			Home About us Contact

Transcriptional Events (transcriptional + event)

Distribution by Scientific Domains

Life Sciences	60%
Medical Sciences	40%

Selected Abstracts

Defining the transcriptome of accelerated and replicatively senescent keratinocytes reveals links to differentiation, interferon signaling, and Notch related pathways,

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2006
Ranjan J. Perera
Abstract Epidermal keratinocytes (KCs) undergo highly orchestrated morphological and molecular changes during transition from proliferative compartment into growth arrested early and late differentiation layers, prior to dying in outermost cornified layers of normal skin. Creation of stratum corneum is vital to barrier function protecting against infection. Transcriptional events in KCs regulating complex processes of differentiation and host defense required to maintain constant epidermal thickness and resistance to infection in either young or aged skin are largely unknown. Furthermore, as terminal differentiation is characterized by irreversible loss of replicative potential culminating in dead layers at the skin surface, this process may be viewed as a form of senescence. However, a complete transcriptional profile of senescent (SN) human KCs has not been previously defined to permit delineation of molecular boundaries involving differentiation and senescence. To fill this void, we utilized global transcriptional analysis of KCs maintained in vitro as either cultures of proliferating (PR) cells, early and late confluent (LC) (accelerated senescence) cultures, or KCs undergoing replicative senescence. Global gene expression profiling revealed early confluent (EC) KCs were somewhat similar to PR KCs, while prominent differences were evident when compared to LC KCs; which were also distinct from replicatively SN KCs. While confluent KCs have in common several genes regulating differentiation with replicatively SN KCs, the latter cells expressed elevated levels of genes involved in interferon signaling and inflammatory pathways. These results provide new insights into cell autonomous transcriptional-based programs operative within KCs contributing to replicative senescence, with partial sharing of genes involved in differentiation. In addition, regulation of KC senescence may involve participation of interferon signaling pathways derived from the important role of KCs in protecting skin from infection. Integrating all of the transcriptional data revealed a key role for Notch receptor mediated signaling in the confluency induced differentiation phenotype using this model system. J. Cell. Biochem. 98: 394,408, 2006. © 2006 Wiley-Liss, Inc. [source]

Signaling mechanisms in skeletal muscle: Acute responses and chronic adaptations to exercise

IUBMB LIFE, Issue 3 2008
Katja S.C. Röckl
Abstract Physical activity elicits physiological responses in skeletal muscle that result in a number of health benefits, in particular in disease states, such as type 2 diabetes. An acute bout of exercise/muscle contraction improves glucose homeostasis by increasing skeletal muscle glucose uptake, while chronic exercise training induces alterations in the expression of metabolic genes, such as those involved in muscle fiber type, mitochondrial biogenesis, or glucose transporter 4 (GLUT4) protein levels. A primary goal of exercise research is to elucidate the mechanisms that regulate these important metabolic and transcriptional events in skeletal muscle. In this review, we briefly summarize the current literature describing the molecular signals underlying skeletal muscle responses to acute and chronic exercise. The search for possible exercise/contraction-stimulated signaling proteins involved in glucose transport, muscle fiber type, and mitochondrial biogenesis is ongoing. Further research is needed because full elucidation of exercise-mediated signaling pathways would represent a significant step toward the development of new pharmacological targets for the treatment of metabolic diseases such as type 2 diabetes. © 2008 IUBMB IUBMB Life, 60(3): 145,153, 2008 [source]

Review article: transcriptional events controlling the terminal differentiation of intestinal endocrine cells

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2000
H. Mutoh
Summary Secretin-producing enteroendocrine cells arise from a multipotential endocrine progenitor in the crypts of the small intestine. As these cells migrate up the crypt-villus axis, they produce secretin and stop dividing as they terminally differentiate and die. Transcription of the secretin gene is controlled by a complex enhancer binding to multiple transcription factors. The basic helix-loop-helix protein, BETA2, binds to an E box sequence and associates with the p300 coactivator to activate transcription of the secretin gene. Basic helix-loop-helix proteins appear to play a pivotal role in the control of cellular differentiation. BETA2 induces cell cycle arrest and apoptosis in addition to activating secretin gene expression. Thus BETA2 may function as a master regulatory gene to coordinate terminal differentiation of secretin cells. [source]

Molecular and histochemical characterisation of two distinct poplar Melampsora leaf rust pathosystems

PLANT BIOLOGY, Issue 2 2010
B. Boyle
Abstract In this study, we compared interactions of two Melampsora foliar rust species with poplar, which resulted in either limited or abundant pathogen proliferation. In the pathosystem exhibiting limited pathogen growth, a defence response was observed after invasion of poplar leaf tissues by the biotroph, with late and clear production of reactive oxygen species (ROS) and other products. Characterisation of the histological, biochemical and transcriptional events occurring in both pathosystems showed striking similarity with components of plant defence reactions observed during qualitative resistance. Key components associated with development of an active defence response, such as up-regulation of pathogenesis-related (PR) genes, were observed during infection. Moreover, the time course and strength of gene induction appear to be critical determinants for the outcome of the tree,pathogen interaction. This work provides basic biochemical characterisation and expression data for the study of so-called partial resistance in the poplar,rust pathosystem, which is also applicable to other plant,pathogen interactions resulting in quantitative disease resistance. [source]

Nonsense-associated altered splicing of the Patched gene fails to suppress carcinogenesis in Gorlin syndrome

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2008
M. Laimer
Summary Mutations in the gene coding for the transmembrane receptor protein Patched (PTCH) are implicated in the autosomal dominant disorder Gorlin syndrome (also known as naevoid basal cell carcinoma syndrome), characterized by congenital abnormalities and cancer predisposition. Tumour promotion is thought to be associated with aberrant function of PTCH, leading to misregulation of the hedgehog signalling network. However, the transcriptional events that underlie the reduced tumour suppression effects of PTCH have not been studied in detail. We describe a patient with Gorlin syndrome who had three molecular aberrations resulting in biallelic disruption of the PTCH gene, leading to abnormal protein expression and development of basal cell carcinoma. Remarkably, within tumour cells, the somatic nonsense mutation G1019X was associated with activation of a cryptic splice donor site, in which an in-frame deletion of the exon sequence containing the nonsense mutation occurred. However, the function of the resulting PTCH protein variant was still compromised. The pathogenetic alterations described give insights into the sequence of events leading to cellular transformation and underscore the importance of the PTCH protein in skin homeostasis. [source]