| 1. |
- Bloise, E, et al.
(författare)
-
Acute Effects of Viral Exposure on P-Glycoprotein Function in the Mouse Fetal Blood-Brain Barrier
- 2017
-
Ingår i: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology. - : S. Karger AG. - 1421-9778. ; 41:3, s. 1044-1050
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Viral infection during pregnancy is known to affect the fetal brain. The toll-like receptor (TLR)-3 is a pattern recognition receptor activated by viruses known to elicit adverse fetal neurological outcomes. The P-glycoprotein (P-gp) efflux transporter protects the developing fetus by limiting the transfer of substrates across both the placenta and the fetal blood-brain barrier (BBB). As such, inhibition of P-gp at these blood-barrier sites may result in increased exposure of the developing fetus to environmental toxins and xenobiotics present in the maternal circulation. We hypothesized that viral exposure during pregnancy would impair P-gp function in the placenta and in the developing BBB. Here we investigated whether the TLR-3 ligand, polyinosinic:polycytidylic acid (PolyI:C), increased accumulation of one P-gp substrate in the fetus and in the developing fetal brain. Methods: Pregnant C57BL/6 mice (GD15.5) were injected (i.p.) with PolyI:C (5 mg/kg or 10 mg/kg) or vehicle (saline). [3H]digoxin (P-gp substrate) was injected (i.v.) 3 or 23h post-treatment and animals were euthanized 1h later. Maternal plasma, ‘fetal-units’ (fetal membranes, amniotic fluid and whole fetus), and fetal brains were collected. Results: PolyI:C exposure (4h) significantly elevated maternal plasma IL-6 (P<0.001) and increased [3H]digoxin accumulation in the fetal brain (P<0.05). In contrast, 24h after PolyI:C exposure, no effect on IL-6 or fetal brain accumulation of P-gp substrate was observed. Conclusion: Viral infection modeled by PolyI:C causes acute increases in fetal brain accumulation of P-gp substrates and by doing so, may increase fetal brain exposure to xenobiotics and environmental toxins present in the maternal circulation.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Fezai, Myriam, et al.
(författare)
-
Inhibition of colon carcinoma cell migration following treatment with purified venom from lesser weever fish (Trachinus Vipera)
- 2017
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 41:6, s. 2279-2288
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Injury by the sting of Lesser weever fish (Trachinus vipera) may lead to severe pain, edema or tissue necrosis. Cellular effects of the venom are still incompletely understood. Previous observations revealed that purified Lesser weever fish venom (LWFV) induces suicidal death of erythrocytes and HCT116 human colon carcinoma cells. The present study addressed the effect of the venom on colon carcinoma cell toxicity, shape and migration both in p53+/+ and/or p53-/- conditions. Methods: Cells were exposed to medium without or with 500 μg/ ml LWFV. Cell shape, cell area and circularity were visualized and quantified by fluorescence microscopy. Cell volume, granularity and cells toxicity were assessed via the apoptotic parameters dissipation of mitochondrial inner transmembrane potential, phosphatidylserine surface exposure and cell membrane permeabilization were measured utilizing flow cytometry. Cell migration was evaluated using wound healing assay and two-dimensional migration assay. Results: LWFV treatment was followed by a marked change of cell shape and size, significant decrease of cell area and circularity, significant impairment of cell migration, as well as induction of apoptosis after long exposition. Conclusions: LWFV exposure leads to cell shrinkage, increased granularity, apoptosis and impairment of cell migration, effects presumably contributing to LWFV-induced tissue injury.
|
|
| 5. |
- Gizurarson, Sigfus, et al.
(författare)
-
Electrophysiological Effects of Lysophosphatidylcholine on HL-1 Cardiomyocytes Assessed with a Microelectrode Array System
- 2012
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 30:2, s. 477-488
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Sudden death due to malignant ventricular arrhythmias is the most important cause of death in acute myocardial infarction. Improved knowledge about the pathophysiology underlying these arrhythmias is essential in the search for new anti-arrhythmic strategies. Lysophosphatidylcholine (LPC), a hydrolysis product of (membrane) phospholipid degradation, is one of the most potent pro-arrhythmic substances that accumulate in the human heart during myocardial ischemia. The aim of this study was to set up and validate an in vitro experimental system for studies on the effects of LPC on electrophysiological parameters in beating cardiomyocytes. Methods and Results: Spontaneously beating HL-1 cardiomyocytes were cultured on multielectrode array microchips for three days for the recording of electrical activities in the form of field potentials (FP). FPs were recorded at baseline and after addition of 2, 4, 8, 12, 16, 20, and 24 mu M of LPC to the cell medium (n=9). We found that LPC could induce rapid effects on electrical parameters in the HL-1 cells. The overall half-maximal effective concentration (EC50) of LPC was around 12 mu M. The beating rate and peak-peak amplitude of FP thus decreased at concentrations >= 12 mu M and were inversely proportional to increased LPC concentration. The duration of FP was significantly prolonged with LPC above 12 mu M and was concentration-dependent. LPC delayed signal propagation, an effect which was mimicked by blocking gap junctions with heptanol and attenuated by pre-treatment with isoprenaline and atropine. Finally, asynchronous activity was induced by LPC at >12 mu M. Conclusions: LPC induced prompt and pronounced electrophysiological alterations that may underlie its observed pro-arrhythmic properties. Our in vitro model with HL-1 cells and microelectrode array system may be a useful tool for preclinical studies of electrophysiological effects of various pathophysiological concepts. Copyright (C) 2012 S Karger AG, Basel
|
|
| 6. |
|
|
| 7. |
- Hafizi, Sassan, et al.
(författare)
-
Profibrotic effects of endothelin-1 via the ETA receptor in cultured human cardiac fibroblasts
- 2004
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 14:4-6, s. 285-292
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Endothelin-1 (ET-1) has been implicated in pathologic remodelling and tissue repair processes in the heart. We investigated the effects of ET-1 on growth and collagen synthesis responses in cardiac fibroblasts isolated from human hearts. We also studied the receptor subtype(s) mediating such responses and the factors regulating their expression. Methods: Fibroblasts were isolated from cardiac transplant recipient hearts and characterised by immunocytochemistry. Serum-starved cells were exposed to ET-1 and incorporation of [H-3]proline and thymidine were measured as indexes of collagen and DNA synthesis respectively. Blocking experiments utilised the selective ETA receptor antagonist BQ123 and the ETB antagonist BQ788. Results: ET-1 elicited a potent collagen synthesis response in cardiac fibroblasts, with a maximum 29+/-5% increase that was abolished by BQ123. Cardiac fibroblasts responded to ET-1 with a concentration-dependent decrease to those of TGF-beta. Radioligand binding studies revealed the presence of high-affinity ET-1 binding sites on these cells, which were upregulated by treatment with the growth factors PDGF and EGF but downregulated by TGF-beta. Conclusions: These results therefore implicate ET-1 as a trophic agent in the human heart with the ability to influence the development of cardiac fibrosis. Copyright (C) 2004 S. Karger AG, Basel.
|
|
| 8. |
|
|
| 9. |
- He, Shudong, et al.
(författare)
-
In Silico Identification and in Vitro Analysis of B and T-Cell Epitopes of the Black Turtle Bean (Phaseolus Vulgaris L.) Lectin
- 2018
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; , s. 1600-1614
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: The incidence of lectin allergic disease is increasing in recent decades, and definitive treatment is still lacking. Identification of B and T-cell epitopes of allergen will be useful in understanding the allergen antibody responses as well as aiding in the development of new diagnostics and therapy regimens for lectin poisoning. In the current study, we mainly addressed these questions. Methods: Three-dimensional structure of the lectin from black turtle bean (Phaseolus vulgaris L.) was modeled using the structural template of Phytohemagglutinin from P. vulgaris (PHA-E, PDB ID: 3wcs.1.A) with high identity. The B and T-cell epitopes were screened and identified by immunoinformatics and subsequently validated by ELISA, lymphocyte proliferation and cytokine profile analyses. Results: Seven potential B-cell epitopes (B1 to B7) were identified by sequence and structure based methods, while three T-cell epitopes (T1 to T3) were identified by the predictions of binding score and inhibitory concentration. The epitope peptides were synthesized. Significant IgE binding capability was found in B-cell epitopes (B2, B5, B6 and B7) and T2 (a cryptic B-cell epitope). T1 and T2 induced significant lymphoproliferation, and the release of IL-4 and IL-5 cytokine confirmed the validity of T-cell epitope prediction. Abundant hydrophobic amino acids were found in B-cell epitope and T-cell epitope regions by amino acid analysis. Positively charged amino acids, such as His residue, might be more favored for B-cell epitope. Conclusion: The present approach can be applied for the identification of epitopes in novel allergen proteins and thus for designing diagnostics and therapies in lectin allergy.
|
|
| 10. |
- Janson, Veronica, et al.
(författare)
-
Acquisition of Cisplatin-resistance in Malignant Mesothelioma Cells Abrogates Na,K(+),2Cl(-;)-cotransport Activity and Cisplatin-induced Early Membrane Blebbing
- 2008
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger. - 1015-8987 .- 1421-9778. ; 22:1-4, s. 45-56
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: Resistance mechanisms are important limiting factors in the treatment of solid malignancies with cis-diamminedichloroplatinum(II) (cisplatin). To gain further understanding of the effects of acquired cisplatin-resistance, we compared a human malignant pleural mesothelioma cell line (p31) to a sub-line (p31res1.2) with acquired cisplatin-resistance.METHODS AND RESULTS: The role of Na(+),K(+),2Cl(-)-cotransport (NKCC1) activity in cisplatin-induced morphological changes and acquired cisplatin-resistance was investigated in a time-resolved manner. Acquisition of cisplatin-resistance resulted in markedly reduced NKCC1 activity, absence of cisplatin-induced early membrane blebbing, and increased basal caspase-3 activity. At equitoxic cisplatin concentrations, P31res1.2 cells had a faster activation of caspase-3 than P31 cells, but the end-stage cytotoxicity and number of cells with DNA fragmentation was similar. Bumetanide inhibition of NKCC1 activity in P31 cells repressed cisplatin-induced early-phase membrane blebbing but did not increase P31 cell resistance to cisplatin.CONCLUSIONS: Together, these results suggest that active NKCC1 was necessary for cisplatin-induced early membrane blebbing of P31 cells, but not for cisplatin-resistance. Thus, acquisition of cisplatin-resistance can affect mechanisms that have profound effects on cisplatin-induced morphological changes but are not necessary for the subsequent progression to apoptosis.
|
|
| 11. |
- Jemaà, Mohamed, et al.
(författare)
-
Methods Employed in Cytofluorometric Assessment of Eryptosis, the Suicidal Erythrocyte Death
- 2017
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 43:2, s. 431-444
-
Forskningsöversikt (refereegranskat)abstract
- Suicidal erythrocyte death or eryptosis contributes to or even accounts for anemia in a wide variety of clinical conditions, such as iron deficiency, dehydration, hyperphosphatemia, vitamin D excess, chronic kidney disease (CKD), hemolytic-uremic syndrome, diabetes, hepatic failure, malignancy, arteriitis, sepsis, fever, malaria, sickle-cell disease, beta-thalassemia, Hb-C and G6PD-deficiency, Wilsons disease, as well as advanced age. Moreover, eryptosis is triggered by a myriad of xenobiotics and endogenous substances including cytotoxic drugs and uremic toxins. Eryptosis is characterized by cell membrane scrambling with phosphatidylserine exposure to the erythrocyte surface. Triggers of eryptosis include oxidative stress, hyperosmotic shock, and energy depletion. Signalling involved in the regulation of eryptosis includes Ca2+ entry, ceramide, caspases, calpain, p38 kinase, protein kinase C, Janus-activated kinase 3, casein kinase 1α, cyclin-dependent kinase 4, AMP-activated kinase, p21-activated kinase 2, cGMP-dependent protein kinase, mitogen- and stress-activated kinase MSK1/2, and ill-defined tyrosine kinases. Inhibitors of eryptosis may prevent anaemia in clinical conditions associated with enhanced eryptosis and stimulators of eryptosis may favourably influence the clinical course of malaria. Additional experimentation is required to uncover further clinical conditions with enhanced eryptosis, as well as further signalling pathways, further stimulators, and further inhibitors of eryptosis. Thus, a detailed description of the methods employed in the analysis of eryptosis may help those, who enter this exciting research area. The present synopsis describes the experimental procedures required for the analysis of phosphatidylserine exposure at the cell surface with annexin-V, cell volume with forward scatter, cytosolic Ca2+ activity ([Ca2+]) with Fluo3, oxidative stress with 2′,7′-dichlorodihydrofuorescein diacetate (DCFDA), glutathione (GSH) with mercury orange 1(4-chloromercuryphenyl-azo-2-naphthol), lipid peroxidation with BODIPY 581/591 C11 fluorescence, and ceramide abundance with specific antibodies. The contribution of kinases and caspases is defined with the use of the respective inhibitors. It is hoped that the present detailed description of materials and methods required for the analysis of eryptosis encourages further scientists to enter this highly relevant research area.
|
|
| 12. |
- Jemaà, Mohamed, et al.
(författare)
-
Preferential Killing of Tetraploid Colon Cancer Cells by Targeting the Mitotic Kinase PLK1
- 2020
-
Ingår i: Cellular Physiology and Biochemistry. - : Cell Physiol Biochem Press GmbH and Co KG. - 1015-8987 .- 1421-9778. ; 54:2, s. 303-320
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Chromosomal instability is a well-known factor in the progression of different types of cancer, including colorectal cancer. Chromosomal instability results in severely rearranged karyotypes and aneuploidy. Tetraploidy constitutes an intermediate phase during the polyploidy/aneuploidy cascade in oncogenesis, and tetraploid cells are particularly resistant to chemotherapy. Whether inhibition of the mitotic protein polo-like kinase 1 (PLK1) prevents the survival of tetraploid colon cancer cells is unknown.METHODS: Diploid and tetraploid cells were transfected with siPLK1 or treated with PLK1 inhibitor Bi2536 in combination with spindle poison. Cell toxicity was assessed via crystal violet staining and clonogenic assay. Flow cytometry assessment analyzed numerous cell apoptotic parameters and cell cycle phases. Synergistic activity between Bi2536 and paclitaxel, vincristine or colchicine was calculated using the CompuSyn software.RESULTS: Inhibition or abrogation of PLK1 prevented the survival of colon cancer cells, specifically tetraploid cells. The cell death induced by PLK inhibition was due to mitotic slippage, followed by the activation of the intrinsic pathway of apoptosis. We further demonstrated that co-treatment of the tetraploid colon cancer cells with a PLK1 inhibitor and the microtubule polymerisation inhibitor vincristine or colchicine, but not the microtubule depolymerisation inhibitor paclitaxel, provoked a lethal synergistic effect.CONCLUSION: PLK1 inhibition together with microtubule-targeting chemicals, serve as a potent therapeutic strategy for targeting tetraploid cancer cells.
|
|
| 13. |
- Karimian, Hamed, et al.
(författare)
-
The Chemopreventive Effect of Tanacetum Polycephalum Against LA7-Induced Breast Cancer in Rats and the Apoptotic Effect of a Cytotoxic Sesquiterpene Lactone in MCF7 Cells : A Bioassay-Guided Approach
- 2015
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 36:3, s. 988-1003
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Tanacetum polycephalum L. Schultz-Bip is a member of the Asteraceae family. This study evaluated the chemopreventive effect of a T. polycephalum hexane extract (TPHE) using in in vivo and in vitro models. Methods and Results: Five groups of rats: normal control, cancer control, TPHE low dose, TPHE high dose and positive control (tamoxifen) were used for the in vivo study. Histopathological examination showed that TPHE significantly suppressed the carcinogenic effect of LA7 tumour cells. The tumour sections from TPHE-treated rats demonstrated significantly reduced expression of Ki67 and PCNA compared to the cancer control group. Using a bioassay-guided approach, the cytotoxic compound of TPHE was identified as a tricyclic sesquiterpene lactone, namely, 8 beta-hydroxyl-4 beta, 15-dihydrozaluzanin C (HDZC). Signs of early and late apoptosis were observed in MCF7 cells treated with HDZC and were attributed to the mitochondrial intrinsic pathway based on the up-regulation of Bax and the down-regulation of Bcl-2. HDZC induced cell cycle arrest in MCF7 cells and increased the expression of p21 and p27 at the mRNA and protein levels. Conclusion: This results of this study substantiate the anticancer effect of TPHE and highlight the involvement of HDZC as one of the contributing compounds that act by initiating mitochondrial-mediated apoptosis.
|
|
| 14. |
- Konstantinidis, Georgios, et al.
(författare)
-
Regulation of Myosin Light Chain Function by BMP Signaling Controls Actin Cytoskeleton Remodeling
- 2011
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 28:5, s. 1031-1044
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Actin cytoskeleton dynamics support and coordinate signaling events that control cell proliferation, differentiation and migration. Growth factors provide essential signals that act on multi-protein complexes that regulate actin assembly with myosin. We previously analyzed the action of the transforming growth factor β (TGF-β) and now extend our studies to the bone morphogenetic protein (BMP) 7, an important regulator of stem cell function and bone differentiation. Methods: Using a well-established cell model of actin dynamics, Swiss3T3 fibroblasts, we applied cell biological and biochemical approaches to monitor the pathway that links the BMP-7 receptors to the acto-myosin complex. Results: We demonstrate that BMP-7 induces actin and focal adhesion remodeling in starved fibroblasts as potently as TGF-β. BMP-7 mediates changes of actin dynamics via the kinase ROCK1 and induces rapid activation of RhoA and RhoB with concomitant inactivation of Cdc42. These molecular events correlate well with induction of phosphorylation on Ser19 of the myosin light chain, but not with LIMK1 kinase activation. Depletion of endogenous myosin light chain inhibits actin remodeling induced by BMP-7. This novel pathway regulates fibroblast migration without affecting cell proliferation. Conclusion: We establish a BMP-Rho-ROCK1 pathway, which targets myosin light chain to control actin remodeling in fibroblasts.
|
|
| 15. |
|
|
| 16. |
- Minuth, W, et al.
(författare)
-
Generation of renal tubules at the interface of an artificial interstitium
- 2004
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 14:4-6, s. 387-394
-
Tidskriftsartikel (refereegranskat)abstract
- During kidney development a multitude of tubular portions is formed. Little knowledge is available by which cellbiological mechanism a cluster of embryonic cells is able to generate the threedimensional structure of a tubule. However, this know-how is most important in tissue engineering approaches such as the generation of an artificial kidney module or for the therapy of renal diseases using stem cells. To obtain cellbiological insights in parenchyme development we elaborate a new technique to generate under in vitro conditions renal tubules derived from the embryonic cortex of neonatal rabbits. The aim of the experiments is to establish a specific extracellular environment allowing optimal threedimensional development of renal tubules under serum-free culture conditions. In the present paper we demonstrate features of the renal stem cell niche and show their isolation as intact microcompartiments for advanced tissue culture. Perfusion culture in containers exhibiting a big dead fluid volume results in the development of a flat collecting duct (CD) epithelium at the surface of the tissue explant. In contrast, by fine-tuning the dead fluid volume within a perfusion culture container by an artificial interstitium made of a polyester fleece shows the generation of tubules. It is an up to date unknown morphogenetic information which tells the cells to form tubular structures. Copyright (C) 2004 S. Karger AG, Basel.
|
|
| 17. |
- Muller-Deile, J., et al.
(författare)
-
Overexpression of TGF-beta Inducible microRNA-143 in Zebrafish Leads to Impairment of the Glomerular Filtration Barrier by Targeting Proteoglycans
- 2016
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 40:5, s. 819-830
-
Tidskriftsartikel (refereegranskat)abstract
- Background: TGF-alpha is known as an important stress factor of podocytes in glomerular diseases. Apart from activation of direct pro-apoptotic pathways we wanted to analyze micro-RNA (miRs) driven regulation of components involved in the integrity of the glomerular filtration barrier induced by TGF-alpha. Since miR-143-3p (miR-143) is described as a TGF-alpha inducible miR in other cell types, we examined this specific miR and its ability to induce glomerular pathology. Methods: We analyzed miR-143 expression in cultured human podocytes after stimulation with TGF-alpha. We also microinjected zebrafish eggs with a miR-143 mimic or with morpholinos specific for its targets syndecan and versican and compared phenotype and proteinuria development. Results: We detected a time dependent, TGF-alpha inducible expression of miR-143 in human podocytes. Targets of miR-143 relevant in glomerular biology are syndecans and versican, which are known components of the glycocalyx. We found that syndecan 1 and 4 were predominantly expressed in podocytes while syndecan 3 was largely expressed in glomerular endothelial cells. Versican could be detected in both cell types. After injection of a miR-143 mimic in zebrafish larvae, syndecan 3, 4 and versican were significantly downregulated. Moreover, miR-143 overexpression or versican knockdown by morpholino caused loss of plasma proteins, edema, podocyte effacement and endothelial damage. In contrast, knockdown of syndecan 3 and syndecan 4 had no effects on glomerular filtration barrier. Conclusion: Expression of versican and syndecan isoforms is indispensable for proper barrier function. Podocyte-derived miR-143 is a mediator for paracrine and autocrine cross talk between podocytes and glomerular endothelial cells and can alter expression of glomerular glycocalyx proteins. (C) 2016 The Author(s) Published by S. Karger AG, Basel
|
|
| 18. |
- Nasizadeh, Sima, et al.
(författare)
-
Proteasomal degradation of a trypanosomal ornithine decarboxylase
- 2003
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 13:5, s. 321-328
-
Tidskriftsartikel (refereegranskat)abstract
- Mammalian ornithine decarboxylase (ODC), which catalyses the first step in polyamine biosynthesis, has a very fast turnover. It is degraded by the 26S proteasome in an ubiquitin-independent process and the degradation is stimulated by polyamines in a feedback control of the enzyme. Interestingly, there is a major difference in the metabolic stability between ODCs from various trypanosomatids. Trypanosoma brucei and Leishmania donovani both contain stable ODCs, whereas Crithidia fasciculata has an ODC with a rapid turnover. In spite of the difference in stability there is a high degree of sequence homology between C. fasciculata ODC and L. donovani ODC. In the present study we demonstrate that C. fasciculata ODC is rapidly degraded also in mammalian systems like CHO cells and rabbit reticulocyte lysate, suggesting that the degradation signals of the enzyme are recognised by the mammalian systems. L. donovani ODC, on the other hand, is degraded very slowly in the same systems. The degradation of C. fasciculata ODC in the mammalian systems is markedly reduced by inhibition of the 26S proteasome. However, unlike mammalian ODC, C. fasciculata ODC is not downregulated by polyamines. Thus, the turnover of C. fasciculata ODC and L. donovani ODC in the mammalian systems reflects the degradation of the enzyme in the parasites, making such systems potentially useful as complements to parasitic knockout models for further analysis of the mechanisms involved in the rapid degradation of C. fasciculata ODC. Copyright (C) 2003 S. Karger AG, Basel.
|
|
| 19. |
- Papadimitriou, Elsa, et al.
(författare)
-
TGFβ-induced early activation of the small GTPase RhoA is Smad2/3-independent and involves Src and the guanine nucleotide exchange factor Vav2
- 2011
-
Ingår i: Cellular Physiology and Biochemistry. - Basel : Karger. - 1015-8987 .- 1421-9778. ; 28:2, s. 229-238
-
Tidskriftsartikel (refereegranskat)abstract
- TGFβ has been shown to induce short- and long-term actin reorganization controlled by Rho-GTPase signaling. A number of direct Smad target genes, rapidly activated by TGFβ, have been previously reported to control the long-term Rho activation and actin reorganization. However, the molecular mechanisms that regulate the prompt stimulation of Rho GTPases by TGFβ remain unknown. In the present study we report that TGFβ rapidly stimulated RhoA and RhoB activation in JEG3 choriocarcinoma cells that lack endogenous Smad3. Inhibition of Smad2 expression via siRNA-mediated silencing or by blocking its phosphorylation using the TβRI inhibitor SB431542 did not prevent the early RhoA/B activation by TGFβ indicating that this effect is Smad2/3-independent. Pre-treatment of the cells with the general tyrosine kinase inhibitor Genistein blocked the TGFβ-induced early RhoA activation. In line with this finding, TGFβ-stimulation resulted in a quick activation of the non-receptor tyrosine kinase Src, followed by activation of the guanine nucleotide exchange factor (GEF) Vav2. Inhibition of Src kinase by the selective inhibitor of the Src family tyrosine kinases PP2 totally blocked the early TGFβ-induced RhoA activation. Similarly, Vav2 silencing via siRNA reduced the TGFβ-induced RhoA activation implying that the rapid Src/Vav2 stimulation was effective in regulating RhoA activation. Our present findings provide for the first time a clear evidence for the role of Src and Vav2-GEF in the early Smad2/3-independent Rho activation by TGFβ.
|
|
| 20. |
- Pelzl, Lisann, et al.
(författare)
-
Lithium Sensitivity of Store Operated Ca2+ Entry and Survival of Fibroblasts Isolated from Chorea-Acanthocytosis Patients
- 2017
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 42, s. 2066-2077
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The widely expressed protein chorein fosters activation of the phosphoinositide 3 kinase (PI3K) pathway thus supporting cell survival. Loss of function mutations of the chorein encoding gene VPS13A (vacuolar protein sorting-associated protein 13A) causes chorea-acanthocytosis (ChAc), a neurodegenerative disorder paralleled by deformations of erythrocytes. In mice, genetic knockout of chorein leads to enhanced neuronal apoptosis. PI3K dependent signalling upregulates Orai1, a pore forming channel protein accomplishing store operated Ca2+ entry (SOCE). Increased Orai1 expression and SOCE have been shown to confer survival of tumor cells. SOCE could be up-regulated by lithium. The present study explored, whether SOCE and/or apoptosis are altered in ChAc fibroblasts and could be modified by lithium treatment. Methods: Fibroblasts were isolated from ChAc patients and age-matched healthy volunteers. Cytosolic Ca2+ activity ([Ca2+]i) was estimated from Fura-2-fluorescence, SOCE from increase of [Ca2+]i following Ca2+ re-addition after Ca2+-store depletion with sarcoendoplasmatic Ca2+-ATPase (SERCA) inhibitor thapsigargin (1 µM), and apoptosis from annexin-V/propidium iodide staining quantified in flow cytometry. Results: SOCE was significantly smaller in ChAc fibroblasts than in control fibroblasts. Lithium (2 mM, 24 hours) significantly increased and Orai1 blocker 2-Aminoethoxydiphenyl Borate (2-APB, 50 µM, 24 hours) significantly decreased SOCE. Annexin-V-binding and propidium iodide staining were significantly higher in ChAc fibroblasts than in control fibroblasts. In ChAc fibroblasts annexin-V-binding and propidium iodide staining were significantly decreased by lithium treatment, significantly increased by 2-APB and virtually lithium insensitive in the presence of 2-APB. Conclusions: In ChAc fibroblasts, downregulation of SOCE contributes to enhanced susceptibility to apoptosis. Both, decreased SOCE and enhanced apoptosis of ChAc fibroblasts can be reversed by lithium treatment.
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Trzybulska, Dorota, et al.
(författare)
-
Alterations in Serum MicroRNA Profile during Hemodialysis-Potential Biological Implications
- 2018
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 46:2, s. 793-801
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Hemodialysis implies significant alterations in the profile of serum components. microRNAs (miRNAs) are present in the human serum and are considered to target distant tissues where they can regulate gene expression, thus affecting homeostasis. Whether hemodialysis alters the profile of miRNAs in the serum is not known. Methods: miRNA profiling in serum samples collected before and after hemodialysis was performed using miRNA qPCR arrays. The results were subsequently validated in an independent group of 10 hemodialyzed men. miRWalk database was used to identify mRNAs targeted by the miRNAs the levels of which changed after hemodialysis. The list of mRNAs was analyzed using the DAVID and PANTHER classification systems to identify pathways controlled by these miRNAs. Results: miRNA profiling showed that the levels of the majority of circulating miRNAs were increased at least two-fold (115 out of 179 tested) while the levels of only five miRNAs were found at least two-fold lower after hemodialysis. Validation study confirmed the majority of the array results. Bioinformatics analysis of validated and significantly upregulated miRNAs revealed that gonadotropin-releasing hormone receptor, cell cycle and cell pluripotency-related pathways were targeted. Conclusion: Hemodialysis alters serum miRNA expression profile and this alteration may result in disruption of pathways contributing to subfertility and increased risk for cancer development being pathologies associated with hemodialysis.
|
|
| 26. |
- Wagner, C A, et al.
(författare)
-
Effects of the serine/threonine kinase SGK1 on the epithelial Na(+) channel (ENaC) and CFTR : implications for cystic fibrosis.
- 2001
-
Ingår i: Cellular Physiology and Biochemistry. - 1015-8987 .- 1421-9778. ; 11:4
-
Tidskriftsartikel (refereegranskat)abstract
- Cystic fibrosis (CF) is characterized by impaired Cl(-) secretion and increased Na(+) reabsorption in several tissues including respiratory epithelium. Many CFTR mutations have been identified over the past years. However, only a poor correlation between the genotype and lung phenotype was found suggesting additional factors influencing the phenotype and course of the disease. The serine/threonine kinase SGK1 has recently been shown to stimulate the activity of the epithelial Na(+) channel ENaC. A variety of stimuli such as aldosterone, cell shrinkage, insulin or TGF-beta1 stimulate transcription and activate the SGK1 kinase. Here we further examined the effects of SGK1 on ENaC and CFTR which have mutual interactions and we analyzed sgk1 mRNA abundance in lung tissue from CF patients. Coexpression of CFTR and h-SGK1 in Xenopus oocytes increased ENaC currents as previously described. In addition CFTR mediated currents were also stimulated. h-SGK1 accelerated the expression of the amiloride sensitive Na(+)- current in Xenopus oocytes paralleled by increased ENaC-protein abundance in the oocyte membrane, an effect which was reversed by a h-SGK1(K127R) mutation lacking the ATP-binding site. The cation selectivity or Na(+) affinity were not affected. However, coexpression of h-SGK1 with ENaC altered the sensitivity of the Na(+)-channel to the inhibitors amiloride and triamterene. The inhibitory effect of CFTR expression on ENaC current was not affected by coexpression of h-SGK1 in Xenopus oocytes. Lung tissue from CF patients strongly expressed the serine/threonine kinase h-sgk1 which was not the case for non-CF lung tissue. Loss of CFTR function itself in a CF lung epithelial cell line did not increase SGK1 expression. In summary, enhanced expression of h-SGK1 in epithelial cells of CF-lung tissue may be a novel pathophysiological factor contributing to increased Na(+) channel activity and thus to increased Na(+) transport in CF.
|
|
| 27. |
- Wu, Chen, et al.
(författare)
-
WT1 Enhances Proliferation and Impedes Apoptosis in KRAS Mutant NSCLC via Targeting cMyc
- 2015
-
Ingår i: Cellular Physiology and Biochemistry. - : S. Karger AG. - 1015-8987 .- 1421-9778. ; 35:2, s. 647-662
-
Tidskriftsartikel (refereegranskat)abstract
- Background: A novel link between oncogenic KRAS signalling and WT1 was recently identified. We sought to investigate the role of WT1 and KRAS in proliferation and apoptosis. Methods: KRAS mutations and WT1 (cMyc) expression were detected using Sanger sequencing and real-time PCR in 77 patients with non-small cell lung cancer (NSCLC). Overexpression and knockdown of WT1 were generated with plasmid and siRNA via transient transfection technology in H1299 and H1568 cells. MTT assay for detection of cell proliferation, and TUNEL assay amd proteomic profiler assay for apoptosis evaluation were carried out. Dual luciferase reporter assay and ChIP-PCR were performed to validate the effect of WT1 on the cMyc promoter. Results: KRAS mutations showed a negative impact on overall survival ( OS). High expressions of WT1 and cMyc were associated with poor OS in KRAS mutant subgroup. The potential mechanisms that WT1 promotes proliferation and impedes apoptosis through affecting multiple apoptosis-related regulators in KRAS mutant NSCLC cells were identified. WT1 could activate cMyc promoter directly in KRAS mutant cells. Conclusion: The results suggest that WT1 and c-MYC expression is important for survival in KRAS mutant tumors as opposed to KRAS wild-type tumors. For treatment of KRAS mutant NSCLC, targeting WT1 and cMyc may provide alternative therapeutic strategies.
|
|
| 28. |
- Wåhlin-Larsson, Britta, 1959-, et al.
(författare)
-
Mechanistic Links Underlying the Impact of C-Reactive Protein on Muscle Mass in Elderly
- 2017
-
Ingår i: Cellular Physiology and Biochemistry. - : Karger. - 1015-8987 .- 1421-9778. ; 44:1, s. 267-278
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Mechanisms underlying the relationship between systemic inflammation and age-related decline in muscle mass are poorly defined. The purpose of this work was to investigate the relationship between the systemic inflammatory marker CRP and muscle mass in elderly and to identify mechanisms by which CRP mediates its effects on skeletal muscle, in-vitro.METHODS: Muscle mass and serum CRP level were determined in a cohort of 118 older women (67±1.7 years). Human muscle cells were differentiated into myotubes and were exposed to CRP. The size of myotubes was determined after immunofluorescent staining using troponin. Muscle protein synthesis was assessed using stable isotope tracers and key signalling pathways controlling protein synthesis were determined using western-blotting.RESULTS: We observed an inverse relationship between circulating CRP level and muscle mass (β= -0.646 (95% CI: -0.888, -0.405) p<0.05) and demonstrated a reduction (p < 0.05) in the size of human myotubes exposed to CRP for 72 h. We next showed that this morphological change was accompanied by a CRP-mediated reduction (p < 0.05) in muscle protein fractional synthetic rate of human myotubes exposed to CRP for 24 h. We also identified a CRP-mediated increased phosphorylation (p<0.05) of regulators of cellular energy stress including AMPK and downstream targets, raptor and ACC-β, together with decreased phosphorylation of Akt and rpS6, which are important factors controlling protein synthesis.CONCLUSION: This work established for the first time mechanistic links by which chronic elevation of CRP can contribute to age-related decline in muscle function.
|
|
| 29. |
- Yang, Y, et al.
(författare)
-
5-Aminolevulinic Acid-Mediated Sonodynamic Therapy Alleviates Atherosclerosis via Enhancing Efferocytosis and Facilitating a Shift in the Th1/Th2 Balance Toward Th2 Polarization
- 2018
-
Ingår i: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology. - : S. Karger AG. - 1421-9778. ; 47:1, s. 83-96
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: We and other groups have demonstrated that 5-aminolevulinic acid (ALA)-mediated sonodynamic therapy (ALA-SDT) induces macrophage and foam cell apoptosis and stabilizes atherosclerosis (AS) plaques in animal models. Lymphocytes also play vital roles in the development of AS. The primary purpose of the present study was to investigate the effects of ALA-SDT on T helper (Th) cell fate and function, Th subset differentiation, and atherosclerotic lesion stability. Methods: We utilized ALA-SDT on Western diet-fed apoE-/-mice in vivo and human Jurkat cells in vitro. Hematoxylin and eosin staining and TUNEL assays were used to evaluate the atherosclerotic plaque size and apoptosis within the atheroma. ALA induced cytotoxicity on cultured Jurkat cells was determined with CCK-8 assay. To address the mechanisms, levels of intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and mitochondrial permeability transition pore (MPTP) opening were evaluated by staining with fluorescent probes. Western blot analysis and confocal microscopy were used to analyze the protein levels of caspases, Bax and cytochrome c and the release of cytochrome c. Cell apoptosis and necrosis and phagocytosis were examined by flow cytometry. ELISAs and immunofluorescent staining were used to assess the corresponding cytokine levels and Th subset cell numbers within the atheroma. Results: Our studies revealed that ALA-SDT significantly enhanced CD4+ cell apoptosis and macrophage-mediated phagocytosis and hence reduced the necrotic core size. ALA-SDT activated the mitochondrial apoptotic signaling pathway with minimal necrosis in Jurkat cells. ALA-SDT inhibited the Th1 response and enhanced the Th2 response. These effects of ALA-SDT were mediated primarily through the generation of ROS. Conclusion: ALA-SDT alleviates AS by enhancing cytotoxic effects on Th cells, subsequently stimulating efferocytosis and facilitating a shift in the Th1/Th2 balance toward Th2 cells, a discovery that might help elucidate the mechanism underlying SDT as a potential treatment to prevent atherothrombotic events.
|
|
