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Journal Article 2011; 32(3): 313-316 PubMed PMID: 21712774 Citation  Keywords:  Amyloid Precursor Protein Secretases:biosynthesis, Amyloid beta-Peptides:biosynthesis, Amyloid beta-Protein Precursor:biosynthesis, Aspartic Acid Endopeptidases:biosynthesis, Cell Line, Cells, Cultured, DNA:biosynthesis, Humans, Luciferases:genetics, RNA,.   

OBJECTIVE: The effect of SUMO on the promoter activity and mRNA expression of BACE gene was investigated to find the connection between sumoylation and APP processing.

METHODS: The BACE promoter activity was measured by reporter gene analysis and BACE mRNA level was investigated using real-time RT-PCR method.

RESULTS: BACE gene promoter activity was inhibited by the over-expression of SUMO proteins and was blocked by disrupting the SP1 site. Endogenous BACE mRNA level was also negatively regulated by the induction of SUMO proteins. Using a specific inhitor of SP1, BACE promoter activity was coordinately inhibited.

CONCLUSIONS: SUMO negatively regulates the BACE expression and SP1 is involved in the process....

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Journal Article 2011; 32(3): 246-252 PubMed PMID: 21712773 Citation  Keywords:  Brain-Derived Neurotrophic Factor:genetics, Cell Line, Cells, Cultured, Down-Regulation, Gene Expression Profiling, Gene Silencing, Genome, Human:genetics, Histones:genetics, Humans, Microarray Analysis, Nerve Tissue Proteins:genetics, Neurons:drug effect.   

OBJECTIVE: The regulator of G-protein signaling (RGS) molecules represent a class of proteins that modulate the signaling activity of G-protein coupled receptors. Regulator of G-protein signaling 4 (RGS4) is of particular interest in schizophrenia due to reported downregulation of RGS4 transcripts in schizophrenia as well as a connection between RGS4 and a number of receptors implicated in schizophrenia. The mechanism of RGS4 involvement in the pathophysiology of this illness is not clear.

METHODS: To elucidate thise role of RGS4 in pathophysiology of schizophrenia, we silenced RGS4 using siRNAs in human neuroblastoma cell lines and we studied the effects of differential RGS4 expression by microarray.

RESULTS AND CONCLUSION: The cell lines with downregulated expression of RGS4 showed 67 genes with changed expression (30 underexpressed and 37 overexpressed). We have detected three subgroups of genes which might be implicated in schizophrenia pathophysiology: histone genes, which suggest epigenetic mechanisms of the disease; genes for transcription factors associated with other genes relevant to schizophrenia pathology (BDNF and DISCI1) and a heterogeneous group containing genes for G-proteins (GPR50 and GPR64) and calcium binding proteins....

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Journal Article 2011; 32(2): 187-192 PubMed PMID: 21552198 Citation  Keywords:  Aging:metabolism, Animals, Animals, Newborn, Atrial Natriuretic Factor:metabolism, Cells, Cultured, Cochlea:cytology, Ear, Inner:physiology, Models, Animal, Rats, Rats, Sprague-Dawley, Receptors, Atrial Natriuretic Factor:metabolism, Stria Vascularis:cyto.   

OBJECTIVE: Atrial natriuretic peptide (ANP) regulates the homeostasis of body fluid and blood pressure as a neuropeptide in the central nervous system. To assess the possible physiological role in the inner ear, we investigated the expression of ANP in primary culture of marginal cells, and then we detected the expression of ANP and its receptor (NPR-A) in cochlear tissues derived from neonatal and adult rats of various ages.

METHODS: Marginal cells were isolated from cochlear stria vascularis of the neonatal rats. The cultured cells were subsequently characterized by morphology, immunocytochemistry, and scanning electron microscope (SEM) analysis. In order to examine the expression of ANP in marginal cells as well as in the developing rats' cochleae, immunocytochemistry and reverse-transcription polymerase chain reaction (RT-PCR) were applied respectively.

RESULTS: The present study demonstrated typical characteristics of marginal cells, including cobblestone, polygonal monolayer, pleomorphic growth pattern and the expression of cell type-specific marker, and SEM analysis. Subsequently, immunoreactive product of ANP were found in cultured marginal cells. The mRNAs encoding ANP and NPR-A receptor was expressed in rats' cochleae from postembryonic stage to early postnatal period. During the maturation stage, ANP expression was gradually down-regulated, while the expression of NPR-A receptor was relatively stable.

CONCLUSION: ANP might be synthesized and secreted by marginal cells of stria vascularis, and could play an important role in modulating the microenvironment of the inner ear. In addition, ANP might contribute to development and growth process of cochlea....

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Journal Article 2011; 32(2): 176-186 PubMed PMID: 21552197 Citation  Keywords:  Adult, Animals, Brain:drug effects, Cells, Cultured, Clozapine:pharmacology, Dopamine:pharmacology, Dopamine Antagonists:pharmacology, Dose-Response Relationship, Drug, Female, Haloperidol:pharmacology, Humans, Interferon-gamma:metabolism, Interleukin-10:.   

OBJECTIVES: Dopamine (DA) administration in sepsis is used to modulate the hypotensive condition and to normalize the blood vessels perfusion. However, whether this administration of DA has an effect on the release of cytokines in vivo deserves investigation.

METHODS AND RESULTS: Pre-exposure of DA (1 µg/ml) to whole blood enhanced IL-10 (30%) production level following LPS stimulation. This IL-10 enhancement became statistically significant (p<0.001) upon the addition of D2-DA receptor (DAR) antagonists, Clozapine or Haloperidol. Furthermore, systemic administration of DA (0.5-50 mg/kg) in mice suppressed significantly LPS-induced TNF-α levels in blood, liver, spleen, brain, and lungs; IL-10 levels in blood, brain and liver; and IFN-γ levels in blood, liver, brain, and lungs. On the other hand, DA enhanced significantly LPS-induced IL-10 production in the lungs and spleen, and IFN-γ levels in the spleen. Administration of Clozapine (54 mg/kg) or Haloperidol (62 mg/kg) with LPS (1 µg) and DA (5 mg/kg) reversed DA suppressive effects on LPS-induced cytokines in blood, IFN-γ in brain and lungs, and enhanced significantly LPS-induced IL-10 production in blood, spleen, liver, and lungs.

CONCLUSIONS: These results indicate that DA modulatory effect on LPS-induced blood cytokines-producing cells is mediated mainly by D2-DAR (D2/ D3/D4) through enhancing immune cells migration and extravasation into tissues. Furthermore, DA selectivity on cytokines modulation is tissue specific, mediated by the type of DAR expressed and on the immune cells lodged in each tissue....

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Journal Article 2011; 32(2): 206-211 PubMed PMID: 21552188 Citation  Keywords:  Animals, Anticonvulsants:pharmacology, Cells, Cultured, Dose-Response Relationship, Drug, Follicle Stimulating Hormone:metabolism, Gonadotropin-Releasing Hormone:pharmacology, Gonadotropins:metabolism, In Vitro Techniques, Luteinizing Hormone:metabolism, .   

OBJECTIVE: Valproate (VPA) a potent antiepileptic drug has been claimed to induce reproductive disturbances in men. Long-term VPA treatment can affect sperm morphology and induce testicular atrophy in non-epileptic rats. It has been reported that VPA reduced testosterone secretion stimulated by hCG in isolated rat Leydig cells. These results suggest direct effect of VPA on testes in rats. However centrally mediated effects at hypothalamo-pituitary level can therefore not be excluded. This study focused on the dose and time-dependent effects of VPA on basal and GnRH-induced LH and FSH release from the primary anterior pituitary cells culture of male rats.

MATERIAL AND METHODS: The dose-dependent effect of 10 nM-100 mM of VPA on basal LH release from anterior pituitary cells after 3h of incubation was examined. To determine the time-dependent effects on LH, FSH, TSH and PRL release short (3 h) and long-term (24 h) incubations in the presence of 10 nM, 100 nM and 1 μM of VPA were maintained.To assess whether VPA can affect GnRH-induced LH and FSH release, cells were incubated for 3 h with 10 nM, 100 nM and 1 μM of VPA in the presence of GnRH. The concentration of rLH, rFSH, rPRL and rTSH in incubation medium was determined by RIA method.

RESULTS: VPA did not affect the basal LH, FSH, PRL and TSH release from the primary anterior pituitary cells culture of male rats. VPA in concentration 1µM significantly suppressed GnRH-induced LH secretion. However VPA at all tested doses diminished GnRH-induced FSH release.

CONCLUSIONS: VPA may diminish gonadotropin release in vitro but this effect can only be achieved after GnRH-dependent specific receptor activation. Both gonadotropins differ in their pattern of response for increasing doses of VPA....

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Journal Article 2010; 31(6): 852-856 PubMed PMID: 21196925 Citation  Keywords:  Cells, Cultured, Enzyme-Linked Immunosorbent Assay, Growth Hormone-Releasing Hormone:pharmacology, Humans, Interleukin-17:secretion, Leukocytes, Mononuclear:drug effects,.   

OBJECTIVES: Growth hormone-releasing hormone (GHRH) plays a crucial role in the secretion of GH from the pituitary, acts as a growth factor in variety of cancer cells and possesses immunomodulatory activity. Interleukin(IL)-17 apart from its pro-inflammatory role has been also shown to play a role in carcinogenesis. The effect of GHRH on the IL-17 has not been studied so far.

AIM: To evaluate the effect of GHRH on the secretion of IL-17 from human peripheral blood mononuclear cells (PBMC) in vitro.

MATERIALS AND METHODS: The concentrations of IL-17 in supernatants from PBMC cultured for 24 hrs were assessed using ELISA kit.

RESULTS: We show for the first time that GHRH can stimulate the secretion of IL-17 from human PBMC in 24 hrs culture, and that GHRH antagonist counteracts this effect.

CONCLUSION: Our study further elucidates the immunomodulatory role of GHRH....

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Comparative Study 2010; 31(5): 657-662 PubMed PMID: 21173747 Citation  Keywords:  Adult, Cells, Cultured, Cytokines:metabolism, Dental Implantation:instrumentation, Dental Implants, Female, Humans, Interferon-gamma:metabolism, Interleukin-1beta:metabolism, Interleukin-4:metabolism, Interleukin-6:metabolism, Lymphocytes:immunology, Male.   

OBJECTIVES: In most of patients in need of implantation treatment in the oral cavity, implants heal well, nevertheless, there are some individuals, in whom titanium implants fail for reasons, which remain unclear.

DESIGN: The aim of our study was to determine if there is a difference between metal influenced IL-1β, IL-4, IL-6, TNF-α and IFN-γ cytokines production in patients with successfully healed implants compared to those, whose implant therapy was unsuccessful.

SETTING: The two study groups included 12 patients with failed dental titanium implants and 9 patients with successfully healed implants. In the subjects, cytokine production was established after lymphocyte cultivation with mercury, nickel and titanium antigens.

RESULTS: IL-1β levels were significantly increased in all patients after stimulation with titanium and in patients with accepted implants compared to patients with failed implants after the stimulation with mercury and titanium. Titanium caused significantly increased IL-6 production in all patients. TNF-α and IFN-γ levels were also significantly increased after the stimulation with titanium. Significantly increased TNF-α levels were found in patients with accepted implants as compared to patients with failed implants.

CONCLUSIONS: Increased production of IL-1β a IL-6 cytokines in reaction to titanium and increased production of TNF-α and IFN-γ cytokines in reaction to mercury, which is very often present in the form of amalgam in the oral cavity of persons in need of implant therapy, can play an important role in immune reactions during implant healing process. In patients with failed titanium implants, decreased production of these cytokines may participate in implant failure....

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Journal Article 2010; 31(3): 325-329 PubMed PMID: 20588247 Citation  Keywords:  Animals, Cell Culture Techniques, Cerebral Cortex:drug effects, Lymphocyte Activation:drug effects, Male, Mice, Mice, Inbred CBA, Mitogens:pharmacology, Phytohemagglutinins:pharmacology, Potassium:pharmacology, Sodium-Potassium-Exchanging ATPase:metabolis.   

OBJECTIVES: We studied a) mitogen lectin (PHA) evoked changes of Na+/K+-ATPase activity in functionally different lymphocytes or brain cortex cells and b) quantitative relationship between PHA- evoked early enzyme activation and late lymphocyte proliferation were analyzed.

MATERIALS AND METHODS: We performed biochemical analyses of Pi released from ATP by Na+/K+-ATPase activity. Lymphocyte proliferation was assayed by 3H-thymidine incorporation.

RESULTS: We demonstrated PHA stimulated Na+/K+-ATPase activity of mouse spleen lymphocytes or freshly isolated brain cortex cells. Besides this, we estimated high stimulation of Na+/K+-ATPase activity and subsequent late 3H-thymidine incorporation into pig lymphocytes as both PHA dose and K+ ion concentration dependent.

CONCLUSIONS: Thus, early PHA dose-dependent stimulation of Na+/K+-ATPase activity is a more general response in different animal species and functionally different cells. We measured both cell type- and PHA-dose dependent enzyme activity stimulation. We can suggest that intensity of early PHA induced Na+/K+-ATPase activation could be in relationship to subsequent elevated level of T lymphocyte proliferation. The Na+/K+-ATPase can be a part of mitogen lectin evoked signal transduction mechanisms....

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