Molecular cloning of the gene promoter encoding the human CaVγ2/Stargazin divergent transcript (CACNG2-DT): characterization and regulation by the cAMP-PKA/CREB signaling pathway

CaVγ2 (Stargazin or TARPγ2) is a protein expressed in various types of neurons whose function was initially associated with a decrease in the functional expression of voltage-gated presynaptic Ca2+ channels (CaV) and which is now known to promote the trafficking of the postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPAR) towards the cell membrane. Alterations in CaVγ2 expression has been associated with several neurological disorders, such as absence epilepsy. However, its regulation at the transcriptional level has not been intensively addressed. It has been reported that the promoter of the Cacng2 gene, encoding the rat CaVγ2, is bidirectional and regulates the transcription of a long non-coding RNA (lncRNA) in the antisense direction. Here, we investigate the proximal promoter region of the human CACNG2 gene in the antisense direction and show that this region includes two functional cAMP response elements that regulate the expression of a lncRNA called CACNG2-DT. The activity of these sites is significantly enhanced by forskolin, an adenylate cyclase activator, and inhibited by H89, a protein kinase A (PKA) antagonist. Therefore, this regulatory mechanism implies the activation of G protein-coupled receptors and downstream phosphorylation. Interestingly, we also found that the expression of CACNG2-DT may increase the levels of the CaVγ2 subunit. Together, these data provide novel information on the organization of the human CACNG2-DT gene promoter, describe modulatory domains and mechanisms that can mediate various regulatory inputs, and provide initial information on the molecular mechanisms that regulate the functional expression of the CaVγ2 protein

Apparent life threatening events (ALTE): diagnostic approach

Apparent Life-Threatening Events (ALTE) are a form of clinical presen- tation of various problems or diseases in children under one year of age. A frequency of 0.6/1000 newborns is estimated. In Mexico, there is no known incidence, systematic approach or guidelines for hospital discharge, so we performed a literature review. Its etiology may be gastrointestinal, neurological, cardiovascular, metabolic, endocrine or-idiopathic. The detailed history and physical examination provide an outline to select the laboratory and imaging studies to perform

Sistema de información geográfico para apoyo al turismo en el centro histórico

Tesis (Ingeniería en Sistemas Computacionales), Instituto Politécnico Nacional, ESCOM, 2012, 1 archivo PDF, (91 pàginas). tesis.ipn.m

Adenosine Stimulate Proliferation and Migration in Triple Negative Breast Cancer Cells.

Emerging evidence suggests that the adenosine (Ado) receptors may play crucial roles in tumor progression. Here, we show that Ado increases proliferation and migration in a triple negative breast cancer model, the MDA-MB 231 cell line. The use of specific agonists and antagonists evidenced that these effects depend on the activation of the A2B receptor, which then triggers an intracellular response mediated by the adenylate cyclase/PKA/cAMP signaling pathway. Ado also increases the expression of NaV1.5 channels, a potential biomarker in breast cancer. Together, these data suggest important roles of the A2B receptors and NaV1.5 channels in the Ado-induced increase in proliferation and migration of the MDA-MB 231 cells

Alternative Splicing as a Target for Cancer Treatment

Alternative splicing is a key mechanism determinant for gene expression in metazoan. During alternative splicing, non-coding sequences are removed to generate different mature messenger RNAs due to a combination of sequence elements and cellular factors that contribute to splicing regulation. A different combination of splicing sites, exonic or intronic sequences, mutually exclusive exons or retained introns could be selected during alternative splicing to generate different mature mRNAs that could in turn produce distinct protein products. Alternative splicing is the main source of protein diversity responsible for 90% of human gene expression, and it has recently become a hallmark for cancer with a full potential as a prognostic and therapeutic tool. Currently, more than 15,000 alternative splicing events have been associated to different aspects of cancer biology, including cell proliferation and invasion, apoptosis resistance and susceptibility to different chemotherapeutic drugs. Here, we present well established and newly discovered splicing events that occur in different cancer-related genes, their modification by several approaches and the current status of key tools developed to target alternative splicing with diagnostic and therapeutic purposes

Expression of Ado receptors in MDA-MB-231 cells.

<p>(A). Percentage of MDA-MB-231 cell proliferation in the presence of Ado with or without dipyridamole (Dipy) an inhibitor of nucleoside transport. (B) RT-PCR of Ado receptor mRNAs in MDA-MB-231 cells. A representative gel is shown (upper panel). Levels of Ado receptor mRNAs were estimated from gene quantitative RT-PCR data and expressed as a percentage of β-actin mRNA expression (lower panel). Cells were incubated for 72 h in the absence (Control) or presence of Ado (50 μM), or the A_2B receptor agonist Bay 60–6583 (1 μM). (C) Immunocytochemistry for the A_2B receptor was performed to verify expression at the protein level in the absence (Ab -) or the presence of specific antibodies (Ab +).</p

Ado increases Na_V1.5 channel functional expression.

<p>(A) Relative effect of Ado on Na_V1.5 mRNA expression in the MDA-MB-231 cells as compared to control. (B) Representative superimposed trace currents through Na_V channels in MDA-MB-231 cells in the absence and the presence of Ado (250 μM). The currents were generated by pulsing the membrane potential from a holding voltage of -80 mV to 0 mV for 50 ms. (C) Mean current-voltage relationship obtained from MDA-MB-231 control cells and cells incubated 48 h in the presence of Ado (250 μM). Cells were depolarized from -70 to +60 mV for 50 ms by 10-mV increments from a holding potential of -80 mV.</p