. It is quite susceptible to death receptor-mediated injury, and its death receptor signaling pathways involve the mitochondrial pathway for efficient cell killing. Also, death receptors can trigger lysosomal disruption in hepatocytes which further promote cell and tissue injury. Interestingly, hepatocytes are protected from cell death by only two anti-apoptotic proteins, Bcl-xL and Mcl-1, which have nonredundant functions. Endoplasmic reticulum stress or the unfolded protein response contributes to hepatocyte cell death during alterations of lipid and fatty acid metabolism. Finally, the current information implicating RIP kinases in necrosis provides an approach to more fully address this mode of cell death in hepatocyte injury. All of these processes contributing to hepatocyte injury are discussed in the context of potential therapeutic strategies. PMID:20664081

  17. Functional correlates of compensatory renal hypertrophy

    PubMed Central

    Hayslett, John P.; Kashgarian, Michael; Epstein, Franklin H.

    1968-01-01

    The functional correlates of compensatory renal hypertrophy were studied by micropuncture techniques in rats after the removal of one kidney. The glomerular filtration rate increased to roughly the same extent in the whole kidney and in individual surface nephrons, resulting in a greater amount of sodium delivered to the tubules for reabsorption. The fraction of the glomerular filtrate absorbed [determined from the tubular fluid-to-plasma ratio (TF/P) for inulin] remained unchanged in both proximal and distal portions of the nephron. The way in which the tubules adjusted to nephrectomy, however, differed in proximal and distal convolutions. After nephrectomy, the reabsorptive half-time, indicated by the rate of shrinkage of a droplet of saline in a tubule blocked with oil, was unchanged in the proximal tubule but significantly shortened in the distal convoluted tubule. Nevertheless, steady-state concentrations of sodium in an isolated raffinose droplet in the distal as well as the proximal tubule were the same in hypertrophied kidneys as in control animals. Possible reasons for this paradox are discussed. Transit time through the proximal tubules was unchanged by compensatory hypertrophy, but transit time to the distal tubules was prolonged. Changes in renal structure resulting from compensatory hypertrophy were also found to differ in the proximal and the distal protions of the nephron. Although tubular volume increased in both protions, the volume increase was twice as great in the proximal tubule as in the distal. In order, therefore, for net reabsorption to increase in the distal tubule, where the changes in tubular volume are not so marked, an increase in reabsorptive capacity per unit length of tubule is required. This increase is reflected in the shortening of reabsorptive half-time in the oil-blocked distal tubule that was actually observed. PMID:5641618

  18. Accessory spleen hypertrophy mimicking colon cancer metastasis.

    PubMed

    Ates, I; Yazici, O; Yazilitas, D; Ozdemir, N; Zengin, N

    2016-09-01

    Accessory spleen is a congenital form of an ectopic splenic tissue. In this report, we present a case of a patient who was followed with the diagnosis of rectal and sigmoid colon cancer and an accessory spleen hypertrophy, which was thought to be colon cancer metastasis in the left hypochondriac region. After colectomy and splenectomy, accessory spleen that mimics cancer metastasis was diffrentially diagnosed using scintigraphy. PMID:27685531

  19. Genetic epidemiology of left ventricular hypertrophy

    PubMed Central

    Bella, Jonathan N; Göring, Harald HH

    2012-01-01

    Left ventricular (LV) hypertrophy is a strong independent predictor of increased cardiovascular morbidity and mortality in clinical and population-based samples. Clinical and hemodynamic stimuli to LV hypertrophy induce not only an increase in cardiac mass and wall thickness but also a fundamental reconfiguration of the protein, cellular and molecular components of the myocardium. Several studies have indicated that LV mass is influenced by genetic factors. The substantial heritability (h2) for LV mass in population-based samples of varying ethnicity indicates robust genetic influences on LV hypertrophy. Genome-wide linkage and association studies in diverse populations have been performed to identify genes influencing LV mass, and although several chromosomal regions have been found to be significantly associated with LV mass, the specific genes and functional variants contained in these chromosomal regions have yet to be identified. In addition, multiple studies have tried to link single-nucleotide polymorphisms (SNPs) in regulatory and pathway genes with common forms of LV hypertrophy, but there is little evidence that these genetic variations are functional. Up to this point in time, the results obtained in genetic studies are of limited clinical value. Much of the heritability remains unexplained, the identity of the underlying gene pathways, genes, and functional variants remains unknown, and the promise of genetically-based risk prediction and personalized medicine remain unfulfilled. However, molecular biological technologies continue to improve rapidly, and the long-term potential of sophisticated genetic investigations using these modern genomic technologies, coupled with smart study designs, remains intact. Ultimately, genetic investigations offer much promise for future prevention, early intervention and treatment of this major public health issue. PMID:23173100

  20. Postoperative thallium-201 myocardial images. Evidence of regression of right ventricular hypertrophy in man.

    PubMed Central

    Yamazaki, H; Tsugu, T; Handa, S; Takagi, Y; Ohsuzu, F; Kondo, M; Kubo, A; Inoue, T; Nakamura, Y

    1982-01-01

    Thallium-201 myocardial scintigraphic studies were performed on 24 patients with chronic right ventricular overload before and after surgical correction of haemodynamic overload. The ages of the patients ranged from 20 to 65 years (mean 39 years) at operation. The degree of right ventricular visualisation remained essentially unchanged in an early postoperative study (four to 60 days), though a decrease in right ventricular cavity size was noted in patients with right ventricular volume overload. On later follow-up (18 to 36 months), thallium uptake in the right ventricle was definitely less than before operation in all 13 patients studied at this time. Because thallium-201 radioactivity reflects myocardial blood flow and mass, our study indicates that right ventricular hypertrophy is largely reversible. Thus, thallium-201 myocardial scintigraphy can be used to assess non-invasively regression of right ventricular hypertrophy in patients with right ventricular overload. Images PMID:6215051

  1. Hepatic stellate cell-expressed endosialin balances fibrogenesis and hepatocyte proliferation during liver damage

    PubMed Central

    Mogler, Carolin; Wieland, Matthias; König, Courtney; Hu, Junhao; Runge, Anja; Korn, Claudia; Besemfelder, Eva; Breitkopf-Heinlein, Katja; Komljenovic, Dorde; Dooley, Steven; Schirmacher, Peter; Longerich, Thomas; Augustin, Hellmut G

    2015-01-01

    Liver fibrosis is a reversible wound-healing response to injury reflecting the critical balance between liver repair and scar formation. Chronic damage leads to progressive substitution of liver parenchyma by scar tissue and ultimately results in liver cirrhosis. Stromal cells (hepatic stellate cells [HSC] and endothelial cells) have been proposed to control the balance between liver fibrosis and regeneration. Here, we show that endosialin, a C-type lectin, expressed in the liver exclusively by HSC and portal fibroblasts, is upregulated in liver fibrosis in mouse and man. Chronic chemically induced liver damage resulted in reduced fibrosis and enhanced hepatocyte proliferation in endosialin-deficient (ENKO) mice. Correspondingly, acute-liver-damage-induced hepatocyte proliferation (partial hepatectomy) was increased in ENKO mice. A candidate-based screen of known regulators of hepatocyte proliferation identified insulin-like growth factor 2 (IGF2) as selectively endosialin-dependent hepatocyte mitogen. Collectively, the study establishes a critical role of HSC in the reciprocal regulation of fibrogenesis vs. hepatocyte proliferation and identifies endosialin as a therapeutic target in non-neoplastic settings. PMID:25680861

  2. Hepatic stellate cell-expressed endosialin balances fibrogenesis and hepatocyte proliferation during liver damage.

    PubMed

    Mogler, Carolin; Wieland, Matthias; König, Courtney; Hu, Junhao; Runge, Anja; Korn, Claudia; Besemfelder, Eva; Breitkopf-Heinlein, Katja; Komljenovic, Dorde; Dooley, Steven; Schirmacher, Peter; Longerich, Thomas; Augustin, Hellmut G

    2015-02-13

    Liver fibrosis is a reversible wound-healing response to injury reflecting the critical balance between liver repair and scar formation. Chronic damage leads to progressive substitution of liver parenchyma by scar tissue and ultimately results in liver cirrhosis. Stromal cells (hepatic stellate cells [HSC] and endothelial cells) have been proposed to control the balance between liver fibrosis and regeneration. Here, we show that endosialin, a C-type lectin, expressed in the liver exclusively by HSC and portal fibroblasts, is upregulated in liver fibrosis in mouse and man. Chronic chemically induced liver damage resulted in reduced fibrosis and enhanced hepatocyte proliferation in endosialin-deficient (EN(KO)) mice. Correspondingly, acute-liver-damage-induced hepatocyte proliferation (partial hepatectomy) was increased in EN(KO) mice. A candidate-based screen of known regulators of hepatocyte proliferation identified insulin-like growth factor 2 (IGF2) as selectively endosialin-dependent hepatocyte mitogen. Collectively, the study establishes a critical role of HSC in the reciprocal regulation of fibrogenesis vs. hepatocyte proliferation and identifies endosialin as a therapeutic target in non-neoplastic settings.

  3. Hepatic stellate cell-expressed endosialin balances fibrogenesis and hepatocyte proliferation during liver damage.

    PubMed

    Mogler, Carolin; Wieland, Matthias; König, Courtney; Hu, Junhao; Runge, Anja; Korn, Claudia; Besemfelder, Eva; Breitkopf-Heinlein, Katja; Komljenovic, Dorde; Dooley, Steven; Schirmacher, Peter; Longerich, Thomas; Augustin, Hellmut G

    2015-03-01

    Liver fibrosis is a reversible wound-healing response to injury reflecting the critical balance between liver repair and scar formation. Chronic damage leads to progressive substitution of liver parenchyma by scar tissue and ultimately results in liver cirrhosis. Stromal cells (hepatic stellate cells [HSC] and endothelial cells) have been proposed to control the balance between liver fibrosis and regeneration. Here, we show that endosialin, a C-type lectin, expressed in the liver exclusively by HSC and portal fibroblasts, is upregulated in liver fibrosis in mouse and man. Chronic chemically induced liver damage resulted in reduced fibrosis and enhanced hepatocyte proliferation in endosialin-deficient (EN(KO)) mice. Correspondingly, acute-liver-damage-induced hepatocyte proliferation (partial hepatectomy) was increased in EN(KO) mice. A candidate-based screen of known regulators of hepatocyte proliferation identified insulin-like growth factor 2 (IGF2) as selectively endosialin-dependent hepatocyte mitogen. Collectively, the study establishes a critical role of HSC in the reciprocal regulation of fibrogenesis vs. hepatocyte proliferation and identifies endosialin as a therapeutic target in non-neoplastic settings. PMID:25680861

  4. In utero Transplanted Human Hepatocytes Allows for Postnatal Engraftment of Human Hepatocytes in Pigs

    PubMed Central

    Fisher, James E; Lillegard, Joseph B; Mckenzie, Travis J; Rodysill, Brian R; Wettstein, Peter J; Nyberg, Scott L

    2012-01-01

    In utero cell transplantation (IUCT) can lead to postnatal engraftment of human cells in the xenogeneic recipient. Most reports of IUCTs have involved hematopoietic stem cells. It is unknown if human hepatocytes used for IUCT in fetal pigs will lead to engraftment of these same cells in the postnatal environment. In this study, fetal pigs received direct liver injections of 1×107 human hepatocytes in utero and were delivered by cesarean-section at term. Piglets received a second direct liver injection of 5×107 human hepatocytes 1 week postnatally. Serum was analyzed for human albumin at 2, 4, and 6 weeks post-engraftment. Piglet livers were harvested 6 weeks after transplantation and examined by immunohistochemistry, PCR and fluorescence in situ hybridization for human specific sequences. Piglets receiving IUCT with human hepatocytes that were postnatally engrafted with human hepatocytes showed significant levels of human albumin production in their serum at all post-engraftment time points. Human albumin gene expression, the presence of human hepatocytes and the presence of human beta-2 microglobulin were all confirmed 6 weeks post-engraftment. IUCT in fetal pigs using human hepatocytes early in gestation allowed for engraftment of human hepatocytes, which remained viable and functional for weeks after transplantation. IUCT followed by postnatal engraftment may provide a future means for large scale expansion of human hepatocytes in genetically-engineered pigs. PMID:23280879

  5. Three 4-Letter Words of Hypertension-Related Cardiac Hypertrophy: TRPC, mTOR, and HDAC

    PubMed Central

    Kurdi, Mazen; Booz, George W.

    2011-01-01

    Left ventricular hypertrophy due to hypertension represents a major risk factor for adverse cardiovascular events and death. In recent years, the prevalence of cardiac hypertrophy has increased due to obesity and an aging population. Notably, a significant number of individuals have persistent cardiac hypertrophy in the face of blood pressure that is normalized by drug treatment. Thus, a better understanding of the processes underlying the cardiac remodeling events that are set into play by hypertension is needed. At the level of the cardiac myocytes, hypertrophic growth is often described as physiological, as occurs with exercise, or pathological, as seen with hypertension. Here we discuss recent developments in three areas that are fundamental to pathological hypertrophic growth of cardiac myocytes. These areas are the transient receptor potential canonical (TRPC) channels, mammalian target of rapamycin (mTOR) complexes, and histone deacetylase (HDAC) enzymes. In the last several years, studies in each of these areas have yielded new and exciting discoveries into the genesis of pathological growth of cardiac myocytes. The phosphoinositide 3-kinase – Akt signaling network may be the common denominator that links these areas together. Defining the interrelationship among TRPC channels, mTOR signaling, and HDAC enzymes is a promising, but challenging area of research. Such knowledge will undoubtedly lead to new drugs that better prevent or reverse left ventricular hypertension. PMID:21320507

  6. Flavonoids Extraction from Propolis Attenuates Pathological Cardiac Hypertrophy through PI3K/AKT Signaling Pathway

    PubMed Central

    Sun, Guang-wei; Qiu, Zhi-dong; Wang, Wei-nan; Sui, Xin

    2016-01-01

    Propolis, a traditional medicine, has been widely used for a thousand years as an anti-inflammatory and antioxidant drug. The flavonoid fraction is the main active component of propolis, which possesses a wide range of biological activities, including activities related to heart disease. However, the role of the flavonoids extraction from propolis (FP) in heart disease remains unknown. This study shows that FP could attenuate ISO-induced pathological cardiac hypertrophy (PCH) and heart failure in mice. The effect of the two fetal cardiac genes, atrial natriuretic factor (ANF) and β-myosin heavy chain (β-MHC), on PCH was reversed by FP. Echocardiography analysis revealed cardiac ventricular dilation and contractile dysfunction in ISO-treated mice. This finding is consistent with the increased heart weight and cardiac ANF protein levels, massive replacement fibrosis, and myocardial apoptosis. However, pretreatment of mice with FP could attenuate cardiac dysfunction and hypertrophy in vivo. Furthermore, the cardiac protection of FP was suppressed by the pan-PI3K inhibitor wortmannin. FP is a novel cardioprotective agent that can attenuate adverse cardiac dysfunction, hypertrophy, and associated disorder, such as fibrosis. The effects may be closely correlated with PI3K/AKT signaling. FP may be clinically used to inhibit PCH progression and heart failure. PMID:27213000

  7. Pathophysiologic assessment of left ventricular hypertrophy and strain in asymptomatic patients with essential hypertension

    SciTech Connect

    Pringle, S.D.; Macfarlane, P.W.; McKillop, J.H.; Lorimer, A.R.; Dunn, F.G.

    1989-05-01

    To investigate the significance of the electrocardiographic (ECG) pattern of left ventricular hypertrophy and strain, two groups of asymptomatic patients with essential hypertension were compared. The patients were similar in terms of age, smoking habit, serum cholesterol and blood pressure levels, but differed in the presence (Group I, n = 23) or absence (Group II, n = 23) of the ECG pattern of left ventricular hypertrophy and strain. Group I patients had significantly more episodes of exercise-induced ST segment depression (14 versus 4, p less than 0.05) and reversible thallium perfusion abnormalities (11 of 23 versus 3 of 23, p less than 0.05) despite similar exercise capacity and absence of chest pain. Nonsustained ventricular tachycardia was detected on 24 h ambulatory ECG monitoring in two patients in Group I, but no patient in Group II. Coronary arteriography performed in 20 Group I patients demonstrated significant coronary artery disease in 8 patients. This study has shown that there is a subgroup of hypertensive patients with ECG left ventricular hypertrophy and strain who have covert coronary artery disease. This can be detected by thallium perfusion scintigraphy, and may contribute to the increased risk known to be associated with this ECG abnormality.

  8. The unique Polarity Phenotype of Hepatocytes

    PubMed Central

    Müsch, Anne

    2014-01-01

    Hepatocytes, the main epithelial cell type of the liver, function like all epithelial cells to mediate the vectorial flow of macromolecules into and out of the organ they encompass. They do so by establishing polarized surface domains and by restricting paracellular flow via their tight junctions and cell-cell adhesion. Yet, the cell and tissue organization of hepatocytes differs profoundly from that of most other epithelia, including those of the digestive and urinary tracts, the lung or the breast. The latter form monolayered tissues in which the apical domains of individual cells align around a central continuous luminal cavity that constitutes the tubules and acini characteristic of these organs. Hepatocytes, by contrast, form capillary-sized lumina with multiple neighbors resulting in a branched, tree-like bile canaliculi network that spreads across the liver parenchyme. I will discuss some of the key molecular features that distinguish the hepatocyte polarity phenotype from that of monopolar, columnar epithelia. PMID:24956563

  9. Inhibition of cardiac hypertrophy by probiotic-fermented purple sweet potato yogurt in spontaneously hypertensive rat hearts.

    PubMed

    Lin, Pei-Pei; Hsieh, You-Miin; Kuo, Wei-Wen; Lin, Chien-Chung; Tsai, Fuu-Jen; Tsai, Chang-Hai; Huang, Chih-Yang; Tsai, Cheng-Chih

    2012-12-01

    Cardiovascular hypertrophy is a common feature of hypertension and an important risk factor for heart damage. The regression of cardiovascular hypertrophy is currently considered an important therapeutic target in reducing the omplications of hypertension. The aim of this study was to investigate the inhibition of cardiac hypertrophy by probiotic-fermented purple sweet potato yogurt (PSPY) with high γ-aminobutyric acid (GABA) content in spontaneously hypertensive rat (SHR) hearts. Six-week-old male SHRs were separated randomly and equally into 4 experimental groups: sterile water, captopril and 2 PSPY groups with different doses (10 and 100%) for 8 weeks. The changes in myocardial architecture and key molecules of the hypertrophy-related pathway in the excised left ventricle from these rats were determined by histopathological analysis, hematoxylin and eosin staining and western blot analysis. Abnormal myocardial architecture and enlarged interstitial spaces observed in the SHRs were significantly decreased in the captopril and PSPY groups compared with the sterile water group. Moreover, the increases in atrial natriuretic peptide, B-type natriuretic peptide, phosphorilated protein kinase Cα and calmodulin-dependent protein kinase II levels in the left ventricle were accompanied by hypertension and increases in phosphorylated extracellular signal-regulated kinase 5 activities with enhanced cardiac hypertrophy. However, the protein levels of the hypertrophic-related pathways were completely reversed by the administration of PSPY. PSPY may repress the activation of ANP and BNP which subsequently inhibit the dephosphorylation of the nuclear factor of activated T-cells, cytoplasmic 3 and ultimately prevent the progression of cardiac hypertrophy.

  10. Cold storage of rat hepatocyte spheroids.

    PubMed

    Liu, Hongling; Yu, Yue; Glorioso, Jaime; Mao, Shennen; Rodysil, Brian; Amiot, Bruce P; Rinaldo, Piero; Nyberg, Scott L

    2014-01-01

    Cell-based therapies for liver disease rely on a high-quality supply of hepatocytes and a means for storage during transportation from site of isolation to site of usage. Unfortunately, frozen cryopreservation is associated with unacceptable loss of hepatocyte viability after thawing. The purpose of this study was to optimize conditions for cold storage of rat hepatocyte spheroids without freezing. Rat hepatocytes were isolated by a two-step perfusion method; hepatocyte spheroids were formed during 48 h of rocked culture in serum-free medium (SFM). Spheroids were then maintained in rocked culture at 37 °C (control condition) or cold stored at 4 °C for 24 or 48 h in six different cold storage solutions: SFM alone; SFM + 1 mM deferoxamine (Def); SFM + 1 μM cyclosporin A (CsA); SFM + 1 mM Def + 1 μM CsA, University of Wisconsin (UW) solution alone, UW + 1 mM Def. Performance metrics after cold storage included viability, gene expression, albumin production, and functional activity of cytochrome P450 enzymes and urea cycle proteins. We observed that cold-induced injury was reduced significantly by the addition of the iron chelator (Def) to both SFM and UW solution. Performance metrics (ammonia detoxification, albumin production) of rat hepatocyte spheroids stored in SFM + Def for 24 h were significantly increased from SFM alone and approached those in control conditions, while performance metrics after cold storage in SFM alone or cold storage for 48 h were both significantly reduced. A serum-free medium supplemented with Def allowed hepatocyte spheroids to tolerate 24 h of cold storage with less than 10% loss in viability and functionality. Further research is warranted to optimize a solution for extended cold storage of hepatocyte spheroids.

  11. Glucose Transporters in Cardiac Metabolism and Hypertrophy

    PubMed Central

    Shao, Dan; Tian, Rong

    2016-01-01

    The heart is adapted to utilize all classes of substrates to meet the high-energy demand, and it tightly regulates its substrate utilization in response to environmental changes. Although fatty acids are known as the predominant fuel for the adult heart at resting stage, the heart switches its substrate preference toward glucose during stress conditions such as ischemia and pathological hypertrophy. Notably, increasing evidence suggests that the loss of metabolic flexibility associated with increased reliance on glucose utilization contribute to the development of cardiac dysfunction. The changes in glucose metabolism in hypertrophied hearts include altered glucose transport and increased glycolysis. Despite the role of glucose as an energy source, changes in other nonenergy producing pathways related to glucose metabolism, such as hexosamine biosynthetic pathway and pentose phosphate pathway, are also observed in the diseased hearts. This article summarizes the current knowledge regarding the regulation of glucose transporter expression and translocation in the heart during physiological and pathological conditions. It also discusses the signaling mechanisms governing glucose uptake in cardiomyocytes, as well as the changes of cardiac glucose metabolism under disease conditions. PMID:26756635

  12. Activation of factor X by rat hepatocytes

    SciTech Connect

    Willingham, A.K.; Matschiner, J.T.

    1986-05-01

    Synthesis and secretion of blood coagulation factor X was studied in hepatocytes prepared by perfusion of rat livers with collagenase. Hepatocytes were incubated in the presence of vitamin K and /sup 3/H-leucine for up to 4h at 37/sup 0/C. Factor X was isolated from the incubation medium by immunochemical techniques and analyzed by SDS-PAGE. The recovered /sup 3/H-labeled proteins migrated, after reduction of disulfides, as two polypeptide chains with apparent molecular weights (M/sub r/) of approximately 42,000 and 22,000 representing the heavy and light chains of factor X respectively. The apparent M/sub r/ of the heavy chain was about 10,000 daltons lighter than seen with the heavy chain of factor X isolated from rat plasma and was more characteristic of the heavy chain of factor Xa. When the levels of factor X secreted by hepatocytes were determined by clotting assays, activity was present as factor Xa. Also, when purified plasma factor X was added to incubations of hepatocytes (>95% parenchymal cells) the added factor X was rapidly converted to factor Xa. Plasma membranes prepared from isolated hepatocytes or from liver homogenates contained an enzyme that converted factor X to factor Xa in a calcium dependent reaction. The physiological significance of a factor X activating enzyme on hepatocyte plasma membranes is not clear.

  13. Selective insulin resistance in hepatocyte senescence

    SciTech Connect

    Aravinthan, Aloysious; Challis, Benjamin; Shannon, Nicholas; Hoare, Matthew; Heaney, Judith; Alexander, Graeme J.M.

    2015-02-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

  14. Induced pluripotent stem cell–derived hepatocytes have the functional and proliferative capabilities needed for liver regeneration in mice

    PubMed Central

    Espejel, Silvia; Roll, Garrett R.; McLaughlin, K. John; Lee, Andrew Y.; Zhang, Jenny Y.; Laird, Diana J.; Okita, Keisuke; Yamanaka, Shinya; Willenbring, Holger

    2010-01-01

    The ability to generate induced pluripotent stem (iPS) cells from a patient’s somatic cells has provided a foundation for organ regeneration without the need for immune suppression. However, it has not been established that the differentiated progeny of iPS cells can effectively reverse failure of a vital organ. Here, we examined whether iPS cell–derived hepatocytes have both the functional and proliferative capabilities needed for liver regeneration in mice with fumarylacetoacetate hydrolase deficiency. To avoid biases resulting from random genomic integration, we used iPS cells generated without viruses. To exclude compensation by hepatocytes not derived from iPS cells, we generated chimeric mice in which all hepatocytes were iPS cell derived. In vivo analyses showed that iPS cells were intrinsically able to differentiate into fully mature hepatocytes that provided full liver function. The iPS cell–derived hepatocytes also replicated the unique proliferative capabilities of normal hepatocytes and were able to regenerate the liver after transplantation and two-thirds partial hepatectomy. Thus, our results establish the feasibility of using iPS cells generated in a clinically acceptable fashion for rapid and stable liver regeneration. PMID:20739754

  15. Induction of mitochondrial biogenesis and respiration is associated with mTOR regulation in hepatocytes of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA).

    PubMed

    Hagland, Hanne R; Nilsson, Linn I H; Burri, Lena; Nikolaisen, Julie; Berge, Rolf K; Tronstad, Karl J

    2013-01-11

    The hypolipidemic effect of peroxisome proliferator-activated receptor (PPAR) activators has been explained by increasing mitochondrial fatty acid oxidation, as observed in livers of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA). PPAR-activation does, however, not fully explain the metabolic adaptations observed in hepatocytes after treatment with TTA. We therefore characterized the mitochondrial effects, and linked this to signalling by the metabolic sensor, the mammalian target of rapamycin (mTOR). In hepatocytes isolated from TTA-treated rats, the changes in cellular content and morphology were consistent with hypertrophy. This was associated with induction of multiple mitochondrial biomarkers, including mitochondrial DNA, citrate synthase and mRNAs of mitochondrial proteins. Transcription analysis further confirmed activation of PPARα-associated genes, in addition to genes related to mitochondrial biogenesis and function. Analysis of mitochondrial respiration revealed that the capacity of both electron transport and oxidative phosphorylation were increased. These effects coincided with activation of the stress related factor, ERK1/2, and mTOR. The protein level and phosphorylation of the downstream mTOR actors eIF4G and 4E-BP1 were induced. In summary, TTA increases mitochondrial respiration by inducing hypertrophy and mitochondrial biogenesis in rat hepatocytes, via adaptive regulation of PPARs as well as mTOR. PMID:23228666

  16. Insulin inhibits hepatocyte iNOS expression induced by cytokines by an Akt-dependent mechanism.

    PubMed

    Harbrecht, Brian G; Nweze, Ikenna; Smith, Jason W; Zhang, Baochun

    2012-01-01

    Hepatocyte inducible nitric oxide synthese (iNOS) expression is a tightly controlled pathway that mediates hepatic inflammation and hepatocyte injury in a variety of disease states. We have shown that cyclic adenosine monophosphate (cAMP) regulates cytokine-induced hepatocyte iNOS expression through mechanisms that involve protein kinase B/Akt. We hypothesized that insulin, which activates Akt signaling in hepatocytes, as well as signaling through p38 and MAPK p42/p44, would regulate iNOS expression during inflammation. In primary rat hepatocytes, insulin inhibited cytokine-stimulated nitrite accumulation and iNOS expression in a dose-dependent manner. Inhibition of MAPK p42/p44 with PD98059 had no effect on iNOS activation, whereas SB203580 to block p38 reversed insulin's inhibitory effect. However, insulin did not increase p38 activation and inhibition of p38 signaling with a dominant negative p38 plasmid had no effect on cytokine- or insulin-mediated effects on iNOS. We found that SB203580 blocked insulin-induced Akt activation. Inhibition of Akt signaling with LY294002 or a dominant negative Akt plasmid increased cytokine-stimulated nitrite production and iNOS protein expression and blocked the inhibitory effects of insulin. NF-κB induces iNOS expression and can be regulated by Akt, but insulin had no effect on cytokine-mediated IκBα levels or NF-κB p65 translocation. Our data demonstrate that insulin inhibits cytokine-stimulated hepatocyte iNOS expression and does so through effects on Akt-mediated signaling. PMID:22038823

  17. Chronic intermittent hypoxia induces cardiac hypertrophy by impairing autophagy through the adenosine 5'-monophosphate-activated protein kinase pathway.

    PubMed

    Xie, Sheng; Deng, Yan; Pan, Yue-Ying; Ren, Jie; Jin, Meng; Wang, Yu; Wang, Zhi-Hua; Zhu, Die; Guo, Xue-Ling; Yuan, Xiao; Shang, Jin; Liu, Hui-Guo

    2016-09-15

    Autophagy is tightly regulated to maintain cardiac homeostasis. Impaired autophagy is closely associated with pathological cardiac hypertrophy. However, the relationship between autophagy and cardiac hypertrophy induced by chronic intermittent hypoxia (CIH) is not known. In the present study, we measured autophagy-related genes and autophagosomes during 10 weeks of CIH in rats, and 6 days in H9C2 cardiomyocytes, and showed that autophagy was impaired. This conclusion was confirmed by the autophagy flux assay. We detected significant hypertrophic changes in myocardium with impaired autophagy. Rapamycin, an autophagy enhancer, attenuated the cardiac hypertrophy induced by CIH. Moreover, silencing autophagy-related gene 5 (ATG5) exerted the opposite effect. The role of adenosine monophosphate-activated protein kinase (AMPK) in regulating autophagy under CIH was confirmed using AICAR to upregulate this enzyme and restore autophagy flux. Restoring autophagy by AICAR or rapamycin significantly reversed the hypertrophic changes in cardiomyocytes. To investigate the mechanism of autophagy impairment, we compared phospho (p)-AMPK, p-Akt, cathepsin D, and NFAT3 levels, along with calcineurin activity, between sham and CIH groups. CIH activated calcineurin, and inhibited AMPK and AMPK-mediated autophagy in an Akt- and NFAT3-independent manner. Collectively, these data demonstrated that impaired autophagy induced by CIH through the AMPK pathway contributed to cardiac hypertrophy. PMID:27412517

  18. Chronic intermittent hypoxia induces cardiac hypertrophy by impairing autophagy through the adenosine 5'-monophosphate-activated protein kinase pathway.

    PubMed

    Xie, Sheng; Deng, Yan; Pan, Yue-Ying; Ren, Jie; Jin, Meng; Wang, Yu; Wang, Zhi-Hua; Zhu, Die; Guo, Xue-Ling; Yuan, Xiao; Shang, Jin; Liu, Hui-Guo

    2016-09-15

    Autophagy is tightly regulated to maintain cardiac homeostasis. Impaired autophagy is closely associated with pathological cardiac hypertrophy. However, the relationship between autophagy and cardiac hypertrophy induced by chronic intermittent hypoxia (CIH) is not known. In the present study, we measured autophagy-related genes and autophagosomes during 10 weeks of CIH in rats, and 6 days in H9C2 cardiomyocytes, and showed that autophagy was impaired. This conclusion was confirmed by the autophagy flux assay. We detected significant hypertrophic changes in myocardium with impaired autophagy. Rapamycin, an autophagy enhancer, attenuated the cardiac hypertrophy induced by CIH. Moreover, silencing autophagy-related gene 5 (ATG5) exerted the opposite effect. The role of adenosine monophosphate-activated protein kinase (AMPK) in regulating autophagy under CIH was confirmed using AICAR to upregulate this enzyme and restore autophagy flux. Restoring autophagy by AICAR or rapamycin significantly reversed the hypertrophic changes in cardiomyocytes. To investigate the mechanism of autophagy impairment, we compared phospho (p)-AMPK, p-Akt, cathepsin D, and NFAT3 levels, along with calcineurin activity, between sham and CIH groups. CIH activated calcineurin, and inhibited AMPK and AMPK-mediated autophagy in an Akt- and NFAT3-independent manner. Collectively, these data demonstrated that impaired autophagy induced by CIH through the AMPK pathway contributed to cardiac hypertrophy.

  19. Cardiac hypertrophy in mice expressing unphosphorylatable phospholemman

    PubMed Central

    Boguslavskyi, Andrii; Pavlovic, Davor; Aughton, Karen; Clark, James E.; Howie, Jacqueline; Fuller, William; Shattock, Michael J.

    2014-01-01

    Aims Elevation of intracellular Na in the failing myocardium contributes to contractile dysfunction, the negative force–frequency relationship, and arrhythmias. Although phospholemman (PLM) is recognized to form the link between signalling pathways and Na/K pump activity, the possibility that defects in its regulation contribute to elevation of intracellular Na has not been investigated. Our aim was to test the hypothesis that the prevention of PLM phosphorylation in a PLM3SA knock-in mouse (in which PLM has been rendered unphosphorylatable) will exacerbate cardiac hypertrophy and cellular Na overload. Testing this hypothesis should determine whether changes in PLM phosphorylation are simply bystander effects or are causally involved in disease progression. Methods and results In wild-type (WT) mice, aortic constriction resulted in hypophosphorylation of PLM with no change in Na/K pump expression. This under-phosphorylation of PLM occurred at 3 days post-banding and was associated with a progressive decline in Na/K pump current and elevation of [Na]i. Echocardiography, morphometry, and pressure-volume (PV) catheterization confirmed remodelling, dilation, and contractile dysfunction, respectively. In PLM3SA mice, expression of Na/K ATPase was increased and PLM decreased such that net Na/K pump current under quiescent conditions was unchanged (cf. WT myocytes); [Na+]i was increased and forward-mode Na/Ca exchanger was reduced in paced PLM3SA myocytes. Cardiac hypertrophy and Na/K pump inhibition were significantly exacerbated in banded PLM3SA mice compared with banded WT. Conclusions Decreased phosphorylation of PLM reduces Na/K pump activity and exacerbates Na overload, contractile dysfunction, and adverse remodelling following aortic constriction in mice. This suggests a novel therapeutic target for the treatment of heart failure. PMID:25103111

  20. Hepatocyte Isolation After Laparoscopic Liver Resection.

    PubMed

    Horner, Rosa; Kluge, Martin; Gassner, Joseph; Nösser, Maximilian; Major, Rebeka Dalma; Reutzel-Selke, Anja; Leder, Annekatrin K; Struecker, Benjamin; Morgul, Mehmet H; Pratschke, Johann; Sauer, Igor M; Raschzok, Nathanael

    2016-09-01

    Liver tissue obtained from partial hepatectomy is a common source for isolation of primary human hepatocytes. Until now, liver resections were most commonly performed by conventional open surgery. Although the laparoscopic approach is currently emerging in liver surgery, data on the outcome of hepatocyte isolation from laparoscopically resected liver tissue are not available. A total of 22 hepatocyte isolations were performed using the two-step collagenase perfusion technique from October 2015 to March 2016. Liver tissue was obtained from n = 15 open liver resections (OLRs) and n = 7 laparoscopic liver resections (LLRs). Isolation parameters (cell yield, viability, and Percoll survival) were assessed and hepatocyte function (plating efficiency, urea, albumin, and aspartate aminotransferase) was measured over a culture period of 6 days (OLR: n = 13; LLR: n = 3). Total cell yield (OLR: 36.81 ± 6.77 × 10(6) cells/g vs. LLR 16.84 ± 10.66 × 10(6) cells/g, p = 0.0318) as well as viable yield (OLR 31.70 ± 6.05 × 10(6) cells/g vs. LLR 14.70 ± 9.89 × 10(6) cells/g, p = 0.0260) was significantly higher in the OLR group. Subgroup analysis revealed that the worse outcome of isolation of laparoscopically resected liver tissue was associated with right-lateral LLRs, whereas hepatocyte isolation from left-lateral LLRs was as effective as from open surgery. Hepatocyte function did not differ between hepatocytes from openly resected versus left-lateral laparoscopically resected liver tissue. We here present the first data on hepatocyte isolation from laparoscopic liver surgery. Although the overall outcome is worse compared with open surgery, our data suggest that liver tissue from laparoscopic resection of the left lobe is an excellent source for primary human hepatocytes. PMID:27481660

  1. Overexpression of microRNA-99a Attenuates Cardiac Hypertrophy

    PubMed Central

    Li, Ran; Bai, Jian; Ding, Liang; Gu, Rong; Wang, Lian; Xu, Biao

    2016-01-01

    Pathological cardiomyocyte hypertrophy is associated with significantly increased risk of heart failure, one of the leading medical causes of mortality worldwide. MicroRNAs are known to be involved in pathological cardiac remodeling. However, whether miR-99a participates in the signaling cascade leading to cardiac hypertrophy is unknown. To evaluate the role of miR-99a in cardiac hypertrophy, we assessed the expression of miR-99a in hypertrophic cardiomyocytes induced by isoprenaline (ISO)/angiotensin-II (Ang II) and in mice model of cardiac hypertrophy induced by transverse aortic constriction (TAC). Expression of miR-99a was evaluated in these hypertrophic cells and hearts. We also found that miR-99a expression was highly correlated with cardiac function of mice with heart failure (8 weeks after TAC surgery). Overexpression of miR-99a attenuated cardiac hypertrophy in TAC mice and cellular hypertrophy in stimuli treated cardiomyocytes through down-regulation of expression of mammalian target of rapamycin (mTOR). These results indicate that miR-99a negatively regulates physiological hypertrophy through mTOR signaling pathway, which may provide a new therapeutic approach for pressure-overload heart failure. PMID:26914935

  2. Adipocyte-specific loss of PPARγ attenuates cardiac hypertrophy

    PubMed Central

    Fang, Xi; Stroud, Matthew J.; Ouyang, Kunfu; Fang, Li; Zhang, Jianlin; Dalton, Nancy D.; Gu, Yusu; Wu, Tongbin; Peterson, Kirk L.; Huang, Hsien-Da; Wang, Nanping

    2016-01-01

    Adipose tissue is a key endocrine organ that governs systemic homeostasis. PPARγ is a master regulator of adipose tissue signaling that plays an essential role in insulin sensitivity, making it an important therapeutic target. The selective PPARγ agonist rosiglitazone (RSG) has been used to treat diabetes. However, adverse cardiovascular effects have seriously hindered its clinical application. Experimental models have revealed that PPARγ activation increases cardiac hypertrophy. RSG stimulates cardiac hypertrophy and oxidative stress in cardiomyocyte-specific PPARγ knockout mice, implying that RSG might stimulate cardiac hypertrophy independently of cardiomyocyte PPARγ. However, candidate cell types responsible for RSG-induced cardiomyocyte hypertrophy remain unexplored. Utilizing cocultures of adipocytes and cardiomyocytes, we found that stimulation of PPARγ signaling in adipocytes increased miR-200a expression and secretion. Delivery of miR-200a in adipocyte-derived exosomes to cardiomyocytes resulted in decreased TSC1 and subsequent mTOR activation, leading to cardiomyocyte hypertrophy. Treatment with an antagomir to miR-200a blunted this hypertrophic response in cardiomyocytes. In vivo, specific ablation of PPARγ in adipocytes was sufficient to blunt hypertrophy induced by RSG treatment. By delineating mechanisms by which RSG elicits cardiac hypertrophy, we have identified pathways that mediate the crosstalk between adipocytes and cardiomyocytes to regulate cardiac remodeling. PMID:27734035

  3. Exploring the cell signalling in hepatocyte differentiation.

    PubMed

    Vasconcellos, Rebecca; Alvarenga, Érika C; Parreira, Ricardo C; Lima, Swiany S; Resende, Rodrigo R

    2016-11-01

    The liver is the second largest organ in the human body and is responsible for several functions that directly contribute to homeostasis. Hepatocytes are the main parenchymal liver cells that regulate multiple biochemical and metabolic functions and the synthesis of substances important to the body. Mesenchymal stem cells (MSCs) are a group of stem cells derived from the mesoderm, which can be obtained from various tissues. Under certain conditions, MSCs can differentiate into several cell types, including hepatocytes. Post-transcriptional regulations of liver development signalling and hepatocyte differentiation have been demonstrated. At the post-transcriptional level, microRNAs have emerged as precursors for determining cell fate during differentiation. MicroRNAs (miRNAs) are small non-coding RNAs involved in the post-transcriptional regulation of gene expression. They can determine the stem cell fate by repressing the translation of target mRNAs. In this review, we outline signalling pathways involved in stem cell differentiation to hepatocytes and its interplay with liver development. Hepatic differentiation models in two-dimensional and three-dimensional cultures used to analyse signalling mechanisms will be described. We also highlight the possible miRNAs involved in this process and the transdifferentiation signalling mechanisms present in hepatocytes.

  4. Exploring the cell signalling in hepatocyte differentiation.

    PubMed

    Vasconcellos, Rebecca; Alvarenga, Érika C; Parreira, Ricardo C; Lima, Swiany S; Resende, Rodrigo R

    2016-11-01

    The liver is the second largest organ in the human body and is responsible for several functions that directly contribute to homeostasis. Hepatocytes are the main parenchymal liver cells that regulate multiple biochemical and metabolic functions and the synthesis of substances important to the body. Mesenchymal stem cells (MSCs) are a group of stem cells derived from the mesoderm, which can be obtained from various tissues. Under certain conditions, MSCs can differentiate into several cell types, including hepatocytes. Post-transcriptional regulations of liver development signalling and hepatocyte differentiation have been demonstrated. At the post-transcriptional level, microRNAs have emerged as precursors for determining cell fate during differentiation. MicroRNAs (miRNAs) are small non-coding RNAs involved in the post-transcriptional regulation of gene expression. They can determine the stem cell fate by repressing the translation of target mRNAs. In this review, we outline signalling pathways involved in stem cell differentiation to hepatocytes and its interplay with liver development. Hepatic differentiation models in two-dimensional and three-dimensional cultures used to analyse signalling mechanisms will be described. We also highlight the possible miRNAs involved in this process and the transdifferentiation signalling mechanisms present in hepatocytes. PMID:27555287

  5. Cardiac Hypertrophy: An Introduction to Molecular and Cellular Basis

    PubMed Central

    Samak, Mostafa; Fatullayev, Javid; Sabashnikov, Anton; Zeriouh, Mohamed; Schmack, Bastian; Farag, Mina; Popov, Aron-Frederik; Dohmen, Pascal M.; Choi, Yeong-Hoon; Wahlers, Thorsten; Weymann, Alexander

    2016-01-01

    Ventricular hypertrophy is an ominous escalation of hemodynamically stressful conditions such as hypertension and valve disease. The pathophysiology of hypertrophy is complex and multifactorial, as it touches on several cellular and molecular systems. Understanding the molecular background of cardiac hypertrophy is essential in order to protect the myocardium from pathological remodeling, or slow down the destined progression to heart failure. In this review we highlight the most important molecular aspects of cardiac hypertrophic growth in light of the currently available published research data. PMID:27450399

  6. Cholangiocarcinomas can originate from hepatocytes in mice

    PubMed Central

    Fan, Biao; Malato, Yann; Calvisi, Diego F.; Naqvi, Syed; Razumilava, Nataliya; Ribback, Silvia; Gores, Gregory J.; Dombrowski, Frank; Evert, Matthias; Chen, Xin; Willenbring, Holger

    2012-01-01

    Intrahepatic cholangiocarcinomas (ICCs) are primary liver tumors with a poor prognosis. The development of effective therapies has been hampered by a limited understanding of the biology of ICCs. Although ICCs exhibit heterogeneity in location, histology, and marker expression, they are currently thought to derive invariably from the cells lining the bile ducts, biliary epithelial cells (BECs), or liver progenitor cells (LPCs). Despite lack of experimental evidence establishing BECs or LPCs as the origin of ICCs, other liver cell types have not been considered. Here we show that ICCs can originate from fully differentiated hepatocytes. Using a mouse model of hepatocyte fate tracing, we found that activated NOTCH and AKT signaling cooperate to convert normal hepatocytes into biliary cells that act as precursors of rapidly progressing, lethal ICCs. Our findings suggest a previously overlooked mechanism of human ICC formation that may be targetable for anti-ICC therapy. PMID:22797301

  7. Hyperinsulinemia is Associated with Increased Soluble Insulin Receptors Release from Hepatocytes

    PubMed Central

    Hiriart, Marcia; Sanchez-Soto, Carmen; Diaz-Garcia, Carlos Manlio; Castanares, Diana T.; Avitia, Morena; Velasco, Myrian; Mas-Oliva, Jaime; Macias-Silva, Marina; González-Villalpando, Clicerio; Delgado-Coello, Blanca; Sosa-Garrocho, Marcela; Vidaltamayo, Román; Fuentes-Silva, Deyanira

    2014-01-01

    It has been generally assumed that insulin circulates freely in blood. However it can also interact with plasma proteins. Insulin receptors are located in the membrane of target cells and consist of an alpha and beta subunits with a tyrosine kinase cytoplasmic domain. The ectodomain, called soluble insulin receptor (SIR) has been found elevated in patients with diabetes mellitus. We explored if insulin binds to SIRs in circulation under physiological conditions and hypothesize that this SIR may be released by hepatocytes in response to high insulin concentrations. The presence of SIR in rat and human plasmas and the culture medium of hepatocytes was explored using Western blot analysis. A purification protocol was performed to isolated SIR using affinity, gel filtration, and ion exchange chromatographies. A modified reverse hemolytic plaque assay was used to measure SIR release from cultured hepatocytes. Incubation with 1 nmol l−1 insulin induces the release of the insulin receptor ectodomains from normal rat hepatocytes. This effect can be partially prevented by blocking protease activity. Furthermore, plasma levels of SIR were higher in a model of metabolic syndrome, where rats are hyperinsulinemic. We also found increased SIR levels in hyperinsulinemic humans. SIR may be an important regulator of the amount of free insulin in circulation. In hyperinsulinemia, the amount of this soluble receptor increases and this could lead to higher amounts of insulin bound to this receptor, rather than free insulin, which is the biologically active form of the hormone. This observation could enlighten the mechanisms of insulin resistance. PMID:24995000

  8. miR-155 functions downstream of angiotensin II receptor subtype 1 and calcineurin to regulate cardiac hypertrophy

    PubMed Central

    Yang, Yong; Zhou, Yong; Cao, Zheng; Tong, Xin Zhu; Xie, Hua Qiang; Luo, Tao; Hua, Xian Ping; Wang, Han Qin

    2016-01-01

    Cardiac hypertrophy is characterized by maladaptive tissue remodeling that may lead to heart failure or sudden death. MicroRNAs (miRs) are negative regulators of angiotensin II and the angiotensin II receptor subtype 1 (AGTR1), which are two components involved in cardiac hypertrophy. In the present study, the interaction between angiotensin II receptor subtype 1 (AGTR1) signaling and miR-155 was investigated. Rat H9C2 (2–1) cardiomyocytes were transfected with miR-155 analogues or inhibitors, then stimulated with angiotensin II to induce cardiac hypertrophy. miR-155 expression was revealed to be altered following transfection with chemically-modified miR-155 analogues and inhibitors in rat cardiomyocytes. In cell cardiac hypertrophy models, the cell surface area, AGTR1, atrial natriuretic peptide and myosin heavy chain-β mRNA expression levels were revealed to be lower in cells stimulated with miR-155 analogue-transfected cells treated with angiotensin II compared with cells stimulated with angiotensin alone (P<0.05), as determined using reverse transcription-polymerase chain reaction (PCR), quantitative PCR and western blot analyses. Furthermore, calcineurin mRNA and protein, intracellular free calcium and nuclear factor of activated T-cells-4 proteins were downregulated in miR-155 analogue-transfected cells treated with angiotensin II, as compared with cells stimulated with angiotensin II alone (P<0.05). In conclusion, the current study indicates that miR-155 may improve cardiac hypertrophy by downregulating AGTR1 and suppressing the calcium signaling pathways activated by AGTR1. PMID:27588076

  9. Mitoprotective antioxidant EUK-134 stimulates fatty acid oxidation and prevents hypertrophy in H9C2 cells.

    PubMed

    Purushothaman, Sreeja; Nair, R Renuka

    2016-09-01

    Oxidative stress is an important contributory factor for the development of cardiovascular diseases like hypertension-induced hypertrophy. Mitochondrion is the major source of reactive oxygen species. Hence, protecting mitochondria from oxidative damage can be an effective therapeutic strategy for the prevention of hypertensive heart disease. Conventional antioxidants are not likely to be cardioprotective, as they cannot protect mitochondria from oxidative damage. EUK-134 is a salen-manganese complex with superoxide dismutase and catalase activity. The possible role of EUK-134, a mitoprotective antioxidant, in the prevention of hypertrophy of H9C2 cells was examined. The cells were stimulated with phenylephrine (50 μM), and hypertrophy was assessed based on cell volume and expression of brain natriuretic peptide and calcineurin. Enhanced myocardial lipid peroxidation and protein carbonyl content, accompanied by nuclear factor-kappa B gene expression, confirmed the presence of oxidative stress in hypertrophic cells. Metabolic shift was evident from reduction in the expression of medium-chain acyl-CoA dehydrogenase. Mitochondrial oxidative stress was confirmed by the reduced expression of mitochondria-specific antioxidant peroxiredoxin-3 and enhanced mitochondrial superoxide production. Compromised mitochondrial function was apparent from reduced mitochondrial membrane potential. Pretreatment with EUK-134 (10 μM) was effective in the prevention of hypertrophic changes in H9C2 cells, reduction of oxidative stress, and prevention of metabolic shift. EUK-134 treatment improved the oxidative status of mitochondria and reversed hypertrophy-induced reduction of mitochondrial membrane potential. Supplementation with EUK-134 is therefore identified as a novel approach to attenuate cardiac hypertrophy and lends scope for the development of EUK-134 as a therapeutic agent in the management of human cardiovascular disease. PMID:27514538

  10. Hepatocyte growth factor, hepatocyte growth factor activator and arginine in a rat fulminant colitis model

    PubMed Central

    Zwintscher, Nathan P.; Shah, Puja M.; Salgar, Shashikumar K.; Newton, Christopher R.; Maykel, Justin A.; Samy, Ahmed; Jabir, Murad; Steele, Scott R.

    2016-01-01

    Introduction Dextran sodium sulfate (DSS) is commonly used to induce a murine fulminant colitis model. Hepatocyte growth factor (HGF) has been shown to decrease the symptoms of inflammatory bowel disease (IBD) but the effect of its activator, HGFA, is not well characterized. Arginine reduces effects of oxidative stress but its effect on IBD is not well known. The primary aim is to determine whether HGF and HGFA, or arginine will decrease IBD symptoms such as pain and diarrhea in a DSS-induced fulminant colitis murine model. Methods A severe colitis was induced in young, male Fischer 344 rats with 4% (w/v) DSS oral solution for seven days; rats were sacrificed on day 10. Rats were divided into five groups of 8 animals: control, HGF (700 mcg/kg/dose), HGF and HGFA (10 mcg/dose), HGF and arginine, and high dose HGF (2800 mcg/kg/dose). Main clinical outcomes were pain, diarrhea and weight loss. Blinded pathologists scored the terminal ileum and distal colon. Results DSS reliably induced severe active colitis in 90% of animals (n = 36/40). There were no differences in injury scores between control and treatment animals. HGF led to 1.38 fewer days in pain (p = 0.036), while arginine led to 1.88 fewer days of diarrhea (P = 0.017) compared to controls. 88% of HGFA-treated rats started regaining weight (P < 0.001). Discussion/Conclusion Although treatment was unable to reverse fulminant disease, HGF and arginine were associated with decreased days of pain and diarrhea. These clinical interventions may reduce associated symptoms for severe IBD patients, even when urgent surgical intervention remains the only viable option. PMID:27144006

  11. Raf-mediated cardiac hypertrophy in adult Drosophila

    PubMed Central

    Yu, Lin; Daniels, Joseph; Glaser, Alex E.; Wolf, Matthew J.

    2013-01-01

    SUMMARY In response to stress and extracellular signals, the heart undergoes a process called cardiac hypertrophy during which cardiomyocytes increase in size. If untreated, cardiac hypertrophy can progress to overt heart failure that causes significant morbidity and mortality. The identification of molecular signals that cause or modify cardiomyopathies is necessary to understand how the normal heart progresses to cardiac hypertrophy and heart failure. Receptor tyrosine kinase (RTK) signaling is essential for normal human cardiac function, and the inhibition of RTKs can cause dilated cardiomyopathies. However, neither investigations of activated RTK signaling pathways nor the characterization of hypertrophic cardiomyopathy in the adult fly heart has been previously described. Therefore, we developed strategies using Drosophila as a model to circumvent some of the complexities associated with mammalian models of cardiovascular disease. Transgenes encoding activated EGFRA887T, Ras85DV12 and Ras85DV12S35, which preferentially signal to Raf, or constitutively active human or fly Raf caused hypertrophic cardiomyopathy as determined by decreased end diastolic lumen dimensions, abnormal cardiomyocyte fiber morphology and increased heart wall thicknesses. There were no changes in cardiomyocyte cell numbers. Additionally, activated Raf also induced an increase in cardiomyocyte ploidy compared with control hearts. However, preventing increases in cardiomyocyte ploidy using fizzy-related (Fzr) RNAi did not rescue Raf-mediated cardiac hypertrophy, suggesting that Raf-mediated polyploidization is not required for cardiac hypertrophy. Similar to mammals, the cardiac-specific expression of RNAi directed against MEK or ERK rescued Raf-mediated cardiac hypertrophy. However, the cardiac-specific expression of activated ERKD334N, which promotes hyperplasia in non-cardiac tissues, did not cause myocyte hypertrophy. These results suggest that ERK is necessary, but not sufficient, for

  12. Cytoskeletal Role in the Contractile Dysfunction of Hypertrophied Myocardium

    NASA Astrophysics Data System (ADS)

    Tsutsui, Hiroyuki; Ishihara, Kazuaki; Cooper, George

    1993-04-01

    Cardiac hypertrophy in response to systolic pressure loading frequently results in contractile dysfunction of unknown cause. In the present study, pressure loading increased the microtubule component of the cardiac muscle cell cytoskeleton, which was responsible for the cellular contractile dysfunction observed. The linked microtubule and contractile abnormalities were persistent and thus may have significance for the deterioration of initially compensatory cardiac hypertrophy into congestive heart failure.

  13. Parotid hypertrophy with bulimia: a report of surgical management.

    PubMed

    Berke, G S; Calcaterra, T C

    1985-05-01

    Benign hypertrophy of the salivary glands can occur in patients with anorexia nervosa. This enlargement has been related to nutritional deficiencies and bulimia, which is a form of episodic binge eating followed by vomiting. The surgical management of a patient with bulimia and benign bilateral parotid enlargement secondary to bulimia will be discussed. Superficial parotidectomy may be a useful adjunct in managing the cosmetic and psychological aspects of patients with anorexia nervosa and bulimia complicated by massive parotid hypertrophy intractable to medical management.

  14. Novel EGFR inhibitors attenuate cardiac hypertrophy induced by angiotensin II.

    PubMed

    Peng, Kesong; Tian, Xinqiao; Qian, Yuanyuan; Skibba, Melissa; Zou, Chunpeng; Liu, Zhiguo; Wang, Jingying; Xu, Zheng; Li, Xiaokun; Liang, Guang

    2016-03-01

    Cardiac hypertrophy is an important risk factor for heart failure. Epidermal growth factor receptor (EGFR) has been found to play a role in the pathogenesis of various cardiovascular diseases. The aim of this current study was to examine the role of EGFR in angiotensin II (Ang II)-induced cardiac hypertrophy and identify the underlying molecular mechanisms. In this study, we observed that both Ang II and EGF could increase the phospohorylation of EGFR and protein kinase B (AKT)/extracellular signal-regulated kinase (ERK), and then induce cell hypertrophy in H9c2 cells. Both pharmacological inhibitors and genetic silencing significantly reduced Ang II-induced EGFR signalling pathway activation, hypertrophic marker overexpression, and cell hypertrophy. In addition, our results showed that Ang II-induced EGFR activation is mediated by c-Src phosphorylation. In vivo, Ang II treatment significantly led to cardiac remodelling including cardiac hypertrophy, disorganization and fibrosis, accompanied by the activation of EGFR signalling pathway in the heart tissues, while all these molecular and pathological alterations were attenuated by the oral administration with EGFR inhibitors. In conclusion, the c-Src-dependent EGFR activation may play an important role in Ang II-induced cardiac hypertrophy, and inhibition of EGFR by specific molecules may be an effective strategy for the treatment of Ang II-associated cardiac diseases. PMID:26762600

  15. Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress.

    PubMed

    Domínguez-Pérez, Mayra; Nuño-Lámbarri, Natalia; Clavijo-Cornejo, Denise; Luna-López, Armando; Souza, Verónica; Bucio, Leticia; Miranda, Roxana U; Muñoz, Linda; Gomez-Quiroz, Luis Enrique; Uribe-Carvajal, Salvador; Gutiérrez-Ruiz, María Concepción

    2016-01-01

    Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system.

  16. Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress

    PubMed Central

    Domínguez-Pérez, Mayra; Nuño-Lámbarri, Natalia; Clavijo-Cornejo, Denise; Luna-López, Armando; Souza, Verónica; Bucio, Leticia; Miranda, Roxana U.; Muñoz, Linda; Gomez-Quiroz, Luis Enrique; Uribe-Carvajal, Salvador; Gutiérrez-Ruiz, María Concepción

    2016-01-01

    Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system. PMID:27143995

  17. Managing turbinate hypertrophy: coblation vs. radiofrequency treatment.

    PubMed

    Passali, D; Loglisci, M; Politi, L; Passali, G C; Kern, E

    2016-06-01

    The role of inferior turbinate hypertrophy in the reduction of nasal airflow is well established. Although chronic nasal obstruction is not life- threatening, it significantly impairs patients' quality of life, affecting many aspects of daily activities; therefore, patients seek medical intervention. 40 patients were selected (27 males and 13 females) between 27 and 64 years of age with a symptom of nasal obstruction. The patients were divided in two groups: Group 1: coblation, 25 patients (18 males and 7 females); Group 2: radiofrequency, 15 patients (7 males and 6 females). These 40 patients were followed for 3 years. Patients were analyzed using both subjective and objective methods. The visual analog scale (VAS) subjective data and objective data including both active anterior rhinomanometry and acoustic rhinometry were recorded and analyzed. Data were collected pre-operatively and at 1 and 3 years post-operatively. According to our data, both coblation and radiofrequency turbinate reduction benefit patients with good results. The complications, found during the follow-up, are limited to minimal bleeding and crusting. Coblation and radiofrequency were significantly less painful than others procedures during the early post-operative period. In our study, both coblation and radiofrequency provide an improvement in nasal airflow with a reduction in nasal obstructive symptoms in the short term, but their efficacy tended to decrease within 3 years.

  18. Proteomic analysis of bovine skeletal muscle hypertrophy.

    PubMed

    Bouley, Julien; Meunier, Bruno; Chambon, Christophe; De Smet, Stefaan; Hocquette, Jean François; Picard, Brigitte

    2005-02-01

    Myostatin plays a major role in muscle growth and development and animals with disruption of this gene display marked increases in muscle mass. Little is known about muscle physiological adaptations in relation to this muscle hypertrophy. To provide a more comprehensive view, we analyzed bovine muscles from control, heterozygote and homozygote young Belgian blue bulls for myostatin deletion, which results in a normal level of inactive myostatin. Heterozygote and homozygote animals were characterized by a higher proportion of fast-twitch glycolytic fibers in Semitendinosus muscle. Differential proteomic analysis of this muscle was performed using two-dimensional gel electrophoresis followed by mass spectrometry. Thirteen proteins, corresponding to 28 protein spots, were significantly altered in response to the myostatin deletion. The observed changes in protein expression are consistent with an increased fast muscle phenotype, suggesting that myostatin negatively controls mainly fast-twitch glycolytic fiber number. Finally, we demonstrated that differential mRNA splicing of fast troponin T is altered by the loss of myostatin function. The structure of mutually exclusive exon 16 appears predominantly expressed in muscles from heterozygote and homozygote animals. This suggests a role for exon 16 of fast troponin T in the physiological adaptation of the fast muscle phenotype.

  19. Induction of mitochondrial biogenesis and respiration is associated with mTOR regulation in hepatocytes of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA)

    SciTech Connect

    Hagland, Hanne R.; Nilsson, Linn I.H.; Burri, Lena; Nikolaisen, Julie; Berge, Rolf K.; Tronstad, Karl J.

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer We investigated mechanisms of mitochondrial regulation in rat hepatocytes. Black-Right-Pointing-Pointer Tetradecylthioacetic acid (TTA) was employed to activate mitochondrial oxidation. Black-Right-Pointing-Pointer Mitochondrial biogenesis and respiration were induced. Black-Right-Pointing-Pointer It was confirmed that PPAR target genes were induced. Black-Right-Pointing-Pointer The mechanism involved activation mTOR. -- Abstract: The hypolipidemic effect of peroxisome proliferator-activated receptor (PPAR) activators has been explained by increasing mitochondrial fatty acid oxidation, as observed in livers of rats treated with the pan-PPAR activator tetradecylthioacetic acid (TTA). PPAR-activation does, however, not fully explain the metabolic adaptations observed in hepatocytes after treatment with TTA. We therefore characterized the mitochondrial effects, and linked this to signalling by the metabolic sensor, the mammalian target of rapamycin (mTOR). In hepatocytes isolated from TTA-treated rats, the changes in cellular content and morphology were consistent with hypertrophy. This was associated with induction of multiple mitochondrial biomarkers, including mitochondrial DNA, citrate synthase and mRNAs of mitochondrial proteins. Transcription analysis further confirmed activation of PPAR{alpha}-associated genes, in addition to genes related to mitochondrial biogenesis and function. Analysis of mitochondrial respiration revealed that the capacity of both electron transport and oxidative phosphorylation were increased. These effects coincided with activation of the stress related factor, ERK1/2, and mTOR. The protein level and phosphorylation of the downstream mTOR actors eIF4G and 4E-BP1 were induced. In summary, TTA increases mitochondrial respiration by inducing hypertrophy and mitochondrial biogenesis in rat hepatocytes, via adaptive regulation of PPARs as well as mTOR.

  20. All hexokinase isoenzymes coexist in rat hepatocytes.

    PubMed Central

    Reyes, A; Cárdenas, M L

    1984-01-01

    The cellular distribution of hexokinase isoenzymes, N-acetylglucosamine Kinase and pyruvate kinases in rat liver was studied. Hepatocytes and non-parenchymal cells with high viability and almost no cross-contamination were obtained by perfusion in situ of the liver with collagenase, with the use of an enriched cell-culture medium in all steps of cell isolation. Separation of hexokinase isoenzymes was done by DEAE-cellulose chromatography, and enzyme activities were measured by a specific radioassay. Cytosol from isolated hepatocytes contained high-affinity hexokinases A, B and C, in addition to hexokinase D. The last-mentioned represented about 95% of total glucose-phosphorylating activity. Only hexokinase A was found associated t the particulate fraction. Isolated non-parenchymal cells contained only hexokinases A, B and C. N-Acetylglucosamine kinase was measured with a specific radioassay and was found as a single enzyme form in both hepatocytes and non-parenchymal cells, with higher activities in the former. Pyruvate kinase isoenzyme L was present only in the hepatocytes and isoenzyme K only in the non-parenchymal liver cells, confirming that they are good cellular markers. PMID:6089733

  1. Ablation of plasma membrane Ca(2+)-ATPase isoform 4 prevents development of hypertrophy in a model of hypertrophic cardiomyopathy.

    PubMed

    Prasad, Vikram; Lorenz, John N; Lasko, Valerie M; Nieman, Michelle L; Jiang, Min; Gao, Xu; Rubinstein, Jack; Wieczorek, David F; Shull, Gary E

    2014-12-01

    The mechanisms linking the expression of sarcomeric mutant proteins to the development of pathological hypertrophy in hypertrophic cardiomyopathy (HCM) remain poorly understood. We investigated the role of the plasma membrane Ca(2+)-ATPase PMCA4 in the HCM phenotype using a transgenic model that expresses mutant (Glu180Gly) α-tropomyosin (Tm180) in heart. Immunoblot analysis revealed that cardiac PMCA4 expression was upregulated early in Tm180 disease pathogenesis. This was accompanied by an increase in levels of the L-type Ca(2+)-channel, which is implicated in pathological hypertrophy. When Tm180 mice were crossed with a PMCA4-null line, loss of PMCA4 caused the abrogation of hypertrophy in Tm180/PMCA4-null double mutant mice. RT-PCR analysis of Tm180/PMCA4-null hearts revealed blunting of the fetal program and reversion of pro-fibrotic Col1a1 and Col3a1 gene expression to wild-type levels. This was accompanied by evidence of reduced L-type Ca(2+)-channel expression, and diminished calcineurin activity. Expression of the metabolic substrate transporters glucose transporter 4 and carnitine palmitoyltransferase 1b was preserved and Tm180-related changes in mRNA levels of various contractile stress-related proteins including the cardiac ankyrin protein CARP and the N2B isoform of titin were reversed in Tm180/PMCA4-null hearts. cGMP levels were increased and phosphorylation of vasodilator-stimulated phosphoprotein was elevated in Tm180/PMCA4-null hearts. These changes were associated with a sharp reduction in left ventricular end-diastolic pressure in Tm180/PMCA4-null hearts, which occurred despite persistence of Tm180-related impairment of relaxation dynamics. These results reveal a novel and specific role for PMCA4 in the Tm180 hypertrophic phenotype, with the "protective" effects of PMCA4 deficiency encompassing multiple determinants of HCM-related hypertrophy. PMID:25280781

  2. Hormonal regulation of hepatocyte tight junctional permeability

    SciTech Connect

    Lowe, P.J.; Miyai, K.; Steinbach, J.H.; Hardison, W.G.M. Univ. of California, San Diego )

    1988-10-01

    The authors have investigated the effects of hormones on the permeability of the hepatocyte tight junction to two probes, ({sup 14}C)sucrose and horseradish peroxidase, using one-pass perfused rat livers. Using a single injection of horseradish peroxidase the authors have demonstrated that this probe can enter bile by two pathways that are kinetically distinct, a fast pathway, which corresponds to the passage of the probe through the hepatocyte tight junctions, and a slow pathway, which corresponds to the transcytotic entry into bile. The passage of horseradish peroxidase through the hepatocyte tight junctions was confirmed by electron microscopic histochemistry. Vasopressin, epinephrine, and angiotensin II, hormones that act in the hepatocyte through the intracellular mediators calcium, the inositol polyphosphates, and diacylglycerol, increased the bile-to-perfusion fluid ratio of ({sup 14}C)sucrose and the rapid entry of horseradish peroxidase into bile, indicating that the permeability of the tight junctions to these probes was increased. The effect of these hormones was dose dependent and in the cases of angiotensin II and epinephrine was inhibited by the specific inhibitors (Sar{sup 1},Thr{sup 8})angiotensin II and prazosin, respectively. Dibutyryl adenosine 3{prime},5{prime}-cyclic monophosphate did not affect the ({sup 14}C)sucrose bile-to-perfusion fluid ratio or the fast entry of horseradish peroxidase into bile. These results suggest that the hepatocyte tight junction can no longer be considered a static system of pores separating blood from bile. It is rather a dynamic barrier potentially capable of influencing the composition of the bile.

  3. The relation between childhood obesity and adenotonsillar hypertrophy.

    PubMed

    Daar, Ghaniya; Sarı, Kamran; Gencer, Zeliha Kapusuz; Ede, Hüseyin; Aydın, Reha; Saydam, Levent

    2016-02-01

    Childhood obesity is a common and significant public health problem all over the world. As a well-known fact obese children have an increased risk of obesity-associated comorbidities, including obstructive sleep apnea, diabetes, and cardiovascular disorders at an earlier age compared to their normal weight peers. They also have an increased risk of poor self-esteem, greater body dissatisfaction, and increased peer teasing that lead to a lower health-related quality of life. While the presence of adenoid hypertrophy and increased rate of obstructive sleep apnea frequently co-exists in majority of cases. We have limited knowledge about the effect of adenotonsillar hypertrophy on development of childhood obesity. In this study, we aimed to investigate the association between obesity, presence of adenotonsillar hypertrophy and the quality of life parameters in obese children as measured by the OSA-18 quality of life questionnaire. Fifty obese children aged between 3 and 18 years and 50 age- and gender-matched otherwise children were enrolled to the study. All subjects were routinely examined by the otolaryngologist before enrollment. The size of adenoid hypertrophy was measured using lateral cephalometric radiographs. The tonsils were also graded using the schema recommended by Brodsky et al. We used OSA-18 questionnaires to evaluate the subjects' quality of life issues. We found, 34 % of obese group had tonsillar hypertrophy while the rate was 6 % in control group. Similarly 16 % of obese group had tonsillar hypertrophy compared to only 4 % in non-obese group. It was also noted that total OSA-18 scores of obese group were significantly higher than those of non-obese group. In subgroup analysis of obese group, total OSA-18 score of obese subjects with either adenoid and/or tonsillar hypertrophy was significantly higher than that of obese subjects without adenoid or tonsillar hypertrophy. As the related literature suggests that the impact of adenotonsillar size on OSA

  4. Apelin ameliorates TNF-α-induced reduction of glycogen synthesis in the hepatocytes through G protein-coupled receptor APJ.

    PubMed

    Chu, Jiaojiao; Zhang, Hangxiang; Huang, Xiuqing; Lin, Yajun; Shen, Tao; Chen, Beidong; Man, Yong; Wang, Shu; Li, Jian

    2013-01-01

    Apelin, a novel adipokine, is the specific endogenous ligand of G protein-coupled receptor APJ. Consistent with its putative role as an adipokine, apelin has been linked to states of insulin resistance. However, the function of apelin in hepatic insulin resistance, a vital part of insulin resistance, and its underlying mechanisms still remains unclear. Here we define the impacts of apelin on TNF-α-induced reduction of glycogen synthesis in the hepatocytes. Our studies indicate that apelin reversed TNF-α-induced reduction of glycogen synthesis in HepG2 cells, mouse primary hepatocytes and liver tissues of C57BL/6J mice by improving JNK-IRS1-AKT-GSK pathway. Moreover, Western blot revealed that APJ, but not apelin, expressed in the hepatocytes and liver tissues of mice. We found that F13A, a competitive antagonist for G protein-coupled receptor APJ, suppressed the effects of apelin on TNF-α-induced reduction of glycogen synthesis in the hepatocytes, suggesting APJ is involved in the function of apelin. In conclusion, we show novel evidence suggesting that apelin ameliorates TNF-α-induced reduction of glycogen synthesis in the hepatocytes through G protein-coupled receptor APJ. Apelin appears as a beneficial adipokine with anti-insulin resistance properties, and thus as a promising therapeutic target in metabolic disorders.

  5. Effects of Trichostatin A on drug uptake transporters in primary rat hepatocyte cultures.

    PubMed

    Ramboer, Eva; Rogiers, Vera; Vanhaecke, Tamara; Vinken, Mathieu

    2015-01-01

    The present study was set up to investigate the effects of Trichostatin A (TSA), a prototypical epigenetic modifier, on the expression and activity of hepatic drug uptake transporters in primary cultured rat hepatocytes. To this end, the expression of the sinusoidal transporters sodium-dependent taurocholate cotransporting polypeptide (Ntcp) and organic anion transporting polypeptide 4 (Oatp4) was monitored by real-time quantitative reverse transcriptase polymerase chain reaction analysis and immunoblotting. The activity of the uptake transporters was analyzed using radiolabeled substrates and chemical inhibitors. Downregulation of the expression and activity of Oatp4 and Ntcp was observed as a function of the cultivation time and could not be counteracted by TSA. In conclusion, the epigenetic modifier TSA does not seem to exert a positive effect on the expression and activity of the investigated uptake transporters in primary rat hepatocyte cultures. PMID:26648816

  6. The transcription factor GATA-6 regulates pathological cardiac hypertrophy

    PubMed Central

    van Berlo, Jop H.; Elrod, John W.; van den Hoogenhof, Maarten M.G.; York, Allen J.; Aronow, Bruce J.; Duncan, Stephen A.; Molkentin, Jeffery D.

    2010-01-01

    Rationale The transcriptional code that programs maladaptive cardiac hypertrophy involves the zinc finger-containing DNA binding factor GATA-4. The highly related transcription factor GATA-6 is also expressed in the adult heart, although its role in controlling the hypertrophic program is unknown. Objective To determine the role of GATA-6 in cardiac hypertrophy and homeostasis. Methods and Results Here we performed a cardiomyocyte-specific conditional gene targeting approach for Gata6, as well as a transgenic approach to overexpress GATA-6 in the mouse heart. Deletion of Gata6-loxP with Nkx2.5-cre produced late embryonic lethality with heart defects, while deletion with β-myosin heavy chain-cre (βMHC-cre) produced viable adults with greater than 95% loss of GATA-6 protein in the heart. These later mice were subjected to pressure overload induced hypertrophy for 2 and 6 weeks, which showed a significant reduction in cardiac hypertrophy similar to that observed Gata4 heart-specific deleted mice. Gata6-deleted mice subjected to pressure overload also developed heart failure while control mice maintained proper cardiac function. Gata6-deleted mice also developed less cardiac hypertrophy following 2 weeks of angiotensin II/phenylephrine infusion. Controlled GATA-6 overexpression in the heart induced hypertrophy with aging and predisposed to greater hypertrophy with pressure overload stimulation. Combinatorial deletion of Gata4 and Gata6 from the adult heart resulted in dilated cardiomyopathy and lethality by 16 weeks of age. Mechanistically, deletion of Gata6 from the heart resulted in fundamental changes in the levels of key regulatory genes and myocyte differentiation-specific genes. Conclusions These results indicate that GATA-6 is both necessary and sufficient for regulating the cardiac hypertrophic response and differentiated gene expression, both alone and in coordination with GATA-4. PMID:20705924

  7. Shensongyangxin protects against pressure overload‑induced cardiac hypertrophy.

    PubMed

    Shen, Di-Fei; Wu, Qing-Qing; Ni, Jian; Deng, Wei; Wei, Cong; Jia, Zhen-Hua; Zhou, Heng; Zhou, Meng-Qiao; Bian, Zhou-Yan; Tang, Qi-Zhu

    2016-01-01

    Shensongyangxin (SSYX) is a medicinal herb, which has long been used in traditional Chinese medicine. Various pharmacological activities of SSYX have been identified. However, the role of SSYX in cardiac hypertrophy remains to be fully elucidated. In present study, aortic banding (AB) was performed to induce cardiac hypertrophy in mice. SSYX (520 mg/kg) was administered by daily gavage between 1 and 8 weeks following surgery. The extent of cardiac hypertrophy was then evaluated by pathological and molecular analyses of heart tissue samples. In addition, in vitro experiments were performed to confirm the in vivo results. The data of the present study demonstrated that SSYX prevented the cardiac hypertrophy and fibrosis induced by AB, as assessed by measurements of heart weight and gross heart size, hematoxylin and eosin staining, cross‑sectional cardiomyocyte area and the mRNA expression levels of hypertrophic markers. SSYX also inhibited collagen deposition and suppressed the expression of transforming growth factor β (TGFβ), connective tissue growth factor, fibronectin, collagen Ⅰα and collagen Ⅲα, which was mediated by the inhibition of the TGFβ/small mothers against decapentaplegic (Smad) signaling pathway. The inhibitory action of SSYX on cardiac hypertrophy was mediated by the inhibition of Akt signaling. In vitro investigations in the rat H9c2 cardiac cells also demonstrated that SSYX attenuated angiotensin II‑induced cardiomyocyte hypertrophy. These findings suggested that SSYX attenuated cardiac hypertrophy and fibrosis in the pressure overloaded mouse heart. Therefore, the cardioprotective effect of SSYX is associated with inhibition of the Akt and TGFβ/Smad signaling pathways. PMID:26648261

  8. Cytoskeletal mechanics in pressure-overload cardiac hypertrophy

    NASA Technical Reports Server (NTRS)

    Tagawa, H.; Wang, N.; Narishige, T.; Ingber, D. E.; Zile, M. R.; Cooper, G. 4th

    1997-01-01

    We have shown that the cellular contractile dysfunction characteristic of pressure-overload cardiac hypertrophy results not from an abnormality intrinsic to the myofilament portion of the cardiocyte cytoskeleton but rather from an increased density of the microtubule component of the extramyofilament portion of the cardiocyte cytoskeleton. To determine how, in physical terms, this increased microtubule density mechanically overloads the contractile apparatus at the cellular level, we measured cytoskeletal stiffness and apparent viscosity in isolated cardiocytes via magnetic twisting cytometry, a technique by which magnetically induced force is applied directly to the cytoskeleton through integrin-coupled ferromagnetic beads coated with Arg-Gly-Asp (RGD) peptide. Measurements were made in two groups of cardiocytes from cats with right ventricular (RV) hypertrophy induced by pulmonary artery banding: (1) those from the pressure-overloaded RV and (2) those from the normally loaded same-animal control left ventricle (LV). Cytoskeletal stiffness increased almost twofold, from 8.53 +/- 0.77 dyne/cm2 in the normally loaded LV cardiocytes to 16.46 +/- 1.32 dyne/cm2 in the hypertrophied RV cardiocytes. Cytoskeletal apparent viscosity increased almost fourfold, from 20.97 +/- 1.92 poise in the normally loaded LV cardiocytes to 87.85 +/- 6.95 poise in the hypertrophied RV cardiocytes. In addition to these baseline data showing differing stiffness and, especially, apparent viscosity in the two groups of cardiocytes, microtubule depolymerization by colchicine was found to return both the stiffness and the apparent viscosity of the pressure overload-hypertrophied RV cells fully to normal. Conversely, microtubule hyperpolymerization by taxol increased the stiffness and apparent viscosity values of normally loaded LV cardiocytes to the abnormal values given above for pressure-hypertrophied RV cardiocytes. Thus, increased microtubule density constitutes primarily a viscous load on

  9. LEFT VENTRICULAR HYPERTROPHY AFTER HYPERTENSIVE PREGNANCY DISORDERS

    PubMed Central

    Scantlebury, Dawn C.; Kane, Garvan C.; Wiste, Heather J.; Bailey, Kent R.; Turner, Stephen T.; Arnett, Donna K.; Devereux, Richard B.; Mosley, Thomas H.; Hunt, Steven C.; Weder, Alan B.; Rodriguez, Beatriz; Boerwinkle, Eric; Weissgerber, Tracey L.; Garovic, Vesna D.

    2015-01-01

    Objective Cardiac changes of hypertensive pregnancy include left ventricular hypertrophy (LVH) and diastolic dysfunction. These are thought to regress postpartum. We hypothesized that women with a history of hypertensive pregnancy would have altered left ventricular (LV) geometry and function when compared to women with only normotensive pregnancies. Methods In this cohort study, we analyzed echocardiograms of 2637 women who participated in the Family Blood Pressure Program (FBPP). We compared LV mass and function in women with hypertensive pregnancy compared to those with normotensive pregnancies. Results Women were evaluated at a mean age of 56 years: 427 (16%) had at least one hypertensive pregnancy; 2210 (84%) had normotensive pregnancies. Compared to women with normotensive pregnancies, women with hypertensive pregnancy had a greater risk of LVH (OR: 1.42, 95% CI 1.01-1.99, p=0.05), after adjusting for age, race, research network of the FBPP, education, parity, BMI, hypertension and diabetes. When duration of hypertension was taken into account, this relationship was no longer significant (OR: 1.19, CI 0.08-1.78 p=0.38). Women with hypertensive pregnancies also had greater left atrial size and lower mitral E/A ratio after adjusting for demographic variables. The prevalence of systolic dysfunction was similar between the groups. Conclusions A history of hypertensive pregnancy is associated with LVH after adjusting for risk factors; this might be explained by longer duration of hypertension. This finding supports current guidelines recommending surveillance of women following a hypertensive pregnancy, and sets the stage for longitudinal echocardiographic studies to further elucidate progression of LV geometry and function after pregnancy. PMID:26243788

  10. Reversibility of Adverse, Calcineurin-Dependent Cardiac Remodeling

    PubMed Central

    Berry, Jeff M.; Le, Vien; Rotter, David; Battiprolu, Pavan K.; Grinsfelder, Bennett; Tannous, Paul; Burchfield, Jana S.; Czubryt, Michael; Backs, Johannes; Olson, Eric N.; Rothermel, Beverly A.; Hill, Joseph A.

    2011-01-01

    Background Studies to dissect the role of calcineurin in pathological cardiac remodeling have relied heavily on murine models, where genetic gain- and loss-of-function manipulations are initiated at or before birth. However, the great majority of clinical cardiac pathology occurs in adults. Yet, nothing is known about the effects of calcineurin when its activation commences in adulthood. Further, despite the fact that ventricular hypertrophy is a well established risk factor for heart failure, the relative pace and progression of these two major phenotypic features of heart disease are unknown. Methods and Results We engineered mice harboring in cardiomyocytes a constitutively active calcineurin transgene driven by a tetracycline-responsive promoter element. Expression of the mutant calcineurin transgene was initiated for variable lengths of time to determine the natural history of disease pathogenesis, and to determine when, if ever, these events are reversible. Activation of the calcineurin transgene in adult mice triggered rapid and robust cardiac growth with features characteristic of pathological hypertrophy. Concentric hypertrophy preceded the development of systolic dysfunction, fetal gene activation, fibrosis, and clinical heart failure. Further, cardiac hypertrophy reversed spontaneously when calcineurin activity was turned off, and expression of fetal genes reverted to baseline. Fibrosis, a prominent feature of pathological cardiac remodeling, manifested partial reversibility. Conclusions Together, these data establish and define the deleterious effects of calcineurin signaling in adult heart and reveal that calcineurin-dependent hypertrophy with concentric geometry precedes systolic dysfunction and heart failure. Furthermore, these findings demonstrate that during much of the disease process, calcineurin-dependent remodeling remains reversible. PMID:21700928

  11. Reduced Oxidative Stress Contributes to the Lipid Lowering Effects of Isoquercitrin in Free Fatty Acids Induced Hepatocytes

    PubMed Central

    Rongyin, Gao; Daoud, Abdelkader; Ding, Lin; Wang, Lulu; Liu, Jun

    2014-01-01

    Oxidative stress interferes with hepatic lipid metabolism at various levels ranging from benign lipid storage to so-called second hit of inflammation activation. Isoquercitrin (IQ) is widely present flavonoid but its effects on hepatic lipid metabolism remain unknown. We used free fatty acids (FFA) induced lipid overload and oxidative stress model in two types of liver cells and measured cell viability, intracellular lipids, and reactive oxygen species (ROS) within hepatocytes. In addition, Intracellular triglycerides (TG), superoxide dismutase (SOD), and malondialdehyde (MDA) were examined. A novel in vitro model was used to evaluate correlation between lipid lowering and antioxidative activities. Furthermore, 34 major cytokines and corresponding ROS levels were analyzed in FFA/LPS induced coculture model between hepatocytes and Kupffer cells. At molecular level AMPK pathway was elucidated. We showed that IQ attenuated FFA induced lipid overload and ROS within hepatocytes. Further, IQ reversed FFA induced increase in intracellular TG SOD and MDA. It was shown that antioxidative activity of IQ correlates with its lipid lowering potentials. IQ reversed major proinflammatory cytokines and oxidative stress in FFA/LPS induced coculture model. Finally, AMPK pathway was found responsible for metabolic benefits at molecular level. IQ strikingly manifests antioxidative and related lipid lowering activities in hepatocytes. PMID:25404990

  12. Endothelial Nogo-B regulates sphingolipid biosynthesis to promote pathological cardiac hypertrophy during chronic pressure overload

    PubMed Central

    Zhang, Yi; Huang, Yan; Cantalupo, Anna; Azevedo, Paula S.; Siragusa, Mauro; Bielawski, Jacek; Giordano, Frank J.; Di Lorenzo, Annarita

    2016-01-01

    We recently discovered that endothelial Nogo-B, a membrane protein of the ER, regulates vascular function by inhibiting the rate-limiting enzyme, serine palmitoyltransferase (SPT), in de novo sphingolipid biosynthesis. Here, we show that endothelium-derived sphingolipids, particularly sphingosine-1-phosphate (S1P), protect the heart from inflammation, fibrosis, and dysfunction following pressure overload and that Nogo-B regulates this paracrine process. SPT activity is upregulated in banded hearts in vivo as well as in TNF-α–activated endothelium in vitro, and loss of Nogo removes the brake on SPT, increasing local S1P production. Hence, mice lacking Nogo-B, systemically or specifically in the endothelium, are resistant to the onset of pathological cardiac hypertrophy. Furthermore, pharmacological inhibition of SPT with myriocin restores permeability, inflammation, and heart dysfunction in Nogo-A/B–deficient mice to WT levels, whereas SEW2871, an S1P1 receptor agonist, prevents myocardial permeability, inflammation, and dysfunction in WT banded mice. Our study identifies a critical role of endothelial sphingolipid biosynthesis and its regulation by Nogo-B in the development of pathological cardiac hypertrophy and proposes a potential therapeutic target for the attenuation or reversal of this clinical condition. PMID:27158676

  13. Pluripotent Stem Cell-Derived Hepatocyte-Like Cells

    PubMed Central

    Schwartz, R. E.; Fleming, H.E.; Bhatia, S. N.

    2014-01-01

    Liver disease is an important clinical problem, impacting over 30 million Americans and over 600 million people worldwide. It is the 12th leading cause of death in the United States and the 16th worldwide. Due to a paucity of donor organs, several thousand Americans die yearly while waiting for liver transplantation. Unfortunately, alternative tissue sources such as fetal hepatocytes and hepatic cell lines are unreliable, difficult to reproduce, and do not fully recapitulate hepatocyte phenotype and function. As a consequence, alternative cell sources that do not have these limitations have been sought. Human embryonic stem (hES) cell- and induced pluripotent stem (iPS) cell-derived hepatocyte-like cells may enable cell based therapeutics, the study of the mechanisms of human disease and human development, and provide a platform for pharmacology and toxicology drug screening. iPS cells can be differentiated in a stepwise fashion with high efficiency and reproducibility into hepatocyte-like cells that exhibit morphologic and phenotypic characteristics of hepatocytes. In addition, iPS-derived hepatocyte-like cells possess some functional hepatic activity as they secrete urea, alpha-1-antitrypsin, and albumin. However, the combined phenotypic and functional traits exhibited by iPS-derived hepatocyte-like cells resemble a relatively immature hepatic phenotype that more closely resembles that of fetal hepatocytes rather than adult hepatocytes. Specifically, iPS-derived hepatocyte-like cells express fetal markers such as alpha fetoprotein and lack key mature hepatocyte functions, as reflected by drastically reduced activity (0.1%) of many detoxification enzymes (i.e. CYP2A6, CYP3A4). These key differences between iPS-derived hepatocyte-like cells and adult hepatocytes have limited the use of stem cells as a renewable source of functional adult human hepatocytes for in vitro and in vivo applications. Unfortunately, the developmental pathways that control hepatocyte

  14. Telmisartan regresses left ventricular hypertrophy in caveolin-1 deficient mice

    PubMed Central

    Kreiger, Marta H; Di Lorenzo, Annarita; Teutsch, Christine; Kauser, Katalin; Sessa, William C.

    2011-01-01

    The role of angiotensin II (Ang II) in promoting cardiac hypertrophy is well known, however the role of the Ang II in a spontaneous model of hypertrophy in mice lacking the protein caveolin-1 (Cav- KO) has not been explored. In this study, WT and Cav-1 KO mice were treated with angiotensin receptor blocker (ARB), telmisartan, and cardiac function assessed by echocardiography. Treatment of Cav-1 KO mice with telmisartan significantly improved cardiac function compared to age-matched, vehicle treated Cav-1 KO mice, while telmisartan did not affected cardiac function in WT mice. Both left ventricular (LV) weight to body weight ratios and LV to tibial length ratios were also reverted by telmisartan in Cav-1 KO but not WT mice. LV hypertrophy was associated with increased expression of natriuretic peptides-A and –B, β-myosin heavy chain and TGF-β and telmisartan treatment normalized the expression of these genes. Telmisartan reduced the expression of collagen genes (Col1A and Col3A) and associated perivascular fibrosis in intramyocardial vessels in Cav-1 KO mice. In conclusion, telmisartan treatment reduces indexes of cardiac hypertrophy in this unique genetic model of spontaneous LV hypertrophy. PMID:20585312

  15. Telmisartan regresses left ventricular hypertrophy in caveolin-1-deficient mice.

    PubMed

    Krieger, Marta H; Di Lorenzo, Annarita; Teutsch, Christine; Kauser, Katalin; Sessa, William C

    2010-11-01

    The role of angiotensin II (Ang II) in promoting cardiac hypertrophy is well known; however, its role in a spontaneous model of hypertrophy in mice lacking the protein caveolin-1 (Cav-1 KO) has not been explored. In this study, WT and Cav-1 KO mice were treated with angiotensin receptor blocker (ARB), telmisartan (Telm), and cardiac function was assessed by echocardiography. Treatment of Cav-1 KO mice with Telm significantly improved cardiac function compared with age-matched vehicle-treated Cav-1 KO mice, whereas Telm did not affect cardiac function in WT mice. Both left ventricular (LV) weight to body weight ratios and LV to tibial length ratios were also reverted by Telm in Cav-1 KO but not in WT mice. LV hypertrophy was associated with increased expression of natriuretic peptides A and B, β-myosin heavy chain and TGF-β, and Telm treatment normalized the expression of these genes. Telm reduced the expression of collagen genes (Col1A and Col3A) and associated perivascular fibrosis in intramyocardial vessels in Cav-1 KO mice. In conclusion, Telm treatment reduces indexes of cardiac hypertrophy in this unique genetic model of spontaneous LV hypertrophy. PMID:20585312

  16. AVE 0991 attenuates cardiac hypertrophy through reducing oxidative stress.

    PubMed

    Ma, Yuedong; Huang, Huiling; Jiang, Jingzhou; Wu, Lingling; Lin, Chunxi; Tang, Anli; Dai, Gang; He, Jiangui; Chen, Yili

    2016-06-10

    AVE 0991, the nonpeptide angiotensin-(1-7) (Ang-(1-7)) analog, is recognized as having beneficial cardiovascular effects. However, the mechanisms have not been fully elucidated. This study was designed to investigate the effects of AVE 0991 on cardiac hypertrophy and the mechanisms involved. Mice were underwent aortic banding to induce cardiac hypertrophy followed by the administration of AVE 0991 (20 mg kg·day (-1)) for 4 weeks. It was shown that AVE 0991 reduced left ventricular hypertrophy and improved heart function, characterized by decreases in left ventricular weight and left ventricular end-diastolic diameter, and increases in ejection fraction. Moreover, AVE 0991 significantly down-regulated mean myocyte diameter and attenuate the gene expression of the hypertrophic markers. Furthermore, AVE 0991 inhibited the expression of NOX 2 and NOX 4, meaning that AVE 0991 reduced oxidative stress of cardiac hypertrophy mice. Our data showed that AVE 0991 treatment could attenuate cardiac hypertrophy and improve heart function, which may be due to reduce oxidative stress. PMID:26403967

  17. Experimental hepatocyte xenotransplantation--a comprehensive review of the literature.

    PubMed

    Zhou, Huidong; Liu, Hong; Ezzelarab, Mohamed; Schmelzer, Eva; Wang, Yi; Gerlach, Jörg; Gridelli, Bruno; Cooper, David K C

    2015-01-01

    Hepatocyte transplantation (Tx) is a potential therapy for certain diseases of the liver, including hepatic failure. However, there is a limited supply of human livers as a source of cells and, after isolation, human hepatocytes can be difficult to expand in culture, limiting the number available for Tx. Hepatocytes from other species, for example, the pig, have therefore emerged as a potential alternative source. We searched the literature through the end of 2014 to assess the current status of experimental research into hepatocyte xenoTx. The literature search identified 51 reports of in vivo cross-species Tx of hepatocytes in a variety of experimental models. Most studies investigated the Tx of human (n = 23) or pig (n = 19) hepatocytes. No studies explored hepatocytes from genetically engineered pigs. The spleen was the most common site of Tx (n = 23), followed by the liver (through the portal vein [n = 6]) and peritoneal cavity (n = 19). In 47 studies (92%), there was evidence of hepatocyte engraftment and function across a species barrier. The data provided by this literature search strengthen the hypothesis that xenoTx of hepatocytes is feasible and potentially successful as a clinical therapy for certain liver diseases, including hepatic failure. By excluding vascular structures, hepatocytes isolated from genetically engineered pig livers may address some of the immunological problems of xenoTx. PMID:25950141

  18. Experimental hepatocyte xenotransplantation--a comprehensive review of the literature.

    PubMed

    Zhou, Huidong; Liu, Hong; Ezzelarab, Mohamed; Schmelzer, Eva; Wang, Yi; Gerlach, Jörg; Gridelli, Bruno; Cooper, David K C

    2015-01-01

    Hepatocyte transplantation (Tx) is a potential therapy for certain diseases of the liver, including hepatic failure. However, there is a limited supply of human livers as a source of cells and, after isolation, human hepatocytes can be difficult to expand in culture, limiting the number available for Tx. Hepatocytes from other species, for example, the pig, have therefore emerged as a potential alternative source. We searched the literature through the end of 2014 to assess the current status of experimental research into hepatocyte xenoTx. The literature search identified 51 reports of in vivo cross-species Tx of hepatocytes in a variety of experimental models. Most studies investigated the Tx of human (n = 23) or pig (n = 19) hepatocytes. No studies explored hepatocytes from genetically engineered pigs. The spleen was the most common site of Tx (n = 23), followed by the liver (through the portal vein [n = 6]) and peritoneal cavity (n = 19). In 47 studies (92%), there was evidence of hepatocyte engraftment and function across a species barrier. The data provided by this literature search strengthen the hypothesis that xenoTx of hepatocytes is feasible and potentially successful as a clinical therapy for certain liver diseases, including hepatic failure. By excluding vascular structures, hepatocytes isolated from genetically engineered pig livers may address some of the immunological problems of xenoTx.

  19. Generation of functional hepatocytes from human spermatogonial stem cells

    PubMed Central

    Chen, Zheng; Sun, Min; Yuan, Qingqing; Niu, Minghui; Yao, Chencheng; Hou, Jingmei; Wang, Hong; Wen, Liping; Liu, Yun; Li, Zheng; He, Zuping

    2016-01-01

    To generate functional human hepatocytes from stem cells and/or extra-hepatic tissues could provide an important source of cells for treating liver diseases. Spermatogonial stem cells (SSCs) have an unlimited plasticity since they can dedifferentiate and transdifferentiate to other cell lineages. However, generation of mature and functional hepatocytes from human SSCs has not yet been achieved. Here we have for the first time reported direct transdifferentiation of human SSCs to mature and functional hepatocytes by three-step induction using the defined condition medium. Human SSCs were first transdifferentiated to hepatic stem cells, as evidenced by their morphology and biopotential nature of co-expressing hepatocyte and cholangiocyte markers but not hallmarks for embryonic stem cells. Hepatic stem cells were further induced to differentiate into mature hepatocytes identified by their morphological traits and strong expression of CK8, CK18, ALB, AAT, TF, TAT, and cytochrome enzymes rather than CK7 or CK19. Significantly, mature hepatocytes derived from human SSCs assumed functional attributes of human hepatocytes, because they could produce albumin, remove ammonia, and uptake and release indocyanine green. Moreover, expression of β-CATENIN, HNF4A, FOXA1 and GATA4 was upregulated during the transdifferentiation of human SSCs to mature hepatocytes. Collectively, human SSCs could directly transdifferentiate to mature and functional hepatocytes. This study could offer an invaluable source of human hepatocytes for curing liver disorders and drug toxicology screening and provide novel insights into mechanisms underlying human liver regeneration. PMID:26840458

  20. EXPERIMENTAL HEPATOCYTE XENOTRANSPLANTATION – A COMPREHENSIVE REVIEW OF THE LITERATURE

    PubMed Central

    Zhou, Huidong; Liu, Hong; Ezzelarab, Mohamed; Schmelzer, Eva; Wang, Yi; Gerlach, Jörg; Gridelli, Bruno; Cooper, David K. C.

    2015-01-01

    Background Hepatocyte transplantation is a potential therapy for certain diseases of the liver, including hepatic failure. However, there is a limited supply of human livers as a source of cells and, after isolation, human hepatocytes can be difficult to expand in culture, limiting the number available for transplantation. Hepatocytes from other species, e.g., the pig, have therefore emerged as a potential alternative source. We searched the literature through the end of 2014 to assess the current status of experimental research into hepatocyte xenotransplantation. Literature search and results The literature search identified 51 reports of in vivo cross-species transplantation of hepatocytes in a variety of experimental models. Most studies investigated the transplantation of human (n=23) or pig (n=19) hepatocytes. No studies explored hepatocytes from genetically-engineered pigs. The spleen was the most common site of transplantation (n=23), followed by the liver (through the portal vein [n=6]) and peritoneal cavity (n=19). In 47 studies (92%), there was evidence of hepatocyte engraftment and function across a species barrier. Conclusions The data provided by this literature search strengthen the hypothesis that xenotransplantation of hepatocytes is feasible and potentially successful as a clinical therapy for certain liver diseases, including hepatic failure. By excluding vascular structures, hepatocytes isolated from genetically-engineered pig livers may address some of the immunological problems of xenotransplantation. PMID:25950141

  1. Assessing the therapeutic potential of lab-made hepatocytes.

    PubMed

    Rezvani, Milad; Grimm, Andrew A; Willenbring, Holger

    2016-07-01

    Hepatocyte transplantation has potential as a bridge or even alternative to whole-organ liver transplantation. Because donor livers are scarce, realizing this potential requires the development of alternative cell sources. To be therapeutically effective, surrogate hepatocytes must replicate the complex function and ability to proliferate of primary human hepatocytes. Ideally, they are also autologous to eliminate the need for immune suppression, which can have severe side effects and may not be sufficient to prevent rejection long term. In the past decade, several methods have been developed to generate hepatocytes from other readily and safely accessible somatic cells. These lab-made hepatocytes show promise in animal models of liver diseases, supporting the feasibility of autologous liver cell therapies. Here, we review recent preclinical studies exemplifying different types of lab-made hepatocytes that can potentially be used in autologous liver cell therapies. To define the therapeutic efficacy of current lab-made hepatocytes, we compare them to primary human hepatocytes, focusing on engraftment efficiency and posttransplant proliferation and function. In addition to summarizing published results, we discuss animal models and assays effective in assessing therapeutic efficacy. This analysis underscores the therapeutic potential of current lab-made hepatocytes, but also highlights deficiencies and uncertainties that need to be addressed in future studies aimed at developing liver cell therapies with lab-made hepatocytes. (Hepatology 2016;64:287-294). PMID:27014802

  2. Metabolism of lipoproteins by human fetal hepatocytes

    SciTech Connect

    Carr, B.R.

    1987-12-01

    The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of (/sup 125/I)iodo-LDL and (/sup 125/I)iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. (/sup 125/I)Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas (/sup 125/I)iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues.

  3. Stimulation of Na/sup +//H/sup +/ antiport is an early event in hypertrophy of renal proximal tubular cells

    SciTech Connect

    Fine, L.G.; Badie-Dezfooly, B.; Lowe, A.G.; Hamzeh, A.; Wells, J.; Salehmoghaddam, S.

    1985-03-01

    Renal hypertrophy in vivo is achieved by an increase in protein content per cell and an increase in cell size with minimal hyperplasia. Hypertrophied renal tubular cells remain quiescent and demonstrate an increase in transcellular transport rates. This situation was simulated in vitro by exposing a confluent, quiescent primary culture of rabbit renal proximal tubular cells to either insulin, prostaglandin E/sub 1/, or hypertonic NaCl for 24 or 48 hr. Protein per cell increased by 20-30% with little or no increase in (/sup 3/H)thymidine incorporation into DNA. Mean cell volume was also increased in insulin- and hypertonic NaCl-treated but not in prostaglandin E/sub 1/-treated cells. Two hours of exposure to the growth stimuli increased amiloride-sensitive Na/sup +/ uptake, Na-dependent H/sup +/ efflux, and ouabain-sensitive Rb/sup +/ uptake, indicating that stimulation of Na/sup +//H/sup +/ antiport (exchange) occurs as an early event in their action. Hypertrophied cells continued to demonstrate enhanced Na/sup +//H/sup +/ antiport after the growth stimuli were removed for 3 hr, by which time their acute effects are reversed.

  4. Methimazole slows hepatocyte streaming in rats.

    PubMed

    Oren, R; Zajicek, G; Maaravi, Y; Kenet, G; Karmely, F; Hubert, A; Raanani, P; Arber, N

    1997-07-01

    Hepatocytes are hypothesized to continually stream from the portal tract to the terminal hepatic vein. By this model, when a cell divides, one of its progeny replaces the dividing ancestor and the other is displaced into a more remote location. The present experiment aims to demonstrate that hypothyroidism affects liver cell turnover. Thirty male adult rats were divided into two groups. One received methimazole for two weeks and the other served as control. Each rat was injected intraperitoneally with 18.5 KBq [3H]thymidine/g body weight. Rats were killed after 1 hr and two and four weeks. Autoradiography was done. The distance of the labeled cells from the portal tract was measured. The mean TSH levels of the methimazole-treated group and controls were 1.45 and 0.25 mM/liter, respectively (P < 0.01). Hepatocyte streaming was lower in hypothyroid (1.8 microns/day) than in untreated rats (2.5 microns/day) (P < 0.01). The respective labeling indices 1 hr after labeling were 0.9% and 1.24% (P < 0.05). We conclude that hypothyroidism diminishes hepatocyte and littoral cell turnover and slows down their streaming.

  5. Strategies to minimize hypertrophy in cartilage engineering and regeneration

    PubMed Central

    Chen, Song; Fu, Peiliang; Cong, Ruijun; Wu, HaiShan; Pei, Ming

    2015-01-01

    Due to a blood supply shortage, articular cartilage has a limited capacity for self-healing once damaged. Articular chondrocytes, cartilage progenitor cells, embryonic stem cells, and mesenchymal stem cells are candidate cells for cartilage regeneration. Significant current attention is paid to improving chondrogenic differentiation capacity; unfortunately, the potential chondrogenic hypertrophy of differentiated cells is largely overlooked. Consequently, the engineered tissue is actually a transient cartilage rather than a permanent one. The development of hypertrophic cartilage ends with the onset of endochondral bone formation which has inferior mechanical properties. In this review, current strategies for inhibition of chondrogenic hypertrophy are comprehensively summarized; the impact of cell source options is discussed; and potential mechanisms underlying these strategies are also categorized. This paper aims to provide guidelines for the prevention of hypertrophy in the regeneration of cartilage tissue. This knowledge may also facilitate the retardation of osteophytes in the treatment of osteoarthritis. PMID:26000333

  6. GENE EXPRESSION ALTERATIONS OBSERVED IN PRIMARY CULTURED RAT HEPATOCYTES AFTER TREATMENT WITH CHLORINATED OR CHLORINATED AND OZONATED DRINKING WATER FROM EAST FORK LAKE, OHIO

    EPA Science Inventory

    Drinking water from East Fork Lake was spiked with iodide and bromide, disinfected with chlorine or ozone + chlorine, concentrated ~100-fold using reverse osmosis, and volatile disinfection by-products (DBPs) added back. Primary rat hepatocytes were exposed to full-strength, 1:10...

  7. Extra-Esophageal Pepsin from Stomach Refluxate Promoted Tonsil Hypertrophy

    PubMed Central

    Kim, Jin Hyun; Jeong, Han-Sin; Kim, Kyung Mi; Lee, Ye Jin; Jung, Myeong Hee; Park, Jung Je; Kim, Jin Pyeong; Woo, Seung Hoon

    2016-01-01

    Background Gastroesophageal reflux is associated with numerous pathologic conditions of the upper aerodigestive tract. Gastric pepsin within reflux contributes to immunologic reactions in the tonsil. In this study, we aimed to find the relationships between pepsin and tonsillar hypertrophy. Methods and finding We explored the notion whether tonsillar hypertrophy was due to pepsin-mediated gastric reflux in tonsil hypertrophy. Fifty-four children with tonsil hypertrophy and 30 adults with tonsillitis were recruited before surgical treatment. Blood and tonsil tissues from each patient were harvested for analysis of changes in lymphocyte and macrophage numbers coupled with histological and biochemical analysis. Pepsin was expressed at different levels in tonsil tissues from each tonsillar hypertrophy. Pepsin-positive cells were found in the crypt epithelium, surrounding the lymphoid follicle with developing fibrosis, and also surrounding the lymphoid follicle that faced the crypt. And also, pepsin staining was well correlated with damaged tonsillar squamous epithelium and TGF-β1 and iNOS expression in the tonsil section. In addition, pepsin and TGF-β1-positive cells were co-localized with CD68-positive cells in the crypt and surrounding germinal centers. In comparison of macrophage responsiveness to pepsin, peripheral blood mononuclear cells (PBMNCs) were noticeably larger in the presence of activated pepsin in the child group. Furthermore, CD11c and CD163-positive cells were significantly increased by activated pepsin. However, this was not seen for the culture of PBMNCs from the adult group. Conclusions The lymphocytes and monocytes are in a highly proliferative state in the tonsillar hypertrophy and associated with increased expression of pro-inflammatory factors as a result of exposure to stomach reflux pepsin. PMID:27058240

  8. Resistance training and cardiac hypertrophy: unravelling the training effect.

    PubMed

    Haykowsky, Mark J; Dressendorfer, Rudolph; Taylor, Dylan; Mandic, Sandra; Humen, Dennis

    2002-01-01

    Resistance training (RT) is a popular method of conditioning to enhance sport performance as well as an effective form of exercise to attenuate the age-mediated decline in muscle strength and mass. Although the benefits of RT on skeletal muscle morphology and function are well established, its effect on left ventricular (LV) morphology remains equivocal. Some investigations have found that RT is associated with an obligatory increase in LV wall thickness and mass with minimal alteration in LV internal cavity dimension, an effect called concentric hypertrophy. However, others report that short- (<5 years) to long-term (>18 years) RT does not alter LV morphology, arguing that concentric hypertrophy is not an obligatory adaptation secondary to this form of exertion. This disparity between studies on whether RT consistently results in cardiac hypertrophy could be caused by: (i) acute cardiopulmonary mechanisms that minimise the increase in transmural pressure (i.e. ventricular pressure minus intrathoracic pressure) and LV wall stress during exercise; (ii) the underlying use of anabolic steroids by the athletes; or (iii) the specific type of RT performed. We propose that when LV geometry is altered after RT, the pattern is usually concentric hypertrophy in Olympic weightlifters. However, the pattern of eccentric hypertrophy (increased LV mass secondary to an increase in diastolic internal cavity dimension and wall thickness) is not uncommon in bodybuilders. Of particular interest, nearly 40% of all RT athletes have normal LV geometry, and these athletes are typically powerlifters. RT athletes who use anabolic steroids have been shown to have significantly higher LV mass compared with drug-free sport-matched athletes. This brief review will sort out some of the factors that may affect the acute and chronic outcome of RT on LV morphology. In addition, a conceptual framework is offered to help explain why cardiac hypertrophy is not always found in RT athletes. PMID

  9. Supra-physiological dose of testosterone induces pathological cardiac hypertrophy.

    PubMed

    Pirompol, Prapawadee; Teekabut, Vassana; Weerachatyanukul, Wattana; Bupha-Intr, Tepmanas; Wattanapermpool, Jonggonnee

    2016-04-01

    Testosterone and androgenic anabolic steroids have been misused for enhancement of physical performance despite many reports on cardiac sudden death. Although physiological level of testosterone provided many regulatory benefits to human health, including the cardiovascular function, supra-physiological levels of the hormone induce hypertrophy of the heart with unclear contractile activation. In this study, dose- and time-dependent effects of high-testosterone treatment on cardiac structure and function were evaluated. Adult male rats were divided into four groups of testosterone treatment for 0, 5, 10, and 20 mg/kg BW for 4, 8, or 12 weeks. Increases in both percentage heart:body weight ratio and cardiomyocyte cross-sectional area in representing hypertrophy of the heart were significantly shown in all testosterone-treated groups to the same degree. In 4-week-treated rats, physiological cardiac hypertrophy was apparent with an upregulation of α-MHC without any change in myofilament contractile activation. In contrast, pathological cardiac hypertrophy was observed in 8- and 12-week testosterone-treated groups, as indicated by suppression of myofilament activation and myocardial collagen deposition without transition of MHC isoforms. Only in 12-week testosterone-treated group, eccentric cardiac hypertrophy was demonstrated with unaltered myocardial stiffness, but significant reductions in the phosphorylation signals of ERK1/2 and mTOR. Results of our study suggest that the outcome of testosterone-induced cardiac hypertrophy is not dose dependent but is rather relied on the factor of exposure to duration in inducing maladaptive responses of the heart. PMID:26850730

  10. Conus medulla-cauda compression from nerve root hypertrophy in a child with Dejerine-Sottas syndrome: improvement with laminectomy and duraplasty. Case report.

    PubMed

    Kleopa, Kleopas A; Sutton, Leslie N; Ong, Joseph; Tennekoon, Gihan; Telfeian, Albert E

    2002-09-01

    This 7-year-old boy with Dejerine-Sottas syndrome caused by a mutation in the myelin protein zero gene began to suffer rapid deterioration with increasing leg weakness, loss of the ability to ambulate, and bowel and bladder incontinence. Magnetic resonance imaging of the spine revealed nerve root hypertrophy resulting in compression of the conus medullaris and cauda equina. Decompressive surgery was successful in reversing some of his deficits. PMID:12296688

  11. Investigating the Mechanism of Hyperglycemia-Induced Fetal Cardiac Hypertrophy.

    PubMed

    Han, Sha-sha; Wang, Guang; Jin, Ya; Ma, Zheng-lai; Jia, Wei-jing; Wu, Xia; Wang, Xiao-yu; He, Mei-yao; Cheng, Xin; Li, Wei-jing; Yang, Xuesong; Liu, Guo-sheng

    2015-01-01

    Hyperglycemia in diabetic mothers enhances the risk of fetal cardiac hypertrophy during gestation. However, the mechanism of high-glucose-induced cardiac hypertrophy is not largely understood. In this study, we first demonstrated that the incidence rate of cardiac hypertrophy dramatically increased in fetuses of diabetic mothers using color ultrasound examination. In addition, human fetal cardiac hypertrophy was successfully mimicked in a streptozotocin (STZ)-induced diabetes mouse model, in which mouse cardiac hypertrophy was diagnosed using type-M ultrasound and a histological assay. PH3 immunofluorescent staining of mouse fetal hearts and in vitro-cultured H9c2 cells indicated that cell proliferation decreased in E18.5, E15.5 and E13.5 mice, and cell apoptosis in H9c2 cells increased in the presence of high glucose in a dose-dependent manner. Next, we found that the individual cardiomyocyte size increased in pre-gestational diabetes mellitus mice and in response to high glucose exposure. Meanwhile, the expression of β-MHC and BMP-10 was up-regulated. Nkx2.5 immunofluorescent staining showed that the expression of Nkx2.5, a crucial cardiac transcription factor, was suppressed in the ventricular septum, left ventricular wall and right ventricular wall of E18.5, E15.5 and E13.5 mouse hearts. However, cardiac hypertrophy did not morphologically occur in E13.5 mouse hearts. In cultured H9c2 cells exposed to high glucose, Nkx2.5 expression decreased, as detected by both immunostaining and western blotting, and the expression of KCNE1 and Cx43 was also restricted. Taken together, alterations in cell size rather than cell proliferation or apoptosis are responsible for hyperglycemia-induced fetal cardiac hypertrophy. The aberrant expression of Nkx2.5 and its regulatory target genes in the presence of high glucose could be a principal component of pathogenesis in the development of fetal cardiac hypertrophy. PMID:26418041

  12. [Coronary effects of left ventricular hypertrophy associated with hypertension].

    PubMed

    Trimarco, B; de Luca, N; Ricciardelli, B; Rosiello, G; Lembo, G; Rendina, V; Raponi, M; Marchegiano, R; Volpe, M

    1990-12-01

    Left ventricular hypertrophy secondary to hypertension has been associated with a reduction of maximum coronary flow per unit mass as shown by the increase in the minimal threshold of coronary vascular resistance per gramme. This phenomenon has usually been attributed to an increase in muscle mass with absent or inadequate vascular compensation. However, chronic hypertension may induce a function reduction in coronary flow. In particular, it has been recently shown that coronary vascular resistances are influenced by a cardio-cardiac reflex involving the baroreceptor response. Left ventricular hypertrophy could alter the function of the ventricular receptors and favourise myocardial ischemia by preventing the adaptation of coronary flow to myocardial metabolic demands.

  13. Hypertrophy of palmaris longus muscle, a rare anatomic aberration.

    PubMed

    Barkáts, N

    2015-01-01

    The palmaris longus muscle (PLM) is considered to be a phylogenetically degenerate muscle. For many authors, this may be the cause of its great variability. The loss of function in the PLM makes it an important muscle in plastic and reconstructive surgery. During a study of PLM agenesis rate in the Hungarian population, a 22-year-old female showed an unusual pattern of muscles in her left forearm, which was found to be a hypertrophied PLM. The hypertrophied muscle was causing symptoms of median and ulnar nerve compression.

  14. Perinatal DDT Exposure Induces Hypertension and Cardiac Hypertrophy in Adult Mice

    PubMed Central

    La Merrill, Michele A.; Sethi, Sunjay; Benard, Ludovic; Moshier, Erin; Haraldsson, Borje; Buettner, Christoph

    2016-01-01

    Background: Dichlorodiphenyltrichloroethane (DDT) was used extensively to control malaria, typhus, body lice, and bubonic plague worldwide, until countries began restricting its use in the 1970s. However, the use of DDT to control vector-borne diseases continues in developing countries. Prenatal DDT exposure is associated with elevated blood pressure in humans. Objective: We hypothesized that perinatal DDT exposure causes hypertension in adult mice. Methods: DDT was administered to C57BL/6J dams from gestational day 11.5 to postnatal day 5. Blood pressure (BP) and myocardial wall thickness were measured in male and female adult offspring. Adult mice were treated with an angiotensin converting enzyme (ACE) inhibitor, captopril, to evaluate sensitivity to amelioration of DDT-associated hypertension by ACE inhibition. We further assessed the influence of DDT exposure on the expression of mRNAs that regulate BP through renal ion transport. Results: Adult mice perinatally exposed to DDT exhibited chronically increased systolic BP, increased myocardial wall thickness, and elevated expression of mRNAs of several renal ion transporters. Captopril completely reversed hypertension in mice perinatally exposed to DDT. Conclusions: These data demonstrate that perinatal exposure to DDT causes hypertension and cardiac hypertrophy in adult offspring. A key mechanism underpinning this hypertension is an overactivated renin angiotensin system because ACE inhibition reverses the hypertension induced by perinatal DDT exposure. Citation: La Merrill M, Sethi S, Benard L, Moshier E, Haraldsson B, Buettner C. 2016. Perinatal DDT exposure induces hypertension and cardiac hypertrophy in adult mice. Environ Health Perspect 124:1722–1727; http://dx.doi.org/10.1289/EHP164 PMID:27325568

  15. Inhibition of class I histone deacetylases blunts cardiac hypertrophy through TSC2-dependent mTOR repression

    PubMed Central

    Morales, Cyndi R.; Li, Dan L.; Pedrozo, Zully; May, Herman I.; Jiang, Nan; Kyrychenko, Viktoriia; Cho, Geoffrey; Kim, Soo Young; Wang, Zhao V.; Rotter, David; Rothermel, Beverly A.; Schneider, Jay W.; Lavandero, Sergio; Gillette, Thomas G.; Hill, Joseph A.

    2016-01-01

    Altering chromatin structure through histone posttranslational modifications has emerged as a key driver of transcriptional responses in cells. Modulation of these transcriptional responses by pharmacological inhibition of class I histone deacetylases (HDACs), a group of chromatin remodeling enzymes, has been successful in blocking the growth of some cancer cell types. These inhibitors also attenuate the pathogenesis of pathological cardiac remodeling by blunting and even reversing pathological hypertrophy. The mechanistic target of rapamycin (mTOR) is a critical sensor and regulator of cell growth that as part of mTOR complex I (mTORC1) drives changes in protein synthesis and metabolism in both pathological and physiological hypertrophy. Here, we demonstrated through pharmacological and genetic methods that inhibition of class I HDACs suppressed pathological cardiac hypertrophy through inhibition of mTOR activity. Mice genetically silenced for HDAC1 and HDAC2 had a reduced hypertrophic response to TAC and showed reduced mTOR activity. We determined that the abundance of tuberous sclerosis complex 2 (TSC2), an mTOR inhibitor, was increased through a transcriptional mechanism in cardiomyocytes when class I HDACs were inhibited. In neonatal rat cardiomyocytes, loss of TSC2 abolished HDAC-dependent inhibition of mTOR activity, and increased expression of TSC2 was sufficient to reduce hypertrophy in response to phenylephrine. These findings point to mTOR and TSC2-dependent control of mTOR as critical components of the mechanism by which HDAC inhibitors blunt pathological cardiac growth. These results also suggest a strategy to modulate mTOR activity and facilitate the translational exploitation of HDAC inhibitors in heart disease. PMID:27048565

  16. A Mouse Model of Inducible Liver Injury Caused by Tet-On Regulated Urokinase for Studies of Hepatocyte Transplantation

    PubMed Central

    Song, Xijun; Guo, Yushan; Duo, Shuguang; Che, Jie; Wu, Chen; Ochiya, Takahiro; Ding, Mingxiao; Deng, Hongkui

    2009-01-01

    Mouse models of liver injury provide useful tools for studying hepatocyte engraftment and proliferation. A representative model of liver injury is the albumin-urokinase (Alb-uPA) transgenic model, but neonatal lethality hampers its widespread application. To overcome this problem, we generated a transgenic mouse in which transcription of the reverse tetracycline transactivator was (rtTA) driven by the mouse albumin promoter, and backcrossed the rtTA mice onto severe combined immunodeficient (SCID)/bg mice to generate immunodeficient rtTA/SCID mice. We then produced recombinant adenoviruses Ad.TRE-uPA, in which the urokinase was located downstream of the tetracycline response element (TRE). The rtTA/SCID mouse hepatocytes were then infected with Ad.TRE-uPA to establish an inducible liver injury mouse model. In the presence of doxycycline, uPA was exclusively expressed in endogenous hepatocytes and caused extensive liver injury. Enhanced green fluorescent protein-labeled mouse hepatocytes selectively repopulated the rtTA/SCID mouse liver and replaced over 80% of the recipient liver mass after repeated administration of Ad.TRE-uPA. Compared with the original uPA mice, rtTA/SCID mice did not exhibit problems regarding breeding efficiency, and the time window for transplantation was flexible. In addition, we could control the extent of liver injury to facilitate transplantation surgery by regulating the dose of Ad.TRE-uPA. Our inducible mouse model will be convenient for studies of hepatocyte transplantation and hepatic regeneration, and this system will facilitate screening for potential genetic factors critical for engraftment and proliferation of hepatocytes in vivo. PMID:19808649

  17. Hepatocyte transplantation program: Lessons learned and future strategies.

    PubMed

    Ibars, Eugenia Pareja; Cortes, Miriam; Tolosa, Laia; Gómez-Lechón, Maria José; López, Slivia; Castell, José Vicente; Mir, José

    2016-01-14

    This review aims to share the lessons we learned over time during the setting of the hepatocyte transplantation (HT) program at the Hepatic Cell Therapy Unit at Hospital La Fe in Valencia. New sources of liver tissue for hepatocyte isolation have been explored. The hepatocyte isolation and cryopreservation procedures have been optimized and quality criteria for assessment of functionality of hepatocyte preparations and suitability for HT have been established. The results indicate that: (1) Only highly viable and functional hepatocytes allow to recover those functions lacking in the native liver; (2) Organs with steatosis (≥ 40%) and from elderly donors are declined since low hepatocyte yields, viability and cell survival after cryopreservation, are obtained; (3) Neonatal hepatocytes are cryopreserved without significant loss of viability or function representing high-quality cells to improve human HT; (4) Cryopreservation has the advantage of providing hepatocytes constantly available and of allowing the quality evaluation and suitability for transplantation; and (5) Our results from 5 adults with acute liver failure and 4 from children with inborn metabolic diseases, indicate that HT could be a very useful and safe cell therapy, as long as viable and metabolically functional human hepatocytes are used.

  18. Structural and functional hepatocyte polarity and liver disease.

    PubMed

    Gissen, Paul; Arias, Irwin M

    2015-10-01

    Hepatocytes form a crucially important cell layer that separates sinusoidal blood from the canalicular bile. They have a uniquely organized polarity with a basal membrane facing liver sinusoidal endothelial cells, while one or more apical poles can contribute to several bile canaliculi jointly with the directly opposing hepatocytes. Establishment and maintenance of hepatocyte polarity is essential for many functions of hepatocytes and requires carefully orchestrated cooperation between cell adhesion molecules, cell junctions, cytoskeleton, extracellular matrix and intracellular trafficking machinery. The process of hepatocyte polarization requires energy and, if abnormal, may result in severe liver disease. A number of inherited disorders affecting tight junction and intracellular trafficking proteins have been described and demonstrate clinical and pathophysiological features overlapping those of the genetic cholestatic liver diseases caused by defects in canalicular ABC transporters. Thus both structural and functional components contribute to the final hepatocyte polarity phenotype. Many acquired liver diseases target factors that determine hepatocyte polarity, such as junctional proteins. Hepatocyte depolarization frequently occurs but is rarely recognized because hematoxylin-eosin staining does not identify the bile canaliculus. However, the molecular mechanisms underlying these defects are not well understood. Here we aim to provide an update on the key factors determining hepatocyte polarity and how it is affected in inherited and acquired diseases.

  19. Mesenchymal Stem Cell-Derived Hepatocytes for Functional Liver Replacement

    PubMed Central

    Christ, Bruno; Stock, Peggy

    2012-01-01

    Mesenchymal stem cells represent an alternate cell source to substitute for primary hepatocytes in hepatocyte transplantation because of their multiple differentiation potential and nearly unlimited availability. They may differentiate into hepatocyte-like cells in vitro and maintain specific hepatocyte functions also after transplantation into the regenerating livers of mice or rats both under injury and non-injury conditions. Depending on the underlying liver disease their mode of action is either to replace the diseased liver tissue or to support liver regeneration through their anti-inflammatory and anti-apoptotic as well as their pro-proliferative action. PMID:22737154

  20. Hepatocyte transplantation program: Lessons learned and future strategies

    PubMed Central

    Ibars, Eugenia Pareja; Cortes, Miriam; Tolosa, Laia; Gómez-Lechón, Maria José; López, Slivia; Castell, José Vicente; Mir, José

    2016-01-01

    This review aims to share the lessons we learned over time during the setting of the hepatocyte transplantation (HT) program at the Hepatic Cell Therapy Unit at Hospital La Fe in Valencia. New sources of liver tissue for hepatocyte isolation have been explored. The hepatocyte isolation and cryopreservation procedures have been optimized and quality criteria for assessment of functionality of hepatocyte preparations and suitability for HT have been established. The results indicate that: (1) Only highly viable and functional hepatocytes allow to recover those functions lacking in the native liver; (2) Organs with steatosis (≥ 40%) and from elderly donors are declined since low hepatocyte yields, viability and cell survival after cryopreservation, are obtained; (3) Neonatal hepatocytes are cryopreserved without significant loss of viability or function representing high-quality cells to improve human HT; (4) Cryopreservation has the advantage of providing hepatocytes constantly available and of allowing the quality evaluation and suitability for transplantation; and (5) Our results from 5 adults with acute liver failure and 4 from children with inborn metabolic diseases, indicate that HT could be a very useful and safe cell therapy, as long as viable and metabolically functional human hepatocytes are used. PMID:26811633

  1. Structural and functional hepatocyte polarity and liver disease

    PubMed Central

    Gissen, Paul; Arias, Irwin M.

    2015-01-01

    Summary Hepatocytes form a crucially important cell layer that separates sinusoidal blood from the canalicular bile. They have a uniquely organized polarity with a basal membrane facing liver sinusoidal endothelial cells, while one or more apical poles can contribute to several bile canaliculi jointly with the directly opposing hepatocytes. Establishment and maintenance of hepatocyte polarity is essential for many functions of hepatocytes and requires carefully orchestrated cooperation between cell adhesion molecules, cell junctions, cytoskeleton, extracellular matrix and intracellular trafficking machinery. The process of hepatocyte polarization requires energy and, if abnormal, may result in severe liver disease. A number of inherited disorders affecting tight junction and intracellular trafficking proteins have been described and demonstrate clinical and pathophysiological features overlapping those of the genetic cholestatic liver diseases caused by defects in canalicular ABC transporters. Thus both structural and functional components contribute to the final hepatocyte polarity phenotype. Many acquired liver diseases target factors that determine hepatocyte polarity, such as junctional proteins. Hepatocyte depolarization frequently occurs but is rarely recognized because hematoxylin-eosin staining does not identify the bile canaliculus. However, the molecular mechanisms underlying these defects are not well understood. Here we aim to provide an update on the key factors determining hepatocyte polarity and how it is affected in inherited and acquired diseases. PMID:26116792

  2. Reversible dementias

    PubMed Central

    Tripathi, Manjari; Vibha, Deepti

    2009-01-01

    In recent years, more attention has been given to the early diagnostic evaluation of patients with dementia which is essential to identify patients with cognitive symptoms who may have treatable conditions. Guidelines suggest that all patients presenting with dementia or cognitive symptoms should be evaluated with a range of laboratory tests, and with structural brain imaging with computed tomography (CT) or magnetic resonance imaging (MRI). While many of the disorders reported as ‘reversible dementias’ are conditions that may well be associated with cognitive or behavioral symptoms, these symptoms are not always sufficiently severe to fulfill the clinical criteria for dementia. Thus, while the etiology of a condition may be treatable it should not be assumed that the associated dementia is fully reversible. Potentially reversible dementias should be identified and treatment considered, even if the symptoms are not sufficiently severe to meet the clinical criteria for dementia, and even if partial or full reversal of the cognitive symptoms cannot be guaranteed. In the literature, the most frequently observed potentially reversible conditions identified in patients with cognitive impairment or dementia are depression, adverse effects of drugs, drug or alcohol abuse, space-occupying lesions, normal pressure hydrocephalus, and metabolic conditions land endocrinal conditions like hypothyroidism and nutritional conditions like vitamin B-12 deficiency. Depression is by far the most common of the potentially reversible conditions. The review, hence addresses the common causes of reversible dementia and the studies published so far. PMID:21416018

  3. Echocardiographic assessment of ejection fraction in left ventricular hypertrophy

    PubMed Central

    Wandt, B; Bojo, L; Tolagen, K; Wranne, B

    1999-01-01

    OBJECTIVE—To investigate the value of Simpson's rule, Teichholz's formula, and recording of mitral ring motion in assessing left ventricular ejection fraction (EF) in patients with left ventricular hypertrophy.
DESIGN—Left ventricular ejection fraction calculated by Simpson's rule and by Techholz's formula and estimated by mitral ring motion was compared with values obtained by radionuclide angiography.
SETTING—Secondary referral centre.
PATIENTS—16 patients with left ventricular hypertrophy and a clinical diagnosis of hypertrophic cardiomyopathy or hypertension.
RESULTS—Calculation by Teichholz's formula overestimated left ventricular ejection fraction by 10% (p = 0.002) and estimation based on mitral ring motion—that is, long axis measurements—underestimated ejection fraction by 19% (p = 0.002), without significant correlation between ring motion and ejection fraction. There was no significant difference between mean values of ejection fraction calculated by Simpson's rule and measured by the reference method, but a considerable scatter about the regression line with a standard error of the estimate of 9.3 EF%.
CONCLUSIONS—In patients with left ventricular hypertrophy the ejection fraction, calculated by Teichholz's formula or Simpson's rule, is a poor measure of left ventricular function. When mitral ring motion is used for the assessment in these patients the function should be expressed in ways other than by the ejection fraction.


Keywords: left ventricular hypertrophy; ejection fraction; mitral ring motion; atrioventricular plane displacement PMID:10409535

  4. Cardiomyocyte specific deletion of PP2A causes cardiac hypertrophy

    PubMed Central

    Li, Lei; Fang, Chao; Xu, Di; Xu, Yidan; Fu, Heling; Li, Jianmin

    2016-01-01

    Cardiac hypertrophy is a common pathological alteration in heart disease, which has been reported to be connected with serine/threonine protein phosphatases that control the dephosphorylation of a variety of cardiac proteins. Herein, we generated protein phosphatase type 2A knockout expressing a tamoxifen-inducible Cre recombinase protein fused to two mutant estrogen-receptor ligand-binding domains (MerCreMer) under the control of the a-myosin heavy chain promoter. Cardiac function of mice was determined by echocardiography. Decrease in PP2A activity leads to increased cardiomyocyte hypertrophy and fibrosis. Loss of PP2ACα leads to the heart failure, including the changes of EF, FS, LV, ANP and BNP. On the molecular level, knockout mice shows increased expression of B55a and B56e at 60 days after tamoxifen injection. Additionally, the regulation of the Akt/GSK3β/β-catenin pathway is severely disturbed in knockout mice. In conclusion, cardiomyocyte specific deletion of PP2A gene causes the cardiac hypertrophy. We will use the knockout mice to generate a type of cardiomyocyte hypertrophy mouse model with myocardial fibrosis. PMID:27186301

  5. Beta2-integrins contribute to skeletal muscle hypertrophy in mice.

    PubMed

    Marino, Joseph S; Tausch, Brian J; Dearth, Christopher L; Manacci, Marc V; McLoughlin, Thomas J; Rakyta, Samuel J; Linsenmayer, Matthew P; Pizza, Francis X

    2008-10-01

    We tested the contribution of beta(2)-integrins, which are important for normal function of neutrophils and macrophages, to skeletal muscle hypertrophy after mechanical loading. Using the synergist ablation model of hypertrophy and mice deficient in the common beta-subunit of beta(2)-integrins (CD18(-/-)), we found that overloaded muscles of wild-type mice had greater myofiber size, dry muscle mass, and total protein content compared with CD18(-/-) mice. The hypertrophy in wild-type mice was preceded by elevations in neutrophils, macrophages, satellite cell/myoblast proliferation (5'-bromo-2'-deoxyuridine- and desmin-positive cells), markers of muscle differentiation (MyoD1 and myogenin gene expression and formation and size of regenerating myofibers), signaling for protein synthesis [phosphorylation of Akt and 70-kDa ribosomal protein S6 kinase (p70S6k)], and reduced signaling for protein degradation (decreased gene expression of muscle atrophy F box/atrogin-1). The deficiency in beta(2)-integrins, however, altered the accumulation profile of neutrophils and macrophages, disrupted the temporal profile of satellite cell/myoblast proliferation, reduced the markers of muscle differentiation, and impaired the p70S6k signaling, all of which could serve as mechanisms for the impaired hypertrophy in overloaded CD18(-/-) mice. In conclusion, our findings indicate that beta(2)-integrins contribute to the hypertrophic response to muscle overload by temporally regulating satellite cells/myoblast proliferation and by enhancing muscle differentiation and p70S6k signaling.

  6. Muscle Hypertrophy in Prepubescent Tennis Players: A Segmentation MRI Study

    PubMed Central

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Serrano-Sanchez, Jose A.; Dorado, Cecilia; Calbet, Jose A. L.

    2012-01-01

    Purpose To asses if tennis at prepubertal age elicits the hypertrophy of dominant arm muscles. Methods The volume of the muscles of both arms was determined using magnetic resonance imaging (MRI) in 7 male prepubertal tennis players (TP) and 7 non-active control subjects (CG) (mean age 11.0±0.8 years, Tanner 1–2). Results TP had 13% greater total muscle volume in the dominant than in the contralateral arm. The magnitude of inter-arm asymmetry was greater in TP than in CG (13 vs 3%, P<0.001). The dominant arm of TP was 16% greater than the dominant arm of CG (P<0.01), whilst non-dominant arms had similar total muscle volumes in both groups (P = 0.25), after accounting for height as covariate. In TP, dominant deltoid (11%), forearm supinator (55%) and forearm flexors (21%) and extensors (25%) were hypertrophied compared to the contralateral arm (P<0.05). In CG, the dominant supinator muscle was bigger than its contralateral homonimous (63%, P<0.05). Conclusions Tennis at prepubertal age is associated with marked hypertrophy of the dominant arm, leading to a marked level of asymmetry (+13%), much greater than observed in non-active controls (+3%). Therefore, tennis particpation at prepubertal age is associated with increased muscle volumes in dominant compared to the non-dominant arm, likely due to selectively hypertrophy of the loaded muscles. PMID:22428074

  7. Dance band on the Titanic: biomechanical signaling in cardiac hypertrophy.

    PubMed

    Sussman, Mark A; McCulloch, Andrew; Borg, Thomas K

    2002-11-15

    Biomechanical signaling is a complex interaction of both intracellular and extracellular components. Both passive and active components are involved in the extracellular environment to signal through specific receptors to multiple signaling pathways. This review provides an overview of extracellular matrix, specific receptors, and signaling pathways for biomechanical stimulation in cardiac hypertrophy.

  8. Genistein prevents isoproterenol-induced cardiac hypertrophy in rats.

    PubMed

    Maulik, Subir Kumar; Prabhakar, Pankaj; Dinda, Amit Kumar; Seth, Sandeep

    2012-08-01

    Genistein, an isoflavone and a rich constituent of soy, possesses important regulatory effects on nitric oxide (NO) synthesis and oxidative stress. Transient and low release of NO by endothelial nitric oxide synthase (eNOS) has been shown to be beneficial, while high and sustained release by inducible nitric oxide synthase (iNOS) may be detrimental in pathological cardiac hypertrophy. The present study was designed to evaluate whether genistein could prevent isoproterenol-induced cardiac hypertrophy in male Wistar rats (150-200 g, 10-12 weeks old) rats. Isoproterenol (5 mg·(kg body weight)(-1)) was injected subcutaneously once daily for 14 days to induced cardiac hypertrophy. Genistein (0.1 and 0.2 mg·kg(-1), subcutaneous injection once daily) was administered along with isoproterenol. Heart tissue was studied for myocyte size and fibrosis. Myocardial thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase levels, and 1-OH proline (collagen content) were also estimated. Genistein significantly prevented any isoproterenol-induced increase in heart weight to body weight ratio, left ventricular mass (echocardiographic), myocardial 1-OH proline, fibrosis, myocyte size and myocardial oxidative stress. These beneficial effects of genistein were blocked by a nonselective NOS inhibitor (L-NAME), but not by a selective iNOS inhibitor (aminoguanidine). Thus, the present study suggests that the salutary effects of genistein on isoproterenol-induced cardiac hypertrophy may be mediated through inhibition of iNOS and potentiation of eNOS activities. PMID:22808991

  9. Satellite cell depletion prevents fiber hypertrophy in skeletal muscle.

    PubMed

    Egner, Ingrid M; Bruusgaard, Jo C; Gundersen, Kristian

    2016-08-15

    The largest mammalian cells are the muscle fibers, and they have multiple nuclei to support their large cytoplasmic volumes. During hypertrophic growth, new myonuclei are recruited from satellite stem cells into the fiber syncytia, but it was recently suggested that such recruitment is not obligatory: overload hypertrophy after synergist ablation of the plantaris muscle appeared normal in transgenic mice in which most of the satellite cells were abolished. When we essentially repeated these experiments analyzing the muscles by immunohistochemistry and in vivo and ex vivo imaging, we found that overload hypertrophy was prevented in the satellite cell-deficient mice, in both the plantaris and the extensor digitorum longus muscles. We attribute the previous findings to a reliance on muscle mass as a proxy for fiber hypertrophy, and to the inclusion of a significant number of regenerating fibers in the analysis. We discuss that there is currently no model in which functional, sustainable hypertrophy has been unequivocally demonstrated in the absence of satellite cells; an exception is re-growth, which can occur using previously recruited myonuclei without addition of new myonuclei. PMID:27531949

  10. Metabolic characterization of primary rat hepatocytes cultivated in parallel microfluidic biochips.

    PubMed

    Legendre, Audrey; Baudoin, Régis; Alberto, Giulia; Paullier, Patrick; Naudot, Marie; Bricks, Thibault; Brocheton, Jessy; Jacques, Sébastien; Cotton, Jérôme; Leclerc, Eric

    2013-09-01

    The functionality of primary rat hepatocytes was assessed in an Integrated Dynamic Cell Cultures in Microsystem (IDCCM) device. We characterized the hepatocytes over 96 h of culture and evaluated the impact of dynamic cell culture on their viability, inducibility, and metabolic activity. Reverse Transcription quantitative Polymerase Chain Reaction (RTqPCR) was performed on selected genes: liver transcription factors (HNF4α and CEBP), nuclear receptors sensitive to xenobiotics (AhR, PXR, CAR, and FXR), cytochromes P450 (CYPs) (1A2, 3A2, 3A23/3A1, 7A1, 2B1, 2C6, 2C, 2D1, 2D2, and 2E1), phase II metabolism enzymes (GSTA2, SULT1A1, and UGT1A6), ABC transporters (ABCB1b and ABCC2), and oxidative stress related enzymes (HMOX1 and NQO1). Microperfused-cultured hepatocytes remained viable and differentiated with in vivo-like phenotype and genotype. In contrast with postadhesion gene levels, the first 48 h of perfusion enhanced the expression of xenosensors and their target CYPs. Furthermore, CYP3A1, CYP2B1, GSTA2, SULT1A1, UGT1A1, ABCB1b, and ABCC2 were upregulated in IDCCM and reached above postextraction levels all along the duration of culture. Metabolic activities were also confirmed with the detection of metabolism rate and induced mRNAs after exposure to several inducers: 3-methylcholanthrene, caffeine, phenacetin, paracetamol,, and midazolam. Finally, this metabolic characterization confirms that IDCCM is able to maintain rat hepatocytes functions to investigate drug metabolism.

  11. Effect of honokiol on the induction of drug-metabolizing enzymes in human hepatocytes.

    PubMed

    Cho, Yong-Yeon; Jeong, Hyeon-Uk; Kim, Jeong-Han; Lee, Hye Suk

    2014-01-01

    Honokiol, 2-(4-hydroxy-3-prop-2-enyl-phenyl)-4-prop-2-enyl-phenol, an active component of Magnolia officinalis and Magnolia grandiflora, exerts various pharmacological activities such as antitumorigenic, antioxidative, anti-inflammatory, neurotrophic, and antithrombotic effects. To investigate whether honokiol acts as a perpetrator in drug interactions, messenger ribonucleic acid (mRNA) levels of phase I and II drug-metabolizing enzymes, including cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT), and sulfotransferase 2A1 (SULT2A1), were analyzed by real-time reverse transcription polymerase chain reaction following 48-hour honokiol exposure in three independent cryopreserved human hepatocyte cultures. Honokiol treatment at the highest concentration tested (50 μM) increased the CYP2B6 mRNA level and CYP2B6-catalyzed bupropion hydroxylase activity more than two-fold in three different hepatocyte cultures, indicating that honokiol induces CYP2B6 at higher concentrations. However, honokiol treatment (0.5-50 μM) did not significantly alter the mRNA levels of phase I enzymes (CYP1A2, CYP3A4, CYP2C8, CYP2C9, and CYP2C19) or phase II enzymes (UGT1A1, UGT1A4, UGT1A9, UGT2B7, and SULT2A1) in cryopreserved human hepatocyte cultures. CYP1A2-catalyzed phenacetin O-deethylase and CYP3A4-catalyzed midazolam 1'-hydroxylase activities were not affected by 48-hour honokiol treatment in cryopreserved human hepatocytes. These results indicate that honokiol is a weak CYP2B6 inducer and is unlikely to increase the metabolism of concomitant CYP2B6 substrates and cause pharmacokinetic-based drug interactions in humans.

  12. Effect of honokiol on the induction of drug-metabolizing enzymes in human hepatocytes

    PubMed Central

    Cho, Yong-Yeon; Jeong, Hyeon-Uk; Kim, Jeong-Han; Lee, Hye Suk

    2014-01-01

    Honokiol, 2-(4-hydroxy-3-prop-2-enyl-phenyl)-4-prop-2-enyl-phenol, an active component of Magnolia officinalis and Magnolia grandiflora, exerts various pharmacological activities such as antitumorigenic, antioxidative, anti-inflammatory, neurotrophic, and antithrombotic effects. To investigate whether honokiol acts as a perpetrator in drug interactions, messenger ribonucleic acid (mRNA) levels of phase I and II drug-metabolizing enzymes, including cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT), and sulfotransferase 2A1 (SULT2A1), were analyzed by real-time reverse transcription polymerase chain reaction following 48-hour honokiol exposure in three independent cryopreserved human hepatocyte cultures. Honokiol treatment at the highest concentration tested (50 μM) increased the CYP2B6 mRNA level and CYP2B6-catalyzed bupropion hydroxylase activity more than two-fold in three different hepatocyte cultures, indicating that honokiol induces CYP2B6 at higher concentrations. However, honokiol treatment (0.5–50 μM) did not significantly alter the mRNA levels of phase I enzymes (CYP1A2, CYP3A4, CYP2C8, CYP2C9, and CYP2C19) or phase II enzymes (UGT1A1, UGT1A4, UGT1A9, UGT2B7, and SULT2A1) in cryopreserved human hepatocyte cultures. CYP1A2-catalyzed phenacetin O-deethylase and CYP3A4-catalyzed midazolam 1′-hydroxylase activities were not affected by 48-hour honokiol treatment in cryopreserved human hepatocytes. These results indicate that honokiol is a weak CYP2B6 inducer and is unlikely to increase the metabolism of concomitant CYP2B6 substrates and cause pharmacokinetic-based drug interactions in humans. PMID:25395831

  13. Effect of honokiol on the induction of drug-metabolizing enzymes in human hepatocytes.

    PubMed

    Cho, Yong-Yeon; Jeong, Hyeon-Uk; Kim, Jeong-Han; Lee, Hye Suk

    2014-01-01

    Honokiol, 2-(4-hydroxy-3-prop-2-enyl-phenyl)-4-prop-2-enyl-phenol, an active component of Magnolia officinalis and Magnolia grandiflora, exerts various pharmacological activities such as antitumorigenic, antioxidative, anti-inflammatory, neurotrophic, and antithrombotic effects. To investigate whether honokiol acts as a perpetrator in drug interactions, messenger ribonucleic acid (mRNA) levels of phase I and II drug-metabolizing enzymes, including cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT), and sulfotransferase 2A1 (SULT2A1), were analyzed by real-time reverse transcription polymerase chain reaction following 48-hour honokiol exposure in three independent cryopreserved human hepatocyte cultures. Honokiol treatment at the highest concentration tested (50 μM) increased the CYP2B6 mRNA level and CYP2B6-catalyzed bupropion hydroxylase activity more than two-fold in three different hepatocyte cultures, indicating that honokiol induces CYP2B6 at higher concentrations. However, honokiol treatment (0.5-50 μM) did not significantly alter the mRNA levels of phase I enzymes (CYP1A2, CYP3A4, CYP2C8, CYP2C9, and CYP2C19) or phase II enzymes (UGT1A1, UGT1A4, UGT1A9, UGT2B7, and SULT2A1) in cryopreserved human hepatocyte cultures. CYP1A2-catalyzed phenacetin O-deethylase and CYP3A4-catalyzed midazolam 1'-hydroxylase activities were not affected by 48-hour honokiol treatment in cryopreserved human hepatocytes. These results indicate that honokiol is a weak CYP2B6 inducer and is unlikely to increase the metabolism of concomitant CYP2B6 substrates and cause pharmacokinetic-based drug interactions in humans. PMID:25395831

  14. Reversible Sterilization

    ERIC Educational Resources Information Center

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  15. Roles of hepatocyte nuclear factors in hepatitis B virus infection.

    PubMed

    Kim, Doo Hyun; Kang, Hong Seok; Kim, Kyun-Hwan

    2016-08-21

    Approximately 350 million people are estimated to be persistently infected with hepatitis B virus (HBV) worldwide. HBV maintains persistent infection by employing covalently closed circular DNA (cccDNA), a template for all HBV RNAs. Chronic hepatitis B (CHB) patients are currently treated with nucleos(t)ide analogs such as lamivudine, adefovir, entecavir, and tenofovir. However, these treatments rarely cure CHB because they are unable to inhibit cccDNA transcription and inhibit only a late stage in the HBV life cycle (the reverse transcription step in the nucleocapsid). Therefore, an understanding of the factors regulating cccDNA transcription is required to stop this process. Among numerous factors, hepatocyte nuclear factors (HNFs) play the most important roles in cccDNA transcription, especially in the generation of viral genomic RNA, a template for HBV replication. Therefore, proper control of HNF function could lead to the inhibition of HBV replication. In this review, we summarize and discuss the current understanding of the roles of HNFs in the HBV life cycle and the upstream factors that regulate HNFs. This knowledge will enable the identification of new therapeutic targets to cure CHB. PMID:27610013

  16. Roles of hepatocyte nuclear factors in hepatitis B virus infection

    PubMed Central

    Kim, Doo Hyun; Kang, Hong Seok; Kim, Kyun-Hwan

    2016-01-01

    Approximately 350 million people are estimated to be persistently infected with hepatitis B virus (HBV) worldwide. HBV maintains persistent infection by employing covalently closed circular DNA (cccDNA), a template for all HBV RNAs. Chronic hepatitis B (CHB) patients are currently treated with nucleos(t)ide analogs such as lamivudine, adefovir, entecavir, and tenofovir. However, these treatments rarely cure CHB because they are unable to inhibit cccDNA transcription and inhibit only a late stage in the HBV life cycle (the reverse transcription step in the nucleocapsid). Therefore, an understanding of the factors regulating cccDNA transcription is required to stop this process. Among numerous factors, hepatocyte nuclear factors (HNFs) play the most important roles in cccDNA transcription, especially in the generation of viral genomic RNA, a template for HBV replication. Therefore, proper control of HNF function could lead to the inhibition of HBV replication. In this review, we summarize and discuss the current understanding of the roles of HNFs in the HBV life cycle and the upstream factors that regulate HNFs. This knowledge will enable the identification of new therapeutic targets to cure CHB. PMID:27610013

  17. Roles of hepatocyte nuclear factors in hepatitis B virus infection

    PubMed Central

    Kim, Doo Hyun; Kang, Hong Seok; Kim, Kyun-Hwan

    2016-01-01

    Approximately 350 million people are estimated to be persistently infected with hepatitis B virus (HBV) worldwide. HBV maintains persistent infection by employing covalently closed circular DNA (cccDNA), a template for all HBV RNAs. Chronic hepatitis B (CHB) patients are currently treated with nucleos(t)ide analogs such as lamivudine, adefovir, entecavir, and tenofovir. However, these treatments rarely cure CHB because they are unable to inhibit cccDNA transcription and inhibit only a late stage in the HBV life cycle (the reverse transcription step in the nucleocapsid). Therefore, an understanding of the factors regulating cccDNA transcription is required to stop this process. Among numerous factors, hepatocyte nuclear factors (HNFs) play the most important roles in cccDNA transcription, especially in the generation of viral genomic RNA, a template for HBV replication. Therefore, proper control of HNF function could lead to the inhibition of HBV replication. In this review, we summarize and discuss the current understanding of the roles of HNFs in the HBV life cycle and the upstream factors that regulate HNFs. This knowledge will enable the identification of new therapeutic targets to cure CHB.

  18. Olmesartan Inhibits Cardiac Hypertrophy in Mice Overexpressing Renin Independently of Blood Pressure: Its Beneficial Effects on ACE2/Ang(1-7)/Mas Axis and NADPH Oxidase Expression.

    PubMed

    Tanno, Tomohiro; Tomita, Hirofumi; Narita, Ikuyo; Kinjo, Takahiko; Nishizaki, Kimitaka; Ichikawa, Hiroaki; Kimura, Yoshihiro; Tanaka, Makoto; Osanai, Tomohiro; Okumura, Ken

    2016-06-01

    Enhanced renin-angiotensin activity causes hypertension and cardiac hypertrophy. The angiotensin (Ang)-converting enzyme (ACE)2/Ang(1-7)/Mas axis pathway functions against Ang II type 1 receptor (AT1R) signaling. We investigated whether olmesartan (Olm), an AT1R blocker, inhibits cardiac hypertrophy independently of blood pressure, and evaluated the potential mechanisms. The 3- to 4-month-old male mice overexpressing renin in the liver (Ren-Tg) were given Olm (5 mg/kg/d) and hydralazine (Hyd) (3.5 mg/kg/d) orally for 2 months. Systolic blood pressure was higher in the Ren-Tg mice than in wild-type littermates. Olm and Hyd treatments lowered systolic blood pressure to the same degree. However, cardiac hypertrophy, evaluated by echocardiography, heart weight, cross-sectional area of cardiomyocytes, and gene expression, was inhibited by only Olm treatment, but not by Hyd. Olm treatment reversed decreased gene expressions of ACE2 and Mas receptor of Ren-Tg mice and inhibited enhanced NADPH oxidase (Nox)4 expression and reactive oxygen species, whereas Hyd treatment had no influence on them. These findings indicate that Olm treatment inhibits cardiac hypertrophy independently of blood pressure, not only through its original AT1R blockade but partly through enhancement of ACE2/Ang(1-7)/Mas axis and suppression of Nox4 expression. PMID:26886190

  19. Resistin-induced cardiomyocyte hypertrophy is inhibited by apelin through the inactivation of extracellular signal-regulated kinase signaling pathway in H9c2 embryonic rat cardiomyocytes

    PubMed Central

    Luo, Jian-Wei; Zheng, Xian; Cheng, Guan-Chang; Ye, Qun-Hui; Deng, Yong-Zhi; Wu, Lin

    2016-01-01

    It has been reported that resistin induces, whereas apelin inhibits cardiac hypertrophy. However, the underlying molecular mechanisms of apelin inhibiting resistin-induced cardiac hypertrophy remain unclear. The aim of the current study is to investigate the effects of apelin on resistin-induced cardiomyocyte hypertrophy and elucidate the underlying molecular mechanism. H9c2 cells were used in the present study, and cell surface area and protein synthesis were evaluated. Reverse transcription-quantitative polymerase chain reaction was performed to analyze the expression levels of hypertrophic markers, brain natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC). In addition, western blotting was conducted to examine phosphorylation of extracellular signal-regulated kinase (ERK)1/2. Following treatment of H9c2 cells with resistin, cell surface area, protein synthesis, and BNP and β-MHC mRNA expression levels were increased. Subsequent to co-treatment of H9c2 cells with apelin and resistin, lead to the inhibition of resistin-induced hypertrophic effects by apelin. In addition, treatment with resistin increased phosphorylation of ERK1/2, whereas pretreatment with apelin decreased phosphorylation of ERK1/2, which was increased by resistin. These results indicate that resistin-induced cardiac hypertrophy is inhibited by apelin via inactivation of ERK1/2 cell signaling.

  20. Resistin-induced cardiomyocyte hypertrophy is inhibited by apelin through the inactivation of extracellular signal-regulated kinase signaling pathway in H9c2 embryonic rat cardiomyocytes

    PubMed Central

    Luo, Jian-Wei; Zheng, Xian; Cheng, Guan-Chang; Ye, Qun-Hui; Deng, Yong-Zhi; Wu, Lin

    2016-01-01

    It has been reported that resistin induces, whereas apelin inhibits cardiac hypertrophy. However, the underlying molecular mechanisms of apelin inhibiting resistin-induced cardiac hypertrophy remain unclear. The aim of the current study is to investigate the effects of apelin on resistin-induced cardiomyocyte hypertrophy and elucidate the underlying molecular mechanism. H9c2 cells were used in the present study, and cell surface area and protein synthesis were evaluated. Reverse transcription-quantitative polymerase chain reaction was performed to analyze the expression levels of hypertrophic markers, brain natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC). In addition, western blotting was conducted to examine phosphorylation of extracellular signal-regulated kinase (ERK)1/2. Following treatment of H9c2 cells with resistin, cell surface area, protein synthesis, and BNP and β-MHC mRNA expression levels were increased. Subsequent to co-treatment of H9c2 cells with apelin and resistin, lead to the inhibition of resistin-induced hypertrophic effects by apelin. In addition, treatment with resistin increased phosphorylation of ERK1/2, whereas pretreatment with apelin decreased phosphorylation of ERK1/2, which was increased by resistin. These results indicate that resistin-induced cardiac hypertrophy is inhibited by apelin via inactivation of ERK1/2 cell signaling. PMID:27699016

  1. Reversible Cardiomyopathies

    PubMed Central

    Patel, Harsh; Madanieh, Raef; Kosmas, Constantine E; Vatti, Satya K; Vittorio, Timothy J

    2015-01-01

    Cardiomyopathies (CMs) have many etiological factors that can result in severe structural and functional dysregulation. Fortunately, there are several potentially reversible CMs that are known to improve when the root etiological factor is addressed. In this article, we discuss several of these reversible CMs, including tachycardia-induced, peripartum, inflammatory, hyperthyroidism, Takotsubo, and chronic illness–induced CMs. Our discussion also includes a review on their respective pathophysiology, as well as possible management solutions. PMID:26052233

  2. Hepatocyte membrane water permeability measured by silicone layer filtering centrifugation.

    PubMed

    Gradilone, Sergio A; Ochoa, J Elena; García, Fabiana; Larocca, M Cecilia; Pellegrino, José M; Marinelli, Raúl A

    2002-03-01

    We previously found that hepatocytes are able to control their osmotic membrane water permeability (P(f)) by regulating the number of surface aquaporin water channels. Hepatocyte P(f) has been assessed by phase-contrast microscopy and cell image analysis, an established but relatively laborious procedure. We report here an alternative method to assess hepatocyte P(f) based on a single silicone layer filtering centrifugation system. Isolated rat hepatocytes were incubated in hypotonic or isotonic buffers containing (3)H(2)O as a tracer and, then, were filtered by rapid centrifugation through a silicone layer down to a lysis layer. Osmotically driven radioactivity (i.e., (3)H(2)O) within hepatocytes was calculated as the difference between the dpm in lysis media measured under hypotonic and isotonic conditions. The P(f) calculated from the initial slope of the radioactivity-versus-time curve was 18 microm/s at 4 degrees C. Hepatocytes treated with dibutyryl cyclic AMP, to increase P(f) through the plasma membrane insertion of aquaporins, showed an increased P(f) value of 37 microm/s. The aquaporin blocker dimethyl sulfoxide selectively prevented the agonist-induced hepatocyte P(f). These data are in good agreement with the corresponding values determined by quantitative phase-contrast microscopy; thus, the method developed allows the rapid and reliable measurement of hepatocyte P(f).

  3. Mechanisms of the statins cytotoxicity in freshly isolated rat hepatocytes.

    PubMed

    Abdoli, Narges; Heidari, Reza; Azarmi, Yadollah; Eghbal, Mohammad Ali

    2013-06-01

    Statins are potent drugs, used as lipid-lowering agents in cardiovascular diseases. Hepatotoxicity is one of the serious adverse effects of statins, and the exact mechanism of hepatotoxicity is not yet clear. In this study, the cytotoxic effects of the most commonly used statins, that is, atorvastatin, lovastatin, and simvastatin toward isolated rat hepatocytes, were evaluated. Markers, such as cell death, reactive oxygen species (ROS) formation, lipid peroxidation, mitochondrial membrane potential, and the amount of reduced and oxidized glutathione in the statin-treated hepatocytes, were investigated. It was found that the statins caused cytotoxicity toward rat hepatocytes dose dependently. An elevation in ROS formation, accompanied by a significant amount of lipid peroxidation and mitochondrial depolarization, was observed. Cellular glutathione reservoirs were decreased, and a significant amount of oxidized glutathione was formed. This study suggests that the adverse effect of statins toward hepatocytes is mediated through oxidative stress and the hepatocytes mitochondria play an important role in the statin-induced toxicity.

  4. Insulin internalization in isolated rat hepatocytes

    SciTech Connect

    Galan, J.; Trankina, M.; Noel, R.; Ward, W. )

    1990-02-26

    This project was designed to determine whether neomycin, an aminoglycoside antibiotic, has a significant effect upon the pathways of ligand endocytosis in isolated rat hepatocytes. The pathways studied include receptor-mediated endocytosis and fluid-phase endocytosis. Neomycin causes a dose-dependent acceleration of {sup 125}I-insulin internalization. Since fluid-phase endocytosis can also be a significant factor in {sup 125}I-insulin internalization, lucifer yellow (LY), a marker for fluid-phase endocytosis, was incorporated into an assay similar to the {sup 125}I-insulin internalization procedure. In the presence of 5 mM neomycin, a significant increase in LY uptake was evident at 0.2 and 0.4 mg/ml of LY. At 0.8 mg/ml, a decrease in LY uptake was observed. The increased rate of {sup 125}I-insulin internalization in the presence of neomycin was intriguing. Since one action of neomycin is to inhibit phosphoinositidase C, it suggests that the phosphotidylinositol cycle may be involved in ligand internalization by hepatocytes. At low insulin concentrations, receptor-mediated uptake predominates. Fluid-phase uptake can become an important uptake route as insulin concentrations are increased. Since neomycin stimulates fluid-phase endocytosis, it must also be taken into account when measuring ligand internalization.

  5. Mechanisms of cortisol action in fish hepatocytes.

    PubMed

    Faught, Erin; Vijayan, Mathilakath M

    2016-09-01

    Here we provide an overview of the mechanistic characterization of the hepatic action of cortisol during stress in fish. Cortisol is the main circulating glucocorticoid in fish and its action is mediated through its cytosolic receptor, the glucocorticoid receptor (GR), and regulates the expression of genes involved in growth, metabolism and immune function. When taken together, the data suggests that cortisol may be playing a key role in the energy substrate re-partitioning in hepatocytes to cope with stress. The proposed model is that cortisol upregulates pathways involved in energy substrate mobilization, including gluconeogenesis, while downregulating energy demanding pathways, including growth and immune function. Recent work also points to a role for cortisol in mediating rapid action that is non-genomic and includes modulation of secondary signalling cascades; however, the physiological relevance of these studies remains to be determined. Altogether, studies carried out in hepatocytes are bringing to fore the complex nature of the cortisol signalling pathways in the organismal stress response. The mode of actions and their physiological implications for stress coping awaits further study. PMID:27445122

  6. Ubiquitin-specific protease 14 regulates cardiac hypertrophy progression by increasing GSK-3β phosphorylation.

    PubMed

    Liu, Ningning; Chai, Renjie; Liu, Bin; Zhang, Zhenhui; Zhang, Shuangwei; Zhang, Jingzhi; Liao, Yuning; Cai, Jianyu; Xia, Xiaohong; Li, Aiqun; Liu, Jinbao; Huang, Hongbiao; Liu, Shiming

    2016-09-23

    Cardiac hypertrophy, a compensatory response to various stimuli in the heart, independently predicts cardiovascular ailments and related deaths. Increasing evidence indicates ubiquitin-proteasome signaling contributes to cardiac hypertrophy regulation. Here, we identified ubiquitin-specific protease 14 (USP14), a 19S proteasome associated deubiquitinase (DUB), as a novel target for cardiac hypertrophy therapy via inhibition of the GSK-3β pathway. Indeed, USP14 expression was increased in an animal model of abdominal aorta constriction. In an angiotensin II (AngII) induced primary neonatal rat cardiomyocyte hypertrophy model, USP14 expression was increased in a time-dependent manner, and reduced USP14 deubiquitinase activity or USP14 knockdown resulted in lower expression levels of the myocardial hypertrophy specific marker β-MHC, and subsequent decreased GSK-3β phosphorylation. In conclusion, USP14 mediates the development of cardiac hypertrophy by promoting GSK-3β phosphorylation, suggesting that USP14 might represent a novel therapeutic target for cardiac hypertrophy treatment.

  7. MicroRNA-96 promotes myocardial hypertrophy by targeting mTOR

    PubMed Central

    Sun, Xuemei; Zhang, Chunlai

    2015-01-01

    As a main cause of cardiac hypertrophy, myocardial hypertrophy includes the proliferation and enlongation of myocardial cell, resulting in abnormally cardiac enlargement. However, the pathogenesis and the molecular mechanism that regulate gene expression of myocardial hypertrophy remain incompletely understood. MiRNAs were deemed as an important molecules involved in a variety of pathological processes. MiR-96 has been reported being associated with the tumor proliferation, but whether miR-96 is involved in cardiac hypertrophy remains uncertain. In this study, we have confirmed that, as the myocardial hypertrophy gene, mTOR was a target gene of miR-96, who would promote the occurrence of myocardial hypertrophy. Thus, we got the conclusion that miR-96 could promote myocardial hypertrophy by inhibiting mTOR, miR-96 and mTOR were negatively correlated. PMID:26823769

  8. Cold Preservation of Human Adult Hepatocytes for Liver Cell Therapy.

    PubMed

    Duret, Cedric; Moreno, Daniel; Balasiddaiah, Anangi; Roux, Solene; Briolotti, Phillipe; Raulet, Edith; Herrero, Astrid; Ramet, Helene; Biron-Andreani, Christine; Gerbal-Chaloin, Sabine; Ramos, Jeanne; Navarro, Francis; Hardwigsen, Jean; Maurel, Patrick; Aldabe, Rafael; Daujat-Chavanieu, Martine

    2015-01-01

    Hepatocyte transplantation is a promising alternative therapy for the treatment of hepatic failure, hepatocellular deficiency, and genetic metabolic disorders. Hypothermic preservation of isolated human hepatocytes is potentially a simple and convenient strategy to provide on-demand hepatocytes in sufficient quantity and of the quality required for biotherapy. In this study, first we assessed how cold storage in three clinically safe preservative solutions (UW, HTS-FRS, and IGL-1) affects the viability and in vitro functionality of human hepatocytes. Then we evaluated whether such cold-preserved human hepatocytes could engraft and repopulate damaged livers in a mouse model of liver failure. Human hepatocytes showed comparable viabilities after cold preservation in the three solutions. The ability of fresh and cold-stored hepatocytes to attach to a collagen substratum and to synthesize and secrete albumin, coagulation factor VII, and urea in the medium after 3 days in culture was also equally preserved. Cold-stored hepatocytes were then transplanted in the spleen of immunodeficient mice previously infected with adenoviruses containing a thymidine kinase construct and treated with a single dose of ganciclovir to induce liver injury. Engraftment and liver repopulation were monitored over time by measuring the blood level of human albumin and by assessing the expression of specific human hepatic mRNAs and proteins in the recipient livers by RT-PCR and immunohistochemistry, respectively. Our findings show that cold-stored human hepatocytes in IGL-1 and HTS-FRS preservative solutions can survive, engraft, and proliferate in a damaged mouse liver. These results demonstrate the usefulness of human hepatocyte hypothermic preservation for cell transplantation. PMID:25622096

  9. Differential expression of glutathione S-transferases P1-1 and A1-1 at protein and mRNA levels in hepatocytes derived from human bone marrow mesenchymal stem cells.

    PubMed

    Allameh, Abdolamir; Esmaeli, Shahnaz; Kazemnejad, Somaieh; Soleimani, Masoud

    2009-06-01

    The aim of this study was to find out the profile of cellular glutathione (GSH) and GSH S-transferase (GST) in hepatocytes differentiated from adult mesenchymal stem cells (MSC). For this purpose, we have derived functionally active hepatocyte-like cells from normal human multipotent adult MSC. Then the differentiated cells were characterized by specific hepatic markers. The cellular GSH and GST catalytic activity toward 1-chloro-2,4-dinitrobenzene (CDNB) were determined in hepatocyte-like cells differentiated from MSC compared with undifferentiated MSC. Reverse transcription polymerase chain reaction (RT-PCR) and immunoblotting techniques were used to study GST-P1-1 and GST-A1-1 expression in differentiated and undifferentiated cells. The results showed that there is more than threefold increase in GST catalytic activity in hepatocytes recovered by day 14 of differentiation. GST-P1-1 mRNA expression was detected in both differentiated hepatocyte-like cells and their undifferentiated progenitors. Under similar conditions, only differentiated hepatocyte-like cells expressed GST-A1-1 mRNA. These results were further confirmed by showing that the undifferentiated cells expressed both GST-A and GST-P proteins. Unlike GST, the level of cellular GSH was declined (approximately 20%) in hepatocytes derived from MSC as compared to that of undifferentiated cells. These data may suggest that hepatogenic differentiation of human bone marrow MSC is accompanied with the regulation of factors participating in GSH conjugation pathway.

  10. Type III interferons are expressed by Coxsackievirus-infected human primary hepatocytes and regulate hepatocyte permissiveness to infection

    PubMed Central

    Lind, K; Svedin, E; Utorova, R; Stone, V M; Flodström-Tullberg, M

    2014-01-01

    Hepatitis is a common and potentially fatal manifestation of severe Coxsackievirus infections, particularly in newborn children. Little is known of the immune-mediated mechanisms regulating permissiveness to liver infection. It is well established that type I interferons (IFNs) play an important role in the host innate immune response to Coxsackievirus infections. Recent studies have highlighted a role for another IFN family, the type III IFNs (also called IFN-λ), in anti-viral defence. Whether type III IFNs are produced by hepatocytes during a Coxsackievirus infection remains unknown. Moreover, whether or not type III IFNs protects hepatocytes from a Coxsackievirus infection has not been addressed. In this study, we show that primary human hepatocytes respond to a Coxsackievirus B3 (CVB3) infection by up-regulating the expression of type III IFNs. We also demonstrate that type III IFNs induce an anti-viral state in hepatocytes characterized by the up-regulated expression of IFN-stimulated genes, including IFN-stimulated gene (ISG15), 2′-5′-oligoadenylate synthetase 2 (OAS2), protein kinase regulated by dsRNA (PKR) and myxovirus resistance protein 1 (Mx1). Furthermore, our study reveals that type III IFNs attenuate CVB3 replication both in hepatocyte cell lines and primary human hepatocytes. Our studies suggest that human hepatocytes express type III IFNs in response to a Coxsackievirus infection and highlight a novel role for type III IFNs in regulating hepatocyte permissiveness to this clinically relevant type of virus. PMID:24773058

  11. Inhibition of Hepatocyte Apoptosis: An Important Mechanism of Corn Peptides Attenuating Liver Injury Induced by Ethanol.

    PubMed

    Ma, Zhili; Hou, Tao; Shi, Wen; Liu, Weiwei; He, Hui

    2015-09-11

    In this study, the effects of mixed corn peptides and synthetic pentapeptide (QLLPF) on hepatocyte apoptosis induced by ethanol were investigated in vivo. QLLPF, was previously characterized from corn protein hydrolysis, which had been shown to exert good facilitating alcohol metabolism activity. Mice were pre-treated with the mixed corn peptides and the pentapeptide for 1 week and then treated with ethanol. After treatment of three weeks, the biochemical indices and the key ethanol metabolizing enzymes, the serum TNF-α, liver TGF-β1 concentrations and the protein expressions related to apoptosis were determined. We found that the Bcl-2, Bax and cytochrome c expressions in the intrinsic pathway and the Fas, FasL and NF-κB expressions in the extrinsic pathway together with higher TNF-α and TGF-β1 concentrations were reversed compared with the model group by both the mixed corn peptides and the pentapeptide. The activation of caspase3 was also suppressed. Additionally, apoptosis was further confirmed with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the TUNEL assay demonstrated peptides suppressed hepatocyte apoptosis. Our results suggest that apoptosis induced by ethanol is alleviated in response to the treatment of corn peptides, potentially due to reversing the related protein expression.

  12. Liver Hypertrophy After Percutaneous Portal Vein Embolization: Comparison of N-Butyl-2-Cyanocrylate Versus Sodium Acrylate-Vinyl Alcohol Copolymer Particles in a Swine Model

    SciTech Connect

    Tsoumakidou, Georgia; Theocharis, Stamatis; Ptohis, Nikolaos Alexopoulou, Efthimia; Mantziaras, George; Kelekis, Nikolaos L. Brountzos, Elias N.

    2011-10-15

    Purpose: Percutaneous portal vein embolization (PPVE) induces hypertrophy of the future liver remnant before hepatic resection. The ideal embolic material has not yet been determined. We compared N-butyl-2-cyanocrylate (NBCA) with sodium acrylate-vinyl alcohol copolymer particles using a swine model. Materials and Methods: Twelve pigs underwent PPVE. Six pigs (group A) were embolized with NBCA, and 6 pigs (group B) were embolized with sodium acrylate-vinyl alcohol copolymer particles. Computed tomographic volumetry of the embolized lobe (EL) and the nonembolized lobe (NEL), along with liver function tests, was performed before and at 14 and 28 days after embolization. Tissue samples from both lobes were taken 14 and 28 days after PPVE. Results: NEL-volume and NEL-ratio increases were significantly higher in group A at 14 and 28 days after PPVE (78 and 52% and 91 and 66%, respectively) than in group B (32 and 12% and 28 and 10%, respectively) (p < 0.05). Percent change of the EL-volume was significantly higher for group A at 28 days after PPVE. No statistically significant difference was found between the groups regarding hepatocyte proliferation on the NEL and apoptosis on the EL at both time intervals. Conclusion: PPVE using NBCA is more efficient and causes more NEL hypertrophy than microspheres.

  13. DIOL Triterpenes Block Profibrotic Effects of Angiotensin II and Protect from Cardiac Hypertrophy

    PubMed Central

    Jurado-López, Raquel; Martínez-Martínez, Ernesto; Gómez-Hurtado, Nieves; Delgado, Carmen; Visitación Bartolomé, Maria; San Román, José Alberto; Cordova, Claudia; Lahera, Vicente; Nieto, Maria Luisa; Cachofeiro, Victoria

    2012-01-01

    Background The natural triterpenes, erythrodiol and uvaol, exert anti-inflammatory, vasorelaxing and anti-proliferative effects. Angiotensin II is a well-known profibrotic and proliferative agent that participates in the cardiac remodeling associated with different pathological situations through the stimulation and proliferation of cardiac fibroblasts. Therefore, the aim of the study was to investigate the preventive effects of the natural triterpenes erythrodiol and uvaol on the proliferation and collagen production induced by angiotensin II in cardiac myofibroblasts. Their actions on cardiac hypertrophy triggered by angiotensin II were also studied. Methodology/Principal Findings The effect of erythrodiol and uvaol on angiotensin II-induced proliferation was evaluated in cardiac myofibroblasts from adult rats in the presence or the absence of the inhibitors of PPAR-γ, GW9662 or JNK, SP600125. The effect on collagen levels induced by angiotensin II was evaluated in cardiac myofibroblasts and mouse heart. The presence of low doses of both triterpenes reduced the proliferation of cardiac myofibroblasts induced by angiotensin II. Pretreatment with GW9662 reversed the effect elicited by both triterpenes while SP600125 did not modify it. Both triterpenes at high doses produced an increase in annexing-V binding in the presence or absence of angiotensin II, which was reduced by either SP600125 or GW9662. Erythrodiol and uvaol decreased collagen I and galectin 3 levels induced by angiotensin II in cardiac myofribroblasts. Finally, cardiac hypertrophy, ventricular remodeling, fibrosis, and increases in myocyte area and brain natriuretic peptide levels observed in angiotensin II-infused mice were reduced in triterpene-treated animals. Conclusions/Significance Erythrodiol and uvaol reduce cardiac hypertrophy and left ventricle remodeling induced by angiotensin II in mice by diminishing fibrosis and myocyte area. They also modulate growth and survival of cardiac

  14. Cardiac-specific deletion of acetyl CoA carboxylase 2 (ACC2) prevents metabolic remodeling during pressure-overload hypertrophy

    PubMed Central

    Kolwicz, Stephen C.; Olson, David P.; Marney, Luke C.; Garcia-Menendez, Lorena; Synovec, Robert E.; Tian, Rong

    2012-01-01

    Rationale Decreased fatty acid oxidation (FAO) with increased reliance on glucose are hallmarks of metabolic remodeling that occurs in pathological cardiac hypertrophy and is associated with decreased myocardial energetics and impaired cardiac function. To date, it has not been tested whether prevention of the metabolic switch that occurs during the development of cardiac hypertrophy has unequivocal benefits on cardiac function and energetics. Objectives Since malonyl CoA production via acetyl CoA carboxylase 2 (ACC2) inhibits mitochondrial fatty acid transport, we hypothesized that mice with a cardiac-specific deletion of ACC2 (ACC2H−/−) would maintain cardiac fatty acid oxidation (FAO) and improve function and energetics during the development of pressure-overload hypertrophy. Methods and Results ACC2 deletion led to a significant reduction in cardiac malonyl CoA levels. In isolated perfused heart experiments, left ventricular (LV) function and oxygen consumption were similiar in ACC2H−/− mice despite an ~60% increase in FAO compared to controls (CON). After 8 weeks of pressure-overload via transverse aortic constriction (TAC), ACC2H−/− mice exhibited a substrate utilization profile similar to sham animals while CON-TAC hearts had decreased FAO with increased glycolysis and anaplerosis. Myocardial energetics, assessed by 31P NMR spectroscopy, and cardiac function were maintained in ACC2H−/− after 8 weeks of TAC. Furthermore, ACC2H−/−-TAC demonstrated an attenuation of cardiac hypertrophy with a significant reduction in fibrosis relative to CON-TAC. Conclusions These data suggest that reversion to the fetal metabolic profile in chronic pathological hypertrophy is associated with impaired myocardial function and energetics and maintenance of the inherent cardiac metabolic profile and mitochondrial oxidative capacity is a viable therapeutic strategy. PMID:22730442

  15. Mutagenicity towards Salmonella typhimurium of some known genotoxic agents, activated by isolated hepatocytes of monkey (Macaca fascicularis). Comparison with isolated human hepatocytes.

    PubMed

    Neis, J M; Roelofs, H M; van Gemert, P J; Henderson, P T

    1986-06-01

    This paper describes some striking differences between isolated human and monkey hepatocytes in their capacity to activate some known genotoxic agents into products mutagenic towards Salmonella typhimurium. Isolated monkey hepatocytes, in contrast to human hepatocytes, appeared to activate benzidine (BZ), N-acetylbenzidine (MABZ), N,N'-diacetylbenzidine (DABZ), 2-aminofluorene (2-AF) and 2-acetylaminofluorene (2-AAF) poorly. With monkey hepatocytes BZ was slightly more mutagenic than DABZ, whereas with human hepatocytes DABZ was more active than BZ. N-Nitrosodimethylamine (DMN) and N-nitrosodiethylamine (DEN) were also found to be poorly mutagenic when activated by monkey hepatocytes, unlike the human hepatocytes. However, the polycyclic arylhydrocarbons benzo[a]pyrene (B[a]P) and 7,12-dimethylbenzanthracene (7,12-DMBA) were highly active in the presence of monkey hepatocytes, unlike the human hepatocytes. A metabolic study showed that monkey liver preparations seem to possess a higher monooxygenase activity towards B[a]P than human liver preparations.

  16. Dietary copper supplementation reverses hypertrophic cardiomyopathy induced by chronic pressure overload in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustained pressure overload causes cardiac hypertrophy and the transition to heart failure. We show here that dietary supplementation with physiologically relevant levels of copper (Cu) reverses pre-established hypertrophic cardiomyopathy in the presence of pressure overload induced by ascending aor...

  17. Protein kinase cascades in the regulation of cardiac hypertrophy

    PubMed Central

    Dorn, Gerald W.; Force, Thomas

    2005-01-01

    In broad terms, there are 3 types of cardiac hypertrophy: normal growth, growth induced by physical conditioning (i.e., physiologic hypertrophy), and growth induced by pathologic stimuli. Recent evidence suggests that normal and exercise-induced cardiac growth are regulated in large part by the growth hormone/IGF axis via signaling through the PI3K/Akt pathway. In contrast, pathological or reactive cardiac growth is triggered by autocrine and paracrine neurohormonal factors released during biomechanical stress that signal through the Gq/phospholipase C pathway, leading to an increase in cytosolic calcium and activation of PKC. Here we review recent developments in the area of these cardiotrophic kinases, highlighting the utility of animal models that are helping to identify molecular targets in the human condition. PMID:15765134

  18. Prevention of anemia alleviates heart hypertrophy in copper deficient rats

    SciTech Connect

    Lure, M.D.; Fields, M.; Lewis, C.G. Univ. of Maryland, College Park Georgetown Univ., Washington, DC )

    1991-03-11

    The present investigation was designed to examine the role of anemia in the cardiomegaly and myocardial pathology of copper deficiency. Weanling rats were fed a copper deficient diet containing either starch (ST) or fructose (FRU) for five weeks. Six rats consuming the FRU diet were intraperitoneally injected once a week with 1.0 ml/100g bw of packed red blood cells (RBC) obtained from copper deficient rats fed ST. FRU rats injected with RBC did not develop anemia. Additionally, none of the injected rats exhibited heart hypertrophy or gross pathology and all survived. In contrast, non-injected FRU rats were anemic, exhibited severe signs of copper deficiency which include heart hypertrophy with gross pathology, and 44% died. Maintaining the hematocrit with RBC injections resulted in normal heart histology and prevented the mortality associated with the fructose x copper interaction. The finding suggest that the anemia associated with copper deficiency contributes to heart pathology.

  19. Gingival hypertrophy in a child: Expect the unexpected

    PubMed Central

    Ravikumar, Rekha; Manohar, Rakesh; Latha, Sneha Magatha; Scott, Julius Xavier

    2016-01-01

    Acute leukemia is the most common malignant disorder of childhood. Acute leukemia is characterized by marrow failure due to the replacement of marrow elements by leukemic blasts. Gingival hypertrophy (GH) due to acute myeloid leukemia (AML) in a child is extremely rare. Here, we report a case of AML (subtype M5 of FAB classification) in a 3-year-old male child wherein the disease primarily presented as GH. PMID:27433057

  20. Role of microtubules in the contractile dysfunction of hypertrophied myocardium

    NASA Technical Reports Server (NTRS)

    Zile, M. R.; Koide, M.; Sato, H.; Ishiguro, Y.; Conrad, C. H.; Buckley, J. M.; Morgan, J. P.; Cooper, G. 4th

    1999-01-01

    OBJECTIVES: We sought to determine whether the ameliorative effects of microtubule depolymerization on cellular contractile dysfunction in pressure overload cardiac hypertrophy apply at the tissue level. BACKGROUND: A selective and persistent increase in microtubule density causes decreased contractile function of cardiocytes from cats with hypertrophy produced by chronic right ventricular (RV) pressure overloading. Microtubule depolymerization by colchicine normalizes contractility in these isolated cardiocytes. However, whether these changes in cellular function might contribute to changes in function at the more highly integrated and complex cardiac tissue level was unknown. METHODS: Accordingly, RV papillary muscles were isolated from 25 cats with RV pressure overload hypertrophy induced by pulmonary artery banding (PAB) for 4 weeks and 25 control cats. Contractile state was measured using physiologically sequenced contractions before and 90 min after treatment with 10(-5) mol/liter colchicine. RESULTS: The PAB significantly increased RV systolic pressure and the RV weight/body weight ratio in PAB; it significantly decreased developed tension from 59+/-3 mN/mm2 in control to 25+/-4 mN/mm2 in PAB, shortening extent from 0.21+/-0.01 muscle lengths (ML) in control to 0.12+/-0.01 ML in PAB, and shortening rate from 1.12+/-0.07 ML/s in control to 0.55+/-0.03 ML/s in PAB. Indirect immunofluorescence confocal microscopy showed that PAB muscles had a selective increase in microtubule density and that colchicine caused complete microtubule depolymerization in both control and PAB papillary muscles. Microtubule depolymerization normalized myocardial contractility in papillary muscles of PAB cats but did not alter contractility in control muscles. CONCLUSIONS: Excess microtubule density, therefore, is equally important to both cellular and to myocardial contractile dysfunction caused by chronic, severe pressure-overload cardiac hypertrophy.

  1. Lysosomal iron mobilization and induction of the mitochondrial permeability transition in acetaminophen-induced toxicity to mouse hepatocytes.

    PubMed

    Kon, Kazuyoshi; Kim, Jae-Sung; Uchiyama, Akira; Jaeschke, Hartmut; Lemasters, John J

    2010-09-01

    Acetaminophen induces the mitochondrial permeability transition (MPT) in hepatocytes. Reactive oxygen species (ROS) trigger the MPT and play an important role in AAP-induced hepatocellular injury. Because iron is a catalyst for ROS formation, our aim was to investigate the role of chelatable iron in MPT-dependent acetaminophen toxicity to mouse hepatocytes. Hepatocytes were isolated from fasted male C3Heb/FeJ mice. Necrotic cell killing was determined by propidium iodide fluorometry. Mitochondrial membrane potential was visualized by confocal microscopy of tetramethylrhodamine methylester. Chelatable ferrous ion was monitored by calcein quenching, and 70 kDa rhodamine-dextran was used to visualize lysosomes. Cell killing after acetaminophen (10mM) was delayed and decreased by more than half after 6 h by 1mM desferal or 1mM starch-desferal. In a cell-free system, ferrous but not ferric iron quenched calcein fluorescence, an effect reversed by dipyridyl, a membrane-permeable iron chelator. In hepatocytes loaded with calcein, intracellular calcein fluorescence decreased progressively beginning about 4 h after acetaminophen. Mitochondria then depolarized after about 6 h. Dipyridyl (20mM) dequenched calcein fluorescence. Desferal and starch-desferal conjugate prevented acetaminophen-induced calcein quenching and mitochondrial depolarization. As calcein fluorescence became quenched, lysosomes disappeared, consistent with release of iron from ruptured lysosomes. In conclusion, an increase of cytosolic chelatable ferrous iron occurs during acetaminophen hepatotoxicity, which triggers the MPT and cell killing. Disrupted lysosomes are the likely source of iron, and chelation of this iron decreases acetaminophen toxicity to hepatocytes.

  2. Hypertrophy of cultured bovine aortic endothelium following irradiation

    SciTech Connect

    Rosen, E.M.; Vinter, D.W.; Goldberg, I.D.

    1989-03-01

    The vascular endothelium is a vital multifunctional tissue which covers the entire luminal surface of the circulatory system. Loss of continuity of the endothelial lining normally results in cell migration and proliferation to make up for cell loss and to ensure that exposure of the thrombogenic subendothelium to platelets and clotting factors is minimized. We showed that ionizing radiation (400-3000 cGy) causes dose-dependent cell loss from confluent monolayer cultures of bovine aortic endothelium, which cannot immediately be compensated by cell proliferation. Within 24 h, the remaining attached cells undergo substantial somatic hypertrophy (evidenced by increased protein content, cell volume, and attachment area) but remain diploid. If cell loss is not excessive, monolayer continuity is restored within several days. Although reduced protein degradation may contribute, most of the protein accumulation is due to synthesis of new protein. Unlike endothelium, irradiation of smooth muscle cultures causes neither cell loss nor increased protein synthesis. Hypertrophy of irradiated endothelial cells appears to be a consequence of a proliferative stimulus (cell loss) in a population of cells which is unable to divide. It can be modulated by replating irradiated cells at different densities. We suggest that endothelial hypertrophy is an early vascular homeostatic response before clonal proliferation of surviving cells or repopulation by cells from outside of the irradiated field can compensate for cell loss.

  3. Role of Histone Demethylases in Cardiomyocytes Induced to Hypertrophy

    PubMed Central

    Carulla, Juan; García, Jeison

    2016-01-01

    Epigenetic changes induced by histone demethylases play an important role in differentiation and pathological changes in cardiac cells. However, the role of the jumonji family of demethylases in the development of cardiac hypertrophy remains elusive. In this study, the presence of different histone demethylases in cardiac cells was evaluated after hypertrophy was induced with neurohormones. A cell line from rat cardiomyocytes was used as a biological model. The phenotypic profiles of the cells, as well as the expression of histone demethylases, were studied through immunofluorescence, transient transfection, western blot, and qRT-PCR analysis after inducing hypertrophy by angiotensin II and endothelin-1. An increase in fetal gene expression (ANP, BNP, and β-MHC) was observed in cardiomyocytes after treatment with angiotensin II and endothelin-1. A significant increase in JMJD2A expression, but not in UTX or JMJD2C expression, was observed. When JMJD2A was overexpressed in cardiomyocytes through transient transfection, the effect of neurohormones on fetal cardiac gene expression was increased. We conclude that JMJD2A plays a principal role in the regulation of fetal cardiac genes, which increase in expression during the pathological hypertrophic process. PMID:27722168

  4. Speckle Tracking Based Strain Analysis Is Sensitive for Early Detection of Pathological Cardiac Hypertrophy

    PubMed Central

    An, Xiangbo; Wang, Jingjing; Li, Hao; Lu, Zhizhen; Bai, Yan; Xiao, Han; Zhang, Youyi; Song, Yao

    2016-01-01

    Cardiac hypertrophy is a key pathological process of many cardiac diseases. However, early detection of cardiac hypertrophy is difficult by the currently used non-invasive method and new approaches are in urgent need for efficient diagnosis of cardiac malfunction. Here we report that speckle tracking-based strain analysis is more sensitive than conventional echocardiography for early detection of pathological cardiac hypertrophy in the isoproterenol (ISO) mouse model. Pathological hypertrophy was induced by a single subcutaneous injection of ISO. Physiological cardiac hypertrophy was established by daily treadmill exercise for six weeks. Strain analysis, including radial strain (RS), radial strain rate (RSR) and longitudinal strain (LS), showed marked decrease as early as 3 days after ISO injection. Moreover, unlike the regional changes in cardiac infarction, strain analysis revealed global cardiac dysfunction that affects the entire heart in ISO-induced hypertrophy. In contrast, conventional echocardiography, only detected altered E/E’, an index reflecting cardiac diastolic function, at 7 days after ISO injection. No change was detected on fractional shortening (FS), E/A and E’/A’ at 3 days or 7 days after ISO injection. Interestingly, strain analysis revealed cardiac dysfunction only in ISO-induced pathological hypertrophy but not the physiological hypertrophy induced by exercise. Taken together, our study indicates that strain analysis offers a more sensitive approach for early detection of cardiac dysfunction than conventional echocardiography. Moreover, multiple strain readouts distinguish pathological cardiac hypertrophy from physiological hypertrophy. PMID:26871457

  5. Speckle Tracking Based Strain Analysis Is Sensitive for Early Detection of Pathological Cardiac Hypertrophy.

    PubMed

    An, Xiangbo; Wang, Jingjing; Li, Hao; Lu, Zhizhen; Bai, Yan; Xiao, Han; Zhang, Youyi; Song, Yao

    2016-01-01

    Cardiac hypertrophy is a key pathological process of many cardiac diseases. However, early detection of cardiac hypertrophy is difficult by the currently used non-invasive method and new approaches are in urgent need for efficient diagnosis of cardiac malfunction. Here we report that speckle tracking-based strain analysis is more sensitive than conventional echocardiography for early detection of pathological cardiac hypertrophy in the isoproterenol (ISO) mouse model. Pathological hypertrophy was induced by a single subcutaneous injection of ISO. Physiological cardiac hypertrophy was established by daily treadmill exercise for six weeks. Strain analysis, including radial strain (RS), radial strain rate (RSR) and longitudinal strain (LS), showed marked decrease as early as 3 days after ISO injection. Moreover, unlike the regional changes in cardiac infarction, strain analysis revealed global cardiac dysfunction that affects the entire heart in ISO-induced hypertrophy. In contrast, conventional echocardiography, only detected altered E/E', an index reflecting cardiac diastolic function, at 7 days after ISO injection. No change was detected on fractional shortening (FS), E/A and E'/A' at 3 days or 7 days after ISO injection. Interestingly, strain analysis revealed cardiac dysfunction only in ISO-induced pathological hypertrophy but not the physiological hypertrophy induced by exercise. Taken together, our study indicates that strain analysis offers a more sensitive approach for early detection of cardiac dysfunction than conventional echocardiography. Moreover, multiple strain readouts distinguish pathological cardiac hypertrophy from physiological hypertrophy.

  6. Toxicogenomics directory of chemically exposed human hepatocytes.

    PubMed

    Grinberg, Marianna; Stöber, Regina M; Edlund, Karolina; Rempel, Eugen; Godoy, Patricio; Reif, Raymond; Widera, Agata; Madjar, Katrin; Schmidt-Heck, Wolfgang; Marchan, Rosemarie; Sachinidis, Agapios; Spitkovsky, Dimitry; Hescheler, Jürgen; Carmo, Helena; Arbo, Marcelo D; van de Water, Bob; Wink, Steven; Vinken, Mathieu; Rogiers, Vera; Escher, Sylvia; Hardy, Barry; Mitic, Dragana; Myatt, Glenn; Waldmann, Tanja; Mardinoglu, Adil; Damm, Georg; Seehofer, Daniel; Nüssler, Andreas; Weiss, Thomas S; Oberemm, Axel; Lampen, Alfons; Schaap, Mirjam M; Luijten, Mirjam; van Steeg, Harry; Thasler, Wolfgang E; Kleinjans, Jos C S; Stierum, Rob H; Leist, Marcel; Rahnenführer, Jörg; Hengstler, Jan G

    2014-12-01

    A long-term goal of numerous research projects is to identify biomarkers for in vitro systems predicting toxicity in vivo. Often, transcriptomics data are used to identify candidates for further evaluation. However, a systematic directory summarizing key features of chemically influenced genes in human hepatocytes is not yet available. To bridge this gap, we used the Open TG-GATES database with Affymetrix files of cultivated human hepatocytes incubated with chemicals, further sets of gene array data with hepatocytes from human donors generated in this study, and publicly available genome-wide datasets of human liver tissue from patients with non-alcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular cancer (HCC). After a curation procedure, expression data of 143 chemicals were included into a comprehensive biostatistical analysis. The results are summarized in the publicly available toxicotranscriptomics directory ( http://wiki.toxbank.net/toxicogenomics-map/ ) which provides information for all genes whether they are up- or downregulated by chemicals and, if yes, by which compounds. The directory also informs about the following key features of chemically influenced genes: (1) Stereotypical stress response. When chemicals induce strong expression alterations, this usually includes a complex but highly reproducible pattern named 'stereotypical response.' On the other hand, more specific expression responses exist that are induced only by individual compounds or small numbers of compounds. The directory differentiates if the gene is part of the stereotypical stress response or if it represents a more specific reaction. (2) Liver disease-associated genes. Approximately 20 % of the genes influenced by chemicals are up- or downregulated, also in liver disease. Liver disease genes deregulated in cirrhosis, HCC, and NASH that overlap with genes of the aforementioned stereotypical chemical stress response include CYP3A7, normally expressed in fetal liver; the

  7. Mouse liver repopulation with hepatocytes generated from human fibroblasts

    PubMed Central

    Zhu, Saiyong; Rezvani, Milad; Harbell, Jack; Mattis, Aras N.; Wolfe, Alan R.; Benet, Leslie Z.; Willenbring, Holger; Ding, Sheng

    2014-01-01

    Human induced pluripotent stem cells (iPSCs) promise to revolutionize research and therapy of liver diseases by providing a source of hepatocytes for autologous cell therapy and disease modeling. However, despite progress in advancing the differentiation of iPSCs into hepatocytes (iPSC-Heps) in vitro1–3, cells that replicate the ability of human primary adult hepatocytes (aHeps) to proliferate extensively in vivo have not been reported. This deficiency has hampered efforts to recreate human liver diseases in mice, and has cast doubt on the potential of iPSC-Heps for liver cell therapy. The reason is that extensive post-transplant expansion is needed to establish and sustain a therapeutically effective liver cell mass in patients, a lesson learned from clinical trials of aHep transplantation4. As a solution to this problem, we report generation of human fibroblast-derived hepatocytes that can repopulate mouse livers. Unlike current protocols for deriving hepatocytes from human fibroblasts, ours did not generate iPSCs, but shortcut reprogramming to pluripotency to generate an induced multipotent progenitor cell (iMPC) state from which endoderm progenitor cells (iMPC-EPCs) and subsequently hepatocytes (iMPC-Heps) could be efficiently differentiated. For this, we identified small molecules that aided endoderm and hepatocyte differentiation without compromising proliferation. After transplantation into an immune-deficient mouse model of human liver failure, iMPC-Heps proliferated extensively and acquired levels of hepatocyte function similar to aHeps. Unfractionated iMPC-Heps did not form tumors, most likely because they never entered a pluripotent state. To our knowledge, this is the first demonstration of significant liver repopulation of mice with human hepatocytes generated in vitro, which removes a long-standing roadblock on the path to autologous liver cell therapy. PMID:24572354

  8. Genotoxicity of heterocyclic amines in the Salmonella/hepatocyte system.

    PubMed

    Hayashi, S; Møller, M E; Thorgeirsson, S S

    1985-09-01

    The Salmonella/hepatocyte system was employed to determine the mutagenicity in bacteria as well as the DNA damage induced in mouse hepatocytes following exposure to heterocyclic amines. With hepatocytes from C57BL/6N mice, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) showed a clear mutagenic effect in the Salmonella, while weak mutagenic effects were observed with 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 2-amino-6-methyldipyrido[1,2-a:3',2'-b]imidazole (Glu-P-1), and 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2). All the compounds induced low levels of DNA damage in the hepatocytes. In vivo pretreatment of mice with the potent monooxygenase inducer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 50 micrograms/kg) clearly increased both the mutagenicity in the bacteria and the DNA damage induced in the hepatocytes in vitro. Glu-P-2 showed the lowest mutagenic effect but induced more DNA damage at low concentrations than the other compounds when TCDD-pretreated hepatocytes were used. These data indicate that the genotoxic potency of Glu-P-2 in the intact hepatocyte differs from that observed in the bacteria. Treatment of hepatocytes with a-naphthoflavone, a selective inhibitor of polycyclic hydrocarbon-inducible cytochrome P-450 form(s), prior to exposure to the heterocyclic amines completely inhibited the mutagenic effect in the bacteria. In vivo administration of all the heterocyclic amines 4 hr prior to isolating the hepatocytes resulted in DNA damage, and this effect was augmented by TCDD pretreatment of mice. Our data suggest that agents modulating the activity and composition of the cytochrome P-450 system may greatly influence both toxicity and carcinogenicity of these heterocyclic amines.

  9. Antioxidative effect of a chymotrypsin inhibitor from Momordica cochinchinensis (Cucurbitaceae) seeds in a primary rat hepatocyte culture.

    PubMed

    Tsoi, Alex Yuen-Kam; Ng, Tzi-Bun; Fong, Wing-Ping

    2005-10-01

    The antioxidative activity of a chymotrypsin-specific potato type I inhibitor from Momordica cochinchinensis (MCoCI) (Cucurbitaceae) has been investigated using the primary rat hepatocyte system. tert-Butyl hydroperoxide (t-BHP) was used to induce oxidative stress. Pretreatment of hepatocytes with MCoCI for 24 h significantly reversed t-BHP-induced cell damage, and the associated glutathione depletion and lipid peroxidation. The activities of glutathione-S-transferase and superoxide dismutase were also increased. These results suggested that MCoCI possessed antioxidative activity which may account for some of the pharmacological effects of Momordica cochinchinensis seeds, the traditional Chinese medicine known as Mubiezhi, from which MCoCI was isolated. PMID:15849778

  10. Antioxidative effect of a chymotrypsin inhibitor from Momordica cochinchinensis (Cucurbitaceae) seeds in a primary rat hepatocyte culture.

    PubMed

    Tsoi, Alex Yuen-Kam; Ng, Tzi-Bun; Fong, Wing-Ping

    2005-10-01

    The antioxidative activity of a chymotrypsin-specific potato type I inhibitor from Momordica cochinchinensis (MCoCI) (Cucurbitaceae) has been investigated using the primary rat hepatocyte system. tert-Butyl hydroperoxide (t-BHP) was used to induce oxidative stress. Pretreatment of hepatocytes with MCoCI for 24 h significantly reversed t-BHP-induced cell damage, and the associated glutathione depletion and lipid peroxidation. The activities of glutathione-S-transferase and superoxide dismutase were also increased. These results suggested that MCoCI possessed antioxidative activity which may account for some of the pharmacological effects of Momordica cochinchinensis seeds, the traditional Chinese medicine known as Mubiezhi, from which MCoCI was isolated.

  11. Hypothermic storage of human hepatocytes for transplantation.

    PubMed

    Gramignoli, Roberto; Dorko, Kenneth; Tahan, Veysel; Skvorak, Kristen J; Ellis, Ewa; Jorns, Carl; Ericzon, Bo-Goran; Fox, Ira J; Strom, Stephen C

    2014-01-01

    Transplantation of human hepatocytes is gaining recognition as a bridge or an alternative to orthotopic liver transplantation for patients with acute liver failure and genetic defects. Since most patients require multiple cell infusions over an extended period of time, we investigated hepatic functions in cells maintained in University of Wisconsin solution at 4°C up to 72 h. Eleven different assessments of hepatic viability and function were investigated both pre- and posthypothermic storage, including plating efficiency, caspase-3/7 activity, ammonia metabolism, and drug-metabolizing capacity of isolated hepatocytes. Long-term function, basal, and induced cytochrome P450 activities were measured after exposure to prototypical inducing agents. Cells from 47 different human liver specimens were analyzed. Viability significantly decreased in cells cold stored in UW solution, while apoptosis level and plating efficiency were not significantly different from fresh cells. Luminescent and fluorescent methods assessed phases I and II activities both pre- and post-24-72 h of cold preservation. A robust induction (up to 200-fold) of phase I enzymes was observed in cultured cells. Phase II and ammonia metabolism remained stable during hypothermic storage, although the inductive effect of culture on each metabolic activity was eventually lost. Using techniques that characterize 11 measurements of hepatic viability and function from plating efficiency, to ammonia metabolism, to phases I and II drug metabolism, it was determined that while viability decreased, the remaining viable cells in cold-stored suspensions retained critical hepatic functions for up to 48 h at levels not significantly different from those observed in freshly isolated cells. PMID:23768881

  12. Vasectomy reversal.

    PubMed

    Belker, A M

    1987-02-01

    A vasovasostomy may be performed on an outpatient basis with local anesthesia, but also may be performed on an outpatient basis with epidural or general anesthesia. Local anesthesia is preferred by most of my patients, the majority of whom choose this technique. With proper preoperative and intraoperative sedation, patients sleep lightly through most of the procedure. Because of the length of time often required for bilateral microsurgical vasoepididymostomy, epidural or general anesthesia and overnight hospitalization are usually necessary. Factors influencing the preoperative choice for vasovasostomy or vasoepididymostomy in patients undergoing vasectomy reversal are considered. The preoperative planned choice of vasovasostomy or vasoepididymostomy for patients having vasectomy reversal described herein does not have the support of all urologists who regularly perform these procedures. My present approach has evolved as the data reported in Tables 1 and 2 have become available, but it may change as new information is evaluated. However, it offers a logical method for planning choices of anesthesia and inpatient or outpatient status for patients undergoing vasectomy reversal procedures. PMID:3811050

  13. Vasectomy reversal.

    PubMed

    Belker, A M

    1987-02-01

    A vasovasostomy may be performed on an outpatient basis with local anesthesia, but also may be performed on an outpatient basis with epidural or general anesthesia. Local anesthesia is preferred by most of my patients, the majority of whom choose this technique. With proper preoperative and intraoperative sedation, patients sleep lightly through most of the procedure. Because of the length of time often required for bilateral microsurgical vasoepididymostomy, epidural or general anesthesia and overnight hospitalization are usually necessary. Factors influencing the preoperative choice for vasovasostomy or vasoepididymostomy in patients undergoing vasectomy reversal are considered. The preoperative planned choice of vasovasostomy or vasoepididymostomy for patients having vasectomy reversal described herein does not have the support of all urologists who regularly perform these procedures. My present approach has evolved as the data reported in Tables 1 and 2 have become available, but it may change as new information is evaluated. However, it offers a logical method for planning choices of anesthesia and inpatient or outpatient status for patients undergoing vasectomy reversal procedures.

  14. Bi-modal dose-dependent cardiac response to tetrahydrobiopterin in pressure-overload induced hypertrophy and heart failure.

    PubMed

    Moens, An L; Ketner, Elizabeth A; Takimoto, Eiki; Schmidt, Tim S; O'Neill, Charles A; Wolin, Michael S; Alp, Nicholas J; Channon, Keith M; Kass, David A

    2011-10-01

    The exogenous administration of tetrahydrobiopterin (BH4), an essential cofactor of nitric oxide synthase (NOS), has been shown to reduce left ventricular hypertrophy, fibrosis, and cardiac dysfunction in mice with pre-established heart disease induced by pressure-overload. In this setting, BH4 re-coupled endothelial NOS (eNOS), with subsequent reduction of NOS-dependent oxidative stress and reversal of maladaptive remodeling. However, recent studies suggest the effective BH4 dosing may be narrower than previously thought, potentially due to its oxidation upon oral consumption. Accordingly, we assessed the dose response of daily oral synthetic sapropterin dihydrochloride (6-R-l-erythro-5,6,7,8-tetrahydrobiopterin, 6R-BH4) on pre-established pressure-overload cardiac disease. Mice (n=64) were administered 0-400mg/kg/d BH4 by ingesting small pre-made pellets (consumed over 15-30 min). In a dose range of 36-200mg/kg/d, 6R-BH4 suppressed cardiac chamber remodeling, hypertrophy, fibrosis, and oxidative stress with pressure-overload. However, at both lower and higher doses, BH4 had less or no ameliorative effects. The effective doses correlated with a higher myocardial BH4/BH2 ratio. However, BH2 rose linearly with dose, and at the 400mg/kg/d, this lowered the BH4/BH2 ratio back toward control. These results expose a potential limitation for the clinical use of BH4, as variability of cellular redox and perhaps heart disease could produce a variable therapeutic window among individuals. This article is part of a special issue entitled ''Key Signaling Molecules in Hypertrophy and Heart Failure.'' PMID:21645517

  15. Isolated muscle hypertrophy as a sign of radicular or peripheral nerve injury.

    PubMed Central

    Mattle, H P; Hess, C W; Ludin, H P; Mumenthaler, M

    1991-01-01

    Two patients with isolated neurogenic hypertrophy of the trapezius muscle due to accessory nerve injury and a patient with neurogenic hypertrophy of the anterior tibial muscle due to chronic radicular lesion L4 are described. Electromyography of the affected muscles showed dense continuing spontaneous discharges of complex potentials. Muscle biopsy performed in two patients showed abundant hypertrophic muscle fibres, identified in one case by ATP-ase reaction as being of predominantly type I. In the majority of previously reported patients with neurogenic muscle hypertrophy confined to the calf muscle, a passive stretch mechanism was suggested as a cause of the hypertrophy. It is assumed that the excessive spontaneous muscle activity gave rise to the hypertrophy in these patients. This may also be true in previously reported patients with neurogenic hypertrophy and similar spontaneous activity in electromyography. Images PMID:2056318

  16. Genotoxicity of chlorpyrifos and cypermethrin to ICR mouse hepatocytes.

    PubMed

    Cui, Yong; Guo, Jiangfeng; Xu, Bujin; Chen, Ziyuan

    2011-01-01

    Massive application of pesticides had generated a considerable concern in the public. Potentials of chlorpyrifos [O,O-diethyl-O-(3,5,6-trichloro-2-pyridinyl) phosphorothionate] and cypermethrin [(RS)-α-cyano-3-phenoxybenzyl (1RS)-cis-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] to induce the excision-repairable DNA damage, DNA strand breakage, and DNA hypomethylation in ICR mouse hepatocytes were investigated. It was showed that chlorpyrifos and cypermethrin didn't increase the incorporation of (3)H-TdR into DNA of ICR mouse hepatocytes but increased the frequency of comet cells and decreased the 5MeC percentage of ICR mouse hepatocytes. In conclusion, chlorpyrifos and cypermethrin induced no excision-repairable DNA damage but led to DNA strand breakage and DNA hypomethylation in ICR mouse hepatocytes.

  17. Lingual tonsil hypertrophy causing severe dysphagia: treatment with plasma-mediated radiofrequency-based ablation (Coblation).

    PubMed

    Mowry, Sarah E; Ament, Marvin; Shapiro, Nina L

    2010-03-01

    Lingual tonsil hypertrophy is an uncommon cause of upper aerodigestive tract pathology. We present the case of a 17-year-old boy who developed severe dysphagia and subsequent weight loss as a result of lingual tonsil hypertrophy. He was successfully treated with plasma-mediated radiofrequency-based ablation (Coblation). In the past, traditional surgical procedures for lingual tonsil hypertrophy were difficult to perform and recovery was difficult, but the introduction of Coblation has made lingual tonsillectomy much easier.

  18. Selumetinib, an Oral Anti-Neoplastic Drug, May Attenuate Cardiac Hypertrophy via Targeting the ERK Pathway

    PubMed Central

    Yang, Hao; Luo, Fangbo; Chen, Lihong; Cai, Huawei; Li, Yajiao; You, Guiying; Long, Dan; Li, Shengfu; Zhang, Qiuping; Rao, Li

    2016-01-01

    Aims Although extracellular-regulated kinases (ERK) are a well-known central mediator in cardiac hypertrophy, no clinically available ERK antagonist has been tested for preventing cardiac hypertrophy. Selumetinib is a novel oral MEK inhibitor that is currently under Phase II and Phase III clinical investigation for advanced solid tumors. In this study, we investigated whether Selumetinib could inhibit the aberrant ERK activation of the heart in response to stress as well as prevent cardiac hypertrophy. Methods and Results In an in vitro model of PE-induced cardiac hypertrophy, Selumetinib significantly inhibited the ERK activation and prevented enlargement of cardiomyocytes or reactivation of certain fetal genes. In the pathologic cardiac hypertrophy model of ascending aortic constriction, Selumetinib provided significant ERK inhibition in the stressed heart but not in the other organs. This selective ERK inhibition prevented left ventricular (LV) wall thickening, LV mass increase, fetal gene reactivation and cardiac fibrosis. In another distinct physiologic cardiac hypertrophy model of a swimming rat, Selumetinib provided a similar anti-hypertrophy effect, except that no significant fetal gene reactivation or cardiac fibrosis was observed. Conclusions Selumetinib, a novel oral anti-cancer drug with good safety records in a number of Phase II clinical trials, can inhibit ERK activity in the heart and prevent cardiac hypertrophy. These promising results indicate that Selumetinib could potentially be used to treat cardiac hypertrophy. However, this hypothesis needs to be validated in human clinical trials. PMID:27438013

  19. Perinatal deiodinase 2 expression in hepatocytes defines epigenetic susceptibility to liver steatosis and obesity.

    PubMed

    Fonseca, Tatiana L; Fernandes, Gustavo W; McAninch, Elizabeth A; Bocco, Barbara M L C; Abdalla, Sherine M; Ribeiro, Miriam O; Mohácsik, Petra; Fekete, Csaba; Li, Daofeng; Xing, Xiaoyun; Wang, Ting; Gereben, Balázs; Bianco, Antonio C

    2015-11-10

    Thyroid hormone binds to nuclear receptors and regulates gene transcription. Here we report that in mice, at around the first day of life, there is a transient surge in hepatocyte type 2 deiodinase (D2) that activates the prohormone thyroxine to the active hormone triiodothyronine, modifying the expression of ∼165 genes involved in broad aspects of hepatocyte function, including lipid metabolism. Hepatocyte-specific D2 inactivation (ALB-D2KO) is followed by a delay in neonatal expression of key lipid-related genes and a persistent reduction in peroxisome proliferator-activated receptor-γ expression. Notably, the absence of a neonatal D2 peak significantly modifies the baseline and long-term hepatic transcriptional response to a high-fat diet (HFD). Overall, changes in the expression of approximately 400 genes represent the HFD response in control animals toward the synthesis of fatty acids and triglycerides, whereas in ALB-D2KO animals, the response is limited to a very different set of only approximately 200 genes associated with reverse cholesterol transport and lipase activity. A whole genome methylation profile coupled to multiple analytical platforms indicate that 10-20% of these differences can be related to the presence of differentially methylated local regions mapped to sites of active/suppressed chromatin, thus qualifying as epigenetic modifications occurring as a result of neonatal D2 inactivation. The resulting phenotype of the adult ALB-D2KO mouse is dramatic, with greatly reduced susceptibility to diet-induced steatosis, hypertriglyceridemia, and obesity. PMID:26508642

  20. Perinatal deiodinase 2 expression in hepatocytes defines epigenetic susceptibility to liver steatosis and obesity

    PubMed Central

    Fonseca, Tatiana L.; Fernandes, Gustavo W.; McAninch, Elizabeth A.; Bocco, Barbara M. L. C.; Abdalla, Sherine M.; Ribeiro, Miriam O.; Mohácsik, Petra; Fekete, Csaba; Li, Daofeng; Xing, Xiaoyun; Wang, Ting; Gereben, Balázs; Bianco, Antonio C.

    2015-01-01

    Thyroid hormone binds to nuclear receptors and regulates gene transcription. Here we report that in mice, at around the first day of life, there is a transient surge in hepatocyte type 2 deiodinase (D2) that activates the prohormone thyroxine to the active hormone triiodothyronine, modifying the expression of ∼165 genes involved in broad aspects of hepatocyte function, including lipid metabolism. Hepatocyte-specific D2 inactivation (ALB-D2KO) is followed by a delay in neonatal expression of key lipid-related genes and a persistent reduction in peroxisome proliferator-activated receptor-γ expression. Notably, the absence of a neonatal D2 peak significantly modifies the baseline and long-term hepatic transcriptional response to a high-fat diet (HFD). Overall, changes in the expression of approximately 400 genes represent the HFD response in control animals toward the synthesis of fatty acids and triglycerides, whereas in ALB-D2KO animals, the response is limited to a very different set of only approximately 200 genes associated with reverse cholesterol transport and lipase activity. A whole genome methylation profile coupled to multiple analytical platforms indicate that 10–20% of these differences can be related to the presence of differentially methylated local regions mapped to sites of active/suppressed chromatin, thus qualifying as epigenetic modifications occurring as a result of neonatal D2 inactivation. The resulting phenotype of the adult ALB-D2KO mouse is dramatic, with greatly reduced susceptibility to diet-induced steatosis, hypertriglyceridemia, and obesity. PMID:26508642

  1. Hepatocyte turnover during resolution of a transient hepadnaviral infection

    PubMed Central

    Summers, Jesse; Jilbert, Allison R.; Yang, Wengang; Aldrich, Carol E.; Saputelli, Jeffry; Litwin, Samuel; Toll, Eugene; Mason, William S.

    2003-01-01

    We estimated the amount of hepatocyte turnover in the livers of three woodchucks undergoing clearance of a transient woodchuck hepatitis infection by determining the fate of integrated viral DNA as a genetic marker of the infected cell population. Integrated viral DNA was found to persist in liver tissue from recovered animals at essentially undiminished levels of 1 viral genome per 1,000–3,000 liver cells, suggesting that the hepatocytes in the recovered liver were derived primarily from the infected cell population. We determined the single and multicopy distribution of distinct viral cell junctions isolated from small pieces of liver after clearance of the infection to determine the cumulative amount of hepatocyte proliferation that had occurred during recovery. We estimated that proliferation was equivalent to a minimum of 0.7–1 complete random turnovers of the hepatocyte population of the liver. Our results indicated that during resolution of the transient infections a large fraction of the infected hepatocyte population was killed and replaced by hepatocyte cell division. PMID:14500915

  2. Salvianolate Protects Hepatocytes from Oxidative Stress by Attenuating Mitochondrial Injury

    PubMed Central

    Zhao, Qiang; Peng, Yuan; Huang, Kai; Lei, Yang; Liu, Hong-Liang; Tao, Yan-Yan

    2016-01-01

    Salvianolate is widely used to treat angiocardiopathy in clinic in China, but its application in liver diseases remains unclear. Our study aims to investigate the effect of Salvianolate on rat hepatic injury by protecting hepatocyte mitochondria. To evaluate the effects of Salvianolate on injured hepatocytes, alpha mouse liver 12 (AML-12) cells were induced with hydrogen peroxide (H2O2) and treated with Salvianolate. Cell viability and MitoTracker Green for mitochondria and 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazole-carbocyanide iodine (JC-1) levels and cytochrome C (Cyto-C) expressions were detected in vitro. To identify the effect of Salvianolate on protecting against mitochondria injury, male Wistar rats were injected with carbon tetrachloride (CCl4) and treated with Salvianolate (40 mg·kg−1). Serum liver function, parameters for peroxidative damage, hematoxylin and eosin (H&E) staining, and transmission electron microscope (TEM) of hepatocyte mitochondria were assayed. Our results showed that Salvianolate effectively protected hepatocytes, increased mitochondria vitality, and decreased Cyto-C expressions in vitro. Besides, Salvianolate alleviated the liver function, attenuated the indicators of peroxidation, and relieved the mitochondria injury in vivo. In conclusion, Salvianolate is effective in protecting hepatocytes from injury in vitro and in vivo, and the mechanism might be related to its protective effect on hepatocyte mitochondria against oxidative stress. PMID:27340417

  3. A Hedgehog Survival Pathway in ‘Undead’ Lipotoxic Hepatocytes

    PubMed Central

    Kakisaka, Keisuke; Cazanave, Sophie C.; Werneburg, Nathan W.; Razumilava, Nataliya; Mertens, Joachim C.; Bronk, Steve F.; Gores, Gregory J.

    2012-01-01

    Background & Aims Ballooned hepatocytes in nonalcoholic steatohepatitis (NASH) generate sonic hedgehog (SHH). This observation is consistent with a cellular phenotype in which the cell death program has been initiated but cannot be executed. Our aim was to determine if ballooned hepatocytes have potentially disabled the cell death execution machinery, and if so, can their functional biology be modeled in vitro. Methods Immunohistochemistry was performed on human NASH specimens. In vitro studies were performed using Huh-7 cells with shRNA targeted knockdown of caspase 9 (shC9 cells) or primary hepatocytes from caspase 3−/− mice. Results Ballooned hepatocytes in NASH display diminished expression of the caspase 9. This phenotype was modeled using shC9 cells; these cells were resistant to lipoapoptosis by palmitate (PA) or lysophosphatidylcholine (LPC) despite lipid droplet formation. During lipid loading by either PA or LPC, shC9 cells activate JNK which via AP-1 induces SHH expression. An autocrine hedgehog survival signaling pathway was further delineated in both shC9 and caspase 3−/− cells during lipotoxic stress. Conclusion Ballooned hepatocytes in NASH downregulate caspase 9, a pivotal caspase executing the mitochondrial pathway of apoptosis. Hepatocytes engineered to reduce caspase 9 expression are resistant to lipoapoptosis, in part, due to a hedgehog autocrine survival signaling pathway. PMID:22641094

  4. Hepatocyte apoptosis in dairy cattle during the transition period.

    PubMed

    Tharwat, Mohamed; Takamizawa, Aya; Hosaka, Yoshinao Z; Endoh, Daiji; Oikawa, Shin

    2012-10-01

    The objective of this study was to investigate hepatocyte apoptosis in dairy cows during the transition period. Four clinically healthy, pregnant dairy cattle were used. The cows had no clinical diseases throughout this study. Blood samples were collected and livers were biopsied from the cows at 3 different times: 3 weeks before expected partition (wk -3); during parturition (wk 0), and 3 weeks (wk +3) after parturition. The damage to deoxyribonucleic acid (DNA) caused by hepatocytes was evaluated by comet assay. The apoptotic features of hepatocytes were examined by immunohistochemistry and electron microscopic analyses. The hepatic triglyceride content markedly increased at wk 0 and wk +3 compared with the values at wk -3. The results of the comet assay showed increases in the mean tail moment values of hepatic cells after parturition in all cows, which suggested increased DNA damage. Histopathologically, the hepatocytes began to contain lipid droplets at wk 0 and were severely opacified at wk +3. Caspase-3-positive and single-stranded DNA-(ssDNA)-positive cells were first detected in the liver after parturition. Condensation of nuclear chromatin, a typical sign of apoptosis, was confirmed by transmission electron microscopy after parturition. These results suggest that apoptosis is induced in hepatocytes of dairy cows around parturition and may result from lipotoxicity in hepatocytes.

  5. Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy

    PubMed Central

    Lee, Yun-Sil; Lehar, Adam; Sebald, Suzanne; Liu, Min; Swaggart, Kayleigh A.; Talbot, C. Conover; Pytel, Peter; Barton, Elisabeth R.; McNally, Elizabeth M.; Lee, Se-Jin

    2015-01-01

    Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf−/−) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf−/− mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf−/− mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf−/− mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf−/− mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis. PMID:26206886

  6. Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy.

    PubMed

    Lee, Yun-Sil; Lehar, Adam; Sebald, Suzanne; Liu, Min; Swaggart, Kayleigh A; Talbot, C Conover; Pytel, Peter; Barton, Elisabeth R; McNally, Elizabeth M; Lee, Se-Jin

    2015-10-15

    Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf(-/-)) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf(-/-) mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf(-/-) mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf(-/-) mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf(-/-) mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis.

  7. Intermittent inspiratory muscle training induces fiber hypertrophy in rat diaphragm.

    PubMed

    Bisschop, A; Gayan-Ramirez, G; Rollier, H; Gosselink, R; Dom, R; de Bock, V; Decramer, M

    1997-05-01

    The effects of 8 wk of moderate load intermittent inspiratory resistive loading on diaphragm contractility, and histochemistry of the diaphragm, scalenes, and gastrocnemius were studied in rats. A resistance was placed in the inspiratory port of a Hans-Rudolph valve, through which each animal breathed during 30 min/d, 5 times/wk (loaded group, n = 10). These rats were compared with animals breathing through the same device without inspiratory resistance (control group, n = 10). During loading, animals generated mean inspiratory pressures of -3.2 +/- 1.7 cm H2O with a TI/Ttot of 0.69 +/- 0.06, resulting in a tension-time index of 0.050. At the end of training, the diaphragm mass increased in loaded animals (0.17 +/- 0.01% body mass) compared with control animals (0.15 +/- 0.01%, p < 0.01), while scalene and gastrocnemius mass remained unchanged. Diaphragmatic force as well as fatigue resistance were similar in both groups, whereas time to peak tension was significantly (p < 0.01) shorter in loaded rats (18.8 +/- 1.7 ms) compared with control rats (21.2 +/- 1.8 ms), half-relaxation time remaining unchanged. Finally, hypertrophy of diaphragmatic type IIa (+19%, p < 0.01) and IIx/b (+12%, p < 0.05) was present in the loaded group. Histochemistry of the scalenes remained unchanged, whereas type IIx/b hypertrophy (+12%, p < 0.001) was observed in the gastrocnemius internus. We speculate that the latter was due to multiple escape maneuvers. We conclude that intermittent inspiratory muscle training: (1) caused fast twitch fiber hypertrophy in the diaphragm; (2) did not produce any effect in the scalenes. PMID:9154861

  8. Monomelic muscle hypertrophy following transient ischemic attacks: a case report.

    PubMed

    Isaacs, E R; Larson, P

    1978-01-01

    A 39-year-old right-handed male suffered several episodes of transient right-sided weakness, sensory loss, and Broca's aphasia at age 31. Diagnostic studies failed to demonstrate any cause for these events. Following a complete recovery, he noted the onset of stiffness and increasing muscle bulk in his right arm, which gradually restricted its use. Simultaneous recordings from contracting biceps and triceps muscles in both arms suggested that the hypertrophy was physiologically induced by an abnormal mechanism providing resistance during phasing activity. PMID:750924

  9. Nonalcoholic Lipid Accumulation and Hepatocyte Malignant Transformation

    PubMed Central

    Gu, Juanjuan; Yao, Min; Yao, Dengbing; Wang, Li; Yang, Xuli; Yao, Dengfu

    2016-01-01

    Abstract Worldwide incidence of hepatocellular carcinoma (HCC) is steadily increasing, highlighting its status as a public health concern, particularly due to its significant association with other comorbidities, such as diabetes. However, nonalcoholic fatty liver disease (NAFLD) has emerged as a primary risk factor, with its own prevalence increasing in recent years, and it has gradually caught up with the historical primary etiological factors of infection with hepatitis B virus and hepatitis C virus, exposure to aflatoxin, or alcohol liver disease. The deeply worrisome aspects of all of these high risk factors, however, are their remarkable presence within populations. Systemic and genetic mechanisms involved in the malignant transformation of liver cells, as well as useful biomarkers of early stage HCC are being investigated. However, the exact mechanisms underlying the interrelation of NAFLD and HCC remain largely unknown. In this review, some of the recent advances in our understanding of liver lipid accumulation are summarized and discussed to provide insights into the relationship between NAFLD and hepatocyte malignant transformation. PMID:27350942

  10. Thyroid hormone effect in human hepatocytes.

    PubMed

    Miler, Eliana A; Ríos de Molina, María Del Carmen; Domínguez, Gabriela; Guerra, Liliana N

    2008-01-01

    We have already demonstrated that a combined treatment of methimazole and an antioxidant mixture improved the condition of hyperthyroid patients both biochemically and clinically. Elevated thyroid hormone levels might trigger signs and symptoms of hyperthyroidism through the increase of free radicals. To study the direct effect of thyroid hormone on cellular markers of oxidative stress, we carried out in vitro assays in which 0.1-20.0 nM T3 (6.5-1300.0 ng/dl) doses were added to culture media of the human hepatocyte cell line Hep G2 for 1-24 h. T3 increased malondialdehyde (MDA) and intracellular oxidized glutathione (GSSG) levels; SOD activity was also higher with hormone treatment, whereas catalase and glutathione peroxidase activities showed no variation at different T3 doses and during all experimental times. When ascorbic acid was added to the culture, the MDA level decreased and SOD activity was increased. With higher doses of T3 (e.g. 200 nM), cell death occurred (69% of apoptotic cells). The increase in SOD activity was not enough to overcome the effect of T3 since MDA and GSSG remained high during a 24-h experiment. We showed a beneficial effect of ascorbic acid when cells were exposed to a T3 dose of 20 nM, a higher level of hormone than that achieved in hyperthyroidism. PMID:18647489

  11. Resetting the transcription factor network reverses terminal chronic hepatic failure.

    PubMed

    Nishikawa, Taichiro; Bell, Aaron; Brooks, Jenna M; Setoyama, Kentaro; Melis, Marta; Han, Bing; Fukumitsu, Ken; Handa, Kan; Tian, Jianmin; Kaestner, Klaus H; Vodovotz, Yoram; Locker, Joseph; Soto-Gutierrez, Alejandro; Fox, Ira J

    2015-04-01

    The cause of organ failure is enigmatic for many degenerative diseases, including end-stage liver disease. Here, using a CCl4-induced rat model of irreversible and fatal hepatic failure, which also exhibits terminal changes in the extracellular matrix, we demonstrated that chronic injury stably reprograms the critical balance of transcription factors and that diseased and dedifferentiated cells can be returned to normal function by re-expression of critical transcription factors, a process similar to the type of reprogramming that induces somatic cells to become pluripotent or to change their cell lineage. Forced re-expression of the transcription factor HNF4α induced expression of the other hepatocyte-expressed transcription factors; restored functionality in terminally diseased hepatocytes isolated from CCl4-treated rats; and rapidly reversed fatal liver failure in CCl4-treated animals by restoring diseased hepatocytes rather than replacing them with new hepatocytes or stem cells. Together, the results of our study indicate that disruption of the transcription factor network and cellular dedifferentiation likely mediate terminal liver failure and suggest reinstatement of this network has therapeutic potential for correcting organ failure without cell replacement.

  12. Peroxisome proliferator-activated receptor alpha acts as a mediator of endoplasmic reticulum stress-induced hepatocyte apoptosis in acute liver failure

    PubMed Central

    Zhang, Li; Ren, Feng; Zhang, Xiangying; Wang, Xinxin; Shi, Hongbo; Zhou, Li; Zheng, Sujun; Chen, Yu; Chen, Dexi; Li, Liying; Duan, Zhongping

    2016-01-01

    ABSTRACT Peroxisome proliferator-activated receptor α (PPARα) is a key regulator to ameliorate liver injury in cases of acute liver failure (ALF). However, its regulatory mechanisms remain largely undetermined. Endoplasmic reticulum stress (ER stress) plays an important role in a number of liver diseases. This study aimed to investigate whether PPARα activation inhibits ER stress-induced hepatocyte apoptosis, thereby protecting against ALF. In a murine model of D-galactosamine (D-GalN)- and lipopolysaccharide (LPS)-induced ALF, Wy-14643 was administered to activate PPARα, and 4-phenylbutyric acid (4-PBA) was administered to attenuate ER stress. PPARα activation ameliorated liver injury, because pre-administration of its specific inducer, Wy-14643, reduced the serum aminotransferase levels and preserved liver architecture compared with that of controls. The protective effect of PPARα activation resulted from the suppression of ER stress-induced hepatocyte apoptosis. Indeed, (1) PPARα activation decreased the expression of glucose-regulated protein 78 (Grp78), Grp94 and C/EBP-homologous protein (CHOP) in vivo; (2) the liver protection by 4-PBA resulted from the induction of PPARα expression, as 4-PBA pre-treatment promoted upregulation of PPARα, and inhibition of PPARα by small interfering RNA (siRNA) treatment reversed liver protection and increased hepatocyte apoptosis; (3) in vitro PPARα activation by Wy-14643 decreased hepatocyte apoptosis induced by severe ER stress, and PPARα inhibition by siRNA treatment decreased the hepatocyte survival induced by mild ER stress. Here, we demonstrate that PPARα activation contributes to liver protection and decreases hepatocyte apoptosis in ALF, particularly through regulating ER stress. Therefore, targeting PPARα could be a potential therapeutic strategy to ameliorate ALF. PMID:27482818

  13. Insulin B chain 9-23 gene transfer to hepatocytes protects from type 1 diabetes by inducing Ag-specific FoxP3+ Tregs.

    PubMed

    Akbarpour, Mahzad; Goudy, Kevin S; Cantore, Alessio; Russo, Fabio; Sanvito, Francesca; Naldini, Luigi; Annoni, Andrea; Roncarolo, Maria Grazia

    2015-05-27

    Antigen (Ag)-specific tolerance in type 1 diabetes (T1D) in human has not been achieved yet. Targeting lentiviral vector (LV)-mediated gene expression to hepatocytes induces active tolerance toward the encoded Ag. The insulin B chain 9-23 (InsB9-23) is an immunodominant T cell epitope in nonobese diabetic (NOD) mice. To determine whether auto-Ag gene transfer to hepatocytes induces tolerance and control of T1D, NOD mice were treated with integrase-competent LVs (ICLVs) that selectively target the expression of InsB9-23 to hepatocytes. ICLV treatment induced InsB9-23-specific effector T cells but also FoxP3(+) regulatory T cells (Tregs), which halted islet immune cell infiltration, and protected from T1D. Moreover, ICLV treatment combined with a single suboptimal dose of anti-CD3 monoclonal antibody (mAb) is effective in T1D reversal. Splenocytes from LV.InsB9-23-treated mice, but not from LV.OVA (ovalbumin)-treated control mice, stopped diabetes development, demonstrating that protection is Ag-specific. Depletion of CD4(+)CD25(+)FoxP3(+) T cells led to diabetes progression, indicating that Ag-specific FoxP3(+) Tregs mediate protection. Integrase-defective LVs (IDLVs).InsB9-23, which alleviate the concerns for insertional mutagenesis and support transient transgene expression in hepatocytes, were also efficient in protecting from T1D. These data demonstrate that hepatocyte-targeted auto-Ag gene expression prevents and resolves T1D and that stable integration of the transgene is not required for this protection. Gene transfer to hepatocytes can be used to induce Ag-specific tolerance in autoimmune diseases.

  14. Peroxisome proliferator-activated receptor alpha acts as a mediator of endoplasmic reticulum stress-induced hepatocyte apoptosis in acute liver failure.

    PubMed

    Zhang, Li; Ren, Feng; Zhang, Xiangying; Wang, Xinxin; Shi, Hongbo; Zhou, Li; Zheng, Sujun; Chen, Yu; Chen, Dexi; Li, Liying; Zhao, Caiyan; Duan, Zhongping

    2016-07-01

    Peroxisome proliferator-activated receptor α (PPARα) is a key regulator to ameliorate liver injury in cases of acute liver failure (ALF). However, its regulatory mechanisms remain largely undetermined. Endoplasmic reticulum stress (ER stress) plays an important role in a number of liver diseases. This study aimed to investigate whether PPARα activation inhibits ER stress-induced hepatocyte apoptosis, thereby protecting against ALF. In a murine model of D-galactosamine (D-GalN)- and lipopolysaccharide (LPS)-induced ALF, Wy-14643 was administered to activate PPARα, and 4-phenylbutyric acid (4-PBA) was administered to attenuate ER stress. PPARα activation ameliorated liver injury, because pre-administration of its specific inducer, Wy-14643, reduced the serum aminotransferase levels and preserved liver architecture compared with that of controls. The protective effect of PPARα activation resulted from the suppression of ER stress-induced hepatocyte apoptosis. Indeed, (1) PPARα activation decreased the expression of glucose-regulated protein 78 (Grp78), Grp94 and C/EBP-homologous protein (CHOP) in vivo; (2) the liver protection by 4-PBA resulted from the induction of PPARα expression, as 4-PBA pre-treatment promoted upregulation of PPARα, and inhibition of PPARα by small interfering RNA (siRNA) treatment reversed liver protection and increased hepatocyte apoptosis; (3) in vitro PPARα activation by Wy-14643 decreased hepatocyte apoptosis induced by severe ER stress, and PPARα inhibition by siRNA treatment decreased the hepatocyte survival induced by mild ER stress. Here, we demonstrate that PPARα activation contributes to liver protection and decreases hepatocyte apoptosis in ALF, particularly through regulating ER stress. Therefore, targeting PPARα could be a potential therapeutic strategy to ameliorate ALF. PMID:27482818

  15. Genetic abolishment of hepatocyte proliferation activates hepatic stem cells.

    PubMed

    Endo, Yoko; Zhang, Mingjun; Yamaji, Sachie; Cang, Yong

    2012-01-01

    Quiescent hepatic stem cells (HSCs) can be activated when hepatocyte proliferation is compromised. Chemical injury rodent models have been widely used to study the localization, biomarkers, and signaling pathways in HSCs, but these models usually exhibit severe promiscuous toxicity and fail to distinguish damaged and non-damaged cells. Our goal is to establish new animal models to overcome these limitations, thereby providing new insights into HSC biology and application. We generated mutant mice with constitutive or inducible deletion of Damaged DNA Binding protein 1 (DDB1), an E3 ubiquitin ligase, in hepatocytes. We characterized the molecular mechanism underlying the compensatory activation and the properties of oval cells (OCs) by methods of mouse genetics, immuno-staining, cell transplantation and gene expression profiling. We show that deletion of DDB1 abolishes self-renewal capacity of mouse hepatocytes in vivo, leading to compensatory activation and proliferation of DDB1-expressing OCs. Partially restoring proliferation of DDB1-deficient hepatocytes by ablation of p21, a substrate of DDB1 E3 ligase, alleviates OC proliferation. Purified OCs express both hepatocyte and cholangiocyte markers, form colonies in vitro, and differentiate to hepatocytes after transplantation. Importantly, the DDB1 mutant mice exhibit very minor liver damage, compared to a chemical injury model. Microarray analysis reveals several previously unrecognized markers, including Reelin, enriched in oval cells. Here we report a genetic model in which irreversible inhibition of hepatocyte duplication results in HSC-driven liver regeneration. The DDB1 mutant mice can be broadly applied to studies of HSC differentiation, HSC niche and HSCs as origin of liver cancer. PMID:22384083

  16. Role of macrophages in the immune response to hepatocytes

    SciTech Connect

    Bumgardner, G.L.; Chen, S.; Almond, S.P.; Ascher, N.L.; Payne, W.D.; Matas, A.J. )

    1990-06-01

    The purpose of this study was to determine the role of host macrophages in the development of allospecific cytolytic T cells (allo-CTLs) in response to purified allogeneic MHC Class I+, Class II- hepatocytes in vivo in hepatocyte sponge matrix allografts (HC-SMA). Depletion of antigen-presenting cells (APCs) from responder splenocytes in mixed lymphocyte hepatocyte culture (MLHC) inhibits the development of allo-CTLs in response to purified hepatocytes. First the ability of sponge macrophages to function as accessory cells in indirect presentation of hepatocyte Class I antigen was tested in MLHC. We found that addition of irradiated sponge cells (a source of sponge macrophages) restored the development of allo-CTLs in MLHC depleted of responder APCs. Therefore, radioresistant sponge macrophages can function as accessory cells in MLHC. We next employed silica as an immunotherapy targeted against host macrophages and assessed the effect on development of allo-CTLs in HC-SMA. We found that local (intrasponge) silica treatment completely inhibited the development of allo-CTLs in HC-SMA. Combined local and systemic silica treatment resulted in inhibition of allocytotoxicity comparable to local silica treatment alone in the doses tested. We conclude that host macrophages which infiltrate HC-SMA can function as accessory cells in vitro in MLHC and that both infiltrating host macrophages and lymphocytes participate in the development of an alloimmune response to purified hepatocytes in vivo. This interaction may involve indirect antigen presentation of hepatocyte Class I antigen by macrophages to host lymphocytes which accumulate in HC-SMA.

  17. Prolonged ER Stressed-Hepatocytes drives an Alternative Macrophage Polarization

    PubMed Central

    Xiu, Fangming; Catapano, Michael; Diao, Li; Stanojcic, Mile; Jeschke, Marc G.

    2015-01-01

    Relatively little is known about the effects of hepatocytes on hepatic macrophages, particularly under the situation of endoplasmic reticulum (ER) stress. We examined the effects of hepatocytes conditioned media (CM) from HepG2 treated with ER stress inducers, Tunicamycin (TM) or Thapsigargin (TG), on the secretion of cytokines, expression of ER stress markers and polarization of PMA activated THP-1 cells (pTHP-1). We found that CM decreased the production of the pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and interleukin (IL)-1β as well as other cytokines and chemokines from pTHP-1 cells. These effects are mediated by the inhibition of TLR4 expression and NF-κB signaling pathway. In addition, hepatocytes CM increased the expression of binding immunoglobulin protein (BiP) and the transcription factor C/EBP homologous protein (CHOP) in pTHP-1 cells. Preconditioning with ER stress inhibitor, small molecular chaperone 4-phenylbutyrate (PBA) before addition of ER stressors, attenuated the ER stress in macrophages, the property of hepatocytes CM to alter TNF-α production and NF-κB expression by macrophages. Remarkably, treatment of macrophage with these CM leads to an alternative activation of macrophages mediated by peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling pathway, which might be resulted from the secretion of IL-10 and IL-4 as well as releasing apoptotic bodies from hepatocytes under ER stress. Our results highlight a mechanism of ER stress transmission from hepatocytes to macrophage that drives an alternative activation of macrophages, which depends on the exposure of hepatocytes to severe and prolonged ER stress. PMID:25944791

  18. Hepatocyte behavior within three-dimensional porous alginate scaffolds.

    PubMed

    Glicklis, R; Shapiro, L; Agbaria, R; Merchuk, J C; Cohen, S

    2000-02-01

    A potential approach to facilitate the performance of implanted hepatocytes is to enable their aggregation and re-expression of their differentiated function prior to implantation. Here we examined the behavior of freshly isolated rat adult hepatocytes seeded within a novel three-dimensional (3-D) scaffold based on alginate. The attractive features of this scaffold include a highly porous structure (sponge-like) with interconnecting pores, and pore sizes with diameters of 100-150 microm. Due to their hydrophilic nature, seeding hepatocytes onto the alginate sponges was efficient. DNA measurements showed that the total cell number within the sponges did not change over 2 weeks, indicating that hepatocytes do not proliferate under these culture conditions. Nearly all seeded cells maintained viability, according to the MTT assay. Within 24 h post-seeding, small clusters of viable cells, were seen scattered within the sponge. More than 90% of the seeded cells participated in the aggregation; the high efficiency is attributed to the non-adherent nature of alginate. The spheroids had smooth boundaries and by day 4 in culture reached an average diameter of 100 microm, which is at the same magnitude of the sponge pore size. The cells appeared to synthesize fibronectin which was deposited on the spheroids. No laminin or collagen type IV were detected in the deposit. The 3-D arrangement of hepatocytes within the alginate sponges promoted their functional expression; within a week the cells secreted the maximal albumin secretion rate of 60 microg albumin/10(6) cells/day. Urea secretion rate did not depend on cell aggregation and was similar to that obtained when hepatocytes were cultured on collagen type I coated dishes (100 microg/10(6) cells/day). Our studies show that alginate sponges can provide a conducive environment to facilitate the performance of cultured hepatocytes by enhancing their aggregation.

  19. Water and nonelectrolyte permeability of isolated rat hepatocytes

    SciTech Connect

    Alpini, G.; Garrick, R.A.; Jones, M.J.; Nunes, R.; Tavoloni, N.

    1986-12-01

    We have measured the diffusive permeability coefficients of isolated rat hepatocytes to /sup 3/H/sub 2/O, (/sup 14/C)urea, (/sup 14/C)erythritol, (/sup 14/C)mannitol, (/sup 3/H)sucrose, and (/sup 3/H)inulin, employing a technique previously developed for erythrocytes (Redwood et al., J. Gen. Physiol 64:706-729, 1974). Diffusion coefficients for the tracer molecules were measured in packed hepatocytes, supernatant fluid, and intracellular medium (lysed hepatocytes) and were calculated assuming one-dimensional semi-infinite diffusion through a homogeneous medium. By applying the series-parallel pathway model, the following permeability coefficients (10(-5) cm/sec) for the hepatocyte plasma membrane were obtained. /sup 3/H/sub 2/O, 98.6 +/- 18.4; (/sup 14/C)urea, 18.2 +/- 5.3; (/sup 14/C)erythritol, 4.8 +/- 1.6; (/sup 14/C)mannitol, 3.1 +/- 1.4; (/sup 3/H)sucrose, 0; (/sup 3/H)inulin, 0. These results indicate that isolated rat hepatocytes are highly permeable to water and polar nonelectrolytes, when compared with other transporting epithelia. This relatively high cellular permeability is consistent with a model in which nonelectrolyte permeation is via an aqueous pathway of equivalent pore diameter of 8-12 A. The finding that (/sup 14/C)erythritol and (/sup 14/C)mannitol cross the hepatocyte plasma membrane indicates that these molecules enter the bile canaliculus through the transcellular route. Conversely, the failure of (/sup 3/H)sucrose and (/sup 3/H)inulin to permeate the hepatocyte in the isolated condition supports the concept that biliary entry of these large carbohydrates, at least that fraction which cannot be accounted for by a vesicular mechanism, must occur via the transjunctional shunt pathway.

  20. Keratin 8 modulation of desmoplakin deposition at desmosomes in hepatocytes.

    PubMed

    Loranger, Anne; Gilbert, Stéphane; Brouard, Jean-Simon; Magin, Thomas M; Marceau, Normand

    2006-12-10

    Keratins, the intermediate filament proteins of epithelial cells, connect to desmosomes, the cell-cell adhesion structures at the surface membrane. The building elements of desmosomes include desmoglein and desmocollin, which provide the actual cell adhesive properties, and desmoplakins, which anchor the keratin intermediate filaments to desmosomes. In the work reported here, we address the role of keratin 8 in modulating desmoplakin deposition at surface membrane in mouse hepatocytes. The experimental approach is based on the use of keratin 8- and keratin 18-null mouse hepatocytes as cell models. In wild-type mouse hepatocytes, desmoplakin is aligned with desmoglein and keratin 8 at the surface membrane. In keratin 8-null hepatocytes, the intermediate filament loss leads to alterations in desmoplakin distribution at the surface membrane, but not of desmoglein. Intriguingly, a significant proportion of keratin 18-null hepatocytes express keratin 8 at the surface membrane, associated with a proper desmoplakin alignment with desmoglein at desmosomes. A Triton treatment of the monolayer reveals that most of the desmoplakin present in either wild-type, keratin 8- or keratin 18-null hepatocytes is insoluble. Deletion analysis of keratin 8 further suggests that the recovery of desmoplakin alignment requires the keratin 8 rod domain. In addition, similarly to other works revealing a key role of desmoplakin phosphorylation on its interaction with intermediate filaments, we find that the phosphorylation status of the keratin 8 head domain affects desmoplakin distribution at desmosomes. Together, the data indicate that a proper alignment/deposition of desmoplakin with keratins and desmoglein in hepatocytes requires keratin 8, through a reciprocal phosphoserine-dependent process.

  1. Does the ADMA/DDAH/NO pathway modulate early regression of left ventricular hypertrophy with esmolol?

    PubMed

    Quintana-Villamandos, Begoña; Delgado-Baeza, Emilio

    2016-02-01

    Hypertensive left ventricular hypertrophy (LVH) is a maladaptive response to chronic pressure overload and a strong independent risk factor for cardiovascular disease. Regression of LVH is associated with improved prognosis. Regression of LVH with antihypertensive therapy (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, calcium channel blockers, and diuretics) has been reported, although only after long-term treatment. Asymmetrical dimethylarginine (ADMA), the most potent endogenous NO synthase inhibitor, is emerging as an important cardiovascular risk factor in patients with arterial hypertension and LVH, and dimethylarginine dimethylaminohydrolase (DDAH) is the mechanism that most frequently leads to accumulation of ADMA (plasma ADMA is cleared in small part by renal excretion, although the bulk of ADMA is degraded by DDAH). Left ventricular mass is strongly modulated by the NO system. As an important inhibitor of the bioavailability of NO, ADMA is an underlying mechanism of LVH. Beta-blockers can induce regression of LVH and reduced plasma ADMA levels. Oxidative stress is increased in patients with LVH, and this in turn increases generation of ADMA. In a previous preclinical study of spontaneously hypertensive rats, we found that short-term treatment (48 h) with esmolol reverses early LVH, increases the bioavailability of NO, and improves antioxidant status in plasma. Therefore, we propose that the ADMA/DDAH/NO pathway could modulate early regression of LVH with esmolol. PMID:26826640

  2. cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

    SciTech Connect

    Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found

  3. Connective tissue growth factor induces cardiac hypertrophy through Akt signaling

    SciTech Connect

    Hayata, Nozomi; Fujio, Yasushi; Yamamoto, Yasuhiro; Iwakura, Tomohiko; Obana, Masanori; Takai, Mika; Mohri, Tomomi; Nonen, Shinpei; Maeda, Makiko; Azuma, Junichi

    2008-05-30

    In the process of cardiac remodeling, connective tissue growth factor (CTGF/CCN2) is secreted from cardiac myocytes. Though CTGF is well known to promote fibroblast proliferation, its pathophysiological effects in cardiac myocytes remain to be elucidated. In this study, we examined the biological effects of CTGF in rat neonatal cardiomyocytes. Cardiac myocytes stimulated with full length CTGF and its C-terminal region peptide showed the increase in cell surface area. Similar to hypertrophic ligands for G-protein coupled receptors, such as endothelin-1, CTGF activated amino acid uptake; however, CTGF-induced hypertrophy is not associated with the increased expression of skeletal actin or BNP, analyzed by Northern-blotting. CTGF treatment activated ERK1/2, p38 MAPK, JNK and Akt. The inhibition of Akt by transducing dominant-negative Akt abrogated CTGF-mediated increase in cell size, while the inhibition of MAP kinases did not affect the cardiac hypertrophy. These findings indicate that CTGF is a novel hypertrophic factor in cardiac myocytes.

  4. The role of frataxin in doxorubicin-mediated cardiac hypertrophy.

    PubMed

    Mouli, Shravanthi; Nanayakkara, Gayani; AlAlasmari, Abdullah; Eldoumani, Haitham; Fu, Xiaoyu; Berlin, Avery; Lohani, Madhukar; Nie, Ben; Arnold, Robert D; Kavazis, Andreas; Smith, Forrest; Beyers, Ronald; Denney, Thomas; Dhanasekaran, Muralikrishnan; Zhong, Juming; Quindry, John; Amin, Rajesh

    2015-09-01

    Doxorubicin (DOX) is a highly effective anti-neoplastic agent; however, its cumulative dosing schedules are clinically limited by the development of cardiotoxicity. Previous studies have attributed the cause of DOX-mediated cardiotoxicity to mitochondrial iron accumulation and the ensuing reactive oxygen species (ROS) formation. The present study investigates the role of frataxin (FXN), a mitochondrial iron-sulfur biogenesis protein, and its role in development of DOX-mediated mitochondrial dysfunction. Athymic mice treated with DOX (5 mg/kg, 1 dose/wk with treatments, followed by 2-wk recovery) displayed left ventricular hypertrophy, as observed by impaired cardiac hemodynamic performance parameters. Furthermore, we also observed significant reduction in FXN expression in DOX-treated animals and H9C2 cardiomyoblast cell lines, resulting in increased mitochondrial iron accumulation and the ensuing ROS formation. This observation was paralleled in DOX-treated H9C2 cells by a significant reduction in the mitochondrial bioenergetics, as observed by the reduction of myocardial energy regulation. Surprisingly, similar results were observed in our FXN knockdown stable cell lines constructed by lentiviral technology using short hairpin RNA. To better understand the cardioprotective role of FXN against DOX, we constructed FXN overexpressing cardiomyoblasts, which displayed cardioprotection against mitochondrial iron accumulation, ROS formation, and reduction of mitochondrial bioenergetics. Lastly, our FXN overexpressing cardiomyoblasts were protected from DOX-mediated cardiac hypertrophy. Together, our findings reveal novel insights into the development of DOX-mediated cardiomyopathy. PMID:26209053

  5. Noninvasive evaluation of ventricular hypertrophy in professional athletes.

    PubMed

    Roeske, W R; O'Rourke, R A; Klein, A; Leopold, G; Karliner, J S

    1976-02-01

    Athletes often exhibit ECG findings which are considered to be abnormal. Therefore, we used noninvasive graphic methods to study 42 active professional male basketball players, ranging in age from 21 to 31 years, without clinically evident heart disease. Of the 42, 11 (25%) met the Romhilt-Estes ECG voltage criteria for left ventricular hypertrophy, and 12 (29%) satisfied VCG criteria for left ventricular enlargement; nine (21%) had left ventricular hypertrophy by both methods. In 33 subjects (79%) the 0.04 sec vector in the horizontal plane was anterior, and 29 of these exhibited one or more standard criteria for right ventricular enlargement; the ECG and VCG were concordant for right ventricular hypertrophy in 16 subjects (38%). Submaximal treadmill exercise tests (Bruce protocol) were normal in eight athletes, while in one subject ventricular premature beats occurred during the test. In 24 of 25 athletes (96%) from whom phonocardiograms were obtained a third heart sound was recorded, while in 14 (56%), a fourth heart sound was present. Of the 14 athletes who had a fourth heart sound, 12 (86%) had either ECG or VCG evidence of ventricular hypertrophy. Only four of 23 athletes had an increased cardiothoracic ratio (greater than .50) on routine chest X-ray. Ten athletes and ten control subjects matched for height, weight and body surface area had echocardiograms satisfactory for analysis. The left ventricular end-diastolic dimension in the athletes averaged 53.7 +/- 1.3 (SE) mm compared with a value of 49.9 +/- 0.7 mm in the control subjects (P less than 0.02), and was increased (greater than or equal to 56 mm) in four. Left ventricular posterior wall thickness averaged 11.1 +/- 0.6 mm, compared with a value of 9.8 +/- 0.5 mm in the control subjects (P less than 0.05), and was increased (greater than or equal to 11 mm) in six athletes. The right ventricular end-diastolic dimension averaged 20.8 +/- 1.1 mm compared with a value of 12.9 +/- 2.2 mm in the controls (P

  6. Inhibition of Receptor Interacting Protein Kinases Attenuates Cardiomyocyte Hypertrophy Induced by Palmitic Acid.

    PubMed

    Zhao, Mingyue; Lu, Lihui; Lei, Song; Chai, Hua; Wu, Siyuan; Tang, Xiaoju; Bao, Qinxue; Chen, Li; Wu, Wenchao; Liu, Xiaojing

    2016-01-01

    Palmitic acid (PA) is known to cause cardiomyocyte dysfunction. Cardiac hypertrophy is one of the important pathological features of PA-induced lipotoxicity, but the mechanism by which PA induces cardiomyocyte hypertrophy is still unclear. Therefore, our study was to test whether necroptosis, a receptor interacting protein kinase 1 and 3 (RIPK1 and RIPK3-) dependent programmed necrosis, was involved in the PA-induced cardiomyocyte hypertrophy. We used the PA-treated primary neonatal rat cardiac myocytes (NCMs) or H9c2 cells to study lipotoxicity. Our results demonstrated that cardiomyocyte hypertrophy was induced by PA treatment, determined by upregulation of hypertrophic marker genes and cell surface area enlargement. Upon PA treatment, the expression of RIPK1 and RIPK3 was increased. Pretreatment with the RIPK1 inhibitor necrostatin-1 (Nec-1), the PA-induced cardiomyocyte hypertrophy, was attenuated. Knockdown of RIPK1 or RIPK3 by siRNA suppressed the PA-induced myocardial hypertrophy. Moreover, a crosstalk between necroptosis and endoplasmic reticulum (ER) stress was observed in PA-treated cardiomyocytes. Inhibition of RIPK1 with Nec-1, phosphorylation level of AKT (Ser473), and mTOR (Ser2481) was significantly reduced in PA-treated cardiomyocytes. In conclusion, RIPKs-dependent necroptosis might be crucial in PA-induced myocardial hypertrophy. Activation of mTOR may mediate the effect of necroptosis in cardiomyocyte hypertrophy induced by PA. PMID:27057269

  7. Regression of Copper-Deficient Heart Hypertrophy: Reduction in the Size of Hypertrophic Cardiomyocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary copper deficiency causes cardiac hypertrophy and its transition to heart failure in a mouse model. Copper repletion results in a rapid regression of cardiac hypertrophy and prevention of heart failure. The present study was undertaken to understand dynamic changes of cardiomyocytes in the hy...

  8. Phorbol-ester-induced alterations of free calcium ion transients in single rat hepatocytes.

    PubMed Central

    Woods, N M; Cuthbertson, K S; Cobbold, P H

    1987-01-01

    The effect of the phorbol esters phorbol 12-myristate 13-acetate (TPA) and phorbol 12,13-dibutyrate (PDB) on changes in free Ca2+ concentration ([Ca2+]i) in single rat hepatocytes, microinjected with the photoprotein aequorin, were investigated. [Arg8]vasopressin and phenylephrine induced a series of repetitive [Ca2+]i transients. Phorbol esters inhibited the alpha 1-adrenoceptor-induced response; sub-nanomolar concentrations decreased the transient frequency, and higher concentrations abolished the transients. The inhibitory effect of PDB was readily reversible. Phorbol esters were less effective in decreasing the frequency of [Arg8]-vasopressin-induced transients, and the inhibition could be overcome by high [Arg8]vasopressin concentrations. PMID:3479980

  9. High glucose enhances microRNA-26a to activate mTORC1 for mesangial cell hypertrophy and matrix protein expression

    PubMed Central

    Dey, Nirmalya; Bera, Amit; Das, Falguni; Ghosh-Choudhury, Nandini; Kasinath, Balakuntalam S.; Choudhury, Goutam Ghosh

    2015-01-01

    High glucose milieu inhibits PTEN expression to activate Akt kinase and induces glomerular mesangial cell hypertrophy and matrix protein expression in diabetic nephropathy. Specific mechanism by which high glucose inhibits PTEN expression is not clear. We found that high glucose increased the expression of the microRNA-26a (miR-26a) in mesangial cells. Using a sensor plasmid with 3’UTR-driven luciferase, we showed PTEN as a target of miR-26a in response to high glucose. Overexpression of miR-26a reduced the PTEN protein levels resulting in increased Akt kinase activity similar to high glucose treatment. In contrast, anti-miR-26a reversed high glucose-induced suppression of PTEN with concomitant inhibition of Akt kinase activity. Akt-mediated phosphorylation of tuberin and PRAS40 regulates mTORC1, which is necessary for mesangial cell hypertrophy and matrix protein expression. Inhibition of high glucose-induced miR-26a blocked phosphorylation of tuberin and PRAS40, which lead to suppression of phosphorylation of S6 kinase and 4EBP-1, two substrates of mTORC1. Furthermore, we show that expression of miR-26a induced mesangial cell hypertrophy and increased fibronectin and collagen I (α2) expression similar to that observed with the cells incubated with high glucose. Anti-miR-26a inhibited these phenomena in response to high glucose. Together our results provide the first evidence for the involvement of miR-26a in high glucose-induced mesangial cell hypertrophy and matrix protein expression. These data indicate the potential therapeutic utility of anti-miR-26a for the complications of diabetic kidney disease. PMID:25797045

  10. Molecular switches under TGFβ signalling during progression from cardiac hypertrophy to heart failure.

    PubMed

    Heger, J; Schulz, R; Euler, G

    2016-01-01

    Cardiac hypertrophy is a mechanism to compensate for increased cardiac work load, that is, after myocardial infarction or upon pressure overload. However, in the long run cardiac hypertrophy is a prevailing risk factor for the development of heart failure. During pathological remodelling processes leading to heart failure, decompensated hypertrophy, death of cardiomyocytes by apoptosis or necroptosis and fibrosis as well as a progressive dysfunction of cardiomyocytes are apparent. Interestingly, the induction of hypertrophy, cell death or fibrosis is mediated by similar signalling pathways. Therefore, tiny changes in the signalling cascade are able to switch physiological cardiac remodelling to the development of heart failure. In the present review, we will describe examples of these molecular switches that change compensated hypertrophy to the development of heart failure and will focus on the importance of the signalling cascades of the TGFβ superfamily in this process. In this context, potential therapeutic targets for pharmacological interventions that could attenuate the progression of heart failure will be discussed.

  11. Panmedullary edema with inferior olivary hypertrophy in bilateral medial medullary infarction.

    PubMed

    Inoue, Yasuteru; Miyashita, Fumio; Koga, Masatoshi; Yamada, Naoaki; Toyoda, Kazunori; Minematsu, Kazuo

    2014-03-01

    Bilateral medial medullary infarction (MMI) is a rare type of stroke with poor outcomes. Inferior olivary nucleus hypertrophy results from a pathologic lesion in the Guillain-Mollaret triangle. The relationship between inferior olivary nucleus hypertrophy and the medullary lesion is obscure. To the best of our knowledge, only 1 autopsy case with unilateral medial medullary infarction that was associated with ipsilateral inferior olivary nucleus hypertrophy has been reported. We describe a rare case with acute infarction in the bilateral medial medulla oblongata accompanied by subacute bilateral inferior olivary nucleus hypertrophy and panmedullary edema. The hypertrophy appeared to have been caused by local ischemic damage to the termination of the central tegmental tract at the bilateral inferior olivary nucleus.

  12. A Comprehensive Analysis of Plasmodium Circumsporozoite Protein Binding to Hepatocytes.

    PubMed

    Zhao, Jinghua; Bhanot, Purnima; Hu, Junjie; Wang, Qian

    2016-01-01

    Circumsporozoite protein (CSP) is the dominant protein on the surface of Plasmodium sporozoites and plays a critical role in the invasion by sporozoites of hepatocytes. Contacts between CSP and heparin sulfate proteoglycans (HSPGs) lead to the attachment of sporozoites to hepatocytes and trigger signaling events in the parasite that promote invasion of hepatocytes. The precise sequence elements in CSP that bind HSPGs have not been identified. We performed a systematic in vitro analysis to dissect the association between Plasmodium falciparum CSP (PfCSP) and hepatocytes. We demonstrate that interactions between PfCSP and heparin or a cultured hepatoma cell line, HepG2, are mediated primarily by a lysine-rich site in the amino terminus of PfCSP. Importantly, the carboxyl terminus of PfCSP facilitates heparin-binding by the amino-terminus but does not interact directly with heparin. These findings provide insights into how CSP recognizes hepatocytes and useful information for further functional studies of CSP. PMID:27560376

  13. Hepatocyte cryopreservation: is it time to change the strategy?

    PubMed

    Stéphenne, Xavier; Najimi, Mustapha; Sokal, Etienne M

    2010-01-01

    Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative, or at least as a bridge, to orthotopic liver transplantation. The success of such a therapeutic approach remains limited by the quality of the transplanted cells. Cryopreservation remains the best option for long-term storage of hepatocytes, providing a permanent and sufficient cell supply. However, isolated adult hepatocytes are poorly resistant to such a process, with a significant alteration both at the morphological and functional levels. Hence, the aim of the current review is to discuss the state of the art regarding widely-used hepatocyte cryopreservation protocols, as well as the assays performed to analyse the post-thawing cell quality both in vitro and in vivo. The majority of studies agree upon the poor quality and efficiency of cryopreserved/thawed hepatocytes as compared to freshly isolated hepatocytes. Intracellular ice formation or exposure to hyperosmotic solutions remains the main phenomenon of cryopreservation process, and its effects on cell quality and cell death induction will be discussed. The increased knowledge and understanding of the cryopreservation process will lead to research strategies to improve the viability and the quality of the cell suspensions after thawing. Such strategies, such as vitrification, will be discussed with respect to their potential to significantly improve the quality of cell suspensions dedicated to liver cell-based therapies. PMID:20039443

  14. A Comprehensive Analysis of Plasmodium Circumsporozoite Protein Binding to Hepatocytes

    PubMed Central

    Zhao, Jinghua; Bhanot, Purnima; Hu, Junjie; Wang, Qian

    2016-01-01

    Circumsporozoite protein (CSP) is the dominant protein on the surface of Plasmodium sporozoites and plays a critical role in the invasion by sporozoites of hepatocytes. Contacts between CSP and heparin sulfate proteoglycans (HSPGs) lead to the attachment of sporozoites to hepatocytes and trigger signaling events in the parasite that promote invasion of hepatocytes. The precise sequence elements in CSP that bind HSPGs have not been identified. We performed a systematic in vitro analysis to dissect the association between Plasmodium falciparum CSP (PfCSP) and hepatocytes. We demonstrate that interactions between PfCSP and heparin or a cultured hepatoma cell line, HepG2, are mediated primarily by a lysine-rich site in the amino terminus of PfCSP. Importantly, the carboxyl terminus of PfCSP facilitates heparin-binding by the amino-terminus but does not interact directly with heparin. These findings provide insights into how CSP recognizes hepatocytes and useful information for further functional studies of CSP. PMID:27560376

  15. Molecular cytotoxic mechanisms of chlorpromazine in isolated rat hepatocytes.

    PubMed

    MacAllister, Stephanie L; Young, Cheryl; Guzdek, Anna; Zhidkov, Nickholas; O'Brien, Peter J

    2013-01-01

    Chlorpromazine (CPZ), a member of the largest class of first-generation antipsychotic agents, is known to cause hepatotoxicity in the form of cholestasis and hepatocellular necrosis in some patients. The mechanism of CPZ hepatotoxicity is unclear, but is thought to result from reactive metabolite formation. The goal of this research was to assess potential cytotoxic mechanisms of CPZ using the accelerated cytotoxicity mechanism screening (ACMS) technique with freshly isolated rat hepatocytes. This study identified CPZ cytotoxicity and inhibition of mitochondrial membrane potential (MMP) to be concentration-dependent. Furthermore, inhibition of cytochrome P450s (CYPs), including CYP2D1 and 1A2, delayed CPZ cytotoxicity, suggesting a role for CYP activation of CPZ to a toxic metabolite(s) in this model. Metabolism studies also demonstrated glucuronide and glutathione (GSH) requirement for CPZ detoxification in hepatocytes. Inactivating the 2-electron reduction pathway, NAD(P)H quinone oxidoreductase (NQO1), caused a significant increase in hepatocyte susceptibility to CPZ, indicating quinoneimine contribution to CPZ cytotoxicity. Nontoxic concentrations of peroxidase/H(2)O(2) (inflammatory model) increased cytotoxicity in CPZ-treated hepatocytes and caused additional mitochondrial toxicity. Inflammation further depleted GSH and increased oxidized glutathione (GSSG) levels. Results suggest activation of CPZ to reactive metabolites by 2 pathways in hepatocytes: (i) a CYP-catalyzed quinoneimine pathway, and (ii) a peroxidase-catalyzed oxidation of CPZ to CPZ radicals.

  16. Chemokine Receptors, CXCR1 and CXCR2, Differentially Regulate Exosome Release in Hepatocytes.

    PubMed

    Nojima, Hiroyuki; Konishi, Takanori; Freeman, Christopher M; Schuster, Rebecca M; Japtok, Lukasz; Kleuser, Burkhard; Edwards, Michael J; Gulbins, Erich; Lentsch, Alex B

    2016-01-01

    Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. PMID:27551720

  17. The effects of human umbilical cord perivascular cells on rat hepatocyte structure and functional polarity.

    PubMed

    Gómez-Aristizábal, Alejandro; Davies, John Edward

    2013-06-01

    Hepatocyte culture is a useful tool for the study of their biology and the development of bioartificial livers. However, many challenges have to be overcome since hepatocytes rapidly lose their normal phenotype in vitro. We have recently demonstrated that human umbilical cord perivascular cells (HUCPVCs) are able to provide support to hepatocytes. In the present study we go further into exploring the effects that HUCPVCs have in the functional polarization, and both the internal and external organization, of hepatocytes. Also, we investigate HUCPVC-hepatocyte crosstalk by tracking both the effects of HUCPVCs on hepatocyte transcription factors and those of hepatocytes on the expression of hepatotrophic factors in HUCPVCs. Our results show that HUCPVCs maintain the functional polarity of hepatocytes ex vivo, as judged by the secretion of fluorescein into bile canaliculi, for at least 40 days. Transmission electron microscopy revealed that hepatocytes in coculture organize in an organoid-like structure embedded in extracellular matrix surrounded by HUCPVCs. In coculture, hepatocytes displayed a higher expression of C/EBPα, implicated in maintenance of the mature hepatocyte phenotype, and HUCPVCs upregulated hepatocyte growth factor and Jagged1 indicating that these genes may play important roles in HUCPVC-hepatocyte interactions.

  18. Chemokine Receptors, CXCR1 and CXCR2, Differentially Regulate Exosome Release in Hepatocytes

    PubMed Central

    Nojima, Hiroyuki; Konishi, Takanori; Freeman, Christopher M.; Schuster, Rebecca M.; Japtok, Lukasz; Kleuser, Burkhard; Edwards, Michael J.; Gulbins, Erich; Lentsch, Alex B.

    2016-01-01

    Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. PMID:27551720

  19. BMP type I receptor ALK2 is required for angiotensin II-induced cardiac hypertrophy.

    PubMed

    Shahid, Mohd; Spagnolli, Ester; Ernande, Laura; Thoonen, Robrecht; Kolodziej, Starsha A; Leyton, Patricio A; Cheng, Juan; Tainsh, Robert E T; Mayeur, Claire; Rhee, David K; Wu, Mei X; Scherrer-Crosbie, Marielle; Buys, Emmanuel S; Zapol, Warren M; Bloch, Kenneth D; Bloch, Donald B

    2016-04-15

    Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis. PMID:26873969

  20. Global microRNA profiles and signaling pathways in the development of cardiac hypertrophy.

    PubMed

    Feng, H J; Ouyang, W; Liu, J H; Sun, Y G; Hu, R; Huang, L H; Xian, J L; Jing, C F; Zhou, M J

    2014-05-01

    Hypertrophy is a major predictor of progressive heart disease and has an adverse prognosis. MicroRNAs (miRNAs) that accumulate during the course of cardiac hypertrophy may participate in the process. However, the nature of any interaction between a hypertrophy-specific signaling pathway and aberrant expression of miRNAs remains unclear. In this study, Spague Dawley male rats were treated with transverse aortic constriction (TAC) surgery to mimic pathological hypertrophy. Hearts were isolated from TAC and sham operated rats (n=5 for each group at 5, 10, 15, and 20 days after surgery) for miRNA microarray assay. The miRNAs dysexpressed during hypertrophy were further analyzed using a combination of bioinformatics algorithms in order to predict possible targets. Increased expression of the target genes identified in diverse signaling pathways was also analyzed. Two sets of miRNAs were identified, showing different expression patterns during hypertrophy. Bioinformatics analysis suggested the miRNAs may regulate multiple hypertrophy-specific signaling pathways by targeting the member genes and the interaction of miRNA and mRNA might form a network that leads to cardiac hypertrophy. In addition, the multifold changes in several miRNAs suggested that upregulation of rno-miR-331*, rno-miR-3596b, rno-miR-3557-5p and downregulation of rno-miR-10a, miR-221, miR-190, miR-451 could be seen as biomarkers of prognosis in clinical therapy of heart failure. This study described, for the first time, a potential mechanism of cardiac hypertrophy involving multiple signaling pathways that control up- and downregulation of miRNAs. It represents a first step in the systematic discovery of miRNA function in cardiovascular hypertrophy.

  1. Chimeric mice with hepatocyte-humanized liver as an appropriate model to study human peroxisome proliferator-activated receptor-α.

    PubMed

    Tateno, Chise; Yamamoto, Toshinobu; Utoh, Rie; Yamasaki, Chihiro; Ishida, Yuji; Myoken, Yuka; Oofusa, Ken; Okada, Miyoko; Tsutsui, Naohisa; Yoshizato, Katsutoshi

    2015-02-01

    Peroxisome proliferator (PP)-activated receptor-α (PPARα) agonists exhibit species-specific effects on livers of the rodent and human (h), which has been considered to reside in the difference of PPARα gene structures. However, the contribution of h-hepatocytes (heps) to the species-specificity remains to be clarified. In this study, the effects of fenofibrate were investigated using a hepatocyte-humanized chimeric mouse (m) model whose livers were replaced with h-heps at >70%. Fenofibrate induced hepatocellular hypertrophy, cell proliferation, and peroxisome proliferation in livers of severe combined immunodeficiency (SCID) mice, but not in the h-hep of chimeric mouse livers. Fenofibrate increased the expression of the enzymes of β- and ω-hydroxylation and deoxygenation of lipids at both gene and protein levels in SCID mouse livers, but not in the h-heps of chimeric mouse livers, supporting the studies with h-PPARα-transgenic mice, a hitherto reliable model for studying the regulation of h-PPARα in the h-liver in most respects, except the induction of the peroxisome proliferation. This study indicates the importance of not only h-PPARα gene but also h-heps themselves to correctly predict effects of fibrates on h-livers, and, therefore, suggests that the chimeric mouse is a currently available, consistent, and reliable model to obtain pharmaceutical data concerning the effects of fibrates on h-livers.

  2. Mechanisms of nascent fiber formation during avian skeletal muscle hypertrophy

    NASA Technical Reports Server (NTRS)

    McCormick, K. M.; Schultz, E.

    1992-01-01

    This study examined two putative mechanisms of new fiber formation in postnatal skeletal muscle, namely longitudinal fragmentation of existing fibers and de novo formation. The relative contributions of these two mechanisms to fiber formation in hypertrophying anterior latissimus dorsi (ALD) muscle were assessed by quantitative analysis of their nuclear populations. Muscle hypertrophy was induced by wing-weighting for 1 week. All nuclei formed during the weighting period were labeled by continuous infusion of 5-bromo-2'-deoxyuridine (BrdU), a thymidine analog, and embryonic-like fibers were identified using an antibody to ventricular-like embryonic (V-EMB) myosin. The number of BrdU-labeled and unlabeled nuclei in V-EMB-positive fibers were counted. Wing-weighting resulted in significant muscle enlargement and the appearance of many V-EMB+ fibers. The majority of V-EMB+ fibers were completely independent of mature fibers and had a nuclear density characteristics of developing fibers. Furthermore, nearly 100% of the nuclei in independent V-EMB+ fibers were labeled. These findings strongly suggest that most V-EMB+ fibers were nascent fibers formed de novo during the weighting period by satellite cell activation and fusion. Nascent fibers were found primarily in the space between fascicles where they formed a complex anastomosing network of fibers running at angles to one another. Although wing-weighting induced an increase in the number of branched fibers, there was no evidence that V-EMB+ fibers were formed by longitudinal fragmentation. The location of newly formed fibers in wing-weighted and regenerating ALD muscle was compared to determine whether satellite cells in the ALD muscle were unusual in that, if stimulated to divide, they would form fibers in the inter- and intrafascicular space. In contrast to wing-weighted muscle, nascent fibers were always found closely associated with necrotic fibers. These results suggest that wing-weighting is not simply another

  3. Senescent heart compared with pressure overload-induced hypertrophy.

    PubMed

    Assayag, P; Charlemagne, D; de Leiris, J; Boucher, F; Valère, P E; Lortet, S; Swynghedauw, B; Besse, S

    1997-01-01

    Although systolic left ventricular (LV) function is normal in the elderly, aging is associated in rat papillary muscle with mechanical and sarcoplasmic reticulum Ca2+ ATPase alterations similar to those observed in the hypertrophied heart. However, alterations in the other calcium-regulating proteins implicated in contraction and relaxation are still unknown. To investigate alterations in LV function and calcium-regulating proteins, we measured hemodynamics and Na(+)-Ca2+ exchanger (NCx), ryanodine receptor (RyR2), and sarcoplasmic reticular Ca2+ ATPase (SERCA2) mRNA levels (expressed in densitometric scores normalized to that of poly(A+) mRNA) in left ventricle from 4-month-old (adult, n = 13) and 24-month-old (senescent, n = 15) rats. For ex vivo contractile function, active tension was measured during isolated heart perfusion in adult (n = 11) and senescent (n = 11) rats. For comparison of age-dependent effects of moderate hypertension on both hemodynamics and calcium proteins, renovascular hypertension was induced or a sham operation performed at 2 (n = 11 and n = 6) and 22 (n = 26 and n = 5) months of age. In senescent rats, LV systolic pressure and maximal rates of pressure development were unaltered, although active tension was depressed (4.7 +/- 0.4 versus 8.3 +/- 0.7 g/g heart weight in adults, P < .0001). SERCA2 mRNA levels were decreased in senescent left ventricle (0.98 +/- 0.05 versus 1.18 +/- 0.05 in adults, P < .01), without changes in NCx and RyR2 mRNA accumulation. Renovascular hypertension resulted in 100% mortality in aged rats; in adults, renovascular hypertension resulted, 2 months later, in an increase of LV systolic pressure (170 +/- 7 versus 145 +/- 3 mm Hg in sham-operated rats, P < .05) and in mild LV hypertrophy (+18%, P < .01) associated with a decrease in SERCA2 mRNA levels (1.02 +/- 0.03 versus 1.18 +/- 0.03 in sham-operated rats, P < .001). Contractile dysfunction in senescent isolated heart and decreased SERCA2 mRNA levels were

  4. Inward transport of [3H]-1-methyl-4-phenylpyridinium in rat isolated hepatocytes: putative involvement of a P-glycoprotein transporter.

    PubMed Central

    Martel, F.; Martins, M. J.; Hipólito-Reis, C.; Azevedo, I.

    1996-01-01

    endobiotics and xenobiotics. We proposed that the reversal of transport through P-glycoprotein may be related to the loss of efficacy of alkaline in isolated hepatocytes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:8982496

  5. Acetaminophen metabolism, cytotoxicity, and genotoxicity in rat primary hepatocyte cultures

    SciTech Connect

    Milam, K.M.; Byard, J.L.

    1985-06-30

    Acetaminophen (APAP) metabolism, cytotoxicity, and genotoxicity were measured in primary cultures of rat hepatocytes. Although 3 mM APAP caused a slight increase in cellular release of lactate dehydrogenase into the culture medium, cellular glutathione concentration (an index of APAP metabolism) was reduced by 50%. APAP at 7 mM was significantly more toxic to these hepatocytes and had a similar but more marked effect on glutathione concentrations. In spite of its cytotoxicity, neither dose of APAP stimulated DNA repair synthesis when monitored by the rate of incorporation of (/sup 3/H)thymidine into DNA following exposure to APAP. Thus, although APAP has been shown to be both hepato- and nephrotoxic in several in vivo and in vitro systems, the reactive toxic metabolite of APAP is not genotoxic in rat primary hepatocyte cultures.

  6. Hemoglobin - a novel ligand of hepatocyte ectopic F1-ATPase.

    PubMed

    Gburek, J; Konopska, B; Juszczynska, K; Piwowar, A; Dziegiel, P; Borska, S; Tolosano, E; Golab, K

    2015-12-01

    The liver is largely responsible for free hemoglobin uptake, but the molecular mechanism of this phenomenon has never been revealed. This paper presents the results of the study on hemoglobin binding components of the hepatocyte membrane that were purified using affinity chromatography on a hemoglobin matrix and identified by peptide mass fingerprinting. Both F1-ATPase alpha and beta subunits were retrieved. The binding was confirmed via an intrinsic fluorescence quenching study using a purified recombinant F1-ATPase beta subunit, and the dissociation constant for the complex was estimated from the saturation binding curve (Kd = 7.5 x 10(-7) M). The results indicate that haemoglobin binds to hepatocyte ectopic F1-ATPase. We suggested the plausible role of the receptor in endocytosis of haemoglobin by the hepatocyte.

  7. Ethanol-induced phosphorylation of cytokeratin in cultured hepatocytes

    SciTech Connect

    Kawahara, Hiromu; Cadrin, M.; French, S.W. )

    1990-01-01

    The authors studied the effect of ethanol on the phosphorylation of cytokeratins (CKs) in cultured hepatocytes since CK filaments are resulted by phosphorylation and they are abnormal in alcoholic liver disease. Hepatocytes were obtained from 14-day-old rats and cultured for 48 hrs. The hepatocytes were exposed to ethanol for 30 min. The residual insoluble cytoskeletons were analyzed by two-dimensional gel electrophoresis and autoradiography. 2D gel electrophoresis showed CK 55 and CK 49 or 8 and 18 and actin. The CKs had several isoelectric variants. The most basic spot was the dominant protein which was not phosphorylated. The more acidic spots were phosphorylated. After ethanol treatment, the phosphorylation of CK 55 and CK 49 were markedly increased over controls. They compared these results, with the effect of vasopressin, TPA and db-cAMP on the phosphorylation of CKs. Vasopressin and TPA caused the phosphorylation of CK 55 and 49 but db-cAMP did not.

  8. Determination of metabolic stability using cryopreserved hepatocytes from rainbow trout (Oncorhynchus mykiss)

    EPA Science Inventory

    Standard protocols for isolating, cryopreserving, and thawing rainbow trout hepatocytes are described, along with procedures for using fresh or cryopreserved hepatocytes to assess chemical metabolic stability in fish by means of a substrate depletion approach. Variations on thes...

  9. Cryopreservation of isolated human hepatocytes for transplantation: State of the art.

    PubMed

    Terry, Claire; Dhawan, Anil; Mitry, Ragai R; Hughes, Robin D

    2006-10-01

    Hepatocytes isolated from unused donor livers are being used for transplantation in patients with acute liver failure and liver-based metabolic defects. As large numbers of hepatocytes can be prepared from a single liver and hepatocytes need to be available for emergency and repeated treatment of patients it is essential to be able to cryopreserve and store cells with good thawed cell function. This review considers the current status of cryopreservation of human hepatocytes discussing the different stages involved in the process. These include pre-treatment of cells, freezing solution, cryoprotectants and freezing and thawing protocols. There are detrimental effects of cryopreservation on hepatocyte structure and metabolic function, including cell attachment, which is important to the engraftment of transplanted cells in the liver. Cryopreserved human hepatocytes have been successfully used in clinical transplantation, with evidence of replacement of missing function. Further optimisation of hepatocyte cryopreservation protocols is important for their use in hepatocyte transplantation.

  10. Cryopreservation of isolated human hepatocytes for transplantation: State of the art.

    PubMed

    Terry, Claire; Dhawan, Anil; Mitry, Ragai R; Hughes, Robin D

    2006-10-01

    Hepatocytes isolated from unused donor livers are being used for transplantation in patients with acute liver failure and liver-based metabolic defects. As large numbers of hepatocytes can be prepared from a single liver and hepatocytes need to be available for emergency and repeated treatment of patients it is essential to be able to cryopreserve and store cells with good thawed cell function. This review considers the current status of cryopreservation of human hepatocytes discussing the different stages involved in the process. These include pre-treatment of cells, freezing solution, cryoprotectants and freezing and thawing protocols. There are detrimental effects of cryopreservation on hepatocyte structure and metabolic function, including cell attachment, which is important to the engraftment of transplanted cells in the liver. Cryopreserved human hepatocytes have been successfully used in clinical transplantation, with evidence of replacement of missing function. Further optimisation of hepatocyte cryopreservation protocols is important for their use in hepatocyte transplantation. PMID:16793034

  11. Intrasplenic transplantation of allogeneic hepatocytes prolongs survival in anhepatic rats.

    PubMed

    Arkadopoulos, N; Lilja, H; Suh, K S; Demetriou, A A; Rozga, J

    1998-11-01

    To examine whether hepatocytes transplanted in the spleen can function as an ectopic liver, we performed hepatocyte transplantation in rats that were rendered anhepatic. Total hepatectomy was performed by using a novel single-stage technique. Following hepatectomy, Group 1 rats (n = 16) were monitored until death to determine survival time without prior intervention. Group 2 anhepatic rats (n = 20) were sacrificed at various times to measure blood hepatocyte growth factor (HGF) and transforming growth factor beta1 (TGF-beta1) levels. Group 3 (n = 16) rats received intrasplenic injection of isolated hepatocytes (2.5 x 10(7) cells/rat) followed by total hepatectomy after 3 days. Group 4 (n = 12) sham-transplanted rats received intrasplenic saline infusion, and after 3 days they were rendered anhepatic. Group 2, 3, and 4 rats were maintained on daily Cyclosporine A (10 mg/kg; intramuscularly). Group 1 anhepatic rats survived for 22.4 +/- 5.2 hours (standard deviation). The anhepatic state was associated with a progressive and statistically significant rise in blood HGF and TGF-beta1 levels. Rats that received hepatocyte transplantation before total hepatectomy had a significantly longer survival time than sham-transplanted anhepatic controls (34.1 +/- 8.5 vs. 15.5 +/- 4.8 hrs, P < .01). Additionally, at 12 hours post-hepatectomy, transplanted rats had significantly lower blood ammonia, prothrombin time, international normalized ratio, and TGF-beta1 levels when compared with sham-transplanted controls. In conclusion, intrasplenic transplantation of allogeneic hepatocytes prolonged survival, improved blood chemistry, and lowered blood TGF-beta1 levels in rats rendered anhepatic. PMID:9794923

  12. [Facial asymmetry due to hemi-mandibular hypertrophy].

    PubMed

    Freidel, M; Breton, P; Duclos, P; Angoh, J J

    1989-01-01

    A relatively frequent disorder, hemi-mandibular hypertrophy is today well identified clinically and radiologically. Its expression varies from one case to another but it becomes stabilized at the end of growth. Its etiology is unclear and it can only be corrected surgically: the habitual inclination of the plane of occlusion leads to a bimaxillary action with a tridimensional effect. The results of these osteotomies performed at the same time is stable and dramatic. Although isolated osteotomy of the basilar excess has become a last resort procedure, isolated condylectomy is still an acceptable compromise in toothless patients. The diagnostic approach and result of surgical treatment are analyzed in light of a homogeneous series of 12 cases.

  13. Simple epithelium keratins are required for maintenance of hepatocyte integrity.

    PubMed Central

    Loranger, A.; Duclos, S.; Grenier, A.; Price, J.; Wilson-Heiner, M.; Baribault, H.; Marceau, N.

    1997-01-01

    Keratin 8 (K8)-deficient adult mice develop a severe disease of the gastrointestinal tract characterized mainly by colorectal hyperplasia and inflammation. Given that hepatocytes contain K8/K18 heteropolymers only, this animal model was used to assess the contribution of these simple epithelium keratins to hepatocyte structural and functional integrity. Homozygous mutant (HMZ), heterozygous, and wild-type (WT) mice were examined for hepatocyte structural and metabolic features and their survival to partial hepatectomy. Except for the presence of few necrotic foci, no other tissular or cellular alterations were observed in nonhepatectomized HMZ mouse livers; glycogen and lipid peroxidation levels were essentially normal, but a small reduction in bile flow was observed. In response to a single pentobarbital injection, HMZ mice had longer sleeping times than heterozygous and WT mice. After a two-thirds partial hepatectomy under pentobarbital anesthesia, all HMZ mice died within a few hours, whereas those anesthetized with ether survived for 1 to 2 days. One hour after hepatectomy after pentobarbital anesthesia, many hepatocytes contained erythrocytes and large vacuoles in the cytoplasm, which suggests damage at the plasma membrane level in response to a sudden increase in portal blood flow. In line with these findings, an uptake of trypan blue by HMZ but not WT mouse hepatocytes was observed during a 10 ml/minute perfusion via the portal vein with a dye-supplemented buffer. Subsequent cellular dispersion led to viable WT mouse hepatocytes but largely nonviable HMZ mouse hepatocytes. Better viability was obtained at lower perfusion rates. Partially hepatectomized heterozygous mice developed liver steatosis, a condition that was not associated with a change in K8 content but perhaps linked to the presence of the neo gene. Transgenic HMZ mouse rescue experiments with a full-length K8 gene confirmed that the phenotypic alterations observed in partially hepatectomized HMZ

  14. Homologous beta-adrenergic desensitization in isolated rat hepatocytes.

    PubMed Central

    García-Sáinz, J A; Michel, B

    1987-01-01

    Hepatocytes from hypothyroid rats have a marked beta-adrenergic responsiveness. Preincubation of these hepatocytes with isoprenaline induced a time-dependent and concentration-dependent desensitization of the beta-adrenergic responsiveness without altering that to glucagon (homologous desensitization). The desensitization was evidenced both in the cyclic AMP accumulation and in the stimulation of ureagenesis induced by the beta-adrenergic agonists. Under the same conditions, preincubation with glucagon induced no desensitization. Propranolol was also unable to induce desensitization, but blocked that induced by isoprenaline. Pertussis-toxin treatment did not alter the homologous beta-adrenergic desensitization induced by isoprenaline. PMID:2825633

  15. [Current status and future perspectives of hepatocyte transplantation].

    PubMed

    Pareja, Eugenia; Cortés, Miriam; Gómez-Lechón, M José; Maupoey, Javier; San Juan, Fernando; López, Rafael; Mir, Jose

    2014-02-01

    The imbalance between the number of potential beneficiaries and available organs, originates the search for new therapeutic alternatives, such as Hepatocyte transplantation (HT).Even though this is a treatment option for these patients, the lack of unanimity of criteria regarding indications and technique, different cryopreservation protocols, as well as the different methodology to assess the response to this therapy, highlights the need of a Consensus Conference to standardize criteria and consider future strategies to improve the technique and optimize the results.Our aim is to review and update the current state of hepatocyte transplantation, emphasizing the future research attempting to solve the problems and improve the results of this treatment.

  16. Interspecies differences in metabolism of arsenic by cultured primary hepatocytes

    SciTech Connect

    Drobna, Zuzana; Walton, Felecia S.; Harmon, Anne W.; Thomas, David J.; Styblo, Miroslav

    2010-05-15

    Biomethylation is the major pathway for the metabolism of inorganic arsenic (iAs) in many mammalian species, including the human. However, significant interspecies differences have been reported in the rate of in vivo metabolism of iAs and in yields of iAs metabolites found in urine. Liver is considered the primary site for the methylation of iAs and arsenic (+3 oxidation state) methyltransferase (As3mt) is the key enzyme in this pathway. Thus, the As3mt-catalyzed methylation of iAs in the liver determines in part the rate and the pattern of iAs metabolism in various species. We examined kinetics and concentration-response patterns for iAs methylation by cultured primary hepatocytes derived from human, rat, mice, dog, rabbit, and rhesus monkey. Hepatocytes were exposed to [{sup 73}As]arsenite (iAs{sup III}; 0.3, 0.9, 3.0, 9.0 or 30 nmol As/mg protein) for 24 h and radiolabeled metabolites were analyzed in cells and culture media. Hepatocytes from all six species methylated iAs{sup III} to methylarsenic (MAs) and dimethylarsenic (DMAs). Notably, dog, rat and monkey hepatocytes were considerably more efficient methylators of iAs{sup III} than mouse, rabbit or human hepatocytes. The low efficiency of mouse, rabbit and human hepatocytes to methylate iAs{sup III} was associated with inhibition of DMAs production by moderate concentrations of iAs{sup III} and with retention of iAs and MAs in cells. No significant correlations were found between the rate of iAs methylation and the thioredoxin reductase activity or glutathione concentration, two factors that modulate the activity of recombinant As3mt. No associations between the rates of iAs methylation and As3mt protein structures were found for the six species examined. Immunoblot analyses indicate that the superior arsenic methylation capacities of dog, rat and monkey hepatocytes examined in this study may be associated with a higher As3mt expression. However, factors other than As3mt expression may also contribute to

  17. Serotonin and the 5-HT7 receptor: the link between hepatocytes, IGF-1 and small intestinal neuroendocrine tumors.

    PubMed

    Svejda, Bernhard; Kidd, Mark; Timberlake, Andrew; Harry, Kathy; Kazberouk, Alexander; Schimmack, Simon; Lawrence, Ben; Pfragner, Roswitha; Modlin, Irvin M

    2013-07-01

    Platelet-derived serotonin (5-HT) is involved in liver regeneration. The liver is also the metastatic site for malignant enterochromaffin (EC) cell "carcinoid" (neuroendocrine) neoplasms, the principal cellular source of 5-HT. We hypothesized that 5-HT produced by metastatic EC cells played a role in the hepatic tumor-microenvironment principally via 5-HT₇ receptor-mediated activation of hepatocyte IGF-1 synthesis and secretion. Using isolated rat hepatocytes, we evaluated 5-HT₇ receptor expression (using PCR, sequencing and western blot). ELISA, cell transfection and western blots delineated 5-HT-mediated signaling pathways (pCREB, AKT and ERK). IGF-1 synthesis/secretion was evaluated using QPCR and ELISA. IGF-1 was tested on small intestinal neuroendocrine neoplasm proliferation, while IGF-1 production and 5-HT₇ expression were examined in an in vivo SCID metastasis model. Our results demonstrated evidence for a functional 5-HT₇ receptor. 5-HT activated cAMP/PKA activity, pCREB (130-205%, P < 0.05) and pERK/pAKT (1.2-1.75, P < 0.05). Signaling was reversed by the 5-HT₇ receptor antagonist SB269970. IGF-1 significantly stimulated proliferation of two small intestinal neuroendocrine neoplasm cell lines (EC₅₀: 7-70 pg/mL) and could be reversed by the small molecule inhibitor BMS-754807. IGF-1 and 5-HT were elevated (40-300×) in peri-tumoral hepatic tissue in nude mice, while 5-HT₇ was increased fourfold compared to sham-operated animals. We conclude that hepatocytes express a cAMP-coupled 5-HT₇ receptor, which, at elevated 5-HT concentrations that occur in liver metastases, signals via CREB/AKT and is linked to IGF-1 synthesis and secretion. Because IGF-1 regulates NEN proliferation, identification of a role for 5-HT₇ in the hepatic metastatic tumor microenvironment suggests the potential for novel therapeutic strategies for amine-producing mid-gut tumors. PMID:23578138

  18. Hepatocyte-specific ablation in zebrafish to study biliary-driven liver regeneration.

    PubMed

    Choi, Tae-Young; Khaliq, Mehwish; Ko, Sungjin; So, Juhoon; Shin, Donghun

    2015-05-20

    The liver has a great capacity to regenerate. Hepatocytes, the parenchymal cells of the liver, can regenerate in one of two ways: hepatocyte- or biliary-driven liver regeneration. In hepatocyte-driven liver regeneration, regenerating hepatocytes are derived from preexisting hepatocytes, whereas, in biliary-driven regeneration, regenerating hepatocytes are derived from biliary epithelial cells (BECs). For hepatocyte-driven liver regeneration, there are excellent rodent models that have significantly contributed to the current understanding of liver regeneration. However, no such rodent model exists for biliary-driven liver regeneration. We recently reported on a zebrafish liver injury model in which BECs extensively give rise to hepatocytes upon severe hepatocyte loss. In this model, hepatocytes are specifically ablated by a pharmacogenetic means. Here we present in detail the methods to ablate hepatocytes and to analyze the BEC-driven liver regeneration process. This hepatocyte-specific ablation model can be further used to discover the underlying molecular and cellular mechanisms of biliary-driven liver regeneration. Moreover, these methods can be applied to chemical screens to identify small molecules that augment or suppress liver regeneration.

  19. Association between routine and standardized blood pressure measurements and left ventricular hypertrophy among patients on hemodialysis

    PubMed Central

    2010-01-01

    Background Left ventricular (LV) hypertrophy is common among patients on hemodialysis. While a relationship between blood pressure (BP) and LV hypertrophy has been established, it is unclear which BP measurement method is the strongest correlate of LV hypertrophy. We sought to determine agreement between various blood pressure measurement methods, as well as identify which method was the strongest correlate of LV hypertrophy among patients on hemodialysis. Methods This was a post-hoc analysis of data from a randomized controlled trial. We evaluated the agreement between seven BP measurement methods: standardized measurement at baseline; single pre- and post-dialysis, as well as mean intra-dialytic measurement at baseline; and cumulative pre-, intra- and post-dialysis readings (an average of 12 monthly readings based on a single day per month). Agreement was assessed using Lin's concordance correlation coefficient (CCC) and the Bland Altman method. Association between BP measurement method and LV hypertrophy on baseline cardiac MRI was determined using receiver operating characteristic curves and area under the curve (AUC). Results Agreement between BP measurement methods in the 39 patients on hemodialysis varied considerably, from a CCC of 0.35 to 0.94, with overlapping 95% confidence intervals. Pre-dialysis measurements were the weakest predictors of LV hypertrophy while standardized, post- and inter-dialytic measurements had similar and strong (AUC 0.79 to 0.80) predictive power for LV hypertrophy. Conclusions A single standardized BP has strong predictive power for LV hypertrophy and performs just as well as more resource intensive cumulative measurements, whereas pre-dialysis blood pressure measurements have the weakest predictive power for LV hypertrophy. Current guidelines, which recommend using pre-dialysis measurements, should be revisited to confirm these results. PMID:20576127

  20. Mollusc C-reactive protein crosses species barrier and reverses hepatotoxicity of lead in rodent models.

    PubMed

    Mukherjee, Sandip; Chatterjee, Sarmishtha; Sarkar, Shuvasree; Agarwal, Soumik; Kundu, Rakesh; Maitra, Sudipta; Bhattacharya, Shelley

    2013-08-01

    Achatina fulica C-reactive protein (ACRP) reversed the toxic effects of lead nitrate both in vivo in mice and in vitro in rat hepatocytes restoring the basal level of cell viability, lipid peroxidation, reduced glutathione and superoxides. Cytotoxicity was also significantly ameliorated in rat hepatocytes by in vitro pre-treatments with individual subunits (60, 62, 90 and 110 kDa) of ACRP. Annexin V-Cy3/CFDA dual staining showed significant reduction in the number of apoptotic hepatocytes pre-treated with ACRP. ACRP induced restoration of mitochondrial membrane potential was remarkable. ACRP pre-treatment prevented Pb-induced apoptosis mediated by caspase activation. The antagonistic effect of ACRP may be due to scavenging of reactive oxygen species which maintained the homeostasis of cellular redox potential as well as reduced glutathione status. The results suggest that ACRP crosses the species barrier and it may be utilized as a viable exogenous agent of cytoprotection against heavy metal related toxicity.

  1. Reduction of prohibitin expression contributes to left ventricular hypertrophy via enhancement of mitochondrial reactive oxygen species formation in spontaneous hypertensive rats.

    PubMed

    Zheng, H; Lu, G M

    2015-02-01

    Left ventricular hypertrophy (LVH) in hypertension is characterized by thickening of myocardium and decrease in heart chamber volume in response to mechanical or pathological stress, but the underlying molecular mechanisms remain to be defined. In this work, we investigate whether mitochondrial prohibitin (PHB) was involved in the progression of LVH in spontaneous hypertensive rats (SHR). First, it was found that mitochondrial dysfunction occurred in left ventricles of SHR. Through analysis using quantitative reverse transcription polymerase chain reaction and Western blotting, it was found that PHB mRNA and mitochondrial PHB levels in left ventricles of SHR were significantly lower than that in Wistar-Kyoto rats. Furthermore, PHB mRNA levels were negatively correlated to left ventricles weight-to-body weight ratio in SHR. Knockdown of PHB led to increased formation of mitochondrial reactive oxygen species (ROS) and reduced activities of complex I, mitochondrial adenosine triphosphate generation and mitochondrial membrane potential in cultured cardiomyocytes. Knockdown of PHB contributed to the cardiomyocyte hypertrophy, which could be attenuated by treatment with the Tempol. Angiotensin II (AngII) was increased in plasma and left ventricles of SHR. Incubation with AngII reduced mitochondrial PHB expression in cardiomyocytes, which was reversed when pretreated with losartan. In conclusion, reduction of PHB expression in left ventricles in SHR contributed to LVH, at least in part, through promoting mitochondrial ROS formation.

  2. Myocardial stress and hypertrophy: a complex interface between biophysics and cardiac remodeling.

    PubMed

    Grossman, William; Paulus, Walter J

    2013-09-01

    Pressure and volume overload results in concentric and eccentric hypertrophy of cardiac ventricular chambers with, respectively, parallel and series replication of sarcomeres. These divergent patterns of hypertrophy were related 40 years ago to disparate wall stresses in both conditions, with systolic wall stress eliciting parallel replication of sarcomeres and diastolic wall stress, series replication. These observations are relevant to clinical practice, as they relate to the excessive hypertrophy and contractile dysfunction regularly observed in patients with aortic stenosis. Stress-sensing mechanisms in cardiomyocytes and activation of cardiomyocyte death by elevated wall stress continue to intrigue cardiovascular scientists.

  3. Sequelae to acromegaly: reversibility with treatment of the primary disease.

    PubMed

    Lieberman, S A; Hoffman, A R

    1990-06-01

    Acromegalic patients suffer from a number of cardiovascular, metabolic, and rheumatologic problems, and they may also have an increased incidence of malignancy. We reviewed the literature concerning the reversibility of acromegalic complications. Hypertension, myocardial hypertrophy, left ventricular dysfunction and some rheumatologic abnormalities often continue despite successful treatment of the acromegaly. In contrast, glucose intolerance, soft tissue changes, and carpal tunnel syndrome usually resolve when the acromegaly is cured. Studies of the incidence and mortality of cancer in acromegaly are conflicting, but several suggest an increased incidence of colorectal cancer.

  4. A Microfabricated Platform for Generating Physiologically-Relevant Hepatocyte Zonation.

    PubMed

    McCarty, William J; Usta, O Berk; Yarmush, Martin L

    2016-01-01

    In vitro liver models have been important tools for more than 40 years for academic research and preclinical toxicity screening by the pharmaceutical industry. Hepatocytes, the highly metabolic parenchymal cells of the liver, are efficient at different metabolic chemistries depending on their relative spatial location along the sinusoid from the portal triad to the central vein. Although replicating hepatocyte metabolic zonation is vitally important for physiologically-relevant in vitro liver tissue and organ models, it is most often completely overlooked. Here, we demonstrate the creation of spatially-controlled zonation across multiple hepatocyte metabolism levels through the application of precise concentration gradients of exogenous hormone (insulin and glucagon) and chemical (3-methylcholanthrene) induction agents in a microfluidic device. Observed gradients in glycogen storage via periodic acid-Schiff staining, urea production via carbamoyl phosphatase synthetase I staining, and cell viability after exposure to allyl alcohol and acetaminophen demonstrated the in vitro creation of hepatocyte carbohydrate, nitrogen, alcohol degradation, and drug conjugation metabolic zonation. This type of advanced control system will be crucial for studies evaluating drug metabolism and toxicology using in vitro constructs. PMID:27240736

  5. Preparation of plasma-membrane subfractions from isolated rat hepatocytes.

    PubMed Central

    Wisher, M H; Evans, W H

    1977-01-01

    1. Rat livers were dissociated into their constituent cells by perfusion through the portal vein with a medium containing collagenase, and hepatocytes separated from non-parenchymal cells. 2. It is shown that the procedure described by Wisher & Evans [(1975) Biochem. J. 146, 375-388] for preparation of plasma membranes from liver tissue when applied to isolated hepatocytes also yielded subfractions of similar morphology and marker-enzyme distribution. 3. Thus the distribution of alkaline phosphodiesterase, 5'-nucleotidase and the basal and glucagon-stimulated adenylate cyclase among two 'light' vesicular and one 'heavy' junction-containing plasma-membrane subfractions paralleled that reported for tissue-derived plasma-membrane subfractions. 4. Increased recoveries and specific activities of plasma-membrane marker enzymes were obtained when soya-bean trypsin inhibitor was included in the collagenase-containing perfusion media used to dissociate the liver. 5. Polyacrylamide-gel-electrophoretic analysis of the corresponding plasma-membrane subfractions prepared from liver tissue and isolated hepatocytes were generally similar. 6. The results indicate that the functional polarity of the hepatocyte's plasma membrane is retained after tissue dissociation. The damage occurring to plasma-membrane ectoenzymes by the collagenase-perfusion procedure is discussed. Images PLATE 1 PLATE 2 PLATE 3 PMID:880246

  6. Retinoic Acid-mediated Nuclear Receptor Activation and Hepatocyte Proliferation

    PubMed Central

    Bushue, Nathan; Wan, Yu-Jui Yvonne

    2016-01-01

    Due to their well-known differentiation and apoptosis-inducing abilities, retinoic acid (RA) and its analogs have strong anti-cancer efficacy in human cancers. However, in vivo RA is a liver mitogen. While speculation has persisted that RA-mediated signaling is likely involved in hepatocyte proliferation during liver regeneration, direct evidence is still required. Findings in support of this proposition include observations that a release of retinyl palmitate (the precursor of RA) occurs in liver stellate cells following liver injury. Nevertheless, the biological action of this released vitamin A is virtually unknown. More likely is that the released vitamin A is converted to RA, the biological form, and then bound to a specific receptor (retinoid x receptor; RXRα), which is most abundantly expressed in the liver. Considering the mitogenic effects of RA, the RA-activated RXRα would likely then influence hepatocyte proliferation and liver tissue repair. At present, the mechanism by which RA stimulates hepatocyte proliferation is largely unknown. This review summarizes the activation of nuclear receptors (peroxisome proliferator activated receptor-α, pregnane x receptor, constitutive androstane receptor, and farnesoid x receptor) in an RXRα dependent manner to induce hepatocyte proliferation, providing a link between RA and its proliferative role.

  7. Asialoglycoprotein receptor mediated hepatocyte targeting - strategies and applications.

    PubMed

    D'Souza, Anisha A; Devarajan, Padma V

    2015-04-10

    Hepatocyte resident afflictions continue to affect the human population unabated. The asialoglycoprotein receptor (ASGPR) is primarily expressed on hepatocytes and minimally on extra-hepatic cells. This makes it specifically attractive for receptor-mediated drug delivery with minimum concerns of toxicity. ASGPR facilitates internalization by clathrin-mediated endocytosis and exhibits high affinity for carbohydrates specifically galactose, N-acetylgalactosamine and glucose. Isomeric forms of sugar, galactose density and branching, spatial geometry and galactose linkages are key factors influencing ligand-receptor binding. Popular ligands for ASGPR mediated targeting are carbohydrate polymers, arabinogalactan and pullulan. Other ligands include galactose-bearing glycoproteins, glycopeptides and galactose modified polymers and lipids. Drug-ligand conjugates provide a viable strategy; nevertheless ligand-anchored nanocarriers provide an attractive option for ASGPR targeted delivery and are widely explored. The present review details various ligands and nanocarriers exploited for ASGPR mediated delivery of drugs to hepatocytes. Nanocarrier properties affecting ASGPR mediated uptake are discussed at length. The review also highlights the clinical relevance of ASGPR mediated targeting and applications in diagnostics. ASGPR mediated hepatocyte targeting provides great promise for improved therapy of hepatic afflictions.

  8. A Microfabricated Platform for Generating Physiologically-Relevant Hepatocyte Zonation

    PubMed Central

    McCarty, William J.; Usta, O. Berk; Yarmush, Martin L.

    2016-01-01

    In vitro liver models have been important tools for more than 40 years for academic research and preclinical toxicity screening by the pharmaceutical industry. Hepatocytes, the highly metabolic parenchymal cells of the liver, are efficient at different metabolic chemistries depending on their relative spatial location along the sinusoid from the portal triad to the central vein. Although replicating hepatocyte metabolic zonation is vitally important for physiologically-relevant in vitro liver tissue and organ models, it is most often completely overlooked. Here, we demonstrate the creation of spatially-controlled zonation across multiple hepatocyte metabolism levels through the application of precise concentration gradients of exogenous hormone (insulin and glucagon) and chemical (3-methylcholanthrene) induction agents in a microfluidic device. Observed gradients in glycogen storage via periodic acid-Schiff staining, urea production via carbamoyl phosphatase synthetase I staining, and cell viability after exposure to allyl alcohol and acetaminophen demonstrated the in vitro creation of hepatocyte carbohydrate, nitrogen, alcohol degradation, and drug conjugation metabolic zonation. This type of advanced control system will be crucial for studies evaluating drug metabolism and toxicology using in vitro constructs. PMID:27240736

  9. 3D Cultivation Techniques for Primary Human Hepatocytes

    PubMed Central

    Bachmann, Anastasia; Moll, Matthias; Gottwald, Eric; Nies, Cordula; Zantl, Roman; Wagner, Helga; Burkhardt, Britta; Sánchez, Juan J. Martínez; Ladurner, Ruth; Thasler, Wolfgang; Damm, Georg; Nussler, Andreas K.

    2015-01-01

    One of the main challenges in drug development is the prediction of in vivo toxicity based on in vitro data. The standard cultivation system for primary human hepatocytes is based on monolayer cultures, even if it is known that these conditions result in a loss of hepatocyte morphology and of liver-specific functions, such as drug-metabolizing enzymes and transporters. As it has been demonstrated that hepatocytes embedded between two sheets of collagen maintain their function, various hydrogels and scaffolds for the 3D cultivation of hepatocytes have been developed. To further improve or maintain hepatic functions, 3D cultivation has been combined with perfusion. In this manuscript, we discuss the benefits and drawbacks of different 3D microfluidic devices. For most systems that are currently available, the main issues are the requirement of large cell numbers, the low throughput, and expensive equipment, which render these devices unattractive for research and the drug-developing industry. A higher acceptance of these devices could be achieved by their simplification and their compatibility with high-throughput, as both aspects are of major importance for a user-friendly device.

  10. Effect of matrine on primary human hepatocytes in vitro.

    PubMed

    Gong, Xiaobing; Gao, Yuan; Guo, Guoqing; Vondran, Florian W R; Schwartlander, Ruth; Efimova, Ekaterina; Pless, Gesine; Sauera, Igor M; Neuhaus, Peter

    2015-03-01

    Matrine is a bioactive component of the traditional Chinese medical herb Sophora flavescens that has been used in China to treat various kinds of diseases including virus hepatitis. However, the molecular mechanisms underlying its hepatoprotective effects remains elusive. In the present study, primary human hepatocytes were employed to elucidate the protective effects and molecular mechanisms of matrine. We observed that low concentrations of matrine had no significant impact on albumin secretion, but high concentrations (>140 mg/L) of matrine decreased the albumin secretion in hepatocytes. Western blot data indicated that matrine at 140 mg/L at 72 h induced protein expression of CYP2A6, CYP2B6 and CYP3A4. Furthermore, high concentrations of matrine reduced LDH and AST levels and were cytotoxic to hepatocytes, leading to a decreased cell viability and total protein amount. Moreover, low concentrations of matrine, enhanced the ECOD activity and decreased the level of NO2 (-) induced by cytokines in human hepatocytes. Taken together, the present study sheds novel light on the molecular mechanisms of matrine and potential application of matrine in hepatic diseases.

  11. A Microfabricated Platform for Generating Physiologically-Relevant Hepatocyte Zonation

    NASA Astrophysics Data System (ADS)

    McCarty, William J.; Usta, O. Berk; Yarmush, Martin L.

    2016-05-01

    In vitro liver models have been important tools for more than 40 years for academic research and preclinical toxicity screening by the pharmaceutical industry. Hepatocytes, the highly metabolic parenchymal cells of the liver, are efficient at different metabolic chemistries depending on their relative spatial location along the sinusoid from the portal triad to the central vein. Although replicating hepatocyte metabolic zonation is vitally important for physiologically-relevant in vitro liver tissue and organ models, it is most often completely overlooked. Here, we demonstrate the creation of spatially-controlled zonation across multiple hepatocyte metabolism levels through the application of precise concentration gradients of exogenous hormone (insulin and glucagon) and chemical (3-methylcholanthrene) induction agents in a microfluidic device. Observed gradients in glycogen storage via periodic acid-Schiff staining, urea production via carbamoyl phosphatase synthetase I staining, and cell viability after exposure to allyl alcohol and acetaminophen demonstrated the in vitro creation of hepatocyte carbohydrate, nitrogen, alcohol degradation, and drug conjugation metabolic zonation. This type of advanced control system will be crucial for studies evaluating drug metabolism and toxicology using in vitro constructs.

  12. INTERINDIVIDUAL VARIATION IN THE METABOLISM OF ARSENIC IN HUMAN HEPATOCYTES

    EPA Science Inventory


    The liver is the major site for the enzymatic methylation of inorganic arsenic (iAs) in humans. Primary cultures of normal human hepatocytes isolated from tissue obtained at surgery or from donor livers have been used to study interindividual variation in the capacity of live...

  13. TEMPORAL CHANGE IN GAP JUNCTION FUNCTION IN PRIMARY HEPATOCYTES

    EPA Science Inventory

    TEMPORAL CHANGES IN GAP JUNCTION FUNCTION IN PRIMARY *

    The objective of this study was to examine the reduction in gap junction communication (GJC) in primary hepatocytes due to coincident melatonin and magnetic field treatments to determine if these conditions could prov...

  14. DIFFERENTIATING MECHANISMS OF REACTIVE CHEMICAL TOXICITY IN ISOLATED TROUT HEPATOCYTES

    EPA Science Inventory

    The toxicity of four quinones, 2,3-dimethoxy-1,4-naphthoquinone (DMONQ), 2-methyl 1,4-naphthoquinone (MNQ ),1,4-naphthoquinone (NQ), and 1,4-benzoquinone (BQ), which redox cycle or arlyate in mammalian cells, was determined in isolated trout (Oncorhynchus mykiss) hepatocytes. Mor...

  15. Human hepatocytes and endothelial cells in organotypic membrane systems.

    PubMed

    Salerno, Simona; Campana, Carla; Morelli, Sabrina; Drioli, Enrico; De Bartolo, Loredana

    2011-12-01

    The realization of organotypic liver model that exhibits stable phenotype is a major challenge in the field of liver tissue engineering. In this study we developed liver organotypic co-culture systems by using synthetic and biodegradable membranes with primary human hepatocytes and human umbilical vein endothelial cells (HUVEC). Synthetic membranes prepared by a polymeric blend constituted of modified polyetheretherketone (PEEK-WC) and polyurethane (PU) and biodegradable chitosan membranes were developed by phase inversion technique and used in homotypic and organotypic culture systems. The morphological and functional characteristics of cells in the organotypic co-culture membrane systems were evaluated in comparison with homotypic cultures and traditional systems. Hepatocytes in the organotypic co-culture systems exhibit compact polyhedral cells with round nuclei and well demarcated cell-cell borders like in vivo, as a result of heterotypic interaction with HUVECs. In addition HUVECs formed tube-like structures directly through the interactions with the membranes and hepatocytes and indirectly through the secretion of ECM proteins which secretion improved in the organotypic co-culture membrane systems. The heterotypic cell-cell contacts have beneficial effect on the hepatocyte albumin production, urea synthesis and drug biotransformation. The developed organotypic co-culture membrane systems elicit liver specific functions in vitro and could be applied for the realization of engineered liver tissues to be used in tissue engineering, drug metabolism studies and bioartificial liver devices. PMID:21871658

  16. ARSENICALS INHIBIT THIOREDOXIN REDUCTASE ACTIVITY IN CULTURED RAT HEPATOCYTES

    EPA Science Inventory

    ARSENICALS INHIBIT THIOREDOXIN REDUCTASE ACTIVITY IN CULTURED RAT HEPATOCYTES.

    S. Lin1, L. M. Del Razo1, M. Styblo1, C. Wang2, W. R. Cullen2, and D.J. Thomas3. 1Univ. North Carolina, Chapel Hill, NC; 2Univ. British Columbia, Vancouver, BC, Canada; 3National Health and En...

  17. Mushroom lectin protects arsenic induced apoptosis in hepatocytes of rodents.

    PubMed

    Rana, Tanmoy; Bera, Asit Kumar; Das, Subhashree; Bhattacharya, Debasis; Pan, Diganta; Bandyopadhyay, Subhasish; De, Sumanta; Das, Subrata Kumar

    2011-04-01

    Acute and chronic arsenic exposure result in toxicity both in human and animal beings and cause many hepatic and renal manifestations. The present study stated that mushroom lectin prevents arsenic-induced apoptosis. Apoptosis was measured by morphological alterations, cell proliferation index (CPI), phagocytic activity (nitro blue tetrazolium index; NBT), nitric oxide (NO) production, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, DNA fragmentation and caspase-3 activity. Arsenic exposure at 5 μM in the form of sodium arsenite resulted in significant elevation of deformed cells, NO production, TUNEL stained nuclei of hepatocytes, DNA fragmentation and caspase-3 activity. But the CPI and NBT index were significantly declined in arsenic-treated hepatocytes. The beneficial effect of mushroom lectin at 10 μg/mL, 20 μg/mL and 50 μg/mL) showed increased CPI and phagocytic activity. Mushroom lectin at those concentrations reduced deformed cells, NO production, DNA fragmentation and caspase-3 activity of hepatocytes. But significant better protection was observed in 50 μg/mL mushroom lectin-treated hepatocytes. This finding may be of therapeutic benefit in people suffering from chronic arsenic exposure.

  18. Octylphenol induces vitellogenin production and cell death in fish hepatocytes

    SciTech Connect

    Toomey, B.H.; Monteverdi, G.H.; Di Giulio, R.T.

    1999-04-01

    The effects of octylphenol (OP) on vitellogenin production and cell death in hepatocytes from brown bullhead catfish (Americurus nebulosus) were studied. Production of vitellogenin was induced in hepatocytes exposed to 10 to 50 {micro}M OP, whereas a higher concentration of OP (100 {micro}M) induced apoptotic cell death. By 3 h after the addition of 100 {micro}M OP, dying cells showed chromatin condensation and DNA fragmentation as determined by fluorescence microscopy and gel electrophoresis. Later stages of cell death (nuclear membrane breakdown and cell fragmentation into apoptotic bodies) were identified in cells exposed to OP for at least 6 h. Hepatocytes exposed to 100 {micro}M OP also produced less vitellogenin than cells exposed to 50 {micro}M OP. An estrogen receptor antagonist, tamoxifen, greatly decreased vitellogenin production in OP-exposed hepatocytes from male fish but did not decrease cell death in these cells. Thus, although the ability of OP to induce vitellogenin production is likely mediated through interactions with the estrogen receptor, the induction of apoptotic cell death by OP does not appear to be dependent on its estrogenic activity but may be a more general toxic effect.

  19. Metabolic danger signals, uric acid and ATP, mediate inflammatory cross-talk between hepatocytes and immune cells in alcoholic liver disease.

    PubMed

    Petrasek, Jan; Iracheta-Vellve, Arvin; Saha, Banishree; Satishchandran, Abhishek; Kodys, Karen; Fitzgerald, Katherine A; Kurt-Jones, Evelyn A; Szabo, Gyongyi

    2015-08-01

    Inflammation defines the progression of ALD from reversible to advanced stages. Translocation of bacterial LPS to the liver from the gut is necessary for alcohol-induced liver inflammation. However, it is not known whether endogenous, metabolic danger signals are required for inflammation in ALD. Uric acid and ATP, 2 major proinflammatory danger signals, were evaluated in the serum of human volunteers exposed to a single dose of ethanol or in supernatants of primary human hepatocytes exposed to ethanol. In vitro studies were used to evaluate the role of uric acid and ATP in inflammatory cross-talk between hepatocytes and immune cells. The significance of signaling downstream of uric acid and ATP in the liver was evaluated in NLRP3-deficient mice fed a Lieber-DeCarli ethanol diet. Exposure of healthy human volunteers to a single dose of ethanol resulted in increased serum levels of uric acid and ATP. In vitro, we identified hepatocytes as a significant source of these endogenous inflammatory signals. Uric acid and ATP mediated a paracrine inflammatory cross-talk between damaged hepatocytes and immune cells and significantly increased the expression of LPS-inducible cytokines, IL-1β and TNF-α, by immune cells. Deficiency of NLRP3, a ligand-sensing component of the inflammasome recognizing uric acid and ATP, prevented the development of alcohol-induced liver inflammation in mice and significantly ameliorated liver damage and steatosis. Endogenous metabolic danger signals, uric acid, and ATP are involved in inflammatory cross-talk between hepatocytes and immune cells and play a crucial role in alcohol-induced liver inflammation.

  20. Glycogen synthase kinase 3 regulates IL-1β mediated iNOS expression in hepatocytes by down-regulating c-Jun.

    PubMed

    Lakshmanan, Jaganathan; Zhang, Baochun; Nweze, Ikenna C; Du, Yibo; Harbrecht, Brian G

    2015-01-01

    Excessive nitric oxide from the inducible nitric oxide synthase (iNOS) increases shock-induced hepatic injury, hepatic dysfunction, inflammation, and mortality in animal models. Cytokines increase the expression of iNOS in hepatocytes, but the signaling mechanisms involved are not completely understood. We have previously demonstrated that Akt mediates the inhibitory effect of cAMP and insulin on cytokine-induced hepatocyte iNOS expression. We hypothesized that glycogen synthase kinase 3 (GSK3), a target of Akt phosphorylation, would regulate hepatocyte iNOS expression. In cultured rat hepatocytes, GSK3 inhibitors decreased IL-1β mediated nitric oxide (NO) production and iNOS protein expression, while the phosphatidylinositol 3-kinase (PI3K)/Akt pathway inhibitor LY294002 increased the cytokine-mediated NO production and iNOS expression. Over-expression of the constitutively active form of GSK3β enhanced IL-1β-mediated iNOS expression. GSK3 catalyzes the phosphorylation of c-Jun at the c-terminal Thr239 that facilitates c-Jun degradation. Inhibition of GSK3 with SB216763 and lithium chloride significantly reduced, whereas blocking PI3K/Akt increased phosphorylation of c-Jun at Thr239. The levels of total-c-Jun and c-Jun phosphorylated at Ser63 inversely correlated with c-Jun phosphorylated at Thr239, GSK3 activation and iNOS expression. Over-expression of a dominant negative c-Jun not only caused an increase in IL-1β-mediated iNOS promoter activity and iNOS protein expression but was also able to reverse the SB216763-mediated suppression of iNOS. These results demonstrate that GSK3, a downstream target of Akt, regulates IL-1β-stimulated iNOS expression in hepatocytes by directly phosphorylating c-Jun in an inhibitory manner. PMID:25160751

  1. Metabolism of benzo[a]pyrene and (-)-trans-benzo[a]pyrene-7,8-dihydrodiol by freshly isolated hepatocytes of brown bullheads.

    PubMed

    Steward, A R; Zaleski, J; Sikka, H C

    1990-01-01

    The metabolism of [3H]benzo[a]pyrene (BP) and (-)-trans-[14C]7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP-7,8-diol) was studied in freshly isolated hepatocytes of the wild benthic fish, brown bullhead (Ictalurus nebulosus). Bullhead hepatocytes incubated with 40 microM [3H]BP for 1 h metabolized BP to water soluble metabolites which were separated on silica gel t.l.c. plates to reveal conjugates with glucuronic acid, glutathione, and sulfate (51%, 14% and 4% of total metabolites, respectively). Additional metabolites that were extractable with ethyl acetate were separated by reversed phase HPLC to reveal only two major metabolites: BP-9,10-dihydrodiol and BP-7,8-diol (13% and 2.6% of total metabolites, respectively). Hepatocytes isolated from individual fish displayed an 11-fold variability in the rates at which they metabolized BP (756 +/- 167 pmol x mg dry wt-1 x h-1), which correlated negatively (r = -0.7, P less than 0.01) with an 18-fold variability in the glycogen content of the cells. Hepatocytes isolated from the same fish, in parallel incubations under the same optimum conditions, metabolized BP-7,8-diol 4.5-fold faster than they metabolized BP. The variability in the rate of BP-7,8-diol metabolism was about 7-fold. Major metabolites included glutathione conjugates, glucuronides and sulfates (35%, 25% and 30% of total metabolites, respectively). These conjugates, like those formed from BP, were degradable with gamma-glutamyltransferase, beta-glucuronidase and arylsulfatase, respectively. Ethyl acetate extractable metabolites were predominantly isomeric benzo-ring tetrahydrotetrols (9% of total metabolites). In summary, this study indicates that during short-term incubations bull-head hepatocytes metabolize BP and BP-7,8-diol primarily to conjugated derivatives. The usefulness of thin-layer chromatography for the convenient determination of the rate of BP-7,8-diol metabolism is demonstrated.

  2. Biological effects of sulphated insulin in adipocytes and hepatocytes.

    PubMed

    Zeuzem, S; Taylor, R; Agius, L; Schoeffling, K; Albisser, A M; Alberti, K G

    1985-10-01

    The binding affinity of sulphated insulin compared with unmodified, neutral insulin has been reported to be approximately four times lower in human and rat adipocytes but over twenty times lower in rat hepatocytes. In the present study the biological action of sulphated insulin was assessed in rat hepatocytes and human and rat adipocytes. To achieve half-maximal stimulation of fatty acid synthesis in rat hepatocytes about twenty one times higher concentrations of sulphated than neutral insulin were required (15.07 +/- 5.50 vs 0.71 +/- 0.34 nmol/l), this ratio being similar to the ratio of binding affinity in rat hepatocytes. In human adipocytes, half-maximal stimulation of initial rates of glucose uptake was observed at 11.6 +/- 5.1 vs 2.9 +/- 1.3 pmol/l for sulphated and neutral insulin respectively, and half-maximal inhibition of lipolysis at 31.0 +/- 13.5 vs 7.3 +/- 2.5 pmol/l respectively. These data are consistent with the four-fold lower binding affinity of sulphated insulin to human adipocytes. However, in rat adipocytes the biological potency of sulphated insulin was found to be much lower than anticipated from the binding data, half-maximal stimulation of initial rates of glucose uptake being observed at 757 +/- 299 vs 35 +/- 13 pmol/l respectively and half-maximal inhibition of lipolysis at 35.9 +/- 12.1 vs 1.5 +/- 0.5 pmol/l respectively. Thus, in rat adipocytes, approximately 22 times the concentration of sulphated insulin was required to achieve equivalent biological effect. A discrepancy between binding affinity and biological action with respect to sulphated insulin was identified in rat adipocytes but not human adipocytes nor rat hepatocytes suggesting differences in the binding-action linkage in these cells.

  3. Genomics and proteomics analysis of cultured primary rat hepatocytes.

    PubMed

    Beigel, Juergen; Fella, Kerstin; Kramer, Peter-Juergen; Kroeger, Michaela; Hewitt, Philip

    2008-02-01

    The use of animal models in pharmaceutical research is a costly and sometimes misleading method of generating toxicity data and hence predicting human safety. Therefore, in vitro test systems, such as primary rat hepatocytes, and the developing genomics and proteomics technologies, are playing an increasingly important role in toxicological research. Gene and protein expression analysis were investigated in a time series (up to 5 days) of primary rat hepatocytes cultured on collagen coated dishes. Especially after 24h, a significant down-regulation of many important Phase I and Phase II enzymes (e.g., cytochrome P450's, glutathione-S-transferases, sulfotransferases) involved in xenobiotic metabolism, and antioxidative enzymes (e.g., catalase, superoxide dismutase, glutathione peroxidase) was observed. Acute-phase-response enzymes were frequently up-regulated (e.g., LPS binding protein, alpha-2-macro-globulin, ferritin, serine proteinase inhibitor B, haptoglobin), which is likely to be a result of cellular stress caused by the cell isolation procedure (perfusion) itself. A parallel observation was the increased expression of several structural genes (e.g., beta-actin, alpha-tubulin, vimentin), possibly caused by other proliferating cell types in the culture, such as fibroblasts or alternatively by hepatocyte dedifferentiation. In conclusion, the careful interpretation of data derived from this in vitro system indicates that primary hepatocytes can be successfully used for short-term toxicity studies up to 24h. However, culturing conditions need to be further optimized to reduce the massive changes of gene and protein expression of long-term cultured hepatocytes to allow practical applications as a long-term toxicity test system.

  4. Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

    SciTech Connect

    Ilowski, Maren; Kleespies, Axel; Toni, Enrico N. de; Donabauer, Barbara; Jauch, Karl-Walter; Hengstler, Jan G.; Thasler, Wolfgang E.

    2011-01-07

    Research highlights: {yields} ALR decreases cytochrome c release from mitochondria. {yields} ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. {yields} ALR exerts a liver-specific anti-apoptotic effect. {yields} A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-{beta}, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

  5. HIF-1α and PPARγ during physiological cardiac hypertrophy induced by pregnancy: Transcriptional activities and effects on target genes.

    PubMed

    Soñanez-Organis, José G; Godoy-Lugo, José A; Hernández-Palomares, Magally L E; Rodríguez-Martínez, Daniel; Rosas-Rodríguez, Jesús A; González-Ochoa, Guadalupe; Virgen-Ortiz, Adolfo; Ortiz, Rudy M

    2016-10-15

    Hypoxia inducible factor 1-α (HIF-1α) and peroxisome proliferator-activated receptor γ (PPARγ) are transcription factors that activate genes involved in cellular metabolism. Physiological cardiac hypertrophy induced by pregnancy initiates compensatory changes in metabolism. However, the contributions of HIF-1α and PPARγ to this physiological status and to its reversible, metabolic process (postpartum) in the heart are not well-defined. Therefore, the aim of the present study was to evaluate the transcriptional activities of HIF-1α and PPARγ in the left ventricle of rats before, during, and after pregnancy. Furthermore, the effects of pregnancy on target genes of glycolysis and glycerol-lipid biosynthesis, key regulatory enzymes, and metabolic intermediates were evaluated. The activities of HIF-1α and PPARγ increased 1.2- and 1.6-fold, respectively, during pregnancy, and decreased to basal levels during postpartum. Expressions of mRNA for glucose transport 1 (GLUT1), enzymes of glycolysis (HK2, PFKM, and GAPDH) and glycerol-lipid biosynthesis (GPAT and GPD1) increased 1.6- to 14-fold during pregnancy and returned to basal levels postpartum. The increase in GPD1 expression translated to an increase in its activity, but such was not the case for GAPDH suggesting that post-translational regulation of these proteins is differential during pregnancy. Glycolytic (glucose, lactate, and DHAP) and glycerol-lipid biosynthesis (G3P and FFA) intermediates increased with pregnancy and were maintained postpartum. The results demonstrate that pregnancy-induced, physiological cardiac hypertrophy activates the expression of genes involved in glycolytic and glycerol-lipid biosynthesis suggesting that the shift in cardiac metabolism is mediated by the activation of HIF-1α and PPARγ.

  6. DIETARY SODIUM ALTERS THE PREVALENCE OF ELECTROCARDIOGRAM DETERMINED LEFT VENTRICULAR HYPERTROPHY IN HYPERTENSION

    PubMed Central

    Vaidya, Anand; Bentley-Lewis, Rhonda; Jeunemaitre, Xavier; Adler, Gail K.; Williams, Jonathan S.

    2010-01-01

    BACKGROUND Determination of left ventricular hypertrophy (LVH) via electrocardiogram (ECG) is a known independent risk factor for cardiovascular morbidity and mortality in hypertension. Dietary sodium and hypertension are both associated with unfavorable alterations in left ventricular mass, however to what extent their interplay affects ECG screening for LVH is unclear. METHODS The effects of controlled dietary sodium manipulation on ECG determinants of LVH in hypertensive subjects were evaluated using well established voltage criteria for LVH. ECG’s from 80 hypertensive subjects were evaluated following random sequence assignment to 7 days of high sodium (HS) intake (200 mEq/24h), and then 7 days of low sodium (LS) intake (10 mEq/24h). RESULTS Sodium restriction over 7 days resulted in significant decreases in overall, and LVH-specific, ECG voltages. Most subjects (72%) exhibited decrements in overall ECG voltage with sodium restriction, but a smaller minority (28%) displayed higher voltages when on LS intake (28%). The prevalence of ECG-determined LVH significantly declined with LS diet (HS diet 22/80 [28%] vs. LS diet 8/80 [10%], p<0.05). Subjects exhibiting reversal of LVH status with sodium restriction were younger, demonstrated salt-sensitivity of blood pressure, and lower LVH-specific ECG voltage. CONCLUSIONS Short-term dietary sodium fluctuations can significantly alter overall ECG voltage and the prevalence of ECG-determined LVH in hypertensive individuals. Inclusion of dietary sodium assessment when screening hypertensive subjects for LVH by ECG may improve the consistency of cardiac risk assessment. PMID:19265788

  7. Partial hepatectomy induces delayed hepatocyte proliferation and normal liver regeneration in ovariectomized mice

    PubMed Central

    Umeda, Makoto; Hiramoto, Masaki; Imai, Takeshi

    2015-01-01

    Estrogens play central roles in sexual development, reproduction, and hepatocyte proliferation. The ovaries are one of the main organs for estradiol (E2) production. Ovariectomies (OVXs) were performed on the female mice, and hepatocyte proliferation was analyzed. The ovariectomized mice exhibited delayed hepatocyte proliferation after partial hepatectomy (PH) and also exhibited delayed and reduced E2 induction. Both E2 administration and PH induced the gene expression of estrogen receptor α (ERα). The transcripts of ERα were detected specifically in periportal hepatocytes after E2 administration and PH. Moreover, the E2 concentrations and hepatocyte proliferation rates were highest in the proestrus period of the estrous cycle. Taken together, these findings indicate that E2 accelerated ERα expression in periportal hepatocytes and hepatocyte proliferation in the female mice. PMID:26170710

  8. Identification of small molecules for human hepatocyte expansion and iPS differentiation

    PubMed Central

    Shan, Jing; Schwartz, Robert E.; Ross, Nathan T.; Logan, David J.; Thomas, David; Duncan, Stephen A.; North, Trista E.; Goessling, Wolfram; Carpenter, Anne E.; Bhatia, Sangeeta N.

    2013-01-01

    Cell-based therapies hold the potential to alleviate the growing burden of liver diseases. Such therapies require human hepatocytes, which, within the stromal context of the liver, are capable of many rounds of replication. However, this ability is lost ex vivo and human hepatocyte sourcing has been limiting many fields of research for decades. Here, we developed a high-throughput screening platform for primary human hepatocytes to identify small molecules in two different classes that can be used to generate renewable sources of functional human hepatocytes. One class induced functional proliferation of primary human hepatocytes in vitro. The second class enhanced hepatocyte functions and promoted differentiation of iPS-derived hepatocytes, toward a phenotype more mature than what was previously obtainable. The identification of these small molecules can help to address a major challenge impacting many facets of liver research and may lead to the development of novel therapeutics for liver diseases. PMID:23728495

  9. A new syndrome of short stature, joint limitation and muscle hypertrophy.

    PubMed

    Soljak, M A; Aftimos, S; Gluckman, P D

    1983-06-01

    A further case is presented of a new growth deficiency syndrome first reported by Myre et al. in 1981. The major clinical features are mental retardation, growth deficiency, muscular hypertrophy, joint limitation and abnormal skeletal radiography. PMID:6684009

  10. [Obstructive sleep apnea-hypopnea syndrome in children: beyond adenotonsillar hypertrophy].

    PubMed

    Esteller, Eduard

    2015-01-01

    The prevalence of obstructive sleep apnea-hypopnea syndrome in the general childhood population is 1-2% and the most common cause is adenotonsillar hypertrophy. However, beyond adenotonsillar hypertrophy, there are other highly prevalent causes of this syndrome in children. The causes are often multifactorial and include muscular hypotonia, dentofacial abnormalities, soft tissue hypertrophy of the airway, and neurological disorders). Collaboration between different specialties involved in the care of these children is essential, given the wide variability of conditions and how frequently different factors are involved in their genesis, as well as the different treatments to be applied. We carried out a wide literature review of other causes of obstructive sleep apnea-hypopnea syndrome in children, beyond adenotonsillar hypertrophy. We organised the prevalence of this syndrome in each pathology and the reasons that cause it, as well as their interactions and management, in a consistent manner.

  11. The mechanosensitive APJ internalization via clathrin-mediated endocytosis: A new molecular mechanism of cardiac hypertrophy.

    PubMed

    He, Lu; Chen, Linxi; Li, Lanfang

    2016-05-01

    The G protein-coupled receptor APJ elicits cellular response to diverse extracellular stimulus. Accumulating evidence reveals that APJ receptor plays a prominent role in the cardiomyocyte adapting to hypertrophic stimulation. At present, it remains obscure that the regulatory mechanism of APJ receptor in myocardial hypertrophy. The natural endogenous ligands apelin and Elabela as well as agonists maintain high affinity for the APJ receptor and drive its internalization. Ligand-activated receptor internalization is mainly performed by clathrin-mediated endocytic pathway. Simultaneously, clathrin-mediated endocytosis takes participate in the occurrence and development of cardiac hypertrophy. In this study, we hypothesize that natural ligands and agonists induce the mechanosensitive APJ internalization via clathrin-mediated endocytosis. APJ internalization may contribute to the development of cardiac hypertrophy. The mechanosensitive APJ internalization via clathrin-mediated endocytosis may be a new molecular mechanism of cardiac hypertrophy. PMID:27063076

  12. Thymic involution in the suspended rat - Adrenal hypertrophy and glucocorticoid receptor content

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.; Musacchia, X. J.

    1986-01-01

    The relationship between thymic involution and adrenal hypertrophy is studied. The thymus, adrenal glands, and tissue water content are evaluated in male Sprague rats suspended in antiorthostatic (AO) or orthostatic (O) positions. A 50 percent decrease in the wet weight of the thymus and hypertrophy of the adrenal glands are observed during the seven days of AO suspension. After seven days of recovery the thymus weight is increased to control level; however, the hypertrophy of the adrenal glands remains unchanged. Thymic and renal responses in O postioned rats are similar to AO reactions. Thymic glucocorticoid (GC) receptor concentrations in the rats are analyzed; a 20 percent decrease in GC receptor site concentration, which is related to thymic involution, is detected in both AO and O rats. It is concluded that there is a temporal correlation between thymic involution and adrenal hypertrophy, which is not affected by AO positioning, and thymic involution is not associated with an increased sensitivity to GC.

  13. [Obstructive sleep apnea-hypopnea syndrome in children: beyond adenotonsillar hypertrophy].

    PubMed

    Esteller, Eduard

    2015-01-01

    The prevalence of obstructive sleep apnea-hypopnea syndrome in the general childhood population is 1-2% and the most common cause is adenotonsillar hypertrophy. However, beyond adenotonsillar hypertrophy, there are other highly prevalent causes of this syndrome in children. The causes are often multifactorial and include muscular hypotonia, dentofacial abnormalities, soft tissue hypertrophy of the airway, and neurological disorders). Collaboration between different specialties involved in the care of these children is essential, given the wide variability of conditions and how frequently different factors are involved in their genesis, as well as the different treatments to be applied. We carried out a wide literature review of other causes of obstructive sleep apnea-hypopnea syndrome in children, beyond adenotonsillar hypertrophy. We organised the prevalence of this syndrome in each pathology and the reasons that cause it, as well as their interactions and management, in a consistent manner. PMID:25107357

  14. Mechanoelectrical remodeling and arrhythmias during progression of hypertrophy

    PubMed Central

    Jin, Hongwei; Chemaly, Elie R.; Lee, Ahyoung; Kho, Changwon; Hadri, Lahouaria; Hajjar, Roger J.; Akar, Fadi G.

    2010-01-01

    Despite a clear association between left ventricular (LV) mechanical dysfunction in end-stage heart failure and the incidence of arrhythmias, the majority of sudden cardiac deaths occur at earlier stages of disease development. The mechanisms by which structural, mechanical, and molecular alterations predispose to arrhythmias at the tissue level before the onset of LV dysfunction remain unclear. In a rat model of pressure overload hypertrophy (PoH) produced by ascending aortic banding, we correlated mechanical and structural changes measured in vivo with key electrophysiological changes measured ex vivo in the same animals. We found that action potential prolongation, a hallmark of electrical remodeling at the tissue level, is highly correlated with changes in LV wall thickness but not mechanical function. In contrast, conduction delays are not predicted by either mechanical or structural changes during disease development. Moreover, disrupted Cx43 phosphorylation at intermediate (increased) and late (decreased) stages of PoH are associated with moderate and severe conduction delays, respectively. Interestingly, the level of interaction between Cx43 and the cytoskeletal protein ZO-1 is exclusively decreased at the late stage of PoH. Closely coupled action potentials consistent with afterdepolarization-mediated triggered beats were readily observed in 6 of 15 PoH hearts but never in controls. Similarly, PoH (8/15) but not control hearts exhibited sustained episodes of ventricular tachycardia after rapid stimulation. The initiation and early maintenance of arrhythmias in PoH were formed by rapid and highly uniform activation wavefronts emanating from sites distal to the former site of stimulation. In conclusion, repolarization but not conduction delays are predicted by structural remodeling in PoH. Cx43 phosphorylation is disrupted at intermediate (increased) and late (decreased) stages, which are associated with conduction delays. Dephosphorylation of Cx43 is

  15. Recovery potential of hepatocytes from inhibition of albumin secretion by cadmium

    SciTech Connect

    Wan, X.; Lachapelle, M.; Marion, M.; Fournier, M.; Denizeau, F. )

    1993-01-01

    The aim of this study was to examine albumin production, a typical liver-specific function, in hepatocytes treated with Cd and to examine the reversibility of the perturbations induced by the toxic metal. Cultures of freshly isolated rat hepatocytes were exposed to increasing amounts of Cd in modified Leibowitz L-15 medium for 20 h; the cells were then allowed to recovery by further incubation in Cd-free medium for an additional period of 20 h. The levels of albumin secreted into the extracellular medium were determined by enzyme-linked immunosorbent assay and were found to be reduced by Cd in a concentration-dependent fashion over the first 20 h. Inhibition was seen at Cd concentrations that did not cause any loss of cellular viability (up to 0.5 [mu]M Cd), as judged form the release of lactate dehydrogenase by the cells. After replacement of the exposure medium by Cd-free medium, the same pattern of diminished albumin secretion was obtained, revealing the persistence of the cytotoxic effects when recovery conditions were applied. Moreover, hepatocytes exposed to 0.5 [mu]M Cd for 20 h and processed for visualization of albumin immunoreactive sites using protein A-gold and electron microscopy exhibited very low albumin-specific labeling as compared to the controls (0.6 [+-] 0.05 vs. 20.0 [+-] 2.6 gold particles/[mu]m[sup 2]). Intracellular glutathione levels were not significantly changed by Cd either after the initial exposure or after the incubation that followed in control medium. The accumulation of Cd by the cells, as measured by graphite furnace atomic absorption spectrophotometry, was concentration dependent. It remained stable after medium change, indicating that Cd efflux was negligible upon reestablishment of normal conditions. The present data show that the perturbations in albumin metabolism caused by Cd are not readily alleviated after the cells are returned to Cd-free medium, suggesting a limited short-term recovery potential against cytotoxic damage.

  16. Involvement of pRB family in TGF beta-dependent epithelial cell hypertrophy

    PubMed Central

    1995-01-01

    Although renal hypertrophy is often associated with the progressive loss of renal function, the mechanism of hypertrophy is poorly understood. In both primary cultures of rabbit proximal tubules and NRK- 52E cells (a renal epithelial cell line), transforming growth factor beta 1 (TGF beta) converted epidermal growth factor (EGF)-induced hyperplasia into hypertrophy. TGF beta did not affect EGF-induced increases in c-fos mRNA abundance or cyclin E protein abundance, but inhibited EGF-induced entry into S, G2, and M phases. EGF alone increased the amount of hyperphosphorylated (inactive) pRB; TGF beta blocked EGF-induced pRB phosphorylation, maintaining pRB in the active form. To determine the importance of active pRB in TGF beta-induced hypertrophy, NRK-52E cells were infected with SV40 large T antigen (which inactivates pRB and related proteins and p53), HPV16 E6 (which degrades p53), HPV16 E7 (which binds and inactivates pRB and related proteins), or both HPV16 E6 and E7. In SV40 large T antigen expressing clones, the magnitude of EGF + TGF beta-induced hypertrophy was inhibited and was inversely related to the magnitude of SV40 large T antigen expression. In the HPV16-infected cells, EGF + TGF beta-induced hypertrophy was inhibited in E7- and E6E7-expressing, but not E6- expressing cells. These results suggest a requirement for active pRB in the development of EGF + TGF beta-induced renal epithelial cell hypertrophy. We suggest a model of renal cell hypertrophy mediated by EGF-induced entry into the cell cycle with TGF beta-induced blockade at G1/S, the latter due to maintained activity of pRB or a related protein. PMID:7698989

  17. Ubiquitin-Specific Protease 4 Is an Endogenous Negative Regulator of Pathological Cardiac Hypertrophy.

    PubMed

    He, Ben; Zhao, Yi-Chao; Gao, Ling-Chen; Ying, Xiao-Ying; Xu, Long-Wei; Su, Yuan-Yuan; Ji, Qing-Qi; Lin, Nan; Pu, Jun

    2016-06-01

    Dysregulation of the ubiquitin proteasome system components ubiquitin ligases and proteasome plays an important role in the pathogenesis of cardiac hypertrophy. However, little is known about the role of another ubiquitin proteasome system component, the deubiquitinating enzymes, in cardiac hypertrophy. Here, we revealed a crucial role of ubiquitin specific protease 4 (USP4), a deubiquitinating enzyme prominently expressed in the heart, in attenuating pathological cardiac hypertrophy and dysfunction. USP4 levels were consistently decreased in human failing hearts and in murine hypertrophied hearts. Adenovirus-mediated gain- and loss-of-function approaches indicated that deficiency of endogenous USP4 promoted myocyte hypertrophy induced by angiotensin II in vitro, whereas restoration of USP4 significantly attenuated the prohypertrophic effect of angiotensin II. To corroborate the role of USP4 in vivo, we generated USP4 global knockout mice and mice with cardiac-specific overexpression of USP4. Consistent with the in vitro study, USP4 depletion exacerbated the hypertrophic phenotype and cardiac dysfunction in mice subjected to pressure overload, whereas USP4 transgenic mice presented ameliorated pathological cardiac hypertrophy compared with their control littermates. Molecular analysis revealed that USP4 deficiency augmented the activation of the transforming growth factor β-activated kinase 1 (TAK1)-(JNK1/2)/P38 signaling in response to hypertrophic stress, and blockage of TAK1 activation abolished the pathological effects of USP4 deficiency in vivo. These findings provide the first evidence for the involvement of USP4 in cardiac hypertrophy, and shed light on the therapeutic potential of targeting USP4 in the treatment of cardiac hypertrophy.

  18. Stenosing tenosynovitis of the peroneus brevis tendon associated with hypertrophy of the peroneal tubercle.

    PubMed

    Boya, Hakan; Pinar, Halit

    2010-01-01

    Stenosing peroneal tenosynovitis is not an uncommon ailment. It has a number of different causes, one of which is hypertrophy of the peroneal tubercle. In this report, we present a case of stenosing tenosynovitis of the peroneus brevis tendon associated with hypertrophy of the peroneal tubercle without involvement of the peroneus longus tendon. The condition was fully resolved by means of operative treatment. PMID:20188282

  19. Negative feedback regulation of Homer 1a on norepinephrine-dependent cardiac hypertrophy

    SciTech Connect

    Chiarello, Carmelina; Bortoloso, Elena; Carpi, Andrea; Furlan, Sandra; Volpe, Pompeo

    2013-07-15

    Homers are scaffolding proteins that modulate diverse cell functions being able to assemble signalling complexes. In this study, the presence, sub-cellular distribution and function of Homer 1 was investigated. Homer 1a and Homer 1b/c are constitutively expressed in cardiac muscle of both mouse and rat and in HL-1 cells, a cardiac cell line. As judged by confocal immunofluorescence microscopy, Homer 1a displays sarcomeric and peri-nuclear localization. In cardiomyocytes and cultured HL-1 cells, the hypertrophic agonist norepinephrine (NE) induces α{sub 1}-adrenergic specific Homer 1a over-expression, with a two-to-three-fold increase within 1 h, and no up-regulation of Homer 1b/c, as judged by Western blot and qPCR. In HL-1 cells, plasmid-driven over-expression of Homer 1a partially antagonizes activation of ERK phosphorylation and ANF up-regulation, two well-established, early markers of hypertrophy. At the morphometric level, NE-induced increase of cell size is likewise and partially counteracted by exogenous Homer 1a. Under the same experimental conditions, Homer 1b/c does not have any effect on ANF up-regulation nor on cell hypertrophy. Thus, Homer 1a up-regulation is associated to early stages of cardiac hypertrophy and appears to play a negative feedback regulation on molecular transducers of hypertrophy. -- Highlights: • Homer 1a is constitutively expressed in cardiac tissue. • In HL-1 cells, norepinephrine activates signaling pathways leading to hypertrophy. • Homer 1a up-regulation is an early event of norepinephrine-induced hypertrophy. • Homer 1a plays a negative feedback regulation modulating pathological hypertrophy. • Over-expression of Homer 1a per se does not induce hypertrophy.

  20. Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

    SciTech Connect

    Dever, Joseph T.; Elfarra, Adnan A.

    2009-05-01

    L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 {sup o}C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increases in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.

  1. Chemically induced hepatotoxicity in human stem cell-induced hepatocytes compared with primary hepatocytes and HepG2.

    PubMed

    Kang, Seok-Jin; Lee, Hyuk-Mi; Park, Young-Il; Yi, Hee; Lee, Hunjoo; So, ByungJae; Song, Jae-Young; Kang, Hwan-Goo

    2016-10-01

    Stem cell-induced hepatocytes (SC-iHeps) have been suggested as a valuable model for evaluating drug toxicology. Here, human-induced pluripotent stem cells (QIA7) and embryonic stem cells (WA01) were differentiated into hepatocytes, and the hepatotoxic effects of acetaminophen (AAP) and aflatoxin B1 (AFB1) were compared with primary hepatocytes (p-Heps) and HepG2. In a cytotoxicity assay, the IC50 of SC-iHeps was similar to that in p-Heps and HepG2 in the AAP groups but different from that in p-Heps of the AFB1 groups. In a multi-parameter assay, phenotypic changes in mitochondrial membrane potential, calcium influx and oxidative stress were similar between QIA7-iHeps and p-Heps following AAP and AFB1 treatment but relatively low in WA01-iHeps and HepG2. Most hepatic functional markers (hepatocyte-specific genes, albumin/urea secretion, and the CYP450 enzyme activity) were decreased in a dose-dependent manner following AAP and AFB1 treatment in SC-iHeps and p-Heps but not in HepG2. Regarding CYP450 inhibition, the cell viability of SC-iHeps and p-Heps was increased by ketoconazole, a CYP3A4 inhibitor. Collectively, SC-iHeps and p-Heps showed similar cytotoxicity and hepatocyte functional effects for AAP and AFB1 compared with HepG2. Therefore, SC-iHeps have phenotypic characteristics and sensitivity to cytotoxic chemicals that are more similar to p-Heps than to HepG2 cells.

  2. miR-218 Involvement in Cardiomyocyte Hypertrophy Is Likely through Targeting REST

    PubMed Central

    Liu, Jing-Jing; Zhao, Cui-Mei; Li, Zhi-Gang; Wang, Yu-Mei; Miao, Wei; Wu, Xiu-Juan; Wang, Wen-Jing; Liu, Chang; Wang, Duo; Wang, Kang; Li, Li; Peng, Lu-Ying

    2016-01-01

    MicroRNAs (miRNAs) have been identified as key players in cardiomyocyte hypertrophy, which is associated with significant risks of heart failure. However, many microRNAs are still not recognized for their functions in pathophysiological processes. In this study, we evaluated effects of miR-218 in cardiomyocyte hypertrophy using both in vitro and in vivo models. We found that miR-218 was evidently downregulated in a transverse aortic constriction (TAC) mouse model. Overexpression of miR-218 is sufficient to reduce hypertrophy, whereas the suppression of miR-218 aggravates hypertrophy in primary cardiomyocytes induced by isoprenaline (ISO). In addition, we identified RE1-silencing transcription factor (REST) as a novel target of miR-218; it negatively regulated the expression of REST in hypertrophic cardiomyocytes and the TAC model. These results showed that miR-218 plays a crucial role in cardiomyocyte hypertrophy, likely via targeting REST, suggesting a potential candidate target for interfering hypertrophy. PMID:27258257

  3. Cyclin D2 induces proliferation of cardiac myocytes and represses hypertrophy

    SciTech Connect

    Busk, Peter K. . E-mail: pkbu@novonordisk.com; Hinrichsen, Rebecca; Bartkova, Jirina; Hansen, Ane H.; Christoffersen, Tue E.H.; Bartek, Jiri; Haunso, Stig

    2005-03-10

    The myocytes of the adult mammalian heart are considered unable to divide. Instead, mitogens induce cardiomyocyte hypertrophy. We have investigated the effect of adenoviral overexpression of cyclin D2 on myocyte proliferation and morphology. Cardiomyocytes in culture were identified by established markers. Cyclin D2 induced DNA synthesis and proliferation of cardiomyocytes and impaired hypertrophy induced by angiotensin II and serum. At the molecular level, cyclin D2 activated CDK4/6 and lead to pRB phosphorylation and downregulation of the cell cycle inhibitors p21{sup Waf1/Cip1} and p27{sup Kip1}. Expression of the CDK4/6 inhibitor p16 inhibited proliferation and cyclin D2 overexpressing myocytes became hypertrophic under such conditions. Inhibition of hypertrophy by cyclin D2 correlated with downregulation of p27{sup Kip1}. These data show that hypertrophy and proliferation are highly related processes and suggest that cardiomyocyte hypertrophy is due to low amounts of cell cycle activators unable to overcome the block imposed by cell cycle inhibitors. Cell cycle entry upon hypertrophy may be converted to cell division by increased expression of activators such as cyclin D2.

  4. Syndecan-4 Signaling Is Required for Exercise-Induced Cardiac Hypertrophy

    PubMed Central

    Xie, Jun; He, Guixin; Chen, Qinhua; Sun, Jiayin; Dai, Qin; Lu, Jianrong; Li, Guannan; Wu, Han; Li, Ran; Chen, Jianzhou; Xu, Wei; Xu, Biao

    2016-01-01

    Cardiac hypertrophy can be broadly classified as either physiological or pathological. Physiological stimuli such as exercise cause adaptive cardiac hypertrophy and normal heart function. Pathological stimuli including hypertension and aortic valvular stenosis cause maladaptive cardiac remodeling and ultimately heart failure. Syndecan-4 (synd4) is a transmembrane proteoglycan identified as being involved in cardiac adaptation after injury, but whether it takes part in physiological cardiac hypertrophy is unclear. We observed upregulation of synd4 in exercise-induced hypertrophic myocardium. To evaluate the role of synd4 in the physiological form of cardiac hypertrophy, mice lacking synd4 (synd4–/–) were exercised by swimming for 4 wks. Ultrasonic cardiogram (UCG) and histological analysis revealed that swimming induced the hypertrophic phenotype but was blunted in synd4–/– compared with wild-type (WT) mice. The swimming-induced activation of Akt, a key molecule in physiological hypertrophy was also more decreased than in WT controls. In cultured cardiomyocytes, synd4 overexpression could induce cell enlargement, protein synthesis and distinct physiological molecular alternation. Akt activation also was observed in synd4-overexpressed cardiomyocytes. Furthermore, inhibition of protein kinase C (PKC) prevented the synd4-induced hypertrophic phenotype and Akt phosphorylation. This study identified an essential role of synd4 in mediation of physiological cardiac hypertrophy. PMID:26835698

  5. Proteasome inhibitors attenuated cholesterol-induced cardiac hypertrophy in H9c2 cells.

    PubMed

    Lee, Hyunjung; Park, Jinyoung; Kim, Eunice EunKyeong; Yoo, Young Sook; Song, Eun Joo

    2016-05-01

    The Ubiquitin proteasome system (UPS) plays roles in protein degradation, cell cycle control, and growth and inflammatory cell signaling. Dysfunction of UPS in cardiac diseases has been seen in many studies. Cholesterol acts as an inducer of cardiac hypertrophy. In this study, the effect of proteasome inhibitors on the cholesterol-induced hypertrophic growth in H9c2 cells is examined in order to observe whether UPS is involved in cardiac hypertrophy. The treatment of proteasome inhibitors MG132 and Bortezomib markedly reduced cellular surface area and mRNA expression of β-MHC in cholesterol-induced cardiac hypertrophy. In addition, activated AKT and ERK were significantly attenuated by MG132 and Bortezomib in cholesterol- induced cardiac hypertrophy. We demonstrated that cholesterol- induced cardiac hypertrophy was suppressed by proteasome inhibitors. Thus, regulatory mechanism of cholesterol- induced cardiac hypertrophy by proteasome inhibitors may provide a new therapeutic strategy to prevent the progression of heart failure. [BMB Reports 2016; 49(5): 270-275]. PMID:26592933

  6. The effect of inter-set rest intervals on resistance exercise-induced muscle hypertrophy.

    PubMed

    Henselmans, Menno; Schoenfeld, Brad J

    2014-12-01

    Due to a scarcity of longitudinal trials directly measuring changes in muscle girth, previous recommendations for inter-set rest intervals in resistance training programs designed to stimulate muscular hypertrophy were primarily based on the post-exercise endocrinological response and other mechanisms theoretically related to muscle growth. New research regarding the effects of inter-set rest interval manipulation on resistance training-induced muscular hypertrophy is reviewed here to evaluate current practices and provide directions for future research. Of the studies measuring long-term muscle hypertrophy in groups employing different rest intervals, none have found superior muscle growth in the shorter compared with the longer rest interval group and one study has found the opposite. Rest intervals less than 1 minute can result in acute increases in serum growth hormone levels and these rest intervals also decrease the serum testosterone to cortisol ratio. Long-term adaptations may abate the post-exercise endocrinological response and the relationship between the transient change in hormonal production and chronic muscular hypertrophy is highly contentious and appears to be weak. The relationship between the rest interval-mediated effect on immune system response, muscle damage, metabolic stress, or energy production capacity and muscle hypertrophy is still ambiguous and largely theoretical. In conclusion, the literature does not support the hypothesis that training for muscle hypertrophy requires shorter rest intervals than training for strength development or that predetermined rest intervals are preferable to auto-regulated rest periods in this regard.

  7. Proteasome inhibitors attenuated cholesterol-induced cardiac hypertrophy in H9c2 cells

    PubMed Central

    Lee, Hyunjung; Park, Jinyoung; Kim, Eunice EunKyeong; Yoo, Young Sook; Song, Eun Joo

    2016-01-01

    The Ubiquitin proteasome system (UPS) plays roles in protein degradation, cell cycle control, and growth and inflammatory cell signaling. Dysfunction of UPS in cardiac diseases has been seen in many studies. Cholesterol acts as an inducer of cardiac hypertrophy. In this study, the effect of proteasome inhibitors on the cholesterol-induced hypertrophic growth in H9c2 cells is examined in order to observe whether UPS is involved in cardiac hypertrophy. The treatment of proteasome inhibitors MG132 and Bortezomib markedly reduced cellular surface area and mRNA expression of β-MHC in cholesterol-induced cardiac hypertrophy. In addition, activated AKT and ERK were significantly attenuated by MG132 and Bortezomib in cholesterol-induced cardiac hypertrophy. We demonstrated that cholesterol-induced cardiac hypertrophy was suppressed by proteasome inhibitors. Thus, regulatory mechanism of cholesterol-induced cardiac hypertrophy by proteasome inhibitors may provide a new therapeutic strategy to prevent the progression of heart failure. [BMB Reports 2016; 49(5): 270-275] PMID:26592933

  8. G protein-coupled receptor 56 regulates mechanical overload-induced muscle hypertrophy

    PubMed Central

    White, James P.; Wrann, Christiane D.; Rao, Rajesh R.; Nair, Sreekumaran K.; Jedrychowski, Mark P.; You, Jae-Sung; Martínez-Redondo, Vicente; Gygi, Steven P.; Ruas, Jorge L.; Hornberger, Troy A.; Wu, Zhidan; Glass, David J.; Piao, Xianhua; Spiegelman, Bruce M.

    2014-01-01

    Peroxisome proliferator-activated receptor gamma coactivator 1-alpha 4 (PGC-1α4) is a protein isoform derived by alternative splicing of the PGC1α mRNA and has been shown to promote muscle hypertrophy. We show here that G protein-coupled receptor 56 (GPR56) is a transcriptional target of PGC-1α4 and is induced in humans by resistance exercise. Furthermore, the anabolic effects of PGC-1α4 in cultured murine muscle cells are dependent on GPR56 signaling, because knockdown of GPR56 attenuates PGC-1α4–induced muscle hypertrophy in vitro. Forced expression of GPR56 results in myotube hypertrophy through the expression of insulin-like growth factor 1, which is dependent on Gα12/13 signaling. A murine model of overload-induced muscle hypertrophy is associated with increased expression of both GPR56 and its ligand collagen type III, whereas genetic ablation of GPR56 expression attenuates overload-induced muscle hypertrophy and associated anabolic signaling. These data illustrate a signaling pathway through GPR56 which regulates muscle hypertrophy associated with resistance/loading-type exercise. PMID:25336758

  9. Physiological activation of Akt by PHLPP1 deletion protects against pathological hypertrophy

    PubMed Central

    Moc, Courtney; Taylor, Amy E.; Chesini, Gino P.; Zambrano, Cristina M.; Barlow, Melissa S.; Zhang, Xiaoxue; Gustafsson, Åsa B.; Purcell, Nicole H.

    2015-01-01

    Aims To examine the role of physiological Akt signalling in pathological hypertrophy through analysis of PHLPP1 (PH domain leucine-rich repeat protein phosphatase) knock-out (KO) mice. Methods and results To investigate the in vivo requirement for ‘physiological’ control of Akt activation in cardiac growth, we examined the effect of deleting the Akt phosphatase, PHLPP, on the induction of cardiac hypertrophy. Basal Akt phosphorylation increased nearly two-fold in the cardiomyocytes from PHLPP1 KO mice and physiological hypertrophy induced by swimming exercise was accentuated as assessed by increased heart size and myocyte cell area. In contrast, the development of pathophysiological hypertrophy induced by pressure overload and assessed by increases in heart size, myocyte cell area, and hypertrophic gene expression was attenuated. This attenuation coincided with decreased fibrosis and cell death in the KO mice. Cast moulding revealed increased capillary density basally in the KO hearts, which was further elevated relative to wild-type mouse hearts in response to pressure overload. In vitro studies with isolated myocytes in co-culture also demonstrated that PHLPP1 deletion in cardiomyocytes can enhance endothelial tube formation. Expression of the pro-angiogenic factor VEGF was also elevated basally and accentuated in response to transverse aortic constriction in hearts from KO mice. Conclusion Our data suggest that enhancing Akt activity by inhibiting its PHLPP1-mediated dephosphorylation promotes processes associated with physiological hypertrophy that may be beneficial in attenuating the development of pathological hypertrophy. PMID:25411382

  10. Cardiac hypertrophy in chick embryos induced by hypothermia

    SciTech Connect

    Boehm, C.; Johnson, T.R.; Caston, J.D.; Przybylski, R.J.

    1987-01-01

    A decrease in incubation temperature from 38 to 32/sup 0/C elicits a decrease in chicken embryo size and weight with concomitant heart enlargement if done after day 10 of incubation. When assayed at day 18 of incubation with the hypothermia started on day 11 or 14, evidence is presented that the heart enlargement is an hypertrophy with no detectable hyperplasia. Supporting data are presented for various physical parameters showing increases in heart wet and dry weight, volume, area, wall thickness, and cell size. There was little difference in DNA content and nuclear (/sup 3/H)thymidine labeling index between hearts of control and hypothermic embryos. Hearts of hypothermic embryos showed a slight increase in water content and considerable increases in RNA, protein, and glycogen content per unit DNA. The average size of polysomes isolated from hypothermic hearts was larger than that of polysomes isolated from controls. Microscopic studies showed no obvious increase in amount of capillary beds, connective tissue, and myocardial cells. Annulate lamellae were found only in myocardial cells of hypothermic embryos in sparse amounts and low frequency but always associated with large deposits of glycogen.

  11. Surgical therapy for benign prostatic hypertrophy/bladder outflow obstruction

    PubMed Central

    Thiruchelvam, Nikesh

    2014-01-01

    Monopolar transurethral resection of the prostate (TURP) with endoscopic electrocautery remains the gold standard surgical technique for benign prostatic hypertrophy (BPH) by which all new procedures are compared. We reviewed the current literature, and international urological guidelines and consensus opinion on various surgical options for BPH and present a brief overview of alternative techniques including bipolar TURP, transurethral incision of the prostate, transurethral vaporization of the prostate, laser prostatectomy (with holmium, thulium and potassium titanyl phosphate greenlight lasers) and open prostatectomy (with mention of new techniques including laparoscopic and robotic prostatectomy). Emerging, experimental and less established techniques are also described including endoscopic heat generation (transurethral microwave thermotherapy, radiofrequency transurethral needle ablation of the prostate, high intensity focused ultrasound, hot water induced thermotherapy, pulsed electromagnetic radiofrequency), injection therapy (transurethral ethanol ablation and botulinum toxin) and mechanical devices (intraprostatic stents and urethral lift devices). Despite a plethora of surgical options, none have realistically improved outcomes in the long-term compared with TURP. Improvements have been made on improving surgical morbidity and time in hospital. Questions remain in this area, including what specific elements of bladder outflow obstruction (BOO) result in damage to the urinary tract, how does BPH contribute to BOO and how much prostate volume reduction is necessary to relieve BOO or lower urinary tract symptoms. Given these unanswered questions and the multitude of procedures available, it is clear that appropriate counselling is necessary in all men who undergo BPH surgery. PMID:24744521

  12. Defining Left Ventricular Hypertrophy in Children on Peritoneal Dialysis

    PubMed Central

    Bakkaloglu, Sevcan A.; Zaritsky, Joshua; Suarez, Angela; Wong, William; Ranchin, Bruno; Qi, Cao; Szabo, Attila J.; Coccia, Paula A.; Harambat, Jérôme; Mitu, Florin; Warady, Bradley A.; Schaefer, Franz

    2011-01-01

    Summary Background and objectives Left ventricular hypertrophy (LVH) is an important end point of dialysis-associated cardiovascular disease. The objective of this study was to evaluate the effect of different pediatric reference systems on the estimated prevalence of LVH in children on chronic peritoneal dialysis (CPD). Design, setting, participants, & measurements Echocardiographic studies in 507 pediatric CPD patients from neonatal age to 19 years were collected in 55 pediatric dialysis units around the globe. We compared the prevalence of LVH on the basis of the traditional cutoff of left ventricular mass (LVM) index (>38.5 g/m2.7) with three novel definitions of LVH that were recently established in healthy pediatric cohorts. Results Application of the new reference systems eliminated the apparently increased prevalence of LVH in young children obtained by the traditional fixed LVM index cutoff currently still recommended by consensus guidelines. However, substantial differences of LVM distribution between the new reference charts resulted in a marked discrepancy in estimated LVH prevalence ranging between 27.4% and 51.7%. Conclusions Although our understanding of the anthropometric determinants of heart size during childhood is improving, more consistent normative echocardiographic data from large populations of healthy children are required for cardiovascular diagnostics and research. PMID:21737857

  13. Integrin activation and focal complex formation in cardiac hypertrophy

    NASA Technical Reports Server (NTRS)

    Laser, M.; Willey, C. D.; Jiang, W.; Cooper, G. 4th; Menick, D. R.; Zile, M. R.; Kuppuswamy, D.

    2000-01-01

    Cardiac hypertrophy is characterized by both remodeling of the extracellular matrix (ECM) and hypertrophic growth of the cardiocytes. Here we show increased expression and cytoskeletal association of the ECM proteins fibronectin and vitronectin in pressure-overloaded feline myocardium. These changes are accompanied by cytoskeletal binding and phosphorylation of focal adhesion kinase (FAK) at Tyr-397 and Tyr-925, c-Src at Tyr-416, recruitment of the adapter proteins p130(Cas), Shc, and Nck, and activation of the extracellular-regulated kinases ERK1/2. A synthetic peptide containing the Arg-Gly-Asp (RGD) motif of fibronectin and vitronectin was used to stimulate adult feline cardiomyocytes cultured on laminin or within a type-I collagen matrix. Whereas cardiocytes under both conditions showed RGD-stimulated ERK1/2 activation, only collagen-embedded cells exhibited cytoskeletal assembly of FAK, c-Src, Nck, and Shc. In RGD-stimulated collagen-embedded cells, FAK was phosphorylated only at Tyr-397 and c-Src association occurred without Tyr-416 phosphorylation and p130(Cas) association. Therefore, c-Src activation is not required for its cytoskeletal binding but may be important for additional phosphorylation of FAK. Overall, our study suggests that multiple signaling pathways originate in pressure-overloaded heart following integrin engagement with ECM proteins, including focal complex formation and ERK1/2 activation, and many of these pathways can be activated in cardiomyocytes via RGD-stimulated integrin activation.

  14. Contact laser vaporization of the prostate for benign prostatic hypertrophy

    NASA Astrophysics Data System (ADS)

    Gomella, Leonard G.; Lotfi, M. A.; Milam, Douglas F.; Albala, David; Reagan, Gary

    1994-05-01

    The contact laser applications for the removal of the enlarged prostate are distinctly different than the majority of non-contact Nd:YAG lasers that rely on coagulation necrosis and delayed sloughing. Contact Nd:YAG laser allows cutting, coagulation and vaporization of tissue with minimal penetration beyond the contact surface. Using the contact laser prostatectomy technique, the contact laser probe directly touches and immediately vaporizes the prostatic tissue under the probe. The net result is the immediate removal of the obstructing tissue, in a manner similar to the standard electrosurgical TURP. This immediate removal of tissue offers the patient treated with the contact laser the potential for decreased catheter time and a more rapid resolution of symptoms. Our initial experience suggests that the contact technique may be better suited for the smaller prostate gland (i.e. less than 30 gm). The contact laser may also be used for a procedure termed the `laser assisted TURP': a standard electrosurgical TURP is performed and the contact laser is used for hemostasis. Several investigators have reported non-randomized results of the contact technique with good outcomes. A prospective randomized trial of the contact laser prostatectomy vrs the electrosurgical TURP is underway. The contact laser vaporization of the prostate holds great promise for the treatment of symptomatic benign prostatic hypertrophy: it is virtually bloodless and allows immediate visualization of the TUR defect.

  15. Ghrelin and its promoter variant associated with cardiac hypertrophy.

    PubMed

    Ukkola, O; Pääkkö, T; Kesäniemi, Y A

    2012-07-01

    The roles of ghrelin, a peptide hormone that has a role in regulating food intake and energy homeostasis, in the cardiovascular system have not yet been unambiguously established. We evaluated the association between plasma ghrelin concentrations and -501A>C single-nucleotide polymorphism (SNP) in the ghrelin gene 5' flanking area and echocardiographic measurements in 1037 middle-aged subjects. Left ventricular mass index (LVMI) was calculated according to Devereux's method. The ambulatory blood pressure (BP) was recorded using the fully automatic SpaceLabs 90207 oscillometric unit. Results suggested that plasma ghrelin was not related to mean ambulatory BP values. However, the highest plasma ghrelin tertile was associated with increased intraventricular septum (P=0.043) and posterior ventricular wall (P=0.002) thicknesses as well as left ventricular mass (P=0.05). After adjustment for age, sex, body mass index and systolic BP, the association persisted between ghrelin tertiles and intraventricular septum (P=0.05) and posterior ventricular wall (P=0.001) thicknesses. The SNP -501A>C polymorphism was associated with LVMI after adjustments for age, sex and systolic BP. In conclusion, ghrelin and its promoter variant are associated with cardiac hypertrophy indexes independent of BP. Positive correlation between ghrelin levels and increased wall thickness parameters may reflect compensatory up-regulation of ghrelin concentrations or direct effects of ghrelin on myocardium. The effects of the SNP seem not to be mediated through its effects on ghrelin plasma levels. PMID:21614024

  16. Limited myocardial perfusion reserve in patients with left ventricular hypertrophy

    SciTech Connect

    Goldstein, R.A.; Haynie, M. )

    1990-03-01

    Experimental studies in animals have suggested that coronary flow reserve may be limited in patients with left ventricular hypertrophy (LVH). Accordingly, to noninvasively determine the effect of LVH on myocardial perfusion reserve, 25 patients, 9 with LVH and 16 controls, underwent positron imaging with rubidium-82 (82Rb) (30-55 mCi) or nitrogen-13 (13N) ammonia (12-19 mCi) at rest and following intravenous dipyridamole and handgrip stress. LVH was documented by echocardiographic and/or electrocardiographic measurements. LVH patients had either no chest pain (n = 8) and/or a normal coronary angiogram (n = 6). Nine simultaneous transaxial images were acquired, and the mean ratio of stress to rest activity (S:R), based on all regions for each heart, was calculated as an estimate of myocardial perfusion reserve. There were no regional differences in activity (i.e., perfusion defects) in any of the studies. S:R averaged 1.41 +/- 0.10 (s.d.) for controls and 1.06 +/- 0.09 for patients with LVH (p less than 0.0001). These data provide support for an abnormality in perfusion reserve in patients with LVH.

  17. DNA hydroxymethylation controls cardiomyocyte gene expression in development and hypertrophy

    PubMed Central

    Greco, Carolina M.; Kunderfranco, Paolo; Rubino, Marcello; Larcher, Veronica; Carullo, Pierluigi; Anselmo, Achille; Kurz, Kerstin; Carell, Thomas; Angius, Andrea; Latronico, Michael V. G.; Papait, Roberto; Condorelli, Gianluigi

    2016-01-01

    Methylation at 5-cytosine (5-mC) is a fundamental epigenetic DNA modification associated recently with cardiac disease. In contrast, the role of 5-hydroxymethylcytosine (5-hmC)—5-mC's oxidation product—in cardiac biology and disease is unknown. Here we assess the hydroxymethylome in embryonic, neonatal, adult and hypertrophic mouse cardiomyocytes, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks during heart development and failure. DNA hydroxymethylation marks the body of highly expressed genes as well as distal regulatory regions with enhanced activity. Moreover, pathological hypertrophy is characterized by a shift towards a neonatal 5-hmC distribution pattern. We also show that the ten-eleven translocation 2 (TET2) enzyme regulates the expression of key cardiac genes, such as Myh7, through 5-hmC deposition on the gene body and at enhancers. Thus, we provide a genome-wide analysis of 5-hmC in the cardiomyocyte and suggest a role for this epigenetic modification in heart development and disease. PMID:27489048

  18. Absence of left ventricular hypertrophy in elite college basketball players.

    PubMed

    Wolfe, L A; Martin, R P; Seip, R L

    1985-09-01

    Left ventricular dimensions of 11 successful male college basketball players engaged in pre-season conditioning (mean age, 20.3 years) and 13 tall healthy male controls (mean age, 21.6 years) were studied by echocardiography. Left ventricular internal dimension (LVIDd, mm), posterior wall thickness (PWT, mm), septal thickness (ST, mm), and calculated left ventricular mass (LV mass, g) in the athletes were within or only slightly in excess of echocardiographic normal limits and mean values were not significantly different from the control group. LVIDd (mm/m2 body surface area) was significantly lower in the athletes. However, five guard-type players displayed significantly greater mean values for PWT and LV mass compared to six taller forwards/centers with linear body builds. It was concluded that left ventricular hypertrophy is not a common characteristic of college basketball players. It was hypothesized that cardiac dimensions of young men may vary independently of gross body size in relation to somatotype or other anthropometric variables.

  19. Imatinib Activates Pathological Hypertrophy by Altering Myocyte Calcium Regulation

    PubMed Central

    Barr, Larry; Makarewich, Catherine A.; Berretta, Remus M.; Gao, Hui; Troupes, Constantine D.; Woitek, Felix; Recchia, Fabio; Kubo, Hajime; Force, Thomas; Houser, Steven R.

    2014-01-01

    Background Imatinib mesylate is a selective tyrosine-kinase inhibitor used in the treatment of multiple cancers, most notably chronic myelogenous leukemia (CML). There is evidence that imatinib can induce cardiotoxicity in cancer patients. Our hypothesis is that imatinib alters calcium regulatory mechanisms and can contribute to development of pathological cardiac hypertrophy. Methods/Results Neonatal rat ventricular myocytes (NRVMs) were treated with clinical doses (Low: 2µM, High: 5µM) of imatinib and assessed for molecular changes. Imatinib increased peak systolic Ca2+ and Ca2+ transient decay rates and Western analysis revealed significant increases in phosphorylation of phospholamban (Thr-17) and the ryanodine receptor (Ser-2814), signifying activation of CaMKII. Imatinib significantly increased NRVM volume as assessed by Coulter counter, myocyte surface area and ANP abundance seen by Western. Imatinib induced cell death, but did not activate the classical apoptotic program as assessed by caspase-3 cleavage, indicating a necrotic mechanism of death in myocytes. We expressed AdNFATc3-GFP in NRVMS and showed imatinib treatment significantly increased NFAT translocation that was inhibited by the calcineurin inhibitor FK506 or CaMKII inhibitors. Conclusion These data show that imatinib can activate pathological hypertrophic signaling pathways by altering intracellular Ca2+ dynamics. This is likely a contributing mechanism for the adverse cardiac effects of imatinib. PMID:24931551

  20. Simultaneous bile duct and portal vein ligation induces faster atrophy/hypertrophy complex than portal vein ligation: role of bile acids

    PubMed Central

    Ren, Weizheng; Chen, Geng; Wang, Xiaofeng; Zhang, Aiqun; Li, Chonghui; Lv, Wenping; Pan, Ke; Dong, Jia-hong

    2015-01-01

    Portal vein ligation (PVL) induces atrophy/hypertrophy complex (AHC). We hypothesised that simultaneous bile duct and portal vein ligation (BPL) might induce proper bile acid (BA) retention to enhance AHC by activating BA-mediated FXR signalling in the intact liver and promoting apoptosis in the ligated liver. We established rat models of 90% BPL and 90% PVL and found that BPL was well-tolerated and significantly accelerated AHC. The enhanced BA retention in the intact liver promoted hepatocyte proliferation by promoting the activation of FXR signalling, while that in the ligated liver intensified caspase3-mediated apoptosis. Decreasing the BA pools in the rats that underwent BPL could compromise these effects, whereas increasing the bile acid pools of rats that underwent PVL could induce similar effects. Second-stage resection of posterior-caudate-lobe-spearing hepatectomy was performed 5 days after BPL (B-Hx), PVL (V-Hx) or sham (S-SHx), as well as whole-caudate-lobe-spearing hepatectomy 5 days after sham (S-Hx). The B-Hx group had the most favourable survival rate (93.3%, the S-SHx group 0%, the S-Hx group 26.7%, the V-Hx group 56.7%, P < 0.01) and the most sustained regeneration. We conclude that BPL is a safe and effective method, and the acceleration of AHC was bile acid-dependent. PMID:25678050

  1. Clinical value of regression of electrocardiographic left ventricular hypertrophy after aortic valve replacement.

    PubMed

    Yamabe, Sayuri; Dohi, Yoshihiro; Higashi, Akifumi; Kinoshita, Hiroki; Sada, Yoshiharu; Hidaka, Takayuki; Kurisu, Satoshi; Shiode, Nobuo; Kihara, Yasuki

    2016-09-01

    Electrocardiographic left ventricular hypertrophy (ECG-LVH) gradually regressed after aortic valve replacement (AVR) in patients with severe aortic stenosis. Sokolow-Lyon voltage (SV1 + RV5/6) is possibly the most widely used criterion for ECG-LVH. The aim of this study was to determine whether decrease in Sokolow-Lyon voltage reflects left ventricular reverse remodeling detected by echocardiography after AVR. Of 129 consecutive patients who underwent AVR for severe aortic stenosis, 38 patients with preoperative ECG-LVH, defined by SV1 + RV5/6 of ≥3.5 mV, were enrolled in this study. Electrocardiography and echocardiography were performed preoperatively and 1 year postoperatively. The patients were divided into ECG-LVH regression group (n = 19) and non-regression group (n = 19) according to the median value of the absolute regression in SV1 + RV5/6. Multivariate logistic regression analysis was performed to assess determinants of ECG-LVH regression among echocardiographic indices. ECG-LVH regression group showed significantly greater decrease in left ventricular mass index and left ventricular dimensions than Non-regression group. ECG-LVH regression was independently determined by decrease in the left ventricular mass index [odds ratio (OR) 1.28, 95 % confidence interval (CI) 1.03-1.69, p = 0.048], left ventricular end-diastolic dimension (OR 1.18, 95 % CI 1.03-1.41, p = 0.014), and left ventricular end-systolic dimension (OR 1.24, 95 % CI 1.06-1.52, p = 0.0047). ECG-LVH regression could be a marker of the effect of AVR on both reducing the left ventricular mass index and left ventricular dimensions. The effect of AVR on reverse remodeling can be estimated, at least in part, by regression of ECG-LVH.

  2. Specific factors influencing histotypic aggregation of chick embryo hepatocytes.

    PubMed Central

    Sankaran, L; Proffitt, R T; Petersen, J R; Pogell, B M

    1977-01-01

    Conditions are described for the reproducible assay of substances affecting the in vitro rate of aggregation of isolated chick embryo hepatocytes. Two low molecular weight (less than 1000) fractions--one that promotes hepatocyte aggregation (HAP) and the other that inhibits this stimulation (HAI)--have been isolated and partially purified from adult chicken liver. One major active component of HAP was identified as taurine (2-aminoethanesulfonate). The presence of HAP during the entire time of assay was required for largest aggregate formation. HAP had no effect on aggregation of chick embryo neural retina, kidney, or heart cells. Our results and the fact that puromycin completely inhibits aggregate formation suggest that HAP and HAI influence the specific synthesis and interaction of membrane macromolecules involved in the aggregation process. Images PMID:270696

  3. The cytoskeleton of digitonin-treated rat hepatocytes.

    PubMed

    Fiskum, G; Craig, S W; Decker, G L; Lehninger, A L

    1980-06-01

    Treatment of isolated rat hepatocptes with low concentrations of digitonin increases the permeability of the plsma membrane to cytosolic proteins without causing release of organelles such as mitochondria into the surrounding medium. Electron microscopy showed that treatment of the cells with increasing concentations of digitonin results in a progressive loss in the continuity of the plasma membrane, while most other aspects of cellular morphology remain normal. Depletion of background staining material from the cytosol by digitonin treatment of the cells greatly enhances the visualization of the cytoskeleton. The use of this technique, together with immunofluorescent light microscopy, has verified the presence of an actin-containing filamentous network at the hepatocyte cortex as well as intermediate filaments distributed throughout the cell. Digitonin is thus useful both for selectively permeabilizing the plasma membrane and for intensifying the appearance of intracellular structures such as microfilaments that are normally difficult to observe in cells such as hepatocytes.

  4. [Current status and future perspectives of hepatocyte transplantation].

    PubMed

    Pareja, Eugenia; Cortés, Miriam; Gómez-Lechón, M José; Maupoey, Javier; San Juan, Fernando; López, Rafael; Mir, Jose

    2014-02-01

    The imbalance between the number of potential beneficiaries and available organs, originates the search for new therapeutic alternatives, such as Hepatocyte transplantation (HT).Even though this is a treatment option for these patients, the lack of unanimity of criteria regarding indications and technique, different cryopreservation protocols, as well as the different methodology to assess the response to this therapy, highlights the need of a Consensus Conference to standardize criteria and consider future strategies to improve the technique and optimize the results.Our aim is to review and update the current state of hepatocyte transplantation, emphasizing the future research attempting to solve the problems and improve the results of this treatment. PMID:24007980

  5. Epigenetic Modifications as Antidedifferentiation Strategy for Primary Hepatocytes in Culture.

    PubMed

    Bolleyn, Jennifer; Fraczek, Joanna; Rogiers, Vera; Vanhaecke, Tamara

    2015-01-01

    A well-known problem of cultured primary hepatocytes is their rapid dedifferentiation. During the last years, several strategies to counteract this phenomenon have been developed, of which changing the in vitro environment is the most popular one. However, mimicking the in vivo setting in vitro by adding soluble media additives or the restoration of both cell-cell and cell-extracellular matrix contacts is not sufficient and only delays the dedifferentiation process instead of counteracting it. In this chapter, new strategies to prevent the deterioration of the liver-specific phenotype of primary hepatocytes in culture by targeting the (epi)genetic mechanisms that drive hepatocellular gene expression are described. PMID:26272144

  6. ATF6 pathway of unfolded protein response mediates advanced oxidation protein product-induced hypertrophy and epithelial-to-mesenchymal transition in HK-2 cells.

    PubMed

    Tang, Xun; Liang, Xiujie; Li, Minhui; Guo, Tingting; Duan, Na; Wang, Yue; Rong, Guang; Yang, Lei; Zhang, Shaojie; Zhang, Jun

    2015-09-01

    Advanced oxidation protein products (AOPPs) accelerate the progression of chronic kidney disease. We previously demonstrated that AOPPs induce hypertrophy and epithelial-to-mesenchymal transition (EMT) in human proximal tubular cells (HK-2 cells) through induction of endoplasmic reticulum (ER) stress. However, which pathway of unfolded protein response (UPR) induced by ER stress plays crucial roles in this process remains unclear. In this study, we investigated the roles of the protein kinase RNA-like ER kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE1) pathways of UPR in this process in HK-2 cells. AOPP treatment induced the overexpression of cleaved ATF6 and spliced form of X-box binding protein-1, and induced the phosphorylation of PERK, eukaryotic translation initiation factor 2α and IRE1. Furthermore, silencing of ATF6 increased E-cadherin and zonula occludens-1 expression, lowered the expression of vimentin, and downregulated total protein content, whereas knockdown of PERK or IRE1 resulted in no difference compared with the scramble siRNA-transfected cells. AOPP-induced phosphorylation of Src, which was reproduced by thapsigargin, an inducer of ER stress, was partly reversed by salubrinal, an inhibitor of ER stress. Furthermore, the Src inhibitor saracatinib effectively blocked AOPP-induced phosphorylation of Src, activation of ER stress, hypertrophy, and EMT in HK-2 cells. Collectively, our results indicate that AOPPs induce the PERK, ATF6, and IRE1 pathways of UPR, and the ATF6 pathway rather than the other two pathways mediates AOPP-induced HK-2-cell hypertrophy and EMT. We also suggest that the ER stress involved in this process is likely mediated by the activation of Src kinase. PMID:26045172

  7. Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

    SciTech Connect

    Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee; Jeong, Jieun; Wi, Anjin; Park, Whoashig; Han, Ho-jae; Park, Soo-hyun

    2015-06-05

    Previously, we reported that CARM1 undergoes ubiquitination-dependent degradation in renal podocytes. It was also reported that CARM1 is necessary for fasting-induced hepatic gluconeogenesis. Based on these reports, we hypothesized that treatment with insulin, a hormone typically present under the ‘fed’ condition, would inhibit gluconeogenesis via CARM1 degradation. HepG2 cells, AML-12 cells, and rat primary hepatocytes were treated with insulin to confirm CARM1 downregulation. Surprisingly, insulin treatment increased CARM1 expression in all cell types examined. Furthermore, treatment with insulin increased histone 3 methylation at arginine 17 and 26 in HepG2 cells. To elucidate the role of insulin-induced CARM1 upregulation, the HA-CARM1 plasmid was transfected into HepG2 cells. CARM1 overexpression did not increase the expression of lipogenic proteins generally increased by insulin signaling. Moreover, CARM1 knockdown did not influence insulin sensitivity. Insulin is known to facilitate hepatic proliferation. Like insulin, CARM1 overexpression increased CDK2 and CDK4 expression. In addition, CARM1 knockdown reduced the number of insulin-induced G2/M phase cells. Moreover, GFP-CARM1 overexpression increased the number of G2/M phase cells. Based on these results, we concluded that insulin-induced CARM1 upregulation facilitates hepatocyte proliferation. These observations indicate that CARM1 plays an important role in liver pathophysiology. - Highlights: • Insulin treatment increases CARM1 expression in hepatocytes. • CARM1 overexpression does not increase the expression of lipogenic proteins. • CARM1 knockdown does not influence insulin sensitivity. • Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation.

  8. Rat hepatocytes exhibit basolateral Na+/HCO/sub 3/- cotransport

    SciTech Connect

    Renner, E.L.; Lake, J.R.; Scharschmidt, B.F.; Zimmerli, B.; Meier, P.J.

    1989-04-01

    Primary cultures and plasma membrane vesicles were used to characterize Na+ and HCO3- transport by rat hepatocytes. Na+ uptake into hepatocytes was stimulated approximately 10-fold by 25 mM extracellular HCO3-.HCO3--stimulated Na+ uptake was saturable, abolished by 4-acetamido-4'-isothiocyano-2,2'-disulfonic acid stilbene (SITS), and unaffected by amiloride or Cl- removal. Neither propionate nor acetate reproduced this effect of HCO3-. 22Na efflux from preloaded hepatocytes was similarly increased approximately 10-fold by an in greater than out HCO3- concentration gradient. 22Na efflux was also increased by valinomycin and an in greater than out K+ concentration gradient in the presence but not absence of HCO3-. Intracellular pH (pHi) measured with the pH-sensitive fluorochrome 2',7'-bis-(2-carboxyethyl)-5-(and 6-)carboxyfluorescein (BCECF) decreased at a rate of 0.227 (+/- 0.074 SEM) pH units/min when extracellular HCO3- concentration was lowered from 25 to 5 mM at constant PCO2. This intracellular acidification rate was decreased 50-60% in the absence of Na+ or presence of SITS, and was unaffected by amiloride or Cl- removal. Membrane hyperpolarization produced by valinomycin and an in greater than out K+ concentration gradient caused pHi to fall; the rate of fall was decreased 50-70% by Na+ removal or SITS, but not amiloride. An inside positive K+ diffusion potential and a simultaneous out greater than in HCO3- gradient produced a transient 4,4'-diisothiocyano-2,2' disulfonic acid stilbene (DIDS) sensitive, amiloride-insensitive 22Na accumulation in basolateral but not canalicular membrane vesicles. Rat hepatocytes thus exhibit electrogenic basolateral Na+/HCO3- cotransport.

  9. Scoparone affects lipid metabolism in primary hepatocytes using lipidomics

    PubMed Central

    Zhang, Aihua; Qiu, Shi; Sun, Hui; Zhang, Tianlei; Guan, Yu; Han, Ying; Yan, Guangli; Wang, Xijun

    2016-01-01

    Lipidomics, which focuses on the global study of molecular lipids in biological systems, could provide valuable insights about disease mechanisms. In this study, we present a nontargeted lipidomics strategy to determine cellular lipid alterations after scoparone exposure in primary hepatocytes. Lipid metabolic profiles were analyzed by high-performance liquid chromatography coupled with time-of-flight mass spectrometry, and a novel imaging TransOmics tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. Chemometric and statistical analyses of the obtained lipid fingerprints revealed the global lipidomic alterations and tested the therapeutic effects of scoparone. Identification of ten proposed lipids contributed to the better understanding of the effects of scoparone on lipid metabolism in hepatocytes. The most striking finding was that scoparone caused comprehensive lipid changes, as represented by significant changes of the identificated lipids. The levels of identified PG(19:1(9Z)/14:0), PE(17:1(9Z)/0:0), PE(19:1(9Z)/0:0) were found to be upregulated in ethanol-induced group, whereas the levels in scoparone group were downregulated. Lipid metabolism in primary hepatocytes was changed significantly by scoparone treatment. We believe that this novel approach could substantially broaden the applications of high mass resolution mass spectrometry for cellular lipidomics. PMID:27306123

  10. Hepatocyte and Sertoli Cell Aquaporins, Recent Advances and Research Trends

    PubMed Central

    Bernardino, Raquel L.; Marinelli, Raul A.; Maggio, Anna; Gena, Patrizia; Cataldo, Ilaria; Alves, Marco G.; Svelto, Maria; Oliveira, Pedro F.; Calamita, Giuseppe

    2016-01-01

    Aquaporins (AQPs) are proteinaceous channels widespread in nature where they allow facilitated permeation of water and uncharged through cellular membranes. AQPs play a number of important roles in both health and disease. This review focuses on the most recent advances and research trends regarding the expression and modulation, as well as physiological and pathophysiological functions of AQPs in hepatocytes and Sertoli cells (SCs). Besides their involvement in bile formation, hepatocyte AQPs are involved in maintaining energy balance acting in hepatic gluconeogenesis and lipid metabolism, and in critical processes such as ammonia detoxification and mitochondrial output of hydrogen peroxide. Roles are played in clinical disorders including fatty liver disease, diabetes, obesity, cholestasis, hepatic cirrhosis and hepatocarcinoma. In the seminiferous tubules, particularly in SCs, AQPs are also widely expressed and seem to be implicated in the various stages of spermatogenesis. Like in hepatocytes, AQPs may be involved in maintaining energy homeostasis in these cells and have a major role in the metabolic cooperation established in the testicular tissue. Altogether, this information represents the mainstay of current and future investigation in an expanding field. PMID:27409609

  11. Hepatitis C Virus Infects Rhesus Macaque Hepatocytes and Simianized Mice

    PubMed Central

    Scull, Margaret A.; Shi, Chao; de Jong, Ype P.; Gerold, Gisa; Ries, Moritz; von Schaewen, Markus; Donovan, Bridget M.; Labitt, Rachael N.; Horwitz, Joshua A.; Gaska, Jenna M.; Hrebikova, Gabriela; Xiao, Jing W.; Flatley, Brenna; Fung, Canny; Chiriboga, Luis; Walker, Christopher M.; Evans, David T.; Rice, Charles M.; Ploss, Alexander

    2015-01-01

    At least 170 million people are chronically infected with hepatitis C virus (HCV). Due to the narrow host range of HCV and restricted use of chimpanzees, there is currently no suitable animal model for HCV pathogenesis studies or the development of a HCV vaccine. To identify cellular determinants of interspecies transmission and establish a novel immunocompetent model system, we examined the ability of HCV to infect hepatocytes from a small non-human primate, the rhesus macaque (Macaca mulatta). We show that the rhesus orthologs of critical HCV entry factors support viral glycoprotein-dependent virion uptake. Primary hepatocytes from rhesus macaques are also permissive for HCV RNA replication and particle production, which is enhanced when antiviral signaling is suppressed. We demonstrate that this may be due to the diminished capacity of HCV to antagonize MAVS-dependent innate cellular defenses. To test the ability of HCV to establish persistent replication in vivo, we engrafted primary rhesus macaque hepatocytes into immunocompromised xenorecipients. Inoculation of resulting simian liver chimeric mice with either HCV genotype 1a or 2a resulted in HCV serum viremia for up to 10 weeks. Conclusion: Together, these data indicate that rhesus macaques may be a viable model for HCV and implicate host immunity as a potential species-specific barrier to HCV infection. We conclude that suppression of host immunity or further viral adaptation may allow robust HCV infection in rhesus macaques and creation of a new animal model for studies of HCV pathogenesis, lentivirus coinfection and vaccine development. PMID:25820364

  12. Duck hepatitis B virus infection of non-hepatocytes.

    PubMed

    Walter, E; Teubner, K; Blum, H E; Offensperger, W B; Offensperger, S; Gerok, W

    1991-02-01

    One hundred and seventeen ducklings, 42 inoculated with duck hepatitis B virus (DHBV) 2 days after hatching and 55 connatally infected, were studied over a 6-month period in parallel with 20 ducklings without DHBV infection. Using immunohistochemical, in situ and blot hybridization analyses, the natural course of hepatic and extrahepatic infection was examined. DHBV infection started in the liver 2-4 days post-inoculation. There, DHBV was found not only in hepatocytes, but also in bile duct epithelial cells. Further, DHBV infection occurred in exocrine and endocrine pancreas (beginning 6-10 days and 20 days post-inoculation, respectively) and in germinal centers of the spleen (beginning 8 weeks post-inoculation). Occasionally viral DNA was also found in kidney glomeruli. Using strand-specific RNA probes, viral DNA in pancreas and spleen was clearly demonstrated to be replicating intermediates. Hepatic and extrahepatic infection with DHBV was not associated with histologic inflammation or pathologic changes in these tissues or the liver. These data indicate that DHBV can infect cells other than hepatocytes. The biological significance of non-hepatocyte infection for the life-cycle of the virus and its potential significance for viral persistence remain to be determined.

  13. Deacylation of bacterial lipopolysaccharide in rat hepatocytes in vitro.

    PubMed Central

    Fukuda, I.; Tanamoto, K.; Kanegasaki, S.; Yajima, Y.; Goto, Y.

    1989-01-01

    The possible role of liver parenchymal cells in the uptake and degradation of bacterial lipopolysaccharide (LPS) was investigated in vitro by employing radiolabelled LPS as substrate. Hepatocytes obtained from Wistar rats by collagenase treatment were found to take up LPS only when it was not linked to the polysaccharide of O-antigen. The amount of LPS taken up increased with time and after 48 h incubation it increased in a dose-dependent manner up to at least 30 micrograms. When incubated with LPS radiolabelled exclusively in the fatty-acid moiety, cultured hepatocytes released lipophilic materials into the culture medium. These were identified as beta-hydroxytetradecanoic acid and triglyceride, in the ratio of 7:I. These results indicate that the R-form of LPS which lacks the O-antigen polysaccharide is taken up and deacylated in hepatocytes, and the derived fatty acids are released into the culture medium either in the free form or after conversion to triglyceride. Images Fig. 6 PMID:2669923

  14. Polyethylene glycol protects primary hepatocytes during supercooling preservation.

    PubMed

    Puts, C F; Berendsen, T A; Bruinsma, B G; Ozer, Sinan; Luitje, Martha; Usta, O Berk; Yarmush, M L; Uygun, K

    2015-08-01

    Cold storage (at 4°C) offers a compromise between the benefits and disadvantages of cooling. It allows storage of organs or cells for later use that would otherwise quickly succumb to warm ischemia, but comprises cold ischemia that, when not controlled properly, can result in severe damage as well by both similar and unique mechanisms. We hypothesized that polyethylene glycol (PEG) 35 kDa would ameliorate these injury pathways and improve cold primary hepatocyte preservation. We show that reduction of the storage temperature to below zero by means of supercooling, or subzero non-freezing, together with PEG supplementation increases the viable storage time of primary rat hepatocytes in University of Wisconsin (UW) solution from 1 day to 4 days. We find that the addition of 5% PEG 35 kDa to the storage medium prevents cold-induced lipid peroxidation and maintains hepatocyte viability and functionality during storage. These results suggest that PEG supplementation in combination with supercooling may enable a more optimized cell and organ preservation.

  15. Characterization and comprehensive proteome profiling of exosomes secreted by hepatocytes.

    PubMed

    Conde-Vancells, Javier; Rodriguez-Suarez, Eva; Embade, Nieves; Gil, David; Matthiesen, Rune; Valle, Mikel; Elortza, Felix; Lu, Shelly C; Mato, Jose M; Falcon-Perez, Juan M

    2008-12-01

    Exosomes represent a discrete population of vesicles that are secreted from various cell types to the extracellular media. Their protein and lipid composition are a consequence of sorting events at the level of the multivesicular body, a central organelle which integrates endocytic and secretory pathways. Characterization of exosomes from different biological samples has shown the presence of common as well as cell-type specific proteins. Remarkably, the protein content of the exosomes is modified upon pathological or stress conditions. Hepatocytes play a central role in the body response to stress metabolizing potentially harmful endogenous substances as well as xenobiotics. In the present study, we described and characterized for the first time exosome secretion in nontumoral hepatocytes, and with the use of a systematic proteomic approach, we establish the first extensive proteome of a hepatocyte-derived exosome population which should be useful in furthering our understanding of the hepatic function and in the identification of components that may serve as biomarkers for hepatic alterations. Our analysis identifies a significant number of proteins previously described among exosomes derived from others cell types as well as proteins involved in metabolizing lipoproteins, endogenous compounds and xenobiotics, not previously described in exosomes. Furthermore, we demonstrated that exosomal membrane proteins can constitute an interesting tool to express nonexosomal proteins into exosomes with therapeutic purposes.

  16. Reversible Thermoset Adhesives

    NASA Technical Reports Server (NTRS)

    Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

    2016-01-01

    Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

  17. Endothelial Bmx tyrosine kinase activity is essential for myocardial hypertrophy and remodeling.

    PubMed

    Holopainen, Tanja; Räsänen, Markus; Anisimov, Andrey; Tuomainen, Tomi; Zheng, Wei; Tvorogov, Denis; Hulmi, Juha J; Andersson, Leif C; Cenni, Bruno; Tavi, Pasi; Mervaala, Eero; Kivelä, Riikka; Alitalo, Kari

    2015-10-20

    Cardiac hypertrophy accompanies many forms of heart disease, including ischemic disease, hypertension, heart failure, and valvular disease, and it is a strong predictor of increased cardiovascular morbidity and mortality. Deletion of bone marrow kinase in chromosome X (Bmx), an arterial nonreceptor tyrosine kinase, has been shown to inhibit cardiac hypertrophy in mice. This finding raised the possibility of therapeutic use of Bmx tyrosine kinase inhibitors, which we have addressed here by analyzing cardiac hypertrophy in gene-targeted mice deficient in Bmx tyrosine kinase activity. We found that angiotensin II (Ang II)-induced cardiac hypertrophy is significantly reduced in mice deficient in Bmx and in mice with inactivated Bmx tyrosine kinase compared with WT mice. Genome-wide transcriptomic profiling showed that Bmx inactivation suppresses myocardial expression of genes related to Ang II-induced inflammatory and extracellular matrix responses whereas expression of RNAs encoding mitochondrial proteins after Ang II administration was maintained in Bmx-inactivated hearts. Very little or no Bmx mRNA was expressed in human cardiomyocytes whereas human cardiac endothelial cells expressed abundant amounts. Ang II stimulation of endothelial cells increased Bmx phosphorylation, and Bmx gene silencing inhibited downstream STAT3 signaling, which has been implicated in cardiac hypertrophy. Furthermore, activation of the mechanistic target of rapamycin complex 1 pathway by Ang II treatment was decreased in the Bmx-deficient hearts. Our results demonstrate that inhibition of the cross-talk between endothelial cells and cardiomyocytes by Bmx inactivation suppresses Ang II-induced signals for cardiac hypertrophy. These results suggest that the endothelial Bmx tyrosine kinase could provide a target to attenuate the development of cardiac hypertrophy. PMID:26430242

  18. Endothelial Bmx tyrosine kinase activity is essential for myocardial hypertrophy and remodeling

    PubMed Central

    Holopainen, Tanja; Räsänen, Markus; Anisimov, Andrey; Tuomainen, Tomi; Zheng, Wei; Tvorogov, Denis; Hulmi, Juha J.; Andersson, Leif C.; Cenni, Bruno; Tavi, Pasi; Mervaala, Eero; Kivelä, Riikka; Alitalo, Kari

    2015-01-01

    Cardiac hypertrophy accompanies many forms of heart disease, including ischemic disease, hypertension, heart failure, and valvular disease, and it is a strong predictor of increased cardiovascular morbidity and mortality. Deletion of bone marrow kinase in chromosome X (Bmx), an arterial nonreceptor tyrosine kinase, has been shown to inhibit cardiac hypertrophy in mice. This finding raised the possibility of therapeutic use of Bmx tyrosine kinase inhibitors, which we have addressed here by analyzing cardiac hypertrophy in gene-targeted mice deficient in Bmx tyrosine kinase activity. We found that angiotensin II (Ang II)-induced cardiac hypertrophy is significantly reduced in mice deficient in Bmx and in mice with inactivated Bmx tyrosine kinase compared with WT mice. Genome-wide transcriptomic profiling showed that Bmx inactivation suppresses myocardial expression of genes related to Ang II-induced inflammatory and extracellular matrix responses whereas expression of RNAs encoding mitochondrial proteins after Ang II administration was maintained in Bmx-inactivated hearts. Very little or no Bmx mRNA was expressed in human cardiomyocytes whereas human cardiac endothelial cells expressed abundant amounts. Ang II stimulation of endothelial cells increased Bmx phosphorylation, and Bmx gene silencing inhibited downstream STAT3 signaling, which has been implicated in cardiac hypertrophy. Furthermore, activation of the mechanistic target of rapamycin complex 1 pathway by Ang II treatment was decreased in the Bmx-deficient hearts. Our results demonstrate that inhibition of the cross-talk between endothelial cells and cardiomyocytes by Bmx inactivation suppresses Ang II-induced signals for cardiac hypertrophy. These results suggest that the endothelial Bmx tyrosine kinase could provide a target to attenuate the development of cardiac hypertrophy. PMID:26430242

  19. Aberrant Glycosylation in the Left Ventricle and Plasma of Rats with Cardiac Hypertrophy and Heart Failure

    PubMed Central

    Nagai-Okatani, Chiaki; Minamino, Naoto

    2016-01-01

    Targeted proteomics focusing on post-translational modifications, including glycosylation, is a useful strategy for discovering novel biomarkers. To apply this strategy effectively to cardiac hypertrophy and resultant heart failure, we aimed to characterize glycosylation profiles in the left ventricle and plasma of rats with cardiac hypertrophy. Dahl salt-sensitive hypertensive rats, a model of hypertension-induced cardiac hypertrophy, were fed a high-salt (8% NaCl) diet starting at 6 weeks. As a result, they exhibited cardiac hypertrophy at 12 weeks and partially impaired cardiac function at 16 weeks compared with control rats fed a low-salt (0.3% NaCl) diet. Gene expression analysis revealed significant changes in the expression of genes encoding glycosyltransferases and glycosidases. Glycoproteome profiling using lectin microarrays indicated upregulation of mucin-type O-glycosylation, especially disialyl-T, and downregulation of core fucosylation on N-glycans, detected by specific interactions with Amaranthus caudatus and Aspergillus oryzae lectins, respectively. Upregulation of plasma α-l-fucosidase activity was identified as a biomarker candidate for cardiac hypertrophy, which is expected to support the existing marker, atrial natriuretic peptide and its related peptides. Proteomic analysis identified cysteine and glycine-rich protein 3, a master regulator of cardiac muscle function, as an O-glycosylated protein with altered glycosylation in the rats with cardiac hypertrophy, suggesting that alternations in O-glycosylation affect its oligomerization and function. In conclusion, our data provide evidence of significant changes in glycosylation pattern, specifically mucin-type O-glycosylation and core defucosylation, in the pathogenesis of cardiac hypertrophy and heart failure, suggesting that they are potential biomarkers for these diseases. PMID:27281159

  20. Aberrant Glycosylation in the Left Ventricle and Plasma of Rats with Cardiac Hypertrophy and Heart Failure.

    PubMed

    Nagai-Okatani, Chiaki; Minamino, Naoto

    2016-01-01

    Targeted proteomics focusing on post-translational modifications, including glycosylation, is a useful strategy for discovering novel biomarkers. To apply this strategy effectively to cardiac hypertrophy and resultant heart failure, we aimed to characterize glycosylation profiles in the left ventricle and plasma of rats with cardiac hypertrophy. Dahl salt-sensitive hypertensive rats, a model of hypertension-induced cardiac hypertrophy, were fed a high-salt (8% NaCl) diet starting at 6 weeks. As a result, they exhibited cardiac hypertrophy at 12 weeks and partially impaired cardiac function at 16 weeks compared with control rats fed a low-salt (0.3% NaCl) diet. Gene expression analysis revealed significant changes in the expression of genes encoding glycosyltransferases and glycosidases. Glycoproteome profiling using lectin microarrays indicated upregulation of mucin-type O-glycosylation, especially disialyl-T, and downregulation of core fucosylation on N-glycans, detected by specific interactions with Amaranthus caudatus and Aspergillus oryzae lectins, respectively. Upregulation of plasma α-l-fucosidase activity was identified as a biomarker candidate for cardiac hypertrophy, which is expected to support the existing marker, atrial natriuretic peptide and its related peptides. Proteomic analysis identified cysteine and glycine-rich protein 3, a master regulator of cardiac muscle function, as an O-glycosylated protein with altered glycosylation in the rats with cardiac hypertrophy, suggesting that alternations in O-glycosylation affect its oligomerization and function. In conclusion, our data provide evidence of significant changes in glycosylation pattern, specifically mucin-type O-glycosylation and core defucosylation, in the pathogenesis of cardiac hypertrophy and heart failure, suggesting that they are potential biomarkers for these diseases. PMID:27281159

  1. Atrial Fibrillation in Hypertrophic Cardiomyopathy: Is the Extent of Septal Hypertrophy Important?

    PubMed Central

    Kim, Eun Kyoung; Lee, Sang-chol; Park, Seung-jung; Kim, June Soo; On, Young Keun

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is a cardiac disease associated with a high incidence of atrial fibrillation (AF). Recent studies have suggested that interventricular septum thickness may influence the risk stratification of patients with AF. We evaluated the effects of septal hypertrophy on morbidity and mortality in patients with HCM. Patients were followed for a median of 6.1 years and were divided into two groups according to the extent of septal hypertrophy. A total of 1,360 HCM patients were enrolled: 482 (33%) apical or apicoseptal, 415 (28%) asymmetric septal, 388 (27%) basal septal, 38 (2.6%) concentric, and 37 (2.5%) diffuse and mixed type. Ninety-two all-cause deaths and 21 cardiac deaths occurred. The total event rates were significantly higher for patients with HCM with more extensive septal hypertrophy (group A) compared to those with HCM ± focal septal hypertrophy (group B), regardless of type (p<0.001). Arrhythmias occurred in 502 patients, with a significantly higher incidence in group A than in group B (p<0.001). Among patients with arrhythmias, the incidence of AF was significantly higher in group A than group B (p<0.001). In univariate Cox analysis, a greater extent of septal hypertrophy (p<0.001), E/E´ ratio (p = 0.011), and mitral regurgitation grade (p = 0.003) were significantly associated with developing AF. In multivariate Cox analyses, a greater extent of septal hypertrophy [odds ratio (OR) 5.44 (2.29–12.92), p<0.001] in patients with HCM was significantly associated with developing AF. In conclusion, a greater extent of septal hypertrophy is an independent predictor of progression to AF in patients with HCM. PMID:27258035

  2. C-Myc regulates substrate oxidation patterns during early pressure-overload hypertrophy

    SciTech Connect

    Ledee, Dolena R.; Smith, Lincoln; Kajimoto, Masaki; Bruce, Margaret; Isern, Nancy G.; Xu, Chun; Portman, Michael A.; Olson, Aaron

    2013-11-26

    Pressure overload cardiac hypertrophy alters substrate metabolism. Prior work showed that myocardial inactivation of c-Myc (Myc) attenuated hypertrophy and decreased expression of glycolytic genes after aortic constriction. Accordingly, we hypothesize that Myc regulates substrate preferences for the citric acid cycle during pressure overload hypertrophy from transverse aortic constriction (TAC) and that these metabolic changes impact cardiac function and growth. To test this hypothesis, we subjected FVB mice with cardiac specific, inducible Myc inactivation (MycKO-TAC) and non-transgenic littermates (Cont-TAC) to transverse aortic constriction (n=7/group). A separate group underwent sham surgery (Sham, n=5). After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketones and unlabeled glucose and insulin. Western blots were used to evaluate metabolic enzymes. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. Compared to Sham, Cont-TAC had increased free fatty acid fractional contribution with a concurrent decrease in unlabeled (presumably glucose) contribution. Myc inactivation (MycKO-TAC) inhibited these metabolic changes. Hypertrophy in general increased protein levels of PKM2; however this change was not linked to Myc status. Protein post-translation modification by O-GlcNAc was significantly greater in Cont-TAC versus both Sham and MycKO-TAC. In conclusion, Myc regulates substrate utilization during early pressure overload hypertrophy. Our results show that the metabolic switch during hypertrophy is not necessary to maintain cardiac function, but it may be important mechanism to promote cardiomyocyte growth. Myc also regulates protein O-GlcNAcylation during hypertrophy.

  3. Mechanisms of cardiac hypertrophy in canine volume overload

    NASA Technical Reports Server (NTRS)

    Matsuo, T.; Carabello, B. A.; Nagatomo, Y.; Koide, M.; Hamawaki, M.; Zile, M. R.; McDermott, P. J.

    1998-01-01

    This study tested whether the modest hypertrophy that develops in dogs in response to mitral regurgitation is due to a relatively small change in the rate of protein synthesis or, alternatively, is due to a decreased rate of protein degradation. After 3 mo of severe experimental mitral regurgitation, the left ventricular (LV) mass-to-body weight ratio increased by 23% compared with baseline values. This increase in LV mass occurred with a small, but not statistically significant, increase in the fractional rate of myosin heavy chain (MHC) synthesis (Ks), as measured using continuous infusion with [3H]leucine in dogs at 2 wk, 4 wk, and 3 mo after creation of severe mitral regurgitation. Translational efficiency was unaffected by mitral regurgitation as measured by the distribution of MHC mRNA in polysome gradients. Furthermore, there was no detectable increase in translational capacity as measured by either total RNA content or the rate of ribosome formation. These data indicate that translational mechanisms that accelerate the rate of cardiac protein synthesis are not responsive to the stimulus of mitral regurgitation. Most of the growth after mitral regurgitation was accounted for by a decrease in the fractional rate of protein degradation, calculated by subtracting fractional rates of protein accumulation at each time point from the corresponding Ks values. We conclude that 1) volume overload produced by severe mitral regurgitation does not trigger substantial increases in the rate of protein synthesis and 2) the modest increase in LV mass results primarily from a decrease in the rate of protein degradation.

  4. Hypertrophy and/or Hyperplasia: Dynamics of Adipose Tissue Growth.

    PubMed

    Jo, Junghyo; Gavrilova, Oksana; Pack, Stephanie; Jou, William; Mullen, Shawn; Sumner, Anne E; Cushman, Samuel W; Periwal, Vipul

    2009-03-01

    Adipose tissue grows by two mechanisms: hyperplasia (cell number increase) and hypertrophy (cell size increase). Genetics and diet affect the relative contributions of these two mechanisms to the growth of adipose tissue in obesity. In this study, the size distributions of epididymal adipose cells from two mouse strains, obesity-resistant FVB/N and obesity-prone C57BL/6, were measured after 2, 4, and 12 weeks under regular and high-fat feeding conditions. The total cell number in the epididymal fat pad was estimated from the fat pad mass and the normalized cell-size distribution. The cell number and volume-weighted mean cell size increase as a function of fat pad mass. To address adipose tissue growth precisely, we developed a mathematical model describing the evolution of the adipose cell-size distributions as a function of the increasing fat pad mass, instead of the increasing chronological time. Our model describes the recruitment of new adipose cells and their subsequent development in different strains, and with different diet regimens, with common mechanisms, but with diet- and genetics-dependent model parameters. Compared to the FVB/N strain, the C57BL/6 strain has greater recruitment of small adipose cells. Hyperplasia is enhanced by high-fat diet in a strain-dependent way, suggesting a synergistic interaction between genetics and diet. Moreover, high-fat feeding increases the rate of adipose cell size growth, independent of strain, reflecting the increase in calories requiring storage. Additionally, high-fat diet leads to a dramatic spreading of the size distribution of adipose cells in both strains; this implies an increase in size fluctuations of adipose cells through lipid turnover.

  5. Permissivity of primary hepatocytes and hepatoma cell lines to support hepatitis C virus infection.

    PubMed

    Wilson, Garrick K; Farquhar, Michelle J; Meredith, Luke; Dhawan, Anil; Mitry, Ragai; Balfe, Peter; McKeating, Jane A

    2015-06-01

    The major cell type supporting hepatitis C virus (HCV) infection is the hepatocyte; however, most reports studying viral entry and replication utilize transformed hepatoma cell lines. We demonstrate that HCV pseudoparticles (HCVpp) infect primary hepatocytes with comparable rates to hepatoma cells, demonstrating the limited variability in donor hepatocytes to support HCV receptor-glycoprotein-dependent entry. In contrast, we observed a 2-log range in viral replication between the same donor hepatocytes. We noted that cell proliferation augments pseudoparticle reporter activity and arresting hepatoma cells yields comparable levels of infection to hepatocytes. This study demonstrates comparable rates of HCVpp entry into primary hepatocytes and hepatoma cells, validating the use of transformed cells as a model system to study HCV entry. PMID:25667327

  6. Effect of Concentrated Fibroblast-Conditioned Media on In Vitro Maintenance of Rat Primary Hepatocyte.

    PubMed

    Jeong, Dayeong; Han, Chungmin; Kang, Inhye; Park, Hyun Taek; Kim, Jiyoon; Ryu, Hayoung; Gho, Yong Song; Park, Jaesung

    2016-01-01

    The effects of concentrated fibroblast-conditioned media were tested to determine whether hepatocyte function can be maintained without direct contact between hepatocytes and fibroblasts. Primary rat hepatocytes cultured with a concentrated conditioned media of NIH-3T3 J2 cell line (final concentration of 55 mg/ml) showed significantly improved survival and functions (albumin and urea) compared to those of control groups. They also showed higher expression levels of mRNA, albumin and tyrosine aminotransferase compared to hepatocyte monoculture. The results suggest that culture with concentrated fibroblast-conditioned media could be an easy method for in vitro maintenance of primary hepatocytes. They also could be contribute to understand and analyze co-culture condition of hepatocyte with stroma cells. PMID:26863621

  7. Taxifolin protects against cardiac hypertrophy and fibrosis during biomechanical stress of pressure overload

    SciTech Connect

    Guo, Haipeng; Zhang, Xin; Cui, Yuqian; Zhou, Heng; Xu, Dachun; Shan, Tichao; Zhang, Fan; Guo, Yuan; Chen, Yuguo; Wu, Dawei

    2015-09-01

    Cardiac hypertrophy is a key pathophysiological component to biomechanical stress, which has been considered to be an independent and predictive risk factor for adverse cardiovascular events. Taxifolin (TAX) is a typical plant flavonoid, which has long been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether TAX can influence the development of cardiac hypertrophy. In vitro studies, we found that TAX concentration-dependently inhibited angiotensin II (Ang II) induced hypertrophy and protein synthesis in cardiac myocytes. Then we established a mouse model by transverse aortic constriction (TAC) to further confirm our findings. It was demonstrated that TAX prevented pressure overload induced cardiac hypertrophy in mice, as assessed by ventricular mass/body weight, echocardiographic parameters, myocyte cross-sectional area, and the expression of ANP, BNP and β-MHC. The excess production of reactive oxygen species (ROS) played critical role in the development of cardiac hypertrophy. TAX arrested oxidative stress and decreased the expression of 4-HNE induced by pressure overload. Moreover, TAX negatively modulated TAC-induced phosphorylation of ERK1/2 and JNK1/2. Further studies showed that TAX significantly attenuated left ventricular fibrosis and collagen synthesis through abrogating the phosphorylation of Smad2 and Smad2/3 nuclear translocation. These results demonstrated that TAX could inhibit cardiac hypertrophy and attenuate ventricular fibrosis after pressure overload. These beneficial effects were at least through the inhibition of the excess production of ROS, ERK1/2, JNK1/2 and Smad signaling pathways. Therefore, TAX might be a potential candidate for the treatment of cardiac hypertrophy and fibrosis. - Highlights: • We focus on the protective effect of taxifolin on cardiac remodeling. • Taxifolin inhibited cardiac hypertrophy and attenuated ventricular fibrosis. • Taxifolin

  8. Heparanase enhances early hepatocyte inclusion in the recipient liver after transplantation in partially hepatectomized rats.

    PubMed

    Tsiperson, Vladislav; Goldshmidt, Orit; Ilan, Neta; Shoshany, Gideon; Vlodavsky, Israel; Veitsman, Ella; Baruch, Yaacov

    2008-03-01

    Hepatocyte transplantation is an emerging approach for the treatment of liver diseases. However, broad clinical application of this method has been limited by restricted source of cells and low efficiency of cell integration within the recipient liver. Heparanase cleaves heparan sulfate proteoglycans in the extracellular matrix and basement membrane, activity that affects cellular invasion associated with cancer metastasis and inflammation. This activity has a multifunctional effect on cell-cell interaction, cell adhesion, and angiogenesis. All these factors are important for successful integration of transplanted hepatocytes. Male donor hepatocytes pretreated with heparanase or untreated were transplanted into recipient female rat spleen following partial hepatectomy. Engraftment efficacy was evaluated by PCR for Y chromosome, histology and PCNA, and heparanase immunohistochemistry. In addition, proliferative activity of hepatocytes in vitro was determined by bromodeoxyuridine immunostaining. The number of heparanase-treated cells detected in the recipient liver was significantly increased three- to fivefold within 24-48 h posttransplantation and twofold at 14 days compared with untreated cells. The transplanted hepatocytes treated with heparanase were clearly seen inside portal vein radicles as cell aggregates up to 72 h posttransplantation. The number of portal radicles filled with heparanase-treated hepatocytes was increased compared to control early after transplantation. Heparanase treatment enhanced hepatocyte and sinusoidal endothelial cell proliferation in the liver, and hepatocyte proliferation within the spleen tissue. Preliminary in vitro studies with isolated hepatocytes treated with heparanase showed increased proliferative activity within 24-48 h of cell culture. These results suggest that preincubation of hepatocytes with heparanase increases the presence of hepatocytes within the recipient liver early following cell transplantation and stimulates

  9. Species-specific toxicity of troglitazone on rats and human by gel entrapped hepatocytes

    SciTech Connect

    Shen, Chong; Meng, Qin; Zhang, Guoliang

    2012-01-01

    Troglitazone, despite passing preclinical trials on animals, was shortly withdrawn from market due to its severe hepatotoxicity in clinic. As rat hepatocyte monolayer consistently showed sensitive troglitazone toxicity as human hepatocyte monolayer in contrast to the species-specific toxicity in vivo, this paper utilized both hepatocytes in three-dimensional culture of gel entrapment to reflect the species difference on hepatotoxicity. Rat hepatocytes in gel entrapment did not show obvious cellular damage even under a long-term exposure for 21 days while gel entrapped human hepatocytes significantly displayed oxidative stress, steatosis, mitochondrial damage and cell death at a short exposure for 4 days. As a result, the detected species-specific toxicity of troglitazone between gel entrapped rat and human hepatocytes consisted well with the situation in vivo but was in a sharp contrast to the performance of two hepatocytes by monolayer culture. Such contradictory toxicity of rat hepatocytes between monolayer and gel entrapment culture could be explained by the fact that troglitazone was cleared more rapidly in gel entrapment than in monolayer culture. Similarly, the differential clearance of troglitazone in rat and human might also explain its species-specific toxicity. Therefore, gel entrapment of hepatocytes might serve as a platform for evaluation of drug toxicity at early stage of drug development by reducing costs, increasing the likelihood of clinical success and limiting human exposure to unsafe drugs. -- Highlights: ► Species-specific toxicity of troglitazone reflected by rat/human hepatocytes ► 3D hepatocytes in 21 days’ long-term culture used for drug hepatotoxicity ► Oversensitive toxicity in hepatocyte monolayer by slow troglitazone clearance.

  10. Tympanometric Findings among Children with Adenoid Hypertrophy in Port Harcourt, Nigeria

    PubMed Central

    Nwosu, Chibuike; Uju Ibekwe, Mathilda

    2016-01-01

    Introduction. Adenoid hypertrophy (AH) is a common childhood disorder. Adenoid plays a significant role in the pathogenesis of otitis media with effusion (OME). The aim of this study is to critically appraise the tympanometric finding among children with adenoid hypertrophy in Port Harcourt, Nigeria. Methodology. A Prospective, controlled study carried out among newly diagnosed cases of adenoid hypertrophy at the ENT clinic of the UPTH, between November 2014 and June 2015. Tympanometry was done on each child and each ear was considerably studied as a single entity. Types B and C tympanograms were used as indicators of OME. Data was collected and analyzed using SPSS version 20. Results. Sixty-eight cases of adenoid hypertrophy were seen within the study period and 136 ears were studied. Forty (29.4%) ears had type B tympanogram, while 36 (26.5%) ears had type C. The incidence of OME was 55.9%; there were 12 (17.6%) unilateral OME, while bilateral OME was 32 (47.1%). Grade 3 AH was prevalent and was statistically significant with the OME. Conclusion. This study had shown adenoidal hypertrophy as a significant risk factor for OME in children. There was more bilateral OME than unilateral. The more severe grade of AH was more prevalent and it was shown to be statistically significant with OME, thus being a significant risk factor for OME in children. This establishes the need for prompt hearing evaluation and management. PMID:27563311

  11. Ligustrazine Inhibits Cartilage Endplate Hypertrophy via Suppression of TGF-β1

    PubMed Central

    Liu, Shufen; Zhao, Bizeng; Shi, Huipeng; Liang, Qianqian; Fu, Yishan; Yang, Zhu

    2016-01-01

    CEP hypertrophy is one of the characteristics of intervertebral disc degeneration (IDD). LIG exerts a protective effect on IDD in animal model. The effect of LIG on CEP hypertrophy is further investigated in the present study. Cells were isolated from hypertrophic samples obtained from patients during vertebral fusion surgery. Cellular proliferation and the expression of type I collagen (Col I) and TGF-β1 were tested. In the bipedal rats, the edges of the CEP and the sizes of noncartilaginous outgrowth, as well as the expression of osteogenic markers, Col1a, ALP, Runx2, and TGF-β1, were detected. Within two passages, the condensed hypertrophic CEP cells exhibited osteogenic capacity by bony-like nodules and ALP positive staining, along with increased expression of Col I and TGF-β1. LIG inhibited proliferation of CEP cells and downregulated the expression of Col I and TGF-β1 in vitro. Furthermore, LIG attenuated CEP hypertrophy on the lumbar spine of bipedal rats by reducing Col1a, ALP, Runx2, and TGF-β1 mRNA expression and TGF-β1 distribution in vivo. We concluded LIG exerted a preventive effect on CEP hypertrophy via suppression of TGF-β1 levels. This information could be used to develop alternative therapeutic methods to treat spinal CEP hypertrophy. PMID:27563332

  12. Ligustrazine Inhibits Cartilage Endplate Hypertrophy via Suppression of TGF-β1.

    PubMed

    Liu, Shufen; Zhao, Bizeng; Shi, Huipeng; Liang, Qianqian; Fu, Yishan; Yang, Zhu; Xu, Leqin; Wang, Yongjun; Bian, Qin

    2016-01-01

    CEP hypertrophy is one of the characteristics of intervertebral disc degeneration (IDD). LIG exerts a protective effect on IDD in animal model. The effect of LIG on CEP hypertrophy is further investigated in the present study. Cells were isolated from hypertrophic samples obtained from patients during vertebral fusion surgery. Cellular proliferation and the expression of type I collagen (Col I) and TGF-β1 were tested. In the bipedal rats, the edges of the CEP and the sizes of noncartilaginous outgrowth, as well as the expression of osteogenic markers, Col1a, ALP, Runx2, and TGF-β1, were detected. Within two passages, the condensed hypertrophic CEP cells exhibited osteogenic capacity by bony-like nodules and ALP positive staining, along with increased expression of Col I and TGF-β1. LIG inhibited proliferation of CEP cells and downregulated the expression of Col I and TGF-β1 in vitro. Furthermore, LIG attenuated CEP hypertrophy on the lumbar spine of bipedal rats by reducing Col1a, ALP, Runx2, and TGF-β1 mRNA expression and TGF-β1 distribution in vivo. We concluded LIG exerted a preventive effect on CEP hypertrophy via suppression of TGF-β1 levels. This information could be used to develop alternative therapeutic methods to treat spinal CEP hypertrophy. PMID:27563332

  13. Mulberry hypertrophy and accompanying sinonasal pathologies: A review of 68 cases.

    PubMed

    Akduman, Davut; Haksever, Mehmet; Yanilmaz, Muhammed; Solmaz, Fevzi

    2016-08-01

    Mulberry hypertrophy occasionally coexists with sinonasal pathologies. There are very few reports in the literature on this clinical entity. We conducted a retrospective study to draw attention to this condition in the context of accompanying sinonasal pathologies. Our study group was made up of 68 patients-51 males and 17 females, aged 13 to 57 years (mean: 34.9)-who had been diagnosed with mulberry hypertrophy and at least one accompanying sinonasal pathology. All patients had a long-standing chronic discharge. Forty-nine of these patients (72.1%) had unilateral mulberry hypertrophy. The most common concomitant pathologies were chronic rhinosinusitis and ostiomeatal complex disease; others included septal deviation, nasal polyposis, allergic rhinitis, and concha bullosa. Thirty-six patients (52.9%) with varying degrees of choanal/nasal obstruction were operated on with endoscopic excision to treat the mulberry hypertrophy. In all, most patients underwent some sort of surgery to treat either the mulberry hypertrophy or the accompanying sinonasal pathology. Based on our findings, we suggest a clinical staging system to serve as a way to standardize management and guide future basic and clinical research. PMID:27551846

  14. Left ventricular cellular hypertrophy in pressure- and volume-overload valvular heart disease.

    PubMed

    Schoen, F J; Lawrie, G M; Titus, J L

    1984-09-01

    To determine the dependence of myocyte hypertrophy in chronic valvular heart disease on the site and type of lesion, the myocardium was studied from 11 patients with either pressure-overload hypertrophy (PO; four patients with aortic stenosis and two with mixed aortic stenosis/insufficiency) or pure volume-overload hypertrophy (VO; two patients with mitral regurgitation and three with aortic insufficiency). These patients, all without coronary artery disease, died zero to 34 days after valve replacement surgery. Diameters of 25 longitudinally oriented myocytes in the circular midwall myocardium were measured with a calibrated light microscope eyepiece reticle on each of five transmural, transverse, histologic sections from the apical, anterolateral, posterolateral, anteroseptal, and posteroseptal left ventricle. Statistical analysis by modified two-way analysis of variance (ANOVA) demonstrated that mean myocyte size (based on 125 measurements) varied widely among cases but was not statistically different among sites. The myocyte diameter for PO lesions (25.9 +/- 1.1 micron, mean +/- SEM) was significantly greater (P less than 0.05) than that for pure VO lesions (20.4 +/- 0.7 micron), despite equal relative heart weights (measured/predicted from body weight: 2.5 +/- 0.2 [mean +/- SD] versus 2.5 +/- 0.5). This study suggests that 1) cellular hypertrophy in valvular heart disease occurs uniformly throughout the left ventricular myocardium; and 2) mean myocyte diameters are greater in PO than in VO hypertrophy for equivalent cardiac enlargement. PMID:6236142

  15. DYRK1A Is a Novel Negative Regulator of Cardiomyocyte Hypertrophy*

    PubMed Central

    Kuhn, Christian; Frank, Derk; Will, Rainer; Jaschinski, Christoph; Frauen, Robert; Katus, Hugo A.; Frey, Norbert

    2009-01-01

    Activation of the phosphatase calcineurin and its downstream targets, transcription factors of the NFAT family, results in cardiomyocyte hypertrophy. Recently, it has been shown that the dual specificity tyrosine (Y) phosphorylation-regulated kinase 1A (DYRK1A) is able to antagonize calcineurin signaling by directly phosphorylating NFATs. We thus hypothesized that DYRK1A might modulate the hypertrophic response of cardiomyocytes. In a model of phenylephrine-induced hypertrophy, adenovirus-mediated overexpression of DYKR1A completely abrogated the hypertrophic response and significantly reduced the expression of the natriuretic peptides ANF and BNP. Furthermore, DYRK1A blunted cardiomyocyte hypertrophy induced by overexpression of constitutively active calcineurin and attenuated the induction of the hypertrophic gene program. Conversely, knockdown of DYRK1A, utilizing adenoviruses encoding for a specific synthetic miRNA, resulted in an increase in cell surface area accompanied by up-regulation of ANF- mRNA. Similarly, treatment of cardiomyocytes with harmine, a specific inhibitor of DYRK1A, revealed cardiomyocyte hypertrophy on morphological and molecular level. Moreover, constitutively active calcineurin led to robust induction of an NFAT-dependent luciferase reporter, whereas DYRK1A attenuated calcineurin-induced reporter activation in cardiomyocytes. Conversely, both knockdown and pharmacological inhibition of DYRK1A significantly augmented the effect of calcineurin in this assay. In summary, we identified DYRK1A as a novel negative regulator of cardiomyocyte hypertrophy. Mechanistically, this effect appears to be mediated via inhibition of NFAT transcription factors. PMID:19372220

  16. Protein kinase Cα inhibits myocardin-induced cardiomyocyte hypertrophy through the promotion of myocardin phosphorylation.

    PubMed

    Li, Weizong; Wang, Nan; Li, Man; Gong, Huiqin; Liao, Xinghua; Yang, Xiaolong; Zhang, Tongcun

    2015-09-01

    Myocardin plays a key role in the development of cardiac hypertrophy. However, the upstream signals that control the stability and transactivity of myocardin remain to be fully understood. The expression of protein kinase Cα (PKCα) also induces cardiac hypertrophy. An essential downstream molecule of PKCα, extracellular signal-regulated kinase 1/2, was reported to negatively regulate the activities of myocardin. But, the effect of cooperation between PKCα and myocardin and the potential molecular mechanism by which PKCα regulates myocardin-mediated cardiac hypertrophy are unclear. In this study, a luciferase assay was performed using H9C2 cells transfected with expression plasmids for PKCα and myocardin. Surprisingly, the results showed that PKCα inhibited the transcriptional activity of myocardin. PKCα inhibited myocardin-induced cardiomyocyte hypertrophy, demonstrated by the decrease in cell surface area and fetal gene expression, in cardiomyocyte cells overexpressing PKCα and myocardin. The potential mechanism underlying the inhibition effect of PKCα on the function of myocardin is further explored. PKCα directly promoted the basal phosphorylation of endogenous myocardin at serine and threonine residues. In myocardin-overexpressing cardiomyocyte cells, PKCα induced the excessive phosphorylation of myocardin, resulting in the degradation of myocardin and a transcriptional suppression of hypertrophic genes. These results demonstrated that PKCα inhibits myocardin-induced cardiomyocyte hypertrophy through the promotion of myocardin phosphorylation. PMID:26206583

  17. Integrating GRK2 and NFkappaB in the Pathophysiology of Cardiac Hypertrophy.

    PubMed

    Sorriento, Daniela; Santulli, Gaetano; Franco, Antonietta; Cipolletta, Ersilia; Napolitano, Luigi; Gambardella, Jessica; Gomez-Monterrey, Isabel; Campiglia, Pietro; Trimarco, Bruno; Iaccarino, Guido; Ciccarelli, Michele

    2015-11-01

    G protein coupled receptor kinase type 2 (GRK2) plays an important role in the development and maintenance of cardiac hypertrophy and heart failure even if its exact role is still unknown. In this study, we assessed the effect of GRK2 on the regulation of cardiac hypertrophy. In H9C2 cells, GRK2 overexpression increased atrial natriuretic factor (ANF) activity and enhanced phenylephrine-induced ANF response, and this is associated with an increase of NFκB transcriptional activity. The kinase dead mutant and a synthetic inhibitor of GRK2 activity exerted the opposite effect, suggesting that GRK2 regulates hypertrophy through upregulation of NFκB activity in a phosphorylation-dependent manner. In two different in vivo models of left ventricle hypertrophy (LVH), the selective inhibition of GRK2 activity prevented hypertrophy and reduced NFκB transcription activity. Our results suggest a previously undisclosed role for GRK2 in the regulation of hypertrophic responses and propose GRK2 as potential therapeutic target for limiting LVH. PMID:26224342

  18. Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation.

    PubMed

    Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

    2016-01-01

    Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

  19. Cross talk between miR-214 and PTEN attenuates glomerular hypertrophy under diabetic conditions

    PubMed Central

    Wang, Xiaoxia; Shen, E.; Wang, Yanzhe; Li, Junhui; Cheng, Dongsheng; Chen, Yuqiang; Gui, Dingkun; Wang, Niansong

    2016-01-01

    Glomerular mesangial cells (MCs) hypertrophy is one of the earliest pathological abnormalities in diabetic nephropathy (DN), which correlates with eventual glomerulosclerosis. This study aimed to investigate the therapeutic role of miRNA in diabetic glomerular MCs hypertrophy and synthesis of extracellular matrix (ECM). Microarray analysis revealed a significant up-regulation of miR-214 in the renal cortex of diabetic db/db mice, which was confirmed by real-time PCR of isolated glomeruli and primary cultured human MCs. In vitro studies showed that inhibition of miR-214 significantly reduced expression of α-SMA, SM22 and collagen IV, and partially restored phosphatase and tensin homolog (PTEN) protein level in high glucose-stimulated human MCs. Furthermore, we identified PTEN as the target of miR-214 by a luciferase assay in HEK293 cells. Moreover, overexpression of PTEN ameliorated miR-214-mediated diabetic MC hypertrophy while knockdown of PTEN mimicked the MC hypertrophy. In vivo study further confirmed that inhibition of miR-214 significantly decreased the expression of SM22, α-SMA and collagen IV, partially restored PTEN level, and attenuated albuminuria and mesangial expansion in db/db mice. In conclusion, cross talk between miR-214 and PTEN attenuated glomerular hypertrophy under diabetic conditions in vivo and in vitro. Therefore, miR-214 may represent a novel therapeutic target for DN. PMID:27549568

  20. Tympanometric Findings among Children with Adenoid Hypertrophy in Port Harcourt, Nigeria.

    PubMed

    Nwosu, Chibuike; Uju Ibekwe, Mathilda; Obukowho Onotai, Lucky

    2016-01-01

    Introduction. Adenoid hypertrophy (AH) is a common childhood disorder. Adenoid plays a significant role in the pathogenesis of otitis media with effusion (OME). The aim of this study is to critically appraise the tympanometric finding among children with adenoid hypertrophy in Port Harcourt, Nigeria. Methodology. A Prospective, controlled study carried out among newly diagnosed cases of adenoid hypertrophy at the ENT clinic of the UPTH, between November 2014 and June 2015. Tympanometry was done on each child and each ear was considerably studied as a single entity. Types B and C tympanograms were used as indicators of OME. Data was collected and analyzed using SPSS version 20. Results. Sixty-eight cases of adenoid hypertrophy were seen within the study period and 136 ears were studied. Forty (29.4%) ears had type B tympanogram, while 36 (26.5%) ears had type C. The incidence of OME was 55.9%; there were 12 (17.6%) unilateral OME, while bilateral OME was 32 (47.1%). Grade 3 AH was prevalent and was statistically significant with the OME. Conclusion. This study had shown adenoidal hypertrophy as a significant risk factor for OME in children. There was more bilateral OME than unilateral. The more severe grade of AH was more prevalent and it was shown to be statistically significant with OME, thus being a significant risk factor for OME in children. This establishes the need for prompt hearing evaluation and management. PMID:27563311

  1. Cross talk between miR-214 and PTEN attenuates glomerular hypertrophy under diabetic conditions.

    PubMed

    Wang, Xiaoxia; Shen, E; Wang, Yanzhe; Li, Junhui; Cheng, Dongsheng; Chen, Yuqiang; Gui, Dingkun; Wang, Niansong

    2016-01-01

    Glomerular mesangial cells (MCs) hypertrophy is one of the earliest pathological abnormalities in diabetic nephropathy (DN), which correlates with eventual glomerulosclerosis. This study aimed to investigate the therapeutic role of miRNA in diabetic glomerular MCs hypertrophy and synthesis of extracellular matrix (ECM). Microarray analysis revealed a significant up-regulation of miR-214 in the renal cortex of diabetic db/db mice, which was confirmed by real-time PCR of isolated glomeruli and primary cultured human MCs. In vitro studies showed that inhibition of miR-214 significantly reduced expression of α-SMA, SM22 and collagen IV, and partially restored phosphatase and tensin homolog (PTEN) protein level in high glucose-stimulated human MCs. Furthermore, we identified PTEN as the target of miR-214 by a luciferase assay in HEK293 cells. Moreover, overexpression of PTEN ameliorated miR-214-mediated diabetic MC hypertrophy while knockdown of PTEN mimicked the MC hypertrophy. In vivo study further confirmed that inhibition of miR-214 significantly decreased the expression of SM22, α-SMA and collagen IV, partially restored PTEN level, and attenuated albuminuria and mesangial expansion in db/db mice. In conclusion, cross talk between miR-214 and PTEN attenuated glomerular hypertrophy under diabetic conditions in vivo and in vitro. Therefore, miR-214 may represent a novel therapeutic target for DN. PMID:27549568

  2. The Regulatory Role of Signaling Crosstalk in Hypertrophy of MSCs and Human Articular Chondrocytes

    PubMed Central

    Zhong, Leilei; Huang, Xiaobin; Karperien, Marcel; Post, Janine N.

    2015-01-01

    Hypertrophic differentiation of chondrocytes is a main barrier in application of mesenchymal stem cells (MSCs) for cartilage repair. In addition, hypertrophy occurs occasionally in osteoarthritis (OA). Here we provide a comprehensive review on recent literature describing signal pathways in the hypertrophy of MSCs-derived in vitro differentiated chondrocytes and chondrocytes, with an emphasis on the crosstalk between these pathways. Insight into the exact regulation of hypertrophy by the signaling network is necessary for the efficient application of MSCs for articular cartilage repair and for developing novel strategies for curing OA. We focus on articles describing the role of the main signaling pathways in regulating chondrocyte hypertrophy-like changes. Most studies report hypertrophic differentiation in chondrogenesis of MSCs, in both human OA and experimental OA. Chondrocyte hypertrophy is not under the strict control of a single pathway but appears to be regulated by an intricately regulated network of multiple signaling pathways, such as WNT, Bone morphogenetic protein (BMP)/Transforming growth factor-β (TGFβ), Parathyroid hormone-related peptide (PTHrP), Indian hedgehog (IHH), Fibroblast growth factor (FGF), Insulin like growth factor (IGF) and Hypoxia-inducible factor (HIF). This comprehensive review describes how this intricate signaling network influences tissue-engineering applications of MSCs in articular cartilage (AC) repair, and improves understanding of the disease stages and cellular responses within an OA articular joint. PMID:26287176

  3. Prevention of 11-deoxycorticosterone-salt-induced glomerular hypertrophy and glomerulosclerosis by dietary phosphate binder.

    PubMed Central

    Shimamura, T.

    1990-01-01

    The effects of dietary phosphate binder on deoxycorticosterone (DOC)-salt-hypertensive rats were examined. DOC-treated and non-DOC-treated rats were fed the diet either with or without phosphate binder, dihydroxyaluminum aminoacetate. All rats drank 1% NaCl. DOC-salt-treated rats without binder demonstrated marked glomerular hypertrophy, many globally sclerosed glomeruli, severe proteinuria, focal cardiac fibrosis, and splenomegaly. A significant reduction of glomerular hypertrophy, glomerulosclerosis, severity of proteinuria, splenomegaly, and the myocardial lesion took place when the DOC-salt-treated rats were given phosphate binder. The globally sclerosed glomeruli exhibited remarkable hypertrophy while structurally preserved glomeruli showed little evidence of enlargement. The plasma phosphate level was low in rats with dietary phosphate binder. In conclusion, the dietary phosphate binder ameliorated glomerular hypertrophy, glomerulosclerosis, proteinuria, myocardial fibrosis, and splenomegaly occurring in DOC-salt-treated rats. The data indicated that there was an association between glomerular hypertrophy and glomerulosclerosis in this model. The exact mechanisms of action of the phosphate binder, however, remain far from clear. Images Figure 1 Figure 2 Figure 3 Figure 6 Figure 7 Figure 8 PMID:2316624

  4. Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation

    PubMed Central

    Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

    2016-01-01

    Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

  5. AMPKγ3 is dispensable for skeletal muscle hypertrophy induced by functional overload.

    PubMed

    Riedl, Isabelle; Osler, Megan E; Björnholm, Marie; Egan, Brendan; Nader, Gustavo A; Chibalin, Alexander V; Zierath, Juleen R

    2016-03-15

    Mechanisms regulating skeletal muscle growth involve a balance between the activity of serine/threonine protein kinases, including the mammalian target of rapamycin (mTOR) and 5'-AMP-activated protein kinase (AMPK). The contribution of different AMPK subunits to the regulation of cell growth size remains inadequately characterized. Using AMPKγ3 mutant-overexpressing transgenic Tg-Prkag3(225Q) and AMPKγ3-knockout (Prkag3(-/-)) mice, we investigated the requirement for the AMPKγ3 isoform in functional overload-induced muscle hypertrophy. Although the genetic disruption of the γ3 isoform did not impair muscle growth, control sham-operated AMPKγ3-transgenic mice displayed heavier plantaris muscles in response to overload hypertrophy and underwent smaller mass gain and lower Igf1 expression compared with wild-type littermates. The mTOR signaling pathway was upregulated with functional overload but unchanged between genetically modified animals and wild-type littermates. Differences in AMPK-related signaling pathways between transgenic, knockout, and wild-type mice did not impact muscle hypertrophy. Glycogen content was increased following overload in wild-type mice. In conclusion, our functional, transcriptional, and signaling data provide evidence against the involvement of the AMPKγ3 isoform in the regulation of skeletal muscle hypertrophy. Thus, the AMPKγ3 isoform is dispensable for functional overload-induced muscle growth. Mechanical loading can override signaling pathways that act as negative effectors of mTOR signaling and consequently promote skeletal muscle hypertrophy.

  6. Androgen regulated expression of the alpha 2u-globulin gene in pancreatic hepatocytes of rat

    PubMed Central

    1990-01-01

    Under a copper-deficient regimen, pancreatic cells in the adult rat can be found to undergo differentiation into hepatocytes. Pancreatic hepatocytes induced in male and female rats were examined for the expression of the androgen-inducible hepatic protein, alpha 2u- globulin. Alpha 2u-Globulin protein was demonstrable by immunoperoxidase method in all the pancreatic hepatocytes of male rats. Northern blot analysis confirmed the presence of 1.3 kb alpha 2u- globulin mRNA transcript in the pancreas of male rats with hepatocytes. Orchiectomy resulted in marked decrease of alpha 2u-globulin protein and its mRNA. Administration of dihydrotestosterone to castrated rats resulted in increased levels of alpha 2u-globulin mRNA and the amount of alpha 2u-globulin protein in the pancreatic hepatocytes. Unlike normal males, in intact and ovariectomized females alpha 2u-globulin was not detectable in pancreatic hepatocytes. These results indicate that similar to hepatic parenchymal cells pancreatic hepatocytes synthesize alpha 2u-globulin under androgenic regulation. Furthermore, unlike in liver where it is expressed predominantly in perivenular and midlobular hepatocytes, there is no localized difference in the expression of this gene in the transdifferentiated pancreatic hepatocytes. PMID:1688854

  7. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    PubMed Central

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U.; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol. PMID:26788255

  8. DNA synthesis in periportal and perivenous hepatocytes of intact and hepatectomized young mice.

    PubMed

    Fernández-Blanco, A; Inda, A M; Errecalde, A L

    2015-01-01

    DNA synthesis of hepatocytes in two areas of Intact and Hepatectomized young mice liver along a circadian period was studied. DNA synthesis was significantly different at all analyzed time points in Intact and Hepatectomized animals. Differences between periportal and perivenous hepatocytes were found in hepatectomized animals at 04/42 and 08/46 hr of day/hour post-hepatectomy. DNAs peak in periportal hepatocytes regenerating liver occurs 4 hr earlier than in perivenous hepatocytes, probably reflecting their shorter G1 phase. Besides, daily mean values of regenerating livers were higher than those observed in Intact animals, as a consequence of surgical removal.

  9. Hepatocyte-Ductal Transdifferentiation Is Mediated by Reciprocal Repression of SOX9 and C/EBPα

    PubMed Central

    O'Neill, Kathy E.; Thowfeequ, Shifaan; Li, Wan-Chun; Eberhard, Daniel; Dutton, James R.; Slack, Jonathan M.W.

    2014-01-01

    Abstract Primary hepatocytes rapidly dedifferentiate when cultured in vitro. We have studied the mechanism of hepatocyte dedifferentiation by using two culture media: one that maintains hepatocytes in a differentiated state and another that allows dedifferentiation. We show that dedifferentiation involves partial transformation of hepatocytes into cells that resemble biliary epithelial cells. Lineage labeling and time-lapse filming confirm that the dedifferentiated cells are derived from hepatocytes and not from contaminating ductal or fibroblastic cells in the original culture. Furthermore, we establish that the conversion of hepatocytes to biliary-like cells is regulated by mutual antagonism of CCAAT/enhancer binding protein alpha (C/EBPα) and SOX9, which have opposing effects on the expression of hepatocyte and ductal genes. Thus, hepatocyte dedifferentiation induces the biliary gene expression program by alleviating C/EBPα-mediated repression of Sox9. We propose that reciprocal antagonism of C/EBPα and SOX9 also operates in the formation of hepatocytes and biliary ducts from hepatoblasts during normal embryonic development. These data demonstrate that reprogramming of differentiated cells can be used to model the acquisition and maintenance of cell fate in vivo. PMID:25153359

  10. Gel entrapment culture of rat hepatocytes for investigation of tetracycline-induced toxicity

    SciTech Connect

    Shen Chong; Meng Qin Schmelzer, Eva; Bader, Augustinus

    2009-07-15

    This paper aimed to explore three-dimensionally cultured hepatocytes for testing drug-induced nonalcoholic steatohepatitis. Gel entrapped rat hepatocytes were applied for investigation of the tetracycline-induced steatohepatitis, while hepatocyte monolayer was set as a control. The toxic responses of hepatocytes were systematically evaluated by measuring cell viability, liver-specific function, lipid accumulation, oxidative stress, adenosine triphosphate content and mitochondrial membrane potential. The results suggested that gel entrapped hepatocytes showed cell death after 96 h of tetracycline treatment at 25 {mu}M which is equivalent to toxic serum concentration in rats, while hepatocyte monolayer showed cell death at a high dose of 200 {mu}M. The concentration-dependent accumulation of lipid as well as mitochondrial damage were regarded as two early events for tetracycline hepatotoxicity in gel entrapment culture due to their detectability ahead of subsequent increase of oxidative stress and a final cell death. Furthermore, the potent protection of fenofibrate and fructose-1,6-diphosphate were evidenced in only gel entrapment culture with higher expressions on the genes related to {beta}-oxidation than hepatocyte monolayer, suggesting the mediation of lipid metabolism and mitochondrial damage in tetracycline toxicity. Overall, gel entrapped hepatocytes in three-dimension reflected more of the tetracycline toxicity in vivo than hepatocyte monolayer and thus was suggested as a more relevant system for evaluating steatogenic drugs.

  11. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes.

    PubMed

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  12. Lipopolysaccharide and Tumor Necrosis Factor Alpha Inhibit Interferon Signaling in Hepatocytes by Increasing Ubiquitin-Like Protease 18 (USP18) Expression

    PubMed Central

    MacParland, Sonya A.; Ma, Xue-Zhong; Chen, Limin; Khattar, Ramzi; Cherepanov, Vera; Selzner, Markus; Feld, Jordan J.; Selzner, Nazia

    2016-01-01

    ABSTRACT Inflammation may be maladaptive to the control of viral infection when it impairs interferon (IFN) responses, enhancing viral replication and spread. Dysregulated immunity as a result of inappropriate innate inflammatory responses is a hallmark of chronic viral infections such as, hepatitis B virus and hepatitis C virus (HCV). Previous studies from our laboratory have shown that expression of an IFN-stimulated gene (ISG), ubiquitin-like protease (USP)18 is upregulated in chronic HCV infection, leading to impaired hepatocyte responses to IFN-α. We examined the ability of inflammatory stimuli, including tumor necrosis factor alpha (TNF-α), lipopolysaccharide (LPS), interleukin-6 (IL-6) and IL-10 to upregulate hepatocyte USP18 expression and blunt the IFN-α response. Human hepatoma cells and primary murine hepatocytes were treated with TNF-α/LPS/IL-6/IL-10 and USP18, phosphorylated (p)-STAT1 and myxovirus (influenza virus) resistance 1 (Mx1) expression was determined. Treatment of Huh7.5 cells and primary murine hepatocytes with LPS and TNF-α, but not IL-6 or IL-10, led to upregulated USP18 expression and induced an IFN-α refractory state, which was reversed by USP18 knockdown. Liver inflammation was induced in vivo using a murine model of hepatic ischemia/reperfusion injury. Hepatic ischemia/reperfusion injury led to an induction of USP18 expression in liver tissue and promotion of lymphocytic choriomeningitis replication. These data demonstrate that certain inflammatory stimuli (TNF-α and LPS) but not others (IL-6 and IL-10) target USP18 expression and thus inhibit IFN signaling. These findings represent a new paradigm for how inflammation alters hepatic innate immune responses, with USP18 representing a potential target for intervention in various inflammatory states. IMPORTANCE Inflammation may prevent the control of viral infection when it impairs the innate immune response, enhancing viral replication and spread. Blunted immunity as a result of

  13. Mapping the Cell-Surface N-Glycoproteome of Human Hepatocytes Reveals Markers for Selecting a Homogeneous Population of iPSC-Derived Hepatocytes.

    PubMed

    Mallanna, Sunil K; Cayo, Max A; Twaroski, Kirk; Gundry, Rebekah L; Duncan, Stephen A

    2016-09-13

    When comparing hepatic phenotypes between iPSC-derived hepatocyte-like cells from different liver disease patients, cell heterogeneity can confound interpretation. We proposed that homogeneous cell populations could be generated by fluorescence-activated cell sorting (FACS). Using cell-surface capture proteomics, we identified a total of 300 glycoproteins on hepatocytes. Analyses of the expression profiles during the differentiation of iPSCs revealed that SLC10A1, CLRN3, and AADAC were highly enriched during the final stages of hepatocyte differentiation. FACS purification of hepatocyte-like cells expressing SLC10A1, CLRN3, or AADAC demonstrated enrichment of cells with hepatocyte characteristics. Moreover, transcriptome analyses revealed that cells expressing the liver gene regulatory network were enriched while cells expressing a pluripotent stem cell network were depleted. In conclusion, we report an extensive catalog of cell-surface N-linked glycoproteins expressed in primary hepatocytes and identify cell-surface proteins that facilitate the purification of homogeneous populations of iPSC-derived hepatocyte-like cells.

  14. Magnetic Cell Labeling of Primary and Stem Cell-Derived Pig Hepatocytes for MRI-Based Cell Tracking of Hepatocyte Transplantation

    PubMed Central

    Roach, Dwayne R.; Garrett, Wesley M.; Welch, Glenn; Caperna, Thomas J.; Talbot, Neil C.; Shapiro, Erik M.

    2015-01-01

    Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this work, we describe culture conditions for magnetic cell labeling of cells from two different pig hepatocyte cell sources; primary pig hepatocytes (ppHEP) and stem cell-derived hepatocytes (PICM-19FF). The magnetic particle is a micron-sized iron oxide particle (MPIO) that has been extensively studied for magnetic cell labeling for MRI-based cell tracking. ppHEP could endocytose MPIO with labeling percentages as high as 70%, achieving iron content as high as ~55 pg/cell, with >75% viability. PICM-19FF had labeling >97%, achieving iron content ~38 pg/cell, with viability >99%. Extensive morphological and functional assays indicated that magnetic cell labeling was benign to the cells. The results encourage the use of MRI-based cell tracking for the development and clinical use of hepatocyte transplantation methodologies. Further, these results generally highlight the importance of functional cell assays in the evaluation of contrast agent biocompatibility. PMID:25856627

  15. Cardiac Biomarkers and Left Ventricular Hypertrophy in Asymptomatic Hemodialysis Patients

    PubMed Central

    Koycheva, Reneta Yovcheva; Cholakov, Vasil; Andreev, Jivko; Penev, Margarit; Iliev, Rosen; Nancheva, Krasimira; Tsoneva, Vanya

    2016-01-01

    BACKGROUND: Cardiac biomarkers are often elevated in dialysis patients showing the presence of left ventricular dysfunction. The aim of the study is to establish the plasma levels of high-sensitivity cardiac troponin T (hs TnT), precursor of B-natriuretic peptide (NT-proBNP) and high sensitivity C-reactive protein (hs CRP) and their relation to the presence of left ventricular hypertrophy (LVH) in patients undergoing hemodialysis without signs of acute coronary syndrome or heart failure. MATERIAL AND METHODS: We studied 48 patients - 26 men and 22 women. Pre and postdialysis levels of hs cTnT, NT-proBNP and hs CRP were measured at week interim procedure. Patients were divided in two groups according to the presence of echocardiographic evidence of LVH - gr A - 40 patients (with LVH), and gr B - 8 patients (without LVH). RESULTS: In the whole group of patients was found elevated predialysis levels of all three biomarkers with significant increase (p < 0.05) after dialysis with low-flux dialyzers. Predialysis values of NT-proBNP show moderate positive correlation with hs cTnT (r = 0.47) and weaker with hs CRP (r = 0.163). Such dependence is observed in postdialysis values of these biomarkers. There is a strong positive correlation between the pre and postdialysis levels: for hs cTnT (r = 0.966), for NT-proBNP (r = 0.918) and for hs CRP (r = 0.859). It was found a significant difference in the mean values of hs cTnT in gr. A and gr. B (0.07 ± 0.01 versus 0.03 ± 0.01 ng/mL, p < 0.05) and NT-proBNP (15,605.8 ± 2,072.5 versus 2,745.5 ± 533.55 pg/mL, p < 0.05). Not find a significant difference in hs CRP in both groups. CONCLUSIONS: The results indicate the relationship of the studied cardiac biomarkers with LVH in asymptomatic patients undergoing hemodialysis treatment. PMID:27275331

  16. Sodium bicarbonate supplementation improves hypertrophy-type resistance exercise performance.

    PubMed

    Carr, Benjamin M; Webster, Michael J; Boyd, Joseph C; Hudson, Geoffrey M; Scheett, Timothy P

    2013-03-01

    The aim of the present study was to examine the effects of sodium bicarbonate (NaHCO(3)) administration on lower-body, hypertrophy-type resistance exercise (HRE). Using a double-blind randomized counterbalanced design, 12 resistance-trained male participants (mean ± SD; age = 20.3 ± 2 years, mass = 88.3 ± 13.2 kg, height = 1.80 ± 0.07 m) ingested 0.3 g kg(-1) of NaHCO(3) or placebo 60 min before initiation of an HRE regimen. The protocol employed multiple exercises: squat, leg press, and knee extension, utilizing four sets each, with 10-12 repetition-maximum loads and short rest periods between sets. Exercise performance was determined by total repetitions generated during each exercise, total accumulated repetitions, and a performance test involving a fifth set of knee extensions to failure. Arterialized capillary blood was collected via fingertip puncture at four time points and analyzed for pH, [HCO(3)(-)], base excess (BE), and lactate [Lac(-)]. NaHCO(3) supplementation induced a significant alkaline state (pH: NaHCO(3): 7.49 ± 0.02, placebo: 7.42 ± 0.02, P < 0.05; [HCO(3)(-)]: NaHCO(3): 31.50 ± 2.59, placebo: 25.38 ± 1.78 mEq L(-1), P < 0.05; BE: NaHCO(3): 7.92 ± 2.57, placebo: 1.08 ± 2.11 mEq L(-1), P < 0.05). NaHCO(3) administration resulted in significantly more total repetitions than placebo (NaHCO(3): 139.8 ± 13.2, placebo: 134.4 ± 13.5), as well as significantly greater blood [Lac(-)] after the exercise protocol (NaHCO(3): 17.92 ± 2.08, placebo: 15.55 ± 2.50 mM, P < 0.05). These findings demonstrate ergogenic efficacy for NaHCO(3) during HRE and warrant further investigation into chronic training applications.

  17. Quantum Operation Time Reversal

    SciTech Connect

    Crooks, Gavin E.

    2008-03-25

    The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

  18. Unilateral hypoplasia with contralateral hypertrophy of anterior belly of digastric muscle: a case report.

    PubMed

    Ochoa-Escudero, Martin; Juliano, Amy F

    2016-10-01

    Anomalies of the anterior belly of the digastric muscle (DM) are uncommon. We present a case of hypoplasia of the anterior belly of the left DM with hypertrophy of the anterior belly of the contralateral DM. The importance of recognizing this finding is to differentiate hypoplasia of the anterior belly of the DM from denervation atrophy, and not to confuse contralateral hypertrophy with a submental mass or lymphadenopathy. In denervation atrophy of the anterior belly of the DM, associated atrophy of the ipsilateral mylohyoid muscle is present. Hypertrophy of the anterior belly of the contralateral DM can be differentiated from a submental mass or lymphadenopathy by recognizing its isodensity on computed tomography and isointensity on magnetic resonance imaging to other muscles, without abnormal contrast enhancement.

  19. Identification of genes regulated during mechanical load-induced cardiac hypertrophy

    NASA Technical Reports Server (NTRS)

    Johnatty, S. E.; Dyck, J. R.; Michael, L. H.; Olson, E. N.; Abdellatif, M.; Schneider, M. (Principal Investigator)

    2000-01-01

    Cardiac hypertrophy is associated with both adaptive and adverse changes in gene expression. To identify genes regulated by pressure overload, we performed suppressive subtractive hybridization between cDNA from the hearts of aortic-banded (7-day) and sham-operated mice. In parallel, we performed a subtraction between an adult and a neonatal heart, for the purpose of comparing different forms of cardiac hypertrophy. Sequencing more than 100 clones led to the identification of an array of functionally known (70%) and unknown genes (30%) that are upregulated during cardiac growth. At least nine of those genes were preferentially expressed in both the neonatal and pressure over-load hearts alike. Using Northern blot analysis to investigate whether some of the identified genes were upregulated in the load-independent calcineurin-induced cardiac hypertrophy mouse model, revealed its incomplete similarity with the former models of cardiac growth. Copyright 2000 Academic Press.

  20. Role of diacylglycerol kinase in cellular regulatory processes: a new regulator for cardiomyocyte hypertrophy.

    PubMed

    Takeishi, Yasuchika; Goto, Kaoru; Kubota, Isao

    2007-09-01

    Diacylglycerol (DAG) kinase (DGK) phosphorylates and converts DAG to phosphatidic acid. DGK regulates cellular DAG levels and attenuates DAG signaling. The 10 mammalian DGK isoforms have been identified to date. In cardiac myocytes, DGKalpha, epsilon, and zeta are expressed, and DGKzeta is the predominant isoform. DGKzeta inhibits protein kinase C (PKC) activation and subsequent hypertrophic programs in response to endothelin-1 (ET-1) in neonatal rat cardiomyocytes. DGKzeta blocks cardiac hypertrophy induced by G protein-coupled receptor agonists and pressure overload in vivo. DGKzeta attenuates ventricular remodeling and improves survival after myocardial infarction. These data provide a novel insight for subcellular mechanisms of cardiac hypertrophy and heart failure, and DGKzeta may be a new therapeutic target to prevent cardiac hypertrophy and progression to heart failure. PMID:17659347

  1. Neuroglobin protects cardiomyocytes against apoptosis and cardiac hypertrophy induced by isoproterenol in rats.

    PubMed

    Liu, Zhen-Fang; Zhang, Xiao; Qiao, Yan-Xiang; Xu, Wan-Qun; Ma, Cheng-Tai; Gu, Hua-Li; Zhou, Xiu-Mei; Shi, Lei; Cui, Chang-Xing; Xia, Di; Chen, Yu-Guo

    2015-01-01

    Neuroglobin (Ngb) is well known as a physiological role in oxygen homeostasis of neurons and perhaps a protective role against hypoxia and oxidative stress. In this study, we found that Ngb is expressed in rat heart tissues and it is related to isoproterenol induced cardiac hypertrophy. Moreover, overexpression or knock-down of Ngb influences the expression of hypertrophic markers ANP and BNP and the ratio of hypertrophic cells in rat H9c2 myoblasts when isoproterenol treatment. The Annexin V-FITC/PI Staining, Western blot and qPCR analysis showed that the involvement in p53-mediated apoptosis of cardiomyocytes of Ngb is might be the mechanism. This protein could prevent the cells against ROS and POS-induced apoptosis not only in nervous systems but also in cardiomyocytes. From the results, it is concluded that Ngb is a promising protectant in the cardiac hypertrophy, it may be a candidate target to cardiac hypertrophy for clinic treatment. PMID:26131111

  2. Longitudinal strain bull's eye plot patterns in patients with cardiomyopathy and concentric left ventricular hypertrophy.

    PubMed

    Liu, Dan; Hu, Kai; Nordbeck, Peter; Ertl, Georg; Störk, Stefan; Weidemann, Frank

    2016-05-10

    Despite substantial advances in the imaging techniques and pathophysiological understanding over the last decades, identification of the underlying causes of left ventricular hypertrophy by means of echocardiographic examination remains a challenge in current clinical practice. The longitudinal strain bull's eye plot derived from 2D speckle tracking imaging offers an intuitive visual overview of the global and regional left ventricular myocardial function in a single diagram. The bull's eye mapping is clinically feasible and the plot patterns could provide clues to the etiology of cardiomyopathies. The present review summarizes the longitudinal strain, bull's eye plot features in patients with various cardiomyopathies and concentric left ventricular hypertrophy and the bull's eye plot features might serve as one of the cardiac workup steps on evaluating patients with left ventricular hypertrophy.

  3. Essential role of STIM1 in the development of cardiomyocyte hypertrophy

    SciTech Connect

    Ohba, Takayoshi; Watanabe, Hiroyuki; Murakami, Manabu; Sato, Takako; Ono, Kyoichi; Ito, Hiroshi

    2009-11-06

    Store-operated Ca{sup 2+} entry (SOCE) through transient receptor potential (TRP) channels is important in the development of cardiac hypertrophy. Recently, stromal interaction molecule 1 (STIM1) was identified as a key regulator of SOCE. In this study, we examined whether STIM1 is involved in the development of cardiomyocyte hypertrophy. RT-PCR showed that cultured rat cardiomyocytes constitutively expressed STIM1. Endothelin-1 (ET-1) treatment for 48 h enhanced TRPC1 expression, SOCE, and nuclear factor of activated T cells activation without upregulating STIM1. However, the knockdown of STIM1 suppressed these effects, thereby preventing a hypertrophic response. These results suggest that STIM1 plays an essential role in the development of cardiomyocyte hypertrophy.

  4. Sulforaphane- and phenethyl isothiocyanate-induced inhibition of aflatoxin B1-mediated genotoxicity in human hepatocytes: role of GSTM1 genotype and CYP3A4 gene expression.

    PubMed

    Gross-Steinmeyer, Kerstin; Stapleton, Patricia L; Tracy, Julia H; Bammler, Theo K; Strom, Stephen C; Eaton, David L

    2010-08-01

    Primary cultures of human hepatocytes were used to investigate whether the dietary isothiocyanates, sulforaphane (SFN), and phenethyl isothiocyanate (PEITC) can reduce DNA adduct formation of the hepatocarcinogen aflatoxin B(1) (AFB). Following 48 h of pretreatment, 10 and 50 microM SFN greatly decreased AFB-DNA adduct levels, whereas 25muM PEITC decreased AFB-DNA adducts in some but not all hepatocyte preparations. Microarray and quantitative reverse transcriptase (RT)-PCR analyses of gene expression in SFN and PEITC-treated hepatocytes demonstrated that SFN greatly decreased cytochrome P450 (CYP) 3A4 mRNA but did not induce the expression of either glutathione S-transferase (GST) M1 or GSTT1. The protective effects of SFN required pretreatment; cotreatment of hepatocytes with SFN and AFB in the absence of pretreatment had no effect on AFB-DNA adduct formation. When AFB-DNA adduct formation was evaluated by GST genotype, the presence of one or two functional alleles of GSTM1 was associated with a 75% reduction in AFB-DNA adducts, compared with GSTM1 null. In conclusion, these results demonstrate that the inhibition of AFB-DNA adduct formation by SFN is dependent on changes in gene expression rather than direct inhibition of catalytic activity. Transcriptional repression of genes involved in AFB bioactivation (CYP3A4 and CYP1A2), but not transcriptional activation of GSTs, may be responsible for the protective effects of SFN. Although GSTM1 expression was not induced by SFN, the presence of a functional GSTM1 allele can afford substantial protection against AFB-DNA damage in human liver. The downregulation of CYP3A4 by SFN may have important implications for drug interactions. PMID:20442190

  5. Predictions of cytochrome P450-mediated drug-drug interactions using cryopreserved human hepatocytes: comparison of plasma and protein-free media incubation conditions.

    PubMed

    Mao, Jialin; Mohutsky, Michael A; Harrelson, John P; Wrighton, Steven A; Hall, Stephen D

    2012-04-01

    Cryopreserved human hepatocytes suspended in human plasma (HHSHP) have previously provided accurate CYP3A drug-drug interaction (DDI) predictions from a single IC(50) that captures both reversible and time-dependent inhibition. The goal of this study was to compare the accuracy of DDI predictions by a protein-free human hepatocyte system combined with the fraction unbound in plasma for inhibitor(s) with those obtained with protein-containing incubations. Seventeen CYP3A, CYP2C9, or CYP2D6 inhibitors were incubated with hepatocytes in human plasma or hepatocyte maintenance medium (HMM) for 20 min over a range of concentrations after which midazolam 1'-hydroxylation, diclofenac 4'-hydroxylation or (R)-bufuralol 1'-hydroxylation were used to quantify the corresponding cytochrome P450 (P450) catalytic activities. Two methods were used to predict the human exposure ratio of the victim drug in the presence and absence of inhibitor. The HMM K(i, app) values were combined with the free average systemic plasma concentration ("free [I] with HMM K(i, app)") and the plasma K(i, app) values were combined with the total average systemic plasma concentration ("total [I] with plasma K(i, app)"). Of 63 clinical DDI studies, the total [I] with plasma K(i, app) method predicted 89% of cases within 2-fold of the reported interaction whereas the free [I] with HMM K(i, app) method predicted only 59%. There was a general underprediction by the free [I] with HMM K(i, app) method, which is consistent with an underestimation of in vitro inhibition potency in this system. In conclusion, the HHSHP system proved to be a simple, accurate predictor of DDIs for three major P450s and superior to the protein-free approach. PMID:22228749

  6. Suppression of calcium-sensing receptor ameliorates cardiac hypertrophy through inhibition of autophagy

    PubMed Central

    LIU, LEI; WANG, CHAO; LIN, YAN; XI, YUHUI; LI, HONG; SHI, SA; LI, HONGZHU; ZHANG, WEIHUA; ZHAO, YAJUN; TIAN, YE; XU, CHANGQING; WANG, LINA

    2016-01-01

    The calcium-sensing receptor (CaSR) releases intracellular calcium ([Ca2+]i) by accumulating inositol phosphate. Changes in [Ca2+]i initiate myocardial hypertrophy. Furthermore, autophagy associated with [Ca2+]i. Autophagy has previously been demonstrated to participate in the hypertrophic process. The current study investigated whether suppression of CaSR affects the hypertrophic response via modulating autophagy. Isoproterenol (ISO) was used to induce cardiac hypertrophy in Wistar rats. Hypertrophic status was determined by echocardiographic assessment, hematoxylin and eosin, and Masson's staining. The protein expression levels of CaSR and autophagy level were observed. Changes of hypertrophy and autophagy indicators were observed following intravenous injection of a CaSR inhibitor. An ISO-induced cardiomyocyte hypertrophy model was established and used determine the involvement of GdCl3. [Ca2+]i was determined using Fluo-4/AM dye followed by confocal microscopy. The expression levels of various active proteins were analyzed by western blotting. The size of the heart, expression levels of CaSR and autophagy level were markedly increased in hypertrophic myocardium. In addition, the present study demonstrated that the indicators of hypertrophy and autophagy were effectively suppressed by CaSR inhibitor. Furthermore, similar effects were demonstrated in neonatal rat hypertrophic cardiomyocytes treated with ISO. It was also observed that CaSR regulates the Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ)-AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) signaling pathway induced by ISO in cardiomyocytes. Furthermore, the AMPK inhibition significantly reduced the autophagy level following CaSR stimulation (P<0.05). The results of the present demonstrated that inhibition of CaSR may ameliorate cardiac hypertrophy induced by ISO and the effect may be associated with the inhibition of autophagy and suppression of the Ca

  7. Ca²⁺ signal-induced cardiomyocyte hypertrophy through activation of myocardin.

    PubMed

    Li, Man; Wang, Nan; Gong, Hui-Qin; Li, Wei-Zong; Liao, Xing-Hua; Yang, Xiao-Long; He, Hong-Peng; Cao, Dong-Sun; Zhang, Tong-Cun

    2015-02-15

    Hypertrophic growth of cardiomyocytes in response to pressure overload is an important stage during the development of many cardiac diseases. Ca(2+) overload as well as subsequent activation of Ca(2+) signaling pathways has been reported to induce cardiac hypertrophy. Myocardin, a transcription cofactor of serum response factor (SRF), is a key transducer of hypertrophic signals. However, the direct role of myocardin in Ca(2+) signal-induced cardiomyocyte hypertrophy has not been explained clearly. In the present study, we discovered that embryonic rat heart-derived H9c2 cells responded to the stimulation of calcium ionophore A23187 with a cell surface area enlargement and an increased expression of cardiac hypertrophy marker genes. Increased Ca(2+) also induces an organization of sarcomeres in neonatal rat cardiomyocytes, as revealed by α-actinin staining. Increased Ca(2+) could upregulate the expression of myocardin. Knockdown of myocardin by shRNA attenuates hypertrophic responses triggered by increased intracellular Ca(2+), suggesting that Ca(2+) signals induce cardiomyocyte hypertrophy partly through activation of myocardin. Furthermore, A23187 treatment directly activates myocardin promoter, chelation of Ca(2+) by EGTA inhibits this activation and knockdown of myocardin expression using shRNA also abrogates A23187-induced ANF and SK-α-actin promoter activity. CSA (calcineurin inhibitor) and KN93 (CaMKII inhibitor) inhibit A23187-induced the increase in myocardin expression. These results suggest that myocardin plays a critical role in Ca(2+) signal-induced cardiomyocyte hypertrophy, which may serve as a novel mechanism that is important for cardiac hypertrophy.

  8. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis

    PubMed Central

    2013-01-01

    Protein timing is a popular dietary strategy designed to optimize the adaptive response to exercise. The strategy involves consuming protein in and around a training session in an effort to facilitate muscular repair and remodeling, and thereby enhance post-exercise strength- and hypertrophy-related adaptations. Despite the apparent biological plausibility of the strategy, however, the effectiveness of protein timing in chronic training studies has been decidedly mixed. The purpose of this paper therefore was to conduct a multi-level meta-regression of randomized controlled trials to determine whether protein timing is a viable strategy for enhancing post-exercise muscular adaptations. The strength analysis comprised 478 subjects and 96 ESs, nested within 41 treatment or control groups and 20 studies. The hypertrophy analysis comprised 525 subjects and 132 ESs, nested with 47 treatment or control groups and 23 studies. A simple pooled analysis of protein timing without controlling for covariates showed a small to moderate effect on muscle hypertrophy with no significant effect found on muscle strength. In the full meta-regression model controlling for all covariates, however, no significant differences were found between treatment and control for strength or hypertrophy. The reduced model was not significantly different from the full model for either strength or hypertrophy. With respect to hypertrophy, total protein intake was the strongest predictor of ES magnitude. These results refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion. PMID:24299050

  9. Gram-negative endotoxin lipopolysaccharide induces cardiac hypertrophy: detrimental role of Na(+)-Ca(2+) exchanger.

    PubMed

    Magi, Simona; Nasti, Annamaria Assunta; Gratteri, Santo; Castaldo, Pasqualina; Bompadre, Stefano; Amoroso, Salvatore; Lariccia, Vincenzo

    2015-01-01

    Several molecular pathways involved in the development of cardiac hypertrophy are triggered by perturbation of intracellular Ca(2+) homeostasis. Within the heart, Na(+)/Ca(2+) exchanger 1 (NCX1) is one of the main determinant in controlling Ca(2+) homeostasis. In cardiac hypertrophy and heart failure NCX1 expression and activity have been reported to be altered. It has been shown that chronic bacterial infections (sepsis, endocarditis, and myocarditis) can promote cardiac hypertrophy. Bacterial stressors, such as the Gram-negative endotoxin lipopolysaccharide (LPS), can directly or indirectly affect intracellular Ca(2+) homeostasis in the heart and induce the development of cardiac hypertrophy. The present study aimed at evaluating the potential link between the signal pathways activated in LPS-exposed myocytes and NCX1. In the whole rat heart, LPS perfusion induced an early hypertrophy response during which NCX1 expression significantly increased. Notably, all these changes were completely prevented by the NCX inhibitor SN-6. We further dissect the role of NCX1 in the LPS-induced hypertrophic response in an in vitro cardiac model based on two H9c2 cardiomyoblast clones, namely H9c2-WT (lacking endogenous NCX1 expression) and H9c2-NCX1 (stably transfected with a functional NCX1). H9c2-NCX1 were more susceptible than H9c2-WT to develop a hypertrophic phenotype, and they displayed a significant increase in NCX1 expression and function after LPS treatment. SN-6 completely counteracted both hypertrophic response and exchanger alterations induced by LPS in H9c2-NCX1 cells, but it had no effects on H9c2-WT. Collectively, our results suggest that NCX1 plays a critical role in promoting myocardial hypertrophy triggered by LPS. PMID:25445045

  10. Ca²⁺ signal-induced cardiomyocyte hypertrophy through activation of myocardin.

    PubMed

    Li, Man; Wang, Nan; Gong, Hui-Qin; Li, Wei-Zong; Liao, Xing-Hua; Yang, Xiao-Long; He, Hong-Peng; Cao, Dong-Sun; Zhang, Tong-Cun

    2015-02-15

    Hypertrophic growth of cardiomyocytes in response to pressure overload is an important stage during the development of many cardiac diseases. Ca(2+) overload as well as subsequent activation of Ca(2+) signaling pathways has been reported to induce cardiac hypertrophy. Myocardin, a transcription cofactor of serum response factor (SRF), is a key transducer of hypertrophic signals. However, the direct role of myocardin in Ca(2+) signal-induced cardiomyocyte hypertrophy has not been explained clearly. In the present study, we discovered that embryonic rat heart-derived H9c2 cells responded to the stimulation of calcium ionophore A23187 with a cell surface area enlargement and an increased expression of cardiac hypertrophy marker genes. Increased Ca(2+) also induces an organization of sarcomeres in neonatal rat cardiomyocytes, as revealed by α-actinin staining. Increased Ca(2+) could upregulate the expression of myocardin. Knockdown of myocardin by shRNA attenuates hypertrophic responses triggered by increased intracellular Ca(2+), suggesting that Ca(2+) signals induce cardiomyocyte hypertrophy partly through activation of myocardin. Furthermore, A23187 treatment directly activates myocardin promoter, chelation of Ca(2+) by EGTA inhibits this activation and knockdown of myocardin expression using shRNA also abrogates A23187-induced ANF and SK-α-actin promoter activity. CSA (calcineurin inhibitor) and KN93 (CaMKII inhibitor) inhibit A23187-induced the increase in myocardin expression. These results suggest that myocardin plays a critical role in Ca(2+) signal-induced cardiomyocyte hypertrophy, which may serve as a novel mechanism that is important for cardiac hypertrophy. PMID:25485719

  11. Dominant negative Ras attenuates pathological ventricular remodeling in pressure overload cardiac hypertrophy

    PubMed Central

    Ramos-Kuri, Manuel; Rapti, Kleopatra; Mehel, Hind; Zhang, Shihong; Dhandapany, Perundurai S.; Liang, Lifan; García-Carrancá, Alejandro; Bobe, Regis; Fischmeister, Rodolphe; Adnot, Serge; Lebeche, Djamel; Hajjar, Roger J.; Lipskaia, Larissa; Chemaly, Elie R.

    2015-01-01

    The importance of the oncogene Ras in cardiac hypertrophy is well appreciated. The hypertrophic effects of the constitutively active mutant Ras-Val12 are revealed by clinical syndromes due to the Ras mutations and experimental studies. We examined the possible anti-hypertrophic effect of Ras inhibition in vitro using rat neonatal cardiomyocytes (NRCM) and in vivo in the setting of pressure-overload left ventricular (LV) hypertrophy (POH) in rats. Ras functions were modulated via adenovirus directed gene transfer of active mutant Ras-Val12 or dominant negative mutant N17-DN-Ras (DN-Ras). Ras-Val12 expression in vitro activates NFAT resulting in pro-hypertrophic and cardio-toxic effects on NRCM beating and Z-line organization. In contrast, the DN-Ras was antihypertrophic on NRCM, inhibited NFAT and exerted cardio-protective effects attested by preserved NRCM beating and Z line structure. Additional experiments with silencing H-Ras gene strategy corroborated the antihypertrophic effects of siRNA-H-Ras on NRCM. In vivo, with the POH model, both Ras mutants were associated with similar hypertrophy two weeks after simultaneous induction of POH and Ras-mutant gene transfer. However, LV diameters were higher and LV fractional shortening lower in the Ras-Val12 group compared to control and DN-Ras. Moreover, DN-Ras reduced the cross-sectional area of cardiomyocytes in vivo, and decreased the expression of markers of pathologic cardiac hypertrophy. In isolated adult cardiomyocytes after 2 weeks of POH and Ras-mutant gene transfer, DN-Ras improved sarcomere shortening and calcium transients compared to Ras-Val12. Overall, DN-Ras promotes a more physiological form of hypertrophy, suggesting an interesting therapeutic target for pathological cardiac hypertrophy. PMID:26260012

  12. Dominant negative Ras attenuates pathological ventricular remodeling in pressure overload cardiac hypertrophy.

    PubMed

    Ramos-Kuri, Manuel; Rapti, Kleopatra; Mehel, Hind; Zhang, Shihong; Dhandapany, Perundurai S; Liang, Lifan; García-Carrancá, Alejandro; Bobe, Regis; Fischmeister, Rodolphe; Adnot, Serge; Lebeche, Djamel; Hajjar, Roger J; Lipskaia, Larissa; Chemaly, Elie R

    2015-11-01

    The importance of the oncogene Ras in cardiac hypertrophy is well appreciated. The hypertrophic effects of the constitutively active mutant Ras-Val12 are revealed by clinical syndromes due to the Ras mutations and experimental studies. We examined the possible anti-hypertrophic effect of Ras inhibition in vitro using rat neonatal cardiomyocytes (NRCM) and in vivo in the setting of pressure-overload left ventricular (LV) hypertrophy (POH) in rats. Ras functions were modulated via adenovirus directed gene transfer of active mutant Ras-Val12 or dominant negative mutant N17-DN-Ras (DN-Ras). Ras-Val12 expression in vitro activates NFAT resulting in pro-hypertrophic and cardio-toxic effects on NRCM beating and Z-line organization. In contrast, the DN-Ras was antihypertrophic on NRCM, inhibited NFAT and exerted cardio-protective effects attested by preserved NRCM beating and Z line structure. Additional experiments with silencing H-Ras gene strategy corroborated the antihypertrophic effects of siRNA-H-Ras on NRCM. In vivo, with the POH model, both Ras mutants were associated with similar hypertrophy two weeks after simultaneous induction of POH and Ras-mutant gene transfer. However, LV diameters were higher and LV fractional shortening lower in the Ras-Val12 group compared to control and DN-Ras. Moreover, DN-Ras reduced the cross-sectional area of cardiomyocytes in vivo, and decreased the expression of markers of pathologic cardiac hypertrophy. In isolated adult cardiomyocytes after 2 weeks of POH and Ras-mutant gene transfer, DN-Ras improved sarcomere shortening and calcium transients compared to Ras-Val12. Overall, DN-Ras promotes a more physiological form of hypertrophy, suggesting an interesting therapeutic target for pathological cardiac hypertrophy.

  13. Requirement of intracellular free thiols for hydrogen peroxide-induced hypertrophy in cardiomyocytes.

    PubMed

    Tanaka, Hiroyuki; Sakurai, Koichi; Takahashi, Kiyoshi; Fujimoto, Yukio

    2003-08-01

    Reactive oxygen species (ROS) are by-products of aerobic metabolism and are implicated in the pathogenesis of several diseases. H(2)O(2) produces oxidative stress and acts as a second messenger in several cell types. We tested whether the effect of H(2)O(2) on cellular events could be altered by changes in the intracellular redox status in a cardiomyocyte cell line. Using flow cytometric measurements, we found that adding H(2)O(2) induced hypertrophy in control cells in a time-dependent manner. Pre-incubation of the cells with buthionine sulfoximine (BSO), an inhibitor of de novo GSH synthesis, induced increase in the number of cells of small sizes by the addition of H(2)O(2) as compared to non-BSO pre-incubated control cells, and exacerbated the decrease in viability. Total thiol and GSH levels in H9c2 cells pre-incubated with BSO were about 75 and 30% of control, respectively, and GSH levels fell to below the limitation of detection after the addition of H(2)O(2), although total thiol levels were not markedly decreased. In the cells pre-incubated with BSO, hypertrophy was not observed by the addition of H(2)O(2) at any level of concentration. N-acetyl-L-cysteine and cysteine not only prevented increase in the number of cells of small sizes caused by H(2)O(2) but also induced hypertrophy in cells pre-incubated with BSO. These results suggest that the intracellular free thiol levels determine whether cell death or hypertrophy occurs in cardiomyocytes in the presence of H(2)O(2). On the other hand, the hypertrophied cells did not become larger by adding H(2)O(2), but had high levels of cellular GSH, suggesting the possibility that the hypertrophied cells have tolerance to oxidative stress.

  14. Ghrelin Inhibition Restores Glucose Homeostasis in Hepatocyte Nuclear Factor-1α (MODY3)-Deficient Mice.

    PubMed

    Brial, François; Lussier, Carine R; Belleville, Karine; Sarret, Philippe; Boudreau, François

    2015-09-01

    Hepatocyte nuclear factor-1α (HNF1α) is a transcription factor expressed in tissues of endoderm origin. Mutations in HNF1A are associated with maturity-onset diabetes of the young 3 (MODY3). Mice deficient for Hnf1α are hyperglycemic, with their pancreatic β-cells being defective in glucose-sensing insulin secretion. The specific mechanisms involved in this defect are unclear. Gut hormones control glucose homeostasis. Our objective was to explore whether changes in these hormones play a role in glucose homeostasis in the absence of Hnf1α. An increase in ghrelin gene transcript and a decrease in glucose-dependent insulinotropic polypeptide (GIP) gene transcripts were observed in the gut of Hnf1α-null mice. These changes correlated with an increase of ghrelin and a decrease of GIP-labeled cells. Ghrelin serological levels were significantly induced in Hnf1α-null mice. Paradoxically, GIP levels were also induced in these mice. Treatment of Hnf1α-null mice with a ghrelin antagonist led to a recovery of the diabetic symptoms. We conclude that upregulation of ghrelin in the absence of Hnf1α impairs insulin secretion and can be reversed by pharmacological inhibition of ghrelin/GHS-R interaction. These observations open up on future strategies to counteract ghrelin action in a program that could become beneficial in controlling non-insulin-dependent diabetes. PMID:25979074

  15. Mitochondrial DNA from hepatocytes as a ligand for TLR9: Drivers of nonalcoholic steatohepatitis?

    PubMed

    Handa, Priya; Vemulakonda, Akhila; Kowdley, Kris V; Uribe, Misael; Méndez-Sánchez, Nahum

    2016-08-21

    Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, affecting approximately one third of the Western world. It consists of a wide spectrum of liver disorders, ranging from fatty liver to nonalcoholic steatohepatitis (NASH), which consists of steatosis, ballooning injury and inflammation. Despite an alarming growth in the statistics surrounding NAFLD, there are as yet no effective therapies for its treatment. Innate immune signaling has been thought to play a significant role in initiating and augmenting hepatic inflammation, contributing to the transition from nonalcoholic fatty liver to NASH. An immune response is triggered by countless signals called damage-associated molecular patterns (DAMPs) elicited by lipid-laden and damaged hepatocytes, which are recognized by pattern recognition receptors (PRRs) on hepatic immune cells to initiate inflammatory signaling. In this editorial, in addition to summarizing innate immune signaling in NAFLD and discussing potential therapies that target innate immune pathways, we have described a recent study that demonstrated that mitochondrial DNA serves as a DAMP activating a hepatic PRR, TLR9, in mice and in the plasma of NASH patients. In addition to identifying a new ligand for TLR9 during NASH progression, the study shows that blocking TLR9 reverses NASH, paving the way for the development of future NASH therapy. PMID:27610009

  16. Exogenous Mg-ATP induces a large inhibition of pyruvate kinase in intact rat hepatocytes.

    PubMed

    Ichai, C; El-Mir, M Y; Nogueira, V; Piquet, M A; Chauvin, C; Fontaine, E; Leverve, X M

    2001-03-01

    Mg-ATP infusion in vivo has been reported to be beneficial both to organ function and survival rate in various models of shock. Moreover, a large variety of metabolic effects has been shown to occur in several tissues due to purinergic receptor activation. In the present work we studied the effects of exogenous Mg-ATP in rat liver cells perifused with dihydroxyacetone to investigate simultaneously gluconeogenetic and glycolytic pathways. We found a significant effect on oxidative phosphorylation as characterized by a decrease in oxygen consumption rate and in the cellular ATP-to-ADP ratio associated with an increase in lactate-to-pyruvate ratio. In addition, exogenous Mg-ATP induced rapid and reversible inhibition of both gluconeogenesis and glycolysis. The main effect on gluconeogenesis was located at the level of the fructose cycle, whereas the decrease in glycolysis was due to a strong inhibition of pyruvate kinase. Although pyruvate kinase inhibition induced by exogenous Mg-ATP was allosteric when assessed in vitro after enzyme extraction, we found a large decrease in the apparent maximal velocity when kinetics were assessed in vivo in intact perifused hepatocytes. This newly described short-term regulation of pyruvate kinase occurs only in the intact cell and may open new potentials for the pharmacological regulation of pyruvate kinase in vivo. PMID:11104754

  17. Mitochondrial DNA from hepatocytes as a ligand for TLR9: Drivers of nonalcoholic steatohepatitis?

    PubMed Central

    Handa, Priya; Vemulakonda, Akhila; Kowdley, Kris V; Uribe, Misael; Méndez-Sánchez, Nahum

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, affecting approximately one third of the Western world. It consists of a wide spectrum of liver disorders, ranging from fatty liver to nonalcoholic steatohepatitis (NASH), which consists of steatosis, ballooning injury and inflammation. Despite an alarming growth in the statistics surrounding NAFLD, there are as yet no effective therapies for its treatment. Innate immune signaling has been thought to play a significant role in initiating and augmenting hepatic inflammation, contributing to the transition from nonalcoholic fatty liver to NASH. An immune response is triggered by countless signals called damage-associated molecular patterns (DAMPs) elicited by lipid-laden and damaged hepatocytes, which are recognized by pattern recognition receptors (PRRs) on hepatic immune cells to initiate inflammatory signaling. In this editorial, in addition to summarizing innate immune signaling in NAFLD and discussing potential therapies that target innate immune pathways, we have described a recent study that demonstrated that mitochondrial DNA serves as a DAMP activating a hepatic PRR, TLR9, in mice and in the plasma of NASH patients. In addition to identifying a new ligand for TLR9 during NASH progression, the study shows that blocking TLR9 reverses NASH, paving the way for the development of future NASH therapy.

  18. Mitochondrial DNA from hepatocytes as a ligand for TLR9: Drivers of nonalcoholic steatohepatitis?

    PubMed Central

    Handa, Priya; Vemulakonda, Akhila; Kowdley, Kris V; Uribe, Misael; Méndez-Sánchez, Nahum

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, affecting approximately one third of the Western world. It consists of a wide spectrum of liver disorders, ranging from fatty liver to nonalcoholic steatohepatitis (NASH), which consists of steatosis, ballooning injury and inflammation. Despite an alarming growth in the statistics surrounding NAFLD, there are as yet no effective therapies for its treatment. Innate immune signaling has been thought to play a significant role in initiating and augmenting hepatic inflammation, contributing to the transition from nonalcoholic fatty liver to NASH. An immune response is triggered by countless signals called damage-associated molecular patterns (DAMPs) elicited by lipid-laden and damaged hepatocytes, which are recognized by pattern recognition receptors (PRRs) on hepatic immune cells to initiate inflammatory signaling. In this editorial, in addition to summarizing innate immune signaling in NAFLD and discussing potential therapies that target innate immune pathways, we have described a recent study that demonstrated that mitochondrial DNA serves as a DAMP activating a hepatic PRR, TLR9, in mice and in the plasma of NASH patients. In addition to identifying a new ligand for TLR9 during NASH progression, the study shows that blocking TLR9 reverses NASH, paving the way for the development of future NASH therapy. PMID:27610009

  19. Hepatocyte Lysosomal Membrane Stabilization by Olive Leaves against Chemically Induced Hepatocellular Neoplasia in Rats

    PubMed Central

    Abdel-Hamid, N. M.; El-Moselhy, M. A.; El-Baz, A.

    2011-01-01

    Extensive efforts are exerted looking for safe and effective chemotherapy for hepatocellular carcinoma (HCC). Specific and sensitive early biomarkers for HCC still in query. Present work to study proteolytic activity and lysosomal membrane integrity by hepatocarcinogen, trichloroacetic acid (TCA), in Wistar rats against aqueous olive leaf extract (AOLE).TCA showed neoplastic changes as oval- or irregular-shaped hepatocytes and transformed, vesiculated, and binucleated liver cells. The nuclei were pleomorphic and hyperchromatic. These changes were considerably reduced by AOLE. The results added, probably for the first time, that TCA-induced HCC through disruption of hepatocellular proteolytic enzymes as upregulation of papain, free cathepsin-D and nonsignificant destabilization of lysosomal membrane integrity, a prerequisite for cancer invasion and metastasis. AOLE introduced a promising therapeutic value in liver cancer, mostly through elevating lysosomal membrane integrity. The study substantiated four main points: (1) the usefulness of proteolysis and lysosomalmembrane integrity in early prediction of HCC. (2) TCA carcinogenesis is possibly mediated by lysosomal membrane destabilization, through cathepsin-D disruption, which could be reversed by AOLE administration. (3) A new strategy for management of HCC, using dietary olive leaf system may be a helpful phytotherapeutic trend. (4) A prospective study on serum proteolytic enzyme activity may introduce novel diagnostic tools. PMID:21994869

  20. Allicin Modulates the Antioxidation and Detoxification Capabilities of Primary Rat Hepatocytes

    PubMed Central

    Wu, Chih-Chung; Chu, Yung-Lin; Sheen, Lee-Yan

    2012-01-01

    The effect of allicin, an active ingredient of garlic, on lactate dehydrogenase (LDH) leakage, lipid peroxidation, glutathione (GSH) content, and GSH-related enzyme activity was investigated in primary hepatocytes. In this study, allicin was synthesized in our laboratory as an experimental material, and primary hepatocytes isolated from Sprague-Dawley rats were used as an experimental model. According to the results, hepatocytes treated with 10 μM allicin did not differ from the control on LDH leakage during various incubation times. When the hepatocytes were treated with 10 μM allicin, their levels of thiobarbituric acid reactive-substances (TBARS) did not differ significantly from that of the control within the 8-h incubation. However, the TBARS values of hepatocytes treated with 30 and 50 μM allicin were higher compared to the control after incubation for 4 h and 8 h, respectively. The hepatocyte intracellular GSH content was significantly higher than that of the control after 30 μM allicin treatment, but treatment with 50 μM allicin caused a significant GSH depletion after incubation for 4 h or longer. In addition, when hepatocytes were treated for 24 h with 10 or 30 μM allicin, glutathione peroxidase (GPx) activity was significantly increased compared to that of the control, whereas 50 μM allicin treatment for 24 h or longer significantly decreased the GPx activity. Glutathione reductase (GRd) activity was significantly increased when the hepatocytes were treated with 10 μM allicin for 24 h, but GRd activity significantly decreased when the hepatocytes were treated with 50 μM allicin. However, hepatocytes treated for 24 h with 10 or 30 μM allicin showed significantly increased glutathione S-transferase (GST) activity compared to the control. These results suggest that 10 μM allicin potentially enhances the antioxidation and detoxification capabilities of primary rat hepatocytes. PMID:24716147

  1. Effect of carbohydrates attached to polystyrene on hepatocyte morphology on sugar-derivatized polystyrene matrices.

    PubMed

    Kim, Sang-Heon; Hoshiba, Takashi; Akaike, Toshihiro

    2003-12-15

    Sugar-carrying polymers have been utilized as artificial matrices for cell adhesion in tissue engineering. We have developed sugar-derivatized polystyrenes (PV-sugars) as artificial matrices, which control hepatocyte adhesion and hepatic function. Hepatocytes adhere to PV-sugar matrices in a receptor-mediated manner. In this study, we designed a new galactose-derivatized PV-sugar, poly-(6-O-p-vinylbenzyl-alpha-D-galactose) (PV6Gal) and evaluated the role of carbohydrate attached to polystyrene (PS) backbone in the morphological difference of hepatocyte cultured on PV-sugar matrices. Hepatocytes spread on monosaccharide-derivatized PV-sugars but not on disaccharide-derivatized PV-sugars. The actin filament remained aggregated in the central area of the cell body on disaccharide-derivatized PV-sugars. Hepatocyte cell bodies fully were spread on collagen, and the actin filament was almost completely reorganized. Hepatocyte spreading on monosaccharide-derivatized PV-sugars, however, was caused by protrusive cell-matrix contact like lamellipodia and the actin filament was not completely reorganized. This indicated that hepatocyte spreading on PV-sugar matrices was restricted compared with ECM-mediated cell spreading. In addition, typical spheroid formation of hepatocytes was promoted on disaccharide-derivatized PV-sugars compared with monosaccharide-derivatized PV-sugars. Although hepatocytes adhered with different affinities to PV-sugar matrices, hepatocyte morphology was not affected by the adhesion affinity. We suggest that the type of carbohydrate attached to the PS backbone governs the morphology of hepatocyte cultured on PV-sugar matrices.

  2. Magnetic resonance imaging in the diagnosis of asymmetrical bilateral masseteric hypertrophy.

    PubMed

    Fyfe, E C; Kabala, J; Guest, P G

    1999-01-01

    Asymmetrical bilateral masseteric hypertrophy or unilateral masseteric hypertrophy may present a diagnostic dilemma. While the history and clinical examination are important in differentiating this benign condition from parotid and dental pathology, they cannot necessarily exclude rarer malignant lesions of or within the muscle itself. We present a case where MRI provided clear and elegant confirmation of our provisional clinical diagnosis by illustrating both the soft tissue features and the logical corresponding bony features of this condition, thus obviating the need for further invasive investigations.

  3. Curcumin inhibits activation of TRPM2 channels in rat hepatocytes.

    PubMed

    Kheradpezhouh, E; Barritt, G J; Rychkov, G Y

    2016-04-01

    Oxidative stress is a hallmark of many liver diseases including viral and drug-induced hepatitis, ischemia-reperfusion injury, and non-alcoholic steatohepatitis. One of the consequences of oxidative stress in the liver is deregulation of Ca(2+) homeostasis, resulting in a sustained elevation of the free cytosolic Ca(2+) concentration ([Ca(2+)]c) in hepatocytes, which leads to irreversible cellular damage. Recently it has been shown that liver damage induced by paracetamol and subsequent oxidative stress is, in large part, mediated by Ca(2+) entry through Transient Receptor Potential Melastatin 2 (TRPM2) channels. Involvement of TRPM2 channels in hepatocellular damage induced by oxidative stress makes TRPM2 a potential therapeutic target for treatment of a range of oxidative stress-related liver diseases. We report here the identification of curcumin ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), a natural plant-derived polyphenol in turmeric spice, as a novel inhibitor of TRPM2 channel. Presence of 5µM curcumin in the incubation medium prevented the H2O2- and paracetamol-induced [Ca(2+)]c rise in rat hepatocytes. Furthermore, in patch clamping experiments incubation of hepatocytes with curcumin inhibited activation of TRPM2 current by intracellular ADPR with IC50 of approximately 50nM. These findings enhance understanding of the actions of curcumin and suggest that the known hepatoprotective properties of curcumin are, at least in part, mediated through inhibition of TRPM2 channels.

  4. Curcumin inhibits activation of TRPM2 channels in rat hepatocytes

    PubMed Central

    Kheradpezhouh, E.; Barritt, G.J.; Rychkov, G.Y.

    2015-01-01

    Oxidative stress is a hallmark of many liver diseases including viral and drug-induced hepatitis, ischemia-reperfusion injury, and non-alcoholic steatohepatitis. One of the consequences of oxidative stress in the liver is deregulation of Ca2+ homeostasis, resulting in a sustained elevation of the free cytosolic Ca2+ concentration ([Ca2+]c) in hepatocytes, which leads to irreversible cellular damage. Recently it has been shown that liver damage induced by paracetamol and subsequent oxidative stress is, in large part, mediated by Ca2+ entry through Transient Receptor Potential Melastatin 2 (TRPM2) channels. Involvement of TRPM2 channels in hepatocellular damage induced by oxidative stress makes TRPM2 a potential therapeutic target for treatment of a range of oxidative stress-related liver diseases. We report here the identification of curcumin ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), a natural plant-derived polyphenol in turmeric spice, as a novel inhibitor of TRPM2 channel. Presence of 5 µM curcumin in the incubation medium prevented the H2O2- and paracetamol-induced [Ca2+]c rise in rat hepatocytes. Furthermore, in patch clamping experiments incubation of hepatocytes with curcumin inhibited activation of TRPM2 current by intracellular ADPR with IC50 of approximately 50 nM. These findings enhance understanding of the actions of curcumin and suggest that the known hepatoprotective properties of curcumin are, at least in part, mediated through inhibition of TRPM2 channels. PMID:26609559

  5. Contextualizing Hepatocyte Functionality of Cryopreserved HepaRG Cell Cultures.

    PubMed

    Jackson, Jonathan P; Li, Linhou; Chamberlain, Erica D; Wang, Hongbing; Ferguson, Stephen S

    2016-09-01

    Over the last decade HepaRG cells have emerged as a promising alternative to primary human hepatocytes (PHH) and have been featured in over 300 research publications. Most of these reports employed freshly differentiated HepaRG cells that require time-consuming culture (∼28 days) for full differentiation. Recently, a cryopreserved, predifferentiated format of HepaRG cells (termed here "cryo-HepaRG") has emerged as a new model that improves global availability and experimental flexibility; however, it is largely unknown whether HepaRG cells in this format fully retain their hepatic characteristics. Therefore, we systematically investigated the hepatocyte functionality of cryo-HepaRG cultures in context with the range of interindividual variation observed with PHH in both sandwich-culture and suspension formats. These evaluations uncovered a novel adaptation period for the cryo-HepaRG format and demonstrated the impact of extracellular matrix on cryo-HepaRG functionality. Pharmacologically important drug-metabolizing alleles were genotyped in HepaRG cells and poor metabolizer alleles for CYP2D6, CYP2C9, and CYP3A5 were identified and consistent with higher frequency alleles found in individuals of Caucasian decent. We observed liver enzyme inducibility with aryl hydrocarbon receptor, constitutive androstane receptor (CAR), and pregnane X receptor activators comparable to that of sandwich-cultured PHH. Finally, we show for the first time that cryo-HepaRG supports proper CAR cytosolic sequestration and translocation to hepatocyte nuclei in response to phenobarbital treatment. Taken together, these data reveal important considerations for the use of this cell model and demonstrate that cryo-HepaRG are suitable for metabolism and toxicology screening.

  6. Sparing of the Dystrophin-Deficient Cranial Sartorius Muscle Is Associated with Classical and Novel Hypertrophy Pathways in GRMD Dogs

    PubMed Central

    Nghiem, Peter P.; Hoffman, Eric P.; Mittal, Priya; Brown, Kristy J.; Schatzberg, Scott J.; Ghimbovschi, Svetlana; Wang, Zuyi; Kornegay, Joe N.

    2014-01-01

    Both Duchenne and golden retriever muscular dystrophy (GRMD) are caused by dystrophin deficiency. The Duchenne muscular dystrophy sartorius muscle and orthologous GRMD cranial sartorius (CS) are relatively spared/hypertrophied. We completed hierarchical clustering studies to define molecular mechanisms contributing to this differential involvement and their role in the GRMD phenotype. GRMD dogs with larger CS muscles had more severe deficits, suggesting that selective hypertrophy could be detrimental. Serial biopsies from the hypertrophied CS and other atrophied muscles were studied in a subset of these dogs. Myostatin showed an age-dependent decrease and an inverse correlation with the degree of GRMD CS hypertrophy. Regulators of myostatin at the protein (AKT1) and miRNA (miR-539 and miR-208b targeting myostatin mRNA) levels were altered in GRMD CS, consistent with down-regulation of myostatin signaling, CS hypertrophy, and functional rescue of this muscle. mRNA and proteomic profiling was used to identify additional candidate genes associated with CS hypertrophy. The top-ranked network included α-dystroglycan and like-acetylglucosaminyltransferase. Proteomics demonstrated increases in myotrophin and spectrin that could promote hypertrophy and cytoskeletal stability, respectively. Our results suggest that multiple pathways, including decreased myostatin and up-regulated miRNAs, α-dystroglycan/like-acetylglucosaminyltransferase, spectrin, and myotrophin, contribute to hypertrophy and functional sparing of the CS. These data also underscore the muscle-specific responses to dystrophin deficiency and the potential deleterious effects of differential muscle involvement. PMID:24160322

  7. Comprehensive annotation of the Glossina pallidipes salivary gland hypertrophy virus from Ethiopian tsetse flies: a proteogenomics approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Glossina pallidipes salivary gland hypertrophy virus (GpSGHV; family Hytrosaviridae) can establish a chronic covert asymptomatic infection and an acute overt symptomatic infection in its tsetse fly host (Diptera: Glossinidae). Expression of the disease symptoms, the salivary gland hypertrophy sy...

  8. The effects of compensated cardiac hypertrophy on dihydropyridine and ryanodine receptors in rat, ferret and guinea-pig hearts.

    PubMed

    Rannou, F; Sainte-Beuve, C; Oliviero, P; Do, E; Trouvé, P; Charlemagne, D

    1995-05-01

    The number of dihydropyridine and ryanodine receptors (DHP-R and RyR) has been measured in control and hypertrophied ventricles from rats, guinea pigs and ferrets to determine whether these two channels contribute to the alterations in excitation-contraction coupling (ECC), and in Ca2+ transient during compensated cardiac hypertrophy. We found that ventricular hypertrophy did not change the density of DHP-R. Mild hypertrophy did not alter the density of RyR in the rat but decreased it in the guinea-pig and in the ferret (30% and 36%, respectively). Severe hypertrophy decreased the density of RyR by 20% in the rat and by 34% in the guinea-pig. Therefore, the decrease is greater in ferret and guinea-pig hearts than in rat heart. We conclude that the sarcoplasmic reticulum (SR) Ca2+ release channels but not the L-type Ca2+ channels could contribute to the slowing of intracellular Ca2+ movements and to the reduced velocity of shortening of the hypertrophied hearts. We suggest that, in the guinea pig and ferret hearts which express only the beta myosin heavy chain (MHC) isoform, the reduced velocity of shortening during hypertrophy is related to the decrease in RyR density, whereas in the rat, it is regulated primarily via a shift in the MHC isoform, except in severe hypertrophy in which the moderate decrease in RyR would also be involved. PMID:7473781

  9. H2O 2 induces myocardial hypertrophy in H9c2 cells: a potential role of Ube3a.

    PubMed

    Song, Rui; Zhang, Jie; Zhang, Lijuan; Wang, Guanghua; Wo, Da; Feng, Jian; Li, Xucheng; Li, Jue

    2015-01-01

    Myocardial hypertrophy that often leads to eventual heart failure is a leading cause of mortality worldwide. While both apoptosis and cell proliferation have been reported to play an important part in heart failure, its exact triggering mechanism is still unclear. Reports have shown that low concentrations of H2O2 (10-30 µM) can induce myocardial hypertrophy without affecting survival. The ubiquitin ligase Ube3a has been reported to have a close affiliation with Angelman syndrome; but many ubiquitin ligases have been reported in a variety of cardiovascular conditions including myocardial hypertrophy. However, the relationship between Ube3a and myocardial hypertrophy has never been reported in literature. The rat cardiac myoblast cell line H9c2 and primary neonatal cardiomyocytes showed similar hypertrophic responses in vitro. In this report, we utilized H2O2 treatment on H9c2 cells to induce myocardial hypertrophy and determined the relationship between Ube3a and myocardial hypertrophy. Our results showed that 10-20 μM H2O2 can induce myocardial hypertrophy without affecting cell viability and inducing cell apoptosis, while the corresponding transcription and translation levels of Ube3a are significantly increased during the process. Therefore, these findings underline that Ube3a may play an important role in myocardial hypertrophy. PMID:24917194

  10. Two-year carcinogenicity study in rats with a nonnucleoside reverse transcriptase inhibitor.

    PubMed

    Nambiar, Prashant R; Morton, Daniel; Dochterman, Leland Wayne; Houle, Christopher; Thomford, Peter J; Fate, Gwendolyn; Bailey, Steven A; Finch, Gregory L

    2015-04-01

    Administration of lersivirine, a nonnucleotide reverse transcriptase inhibitor, daily by oral gavage to Sprague-Dawley rats for up to 2 yr was associated with decreased survival, decreased body weights, and an increase in neoplasms and related proliferative lesions in the liver, thyroid, kidney, and urinary bladder. Thyroid follicular adenoma and carcinoma, the associated thyroid follicular hypertrophy/hyperplasia, hepatocellular adenoma/adenocarcinoma, altered cell foci, and hepatocellular hypertrophy were consistent with lersivirine-related induction of hepatic microsomal enzymes. Renal tubular adenoma and renal tubular hyperplasia were attributed to the lersivirine-related exacerbation of chronic progressive nephropathy (CPN), while urinary bladder hyperplasia and transitional cell carcinoma in the renal pelvis and urinary bladder were attributed to urinary calculi. Renal tubular neoplasms associated with increased incidence and severity of CPN, neoplasms of transitional epithelium attributed to crystalluria, and thyroid follicular and hepatocellular neoplasms related to hepatic enzyme induction have low relevance for human risk assessment. PMID:25122632

  11. Effect of long-acting gonadotropin-releasing hormone analog (leuprolide) therapy on prostatic size and symptoms in 15 men with benign prostatic hypertrophy.

    PubMed

    Gabrilove, J L; Levine, A C; Kirschenbaum, A; Droller, M

    1989-09-01

    To determine the effects of reversible medical castration on prostatic size and symptoms we treated 15 patients with benign prostatic hypertrophy with a long-acting GnRH analog, leuprolide (1 mg/day sc), for a minimum of 4 months. The men's serum testosterone, dihydrotestosterone, and estradiol concentrations fell to very low levels within 4-6 weeks after the initiation of treatment. Transrectal ultrasonography of the prostate demonstrated an average shrinkage of 40% after 4 months of treatment (n = 15) and 46% after 6 months of treatment (n = 11). All 15 men had improvement in urinary flow and, to a lesser extent, in nocturia and frequency. The side-effects of the therapy were decreased potency and flushing. The most dramatic improvement occurred in 4 of the 5 men who had complete urinary obstruction before treatment. One man had a suprapubic cystotomy tube removed during the fifth treatment month. Two other men who had Foley catheters before treatment are voiding well without catheters since their third treatment month. Another man who had a very large prostate (300 g) before treatment had one successful voiding trial, although he still has a suprapubic cystotomy tube. One man decided to stop treatment after 6 months. Two months later his hormone values and prostate size had returned to pretreatment levels. One man treated during the fourth and fifth months with fluoxymesterone in addition to leuprolide had regrowth of his prostate while receiving this androgen. We conclude that leuprolide treatment of men with benign prostatic hypertrophy results in shrinkage of prostatic size and concomitant improvement in the obstructive symptoms of prostatism. The prostatic shrinkage reverses when treatment is discontinued or combined with androgen. PMID:2474565

  12. ARFGAP1 Is Dynamically Associated with Lipid Droplets in Hepatocytes

    PubMed Central

    Alamri, Hussam; Feng, Shi Bo; Kalantari, Fariba; Negi, Sarita; Wong, Amy H. Y.; Mazur, Alexander; Asp, Lennart; Fazel, Ali; Salman, Ayat; Lazaris, Anthoula; Metrakos, Peter; Bergeron, John J. M.; Nilsson, Tommy

    2014-01-01

    The ARF GTPase Activating Protein 1 (ARFGAP1) associates mainly with the cytosolic side of Golgi cisternal membranes where it participates in the formation of both COPI and clathrin-coated vesicles. In this study, we show that ARFGAP1 associates transiently with lipid droplets upon addition of oleate in cultured cells. Also, that addition of cyclic AMP shifts ARFGAP1 from lipid droplets to the Golgi apparatus and that overexpression and knockdown of ARFGAP1 affect lipid droplet formation. Examination of human liver tissue reveals that ARFGAP1 is found associated with lipid droplets at steady state in some but not all hepatocytes. PMID:25397679

  13. Lowering blood ammonia prevents hepatocyte injury and apoptosis

    PubMed Central

    Gao, Guanmin; Yu, Zujiang; Yan, Jingya; Li, Jingjing; Shen, Shen; Jia, Bin; Guan, Kelei; Gao, Xiaojuan; Kan, Quancheng

    2015-01-01

    To study hepatocyte injure through establishing the rat model of acute hepatic failure (ALF). ALF rat model was established by administration with D-galactosamine and LPS, and then giving lowering blood ammonia (LBA) treatment. Besides, the intervention groups were injected with ornithine and aspartate. The control groups were injected saline. Blood ammonia, ALT, AST, TNF-α and IL-6 in blood samples were test at 12 hrs and 24 hrs after treatment with LBA. Hepatocyte apoptosis were tested by TUNEL and DNA Ladder. Expression of P53 and SPP1 were detected by RT-PCR. Results: showed that blood ammonia in hepatic failure group and intervention group compared with blank control group was significantly increased at 12 h, 24 h; intervention group compared with hepatic failure group was significantly reduced (P<0.05). Serum ALT, AST in 24 h group were higher than 12 h. 12 h intervention group was decreased compared with hepatic failure group, but there was no significant statistically difference (P>0.05). 24 h intervention group compared with hepatic failure group was significantly reduced (P<0.05). Except the control group, DNA ladder and the TUNEL results showed hepatocyte apoptosis rate increased in 24 h compared with 12 h. Intervention group compared with hepatic failure group was significantly reducing (P<0.05). IL-6, TNF-α, p53 expression levels were increased with time (24 h>12 h). The hepatic failure and intervention group compared with blank control group was significantly increased; Intervention group compared with hepatic failure group was significantly reducing (P<0.05). SPP1 gene was high expression in ALF rat model. SPP1 level in hepatic failure and intervention group compared with control group was significantly increased, and intervention group compared with hepatic failure group was significantly reducing (P<0.05). In conclusion, hepatocyte apoptosis is an important pathological change in ALF rat mode, and lowing ammonia can reduce liver injury and

  14. [Bilateral reversed palmaris longus muscle--a rare cause of peripheral median nerve compression syndrome. Case report].

    PubMed

    Giunta, R; Brunner, U; Wilhelm, K

    1993-10-01

    A rare case of median nerve compression syndrome outside the carpal tunnel in the distal forearm is reported. A 21-year-old man suffered while working from symptoms of temporary median nerve compression in both forearms; this was caused by hypertrophy of reversed palmaris longus muscles. Resection of the abnormal muscle bellies relieved the symptoms immediately. Only ten similar cases have been reported in the literature, and this is the first case with bilateral symptoms.

  15. Effects of methylmercury on primary cultured rat hepatocytes: Cell injury and inhibition of growth factor stimulated DNA synthesis

    SciTech Connect

    Tanno, Keiichi; Fukazawa, Toshiyuki; Tajima, Shizuko; Fujiki, Motoo )

    1992-08-01

    Many more studies deal with the toxicity of methylmercury on nervous tissue than on its toxicity to the liver. Methylmercury accumulates in the liver in higher concentrations than brain and the liver has the primary function of detoxifying methylmercury. According to recent studies, hepatocyte mitochondrial membranes are destroyed by methylmercury and DNA synthesis is inhibited by methylmercury during hepatocyte regeneration. Methylmercury alters the membrane ion permeability of isolate skate hepatocytes, and inhibits the metal-sensitive alcohol dehydrogenase and glutathione reductase of primary cultured rat hepatocytes. However, little is known about the effect of methylmercury on hepatocyte proliferation in primary cultured rat hepatocytes. We therefore used the primary cultured rat hepatocytes to investigate the effects of methylmercury on cell injury and growth factor stimulate DNA synthesis. The primary effect of methylmercury is to inhibit hepatocyte proliferation rather than to cause direct cell injury. 16 refs., 4 figs.

  16. Application of isolated hepatocytes to studies of drug metabolism in large food animals.

    PubMed

    Shull, L R; Kirsch, D G; Lohse, C L; Wisniewski, J A

    1987-03-01

    A definitive hazard assessment of xenobiotics translocated through food animals into edible products such as meat or milk requires a complete analysis of metabolism in food animals. However, large animal metabolism studies present many experimental difficulties. None of several in vitro alternatives such as subcellular fractions has been established as an acceptable predictor of in vivo metabolism. The feasibility of using isolated hepatocytes to predict the metabolism of xenobiotics, both quantitatively and qualitatively, in large ruminant animals (e.g. cattle) is being studied in our laboratory. A procedure was developed for isolating hepatocytes aseptically from the caudate process of the liver which was obtained surgically from 100-125 kg calves. A modified two-step vascular perfusion procedure provides hepatocyte suspensions that are typically greater than or equal to 85% viable and greater than or equal to 1 X 10(7) viable hepatocytes/g of liver (wet wt). Xenobiotic metabolism has been evaluated in suspensions and primary cultures using aldrin epoxidation, ethoxycoumarin O-deethylation, and 7-hydroxycoumarin glucuronidation and sulfation. Metabolic activities are relatively short-lived in suspensions less than or equal to 4 h, but quite stable up to 10 h when cultured on collagen-coated plates in chemically defined medium. Bovine hepatocytes behave similarly in culture to rodent hepatocytes. Although primary culturing of hepatocytes is more difficult than suspensions, primarily due to the asepsis requirements, it is the method of choice for xenobiotic metabolism determinations in isolated hepatocytes of cattle. PMID:3554786

  17. IGF-I mediated inhibition of leptin receptor expression in porcine hepatocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to elucidate hormonal control of leptin receptor gene expression in primary cultures of porcine hepatocytes. Hepatocytes were isolated from pigs (52 kg) and seeded into collagen-coated T-25 flasks. Monolayer cultures were established in medium containing fetal bovine serum fo...

  18. Determination of host genetic susceptibility to genotoxic chemicals in hepatocyte cultures.

    PubMed

    McQueen, C A; Williams, G M

    1982-01-01

    The relationship between acetylator phenotype and genotoxicity, i.e., damage to DNA, has been investigated using freshly isolated hepatocytes, an in-vitro system representing the major organ of N-acetyltransferase (NAT) activity. Hepatocytes were isolated from rapid and slow acetylator rabbits by enzymatic perfusion of the liver. Unscheduled DNA synthesis (UDS), determined by autoradiography, was used as an indicator of DNA damage. Hydralazine (HDZ) elicited UDS in hepatocytes from slow acetylators but little or none in hepatocytes from rapid acetylators. However, hepatocytes from rapid acetylators were more sensitive to the effects of 2-aminofluorene (2-AF). A concentration of 10(-3) M 2-AF was toxic, and 10(-4) M elicited UDS in hepatocytes from rapid acetylators. Hepatocytes from slow acetylators showed UDS when exposed to 10(-3) M. No differences were observed between the two phenotypes in the amount of UDS elicited by 2-acetylaminofluorene. These results demonstrate a correlation between acetylator phenotype and genotoxicity of substrates of NAT. Moreover, as shown by the different responses to HDZ and 2-AF, the sensitive phenotype varies with chemical structure. Thus, the identification of phenotype-dependent differences in the amount of DNA damage in rabbit hepatocytes offers evidence for genetic susceptibility to genotoxic chemicals and indicates that a similar susceptibility would be displayed by humans who express the same polymorphism in NAT activity.

  19. Application of isolated hepatocytes to studies of drug metabolism in large food animals.

    PubMed

    Shull, L R; Kirsch, D G; Lohse, C L; Wisniewski, J A

    1987-03-01

    A definitive hazard assessment of xenobiotics translocated through food animals into edible products such as meat or milk requires a complete analysis of metabolism in food animals. However, large animal metabolism studies present many experimental difficulties. None of several in vitro alternatives such as subcellular fractions has been established as an acceptable predictor of in vivo metabolism. The feasibility of using isolated hepatocytes to predict the metabolism of xenobiotics, both quantitatively and qualitatively, in large ruminant animals (e.g. cattle) is being studied in our laboratory. A procedure was developed for isolating hepatocytes aseptically from the caudate process of the liver which was obtained surgically from 100-125 kg calves. A modified two-step vascular perfusion procedure provides hepatocyte suspensions that are typically greater than or equal to 85% viable and greater than or equal to 1 X 10(7) viable hepatocytes/g of liver (wet wt). Xenobiotic metabolism has been evaluated in suspensions and primary cultures using aldrin epoxidation, ethoxycoumarin O-deethylation, and 7-hydroxycoumarin glucuronidation and sulfation. Metabolic activities are relatively short-lived in suspensions less than or equal to 4 h, but quite stable up to 10 h when cultured on collagen-coated plates in chemically defined medium. Bovine hepatocytes behave similarly in culture to rodent hepatocytes. Although primary culturing of hepatocytes is more difficult than suspensions, primarily due to the asepsis requirements, it is the method of choice for xenobiotic metabolism determinations in isolated hepatocytes of cattle.

  20. Interactions between macrophage/Kupffer cells and hepatocytes in surgical sepsis

    SciTech Connect

    West, M.A.

    1988-01-01

    Experiments were performed to investigate the role of Kupffer cell/macrophage interactions with hepatocytes in modulating liver function during infections using direct in vitro cocultivation of rat macrophages or Kupffer cells with rat hepatocytes. Protein synthesis was assayed as a sensitive indicator of integrated hepatocellular function by measuring {sup 3}H-leucine incorporation into hepatocyte protein. Septic stimuli such as lipoploysaccharide and killed bacteria were added to cocultures of hepatocytes and macrophages or Kupffer cells and the responses compared to hepatocytes alone. Information about the types of proteins synthesized by hepatocytes under various culture conditions was determined using polyacrylamide gel electrophoresis and autoradiography. These experiments showed that septic stimuli alter the amount and type of protein synthesized by hepatocytes and had no direct effect on hepatocytes in the absence of macrophages or Kupffer cells. The mediator(s) appears to be a heat labile, soluble monokine(s) which is distinct from interleukin-1 or tumor necrosis factor. The important role of Kupffer cells/macrophages in mediating alterations in hepatocellular function in sepsis may ultimately improve patient care.

  1. High Throughput Micro-Well Generation of Hepatocyte Micro-Aggregates for Tissue Engineering

    PubMed Central

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates. PMID:25133500

  2. HepatoDyn: A Dynamic Model of Hepatocyte Metabolism That Integrates 13C Isotopomer Data

    PubMed Central

    Foguet, Carles; Selivanov, Vitaly A.; Fanchon, Eric; Guinovart, Joan J.; de Atauri, Pedro; Cascante, Marta

    2016-01-01

    The liver performs many essential metabolic functions, which can be studied using computational models of hepatocytes. Here we present HepatoDyn, a highly detailed dynamic model of hepatocyte metabolism. HepatoDyn includes a large metabolic network, highly detailed kinetic laws, and is capable of dynamically simulating the redox and energy metabolism of hepatocytes. Furthermore, the model was coupled to the module for isotopic label propagation of the software package IsoDyn, allowing HepatoDyn to integrate data derived from 13C based experiments. As an example of dynamical simulations applied to hepatocytes, we studied the effects of high fructose concentrations on hepatocyte metabolism by integrating data from experiments in which rat hepatocytes were incubated with 20 mM glucose supplemented with either 3 mM or 20 mM fructose. These experiments showed that glycogen accumulation was significantly lower in hepatocytes incubated with medium supplemented with 20 mM fructose than in hepatocytes incubated with medium supplemented with 3 mM fructose. Through the integration of extracellular fluxes and 13C enrichment measurements, HepatoDyn predicted that this phenomenon can be attributed to a depletion of cytosolic ATP and phosphate induced by high fructose concentrations in the medium. PMID:27124774

  3. Assessment of magnesium influence on fatty acid content in isolated rat hepatocytes subjected to incubation.

    PubMed

    Całyniuk, B; Grochowska-Niedworok, E; Kardas, M; Muc-Wierzgoń, M; Nowakowska-Zajdel, E

    2016-01-01

    Magnesium salts are components of many dietary supplements used in treatment or prevention of magnesium deficiency. Hypomagnesemia usually results from an improper lifestyle, including unbalanced diet. Isolated hepatocytes of animals or humans are the preferred model used to study the in vitro effects of exogenous factors on cellular metabolic changes. The aim of this study was to evaluate the content of saturated, monounsaturated and polyunsaturated fatty acids and their esters in isolated rat hepatocytes influenced by different magnesium concentrations. The isolated rat hepatocytes were used as the test material. Hepatocytes were prepared in culture medium (Hepatocyte Medium) + MgCl(2) solution to concentrations of 2 mM/dm(3) MgCl(2), 4 mM/dm(3) MgCl(2). After incubation with different concentrations of magnesium ions, changes in the content of fatty acids and their esters were found for the whole hepatocytes and hepatocyte membranes. Despite changes in the fatty acid content in the whole hepatocytes and their membranes, there were no changes in the coefficient of degree of saturation of fatty acids when different concentrations of MgCl2 were used.

  4. Lipopolysaccharide Is Cleared from the Circulation by Hepatocytes via the Low Density Lipoprotein Receptor

    PubMed Central

    Topchiy, Elena; Cirstea, Mihai; Kong, HyeJin Julia; Boyd, John H.; Wang, Yingjin; Russell, James A.; Walley, Keith R.

    2016-01-01

    Sepsis is the leading cause of death in critically ill patients. While decreased Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) function improves clinical outcomes in murine an