Search results for "Cell type"
showing 10 items of 299 documents
The “Janus” Role of C/EBPs Family Members in Cancer Progression
2020
CCAAT/enhancer-binding proteins (C/EBPs) constitute a family of transcription factors composed of six members that are critical for normal cellular differentiation in a variety of tissues. They promote the expression of genes through interaction with their promoters. Moreover, they have a key role in regulating cellular proliferation through interaction with cell cycle proteins. C/EBPs are considered to be tumor suppressor factors due to their ability to arrest cell growth (contributing to the terminal differentiation of several cell types) and for their role in cellular response to DNA damage, nutrient deprivation, hypoxia, and genotoxic agents. However, C/EBPs can elicit completely opposi…
Immunohistochemical localization of cyclooxygenase isoforms in the organ of Corti and the spiral ganglion cells of guinea pig cochlea.
2003
Prostaglandins have been used in experimental models and clinical studies for the therapy of sudden hearing loss and tinnitus with conflicting results. However, little is known about the rate-limiting enzymes of prostaglandin synthesis in the inner ear, the generally constitutively expressed cyclooxygenase 1 (COX-1) and the distress-inducible cycloxygenase 2 (COX-2). To extend our knowledge concerning the physiological expression and localization of these two enzymes, immunohistochemical stainings of the guinea pig cochlea were performed. Light microscopical analysis revealed a homogenous distribution of COX-1 within nearly all cell types of the organ of Corti, but no COX-1 expression in th…
Localization of the two constitutively expressed nitric oxide synthase isoforms (nNOS and eNOS) in the same cell types in the saccule maculae of the …
2003
There is growing evidence for a nitric oxide/cyclic GMP pathway of signal transduction in the vestibular system. Recently, two isoforms of nitric oxide (NO) synthase (nNOS and eNOS) and NO itself have been identified at the light microscopic level in the vestibulocochlear system of mice using specific antibodies and a new fluorescence indicator. In order to acquire more information about signal transduction and tissue modulation in this neuroepithelium at the cellular and subcellular levels, ultrathin sections of London Resin White-embedded saccule maculae of the frog Rana pipiens were incubated with various concentrations of commercially available antibodies to nNOS and eNOS. The immunorea…
Regulation of the expression of inducible nitric oxide synthase.
2003
Nitric oxide (NO), generated by the inducible isoform of nitric oxide synthase (iNOS), has been described to have beneficial microbicidal, antiviral, antiparasital, immunomodulatory, and antitumoral effects. However, aberrant iNOS induction at the wrong place or at the wrong time has detrimental consequences and seems to be involved in the pathophysiology of several human diseases. iNOS is primarily regulated at the expression level by transcriptional and post-transcriptional mechanisms. iNOS expression can be induced in many cell types with suitable agents such as bacterial lipopolysaccharides (LPS), cytokines, and other compounds. Pathways resulting in the induction of iNOS expression may…
Evidence for a possible NOS back-up system in the organ of Corti of the guinea pig
2003
Recently, the two Ca(2+)/calmodulin-regulated nitric oxide synthase isoforms, nNOS and eNOS, and NO itself have been identified in the cochlea of vertebrates using specific antibodies and a new fluorescence indicator. In order to acquire more information about the quantitative and spatial distribution of these two constitutively expressed NOS isoforms (cNOS) in the organ of Corti at the cellular and subcelluar levels, ultrathin sections of London resin (LR) White-embedded cochleae of the guinea pig were incubated with various concentrations of commercially available antibodies to nNOS and eNOS. The immunoreactivity was visualized by a gold-labeled secondary antibody and the amount of the im…
Nitric oxide synthase isozymes antibodies
1995
Three isozymes of nitric oxide synthase (NOS) have been identified, cDNAs isolated and sequenced, and antibodies produced against each isozyme. Isozyme I (found primarily in central and peripheral neuronal cells), II (in cytokine-induced cells), and III (in endothelial cells) show less than 58% identity in the deduced amino acid sequences from humans. Many investigators have produced isozyme-specific antibodies and used these antibodies to locate these proteins in various cells and tissues. NOS-I is constitutively expressed, and the enzymatic activity is regulated by Ca2+ and calmodulin. The anti-NOS-I antibodies have allowed investigators to characterize non-adrenergic non-cholinergic neur…
Cancer stem cells – old concepts, new insights
2008
Cancer has long been viewed as an exclusively genetic disorder. The model of carcinogenesis, postulated by Nowell and Vogelstein, describes the formation of a tumor by the sequential accumulation of mutations in oncogenes and tumor suppressor genes. In this model, tumors are thought to consist of a heterogeneous population of cells that continue to acquire new mutations, resulting in a highly dynamic process, with clones that out compete others due to increased proliferative or survival capacity. However, novel insights in cancer stem cell research suggest another layer of complexity in the process of malignant transformation and preservation. It has been reported that only a small fraction…
Genetic and molecular analysis of six tumor suppressor genes in Drosophila melanogaster
1990
Six Drosophila melanogaster tumor suppressor genes causing malignant or benign tumors in specific cell types are described. The wild-type alleles of these genes are instrumental in the differentiation of particular cell types. In the homozygous state, recessive mutations in the genes interrupt the differentiation of the cells and thus cause their uncontrolled, autonomous, lethal proliferation. The tumors show all major characteristics of malignant and benign neoplastic growth. Genomic sequences of four of the genes have been identified and are currently being characterized. ImagesFIGURE 1.FIGURE 2.FIGURE 2.
The Odd Sibling: Features ofβ3-Adrenoceptor Pharmacology
2014
beta(3)-Adrenoceptor agonists have recently been introduced for the treatment of overactive urinary bladder syndrome. Their target, the beta(3)-adrenoceptor, was discovered much later than beta(1)- and beta(2)-adrenoceptors and exhibits unique properties which make extrapolation of findings from the other two subtypes difficult and the beta(3)-adrenoceptor a less-understood subtype. This article discusses three aspects of beta(3)-adrenoceptor pharmacology. First, the ligand-recognition profile of beta(3)-adrenoceptors differs considerably from that of the other two subtypes, i.e., many antagonists considered as nonselective actually are beta(3)-sparing, including propranolol or nadolol. Man…
Single-cell RNA sequencing of SARS-CoV-2 cell entry factors in the preconceptional human endometrium.
2021
Abstract STUDY QUESTION Are SARS-CoV-2 canonical cell entry machinery, consisting of ACE2, TMPRSS2, NRP1 and LY6E, or alternative potential cell entry machinery, consisting of BSG, ANPEP, CD209, CLEC4G, TMPRSS4, TMPRSS11A, FURIN, CTSB, CTSL and IFITM1, expressed in the human endometrium across the menstrual cycle? SUMMARY ANSWER Analysis of cell entry factors for SARS-CoV-2 by single-cell RNA-sequencing (scRNAseq) in the preconceptional human endometrium reveals low risk of infection. WHAT IS KNOWN ALREADY Gene expression datasets from bulk endometrial tissue show no significant expression of the SARS-CoV-2 receptor ACE2 and TMPRSS2. This is in contrast to reported expression of ACE2 at the…