287 research outputs found
Cooperative activation of atrial naturetic peptide promoter by dHAND and MEF2C
No full textAn intricate array of cell-specific multiprotein complexes participate in programs of cell-specific gene expression through combinatorial interaction with different transcription factors and cofactors. The dHAND basic helix-loop-helix (bHLH) transcription factor, which is essential for heart development and extra embryonic structures, is thought to regulate cardiomyocyte-specific gene expression through combinatorial interactions with other cardiac-restricted transcription factors such as GATA4 and NKX2.5. Here, we determine that dHAND also interacts with the myocyte enhancer binding factor-2c (MEF2C) protein, which belongs to MADS-box transcription factors and is essential for heart development. dHAND and MEF2C synergistically activated expression of the atrial naturetic peptide gene (ANP) in transfected HeLa cells. GST-pulldown and immunoprecipitation assay demonstrate that full-length MEF2C protein is able to interact with dHAND in vitro and in vivo, just like MEF2A and bHLH transcription factors MyoD in skeletal muscle cells. In addition, electrophoretic mobility shift assays (EMSAs) demonstrate that MEF2C and dHAND do not influence each other's DNA binding activity. Using chromatin immunoprecipitation (ChIP) analysis in H9c2 cells we show that dHAND interact with MEF2C to form protein complex and bind A/T sequence in promoter of ANP. Taken together with previous observations, these results suggest the existence of large multiprotein transcriptional complex with core DNA binding proteins that physically interact with other transcriptional factors to form favorable conformation to potentiate transcription. (C) 2004 Wiley-Liss, Inc.Biochemistry & Molecular BiologyCell BiologySCI(E)PubMed0ARTICLE61255-12669
Molecular cloning, characterization, and differential expression pattern of mouse lung surfactant convertase
No full textWe recently reported the purification and partial amino acid sequence of “surfactant convertase,” a 72-kDa glycoprotein involved in the extracellular metabolism of lung surfactant (S. Krishnasamy, N. J. Gross, A. L. Teng, R. M. Schultz, and R. Dhand. Biochem. Biophys. Res. Commun. 235: 180–184, 1997). We report here the isolation of a cDNA clone encoding putative convertase from a mouse lung cDNA library. The cDNA spans a 1,836-bp sequence, with an open reading frame encoding 536 amino acid residues in the mature protein and an 18-amino acid signal peptide at the NH2terminus. The deduced amino acid sequence matches the four partial amino acid sequences (68 residues) that were previously obtained from the purified protein. The deduced amino acid sequence contains an 18-amino acid residue signal peptide, a serine active site consensus sequence, a histidine consensus sequence, five potential N-linked glycosylation sites, and a COOH-terminal secretory-type sequence His-Thr-Glu-His-Lys. Primer-extension analysis revealed that transcription starts 29 nucleotides upstream from the start codon. Northern blot analysis of RNA isolated from various mouse organs showed that convertase is expressed in lung, kidney, and liver as a 1,800-nucleotide-long transcript. The nucleotide and amino acid sequences of putative convertase are 98% homologous with mouse liver carboxylesterase. It thus may be the first member of the carboxylesterase family (EC 3.1.1.1 ) to be expressed in lung parenchyma and the first with a known physiological function.</jats:p
Transcriptional Regulation of Cardio-Pulmonary Development
No full textOrganogenesis is a complex process, disruption of which results in developmental anomalies. In recent years, genetic dissection of the pathways involved in cardiogenesis, have shown a striking similarity in molecular mechanisms across species. One conserved protein is dHAND, a basic helix-loop-helix (bHLH) transcription factor that is required for normal development of the right ventricle, the pharyngeal arches and limb buds. Loss of dHAND leads to apoptosis in the aforementioned tissues and to embryonic lethality at E10.0. A differential display analysis was performed to identify genes dysregulated in dHAND-/- hearts.
Characterization of such genes could potentially shed light on the molecular mechanisms involved in the defects seen in dHAND mutants, while also identifying genes required for normal embryonic development. This thesis represents work on two molecules that were identified in this screen.
Bnip3, a hypoxia inducible, pro-apoptotic molecule that can induce mitochondrial damage, was upregulated in the dHAND-/- pharyngeal arches and heart, suggesting a role for mitochondrial damage in the observed apoptosis. I have shown that while Apaf-1, a downstream mediator of mitochondrial-induced apoptosis, is required for the apoptosis observed in dHAND-null pharyngeal and aortic arch mesenchyme, cardiomyocyte apoptosis in dHAND mutants is Apaf-1 independent. Rescue of pharyngeal arches revealed that premature closure of the pharyngeal arch arteries likely contributes to the early lethality observed in dHAND-/- embryos.
The mouse ortholog of Bcl-2 associated transcription factor (Btf), which was similar to thyroid hormone receptor associated protein 150 (TRAP150), was down regulated in dHAND mutants. TRAPs are a family of transcriptional co-activators that are required for normal cardiac and embryonic development. Mice lacking Btf showed normal cardiac development, however, the animals had hypercellular lungs and died within 24 hours after birth. Analysis of lung ultrastructure and cell specific markers showed presence of immature secretory cells in the proximal airways of the lung and aberrant proximal-distal patterning. The ectopic presence of stem cell-like proximal epithelial cells (Clara cells) in the distal epithelium may explain the hypercellularity observed in btf-null lungs. These results show that Btf is required for normal maturation and patterning of the pulmonary epithelium and survival of the animal
Canada’s refugee health law and policy from a comparative, constitutional, and human rights perspective
No full textUnder the Interim Federal Health Program (IFHP), Canada has provided healthcare coverage for immigrants in financial need, including refugees, for over half a century. Until recently, the program provided migrants with comparable coverage to that available to Canadians on social assistance. In 2012, the government amended the IFHP to significantly reduce coverage for certain classes of migrants, including some on the basis of their country of origin, and removed coverage from others altogether. This article briefly describes the changes in migrant healthcare coverage in Canada, and compares it with analogous coverage in the United States, the United Kingdom, and Australia. The comparison demonstrates that Canada’s recent changes to healthcare coverage fall below a common standard of coverage in these comparator countries. The paper then explores arguments made for and against the constitutionality of the revised IFHP in Canadian Doctors for Refugee Care v Canada, and the consistency of the plan with Canada’s obligations under international human rights law. The authors contend that despite the reluctance of courts thus far to recognize a positive duty on the part of the state to provide health benefits as a means of protecting Charter rights, facets of this case present unique and compelling reasons for doing so. Finally, the paper argues that restoring coverage to levels prior to 2012 would bring Canada in closer conformity to the values and principles expressed in various international human rights treaties.Peer reviewe
Flights of fancy: traffic control for biotechnology high fliers
No full textreview of Guiding Icarus: Merging Bioethics with Corporate Interests, by Rahul K. Dhand
Canada’s Refugee Health Law and Policy from a Comparative, Constitutional, and Human Rights Perspective
No full textUnder the Interim Federal Health Program (IFHP), Canada has provided healthcare coverage for immigrants in financial need, including refugees, for over half a century. Until recently, the program provided migrants with comparable coverage to that available to Canadians on social assistance. In 2012, the government amended the IFHP to significantly reduce coverage for certain classes of migrants, including some on the basis of their country of origin, and removed coverage from others altogether. This article briefly describes the changes in migrant healthcare coverage in Canada, and compares it with analogous coverage in the United States, the United Kingdom, and Australia. The comparison demonstrates that Canada’s recent changes to healthcare coverage fall below a common standard of coverage in these comparator countries. The paper then explores arguments made for and against the constitutionality of the revised IFHP in Canadian Doctors for Refugee Care v Canada, and the consistency of the plan with Canada’s obligations under international human rights law. The authors contend that despite the reluctance of courts thus far to recognize a positive duty on the part of the state to provide health benefits as a means of protecting Charter rights, facets of this case present unique and compelling reasons for doing so. Finally, the paper argues that restoring coverage to levels prior to 2012 would bring Canada in closer conformity to the values and principles expressed in various international human rights treaties.Peer reviewe
A human phosphatidylinositol 3-kinase complex related to yeast Vps34p-Vps15p protein sorting system
No full textPhosphoinositide (PI) 3-kinases have been characterized as enzymes involved in receptor signal transduction in mammalian cells and in a complex which mediates protein trafficking in yeast. PI 3-kinases linked to receptors with intrinsic or associated tyrosine kinase activity are heterodimeric proteins, consisting of p85 adaptor and p110 catalytic subunits, which can generate the 3-phosphorylated forms of phosphatidylinositol (PtdIns), PtdIns4P and PtdIns(4,5)P2 as potential second messengers. Yeast Vps34p kinase, however, has a substrate specificity restricted to PtdIns and is a PtdIns 3-kinase. Here the molecular characterization of a new human PtdIns 3-kinase with extensive sequence homology to Vps34p is described. PtdIns 3-kinase does not associate with p85 and phosphorylates PtdIns, but not PtdIns4P or PtdIns(4,5)P2. In vivo PtdIns 3-kinase is in a complex with a cellular protein of 150 kDa, as detected by immunoprecipitation from human cells. Protein sequence analysis and cDNA cloning show that this 150 kDa protein is highly homologous to Vps15p, a 160 kDa protein serine/threonine kinase associated with yeast Vps34p. These results suggest that the major components of the yeast Vps intracellular trafficking complex are conserved in humans
Constitutional Cases (Pt 3) | Access to Justice (Panel A)
No full textThe 26th iteration of the Constitutional Cases conference was held on Friday, April 14, 2023. Osgoode Hall Law School’s Annual Constitutional Cases Conference, recognized as the leading constitutional law conference in Canada, brings together many highly respected constitutional scholars, lawyers, students, and experts for an insightful and practical analysis of the Supreme Court’s significant constitutional judgments of the past year.
Panel A | Access to Justice Panelists will consider issues of public interest standing, including questions of justiciability, genuine interest, and reasonable and effective means. They will consider broader issues on the intersection between rules of civil procedure and the administration of justice, and access to the justice through a disability rights lens.
Panelists:
00:03:03 Professor Gerard Kennedy, UManitoba Faculty of Law
00:18:30 Elin Sigurdson, Mandell Pinder LLP
00:36:50 Professor Tess Sheldon, UWindsor Faculty of Law, Karen R. Spector, Barrister & Solicitor, and Professor Ruby Dhand, Faculty of Law, Thompson Rivers University
Chair: Professor Faisal Bhabha, Osgoode Hall Law Schoo
Data and the associated R code used to estimate health and economic burden of neurocysticercosis in India
No full textAbstractThis article contains epidemiological, demographic and other data used for estimating health and economic burden of neurocysticercosis (NCC)-associated active epilepsy in India [1]. Most of the data are embedded in the R-code used for analyses so that the reader is able to replicate the results or adapt the code to their own data. However, data used to conduct sensitivity analyses to evaluate the effect of changing important input values such as prevalence and per capita income on health and economic impact of NCC in India are included in tables. Results from sensitivity analyses are also presented in tables and figures. The paper also includes three scenarios with different age weighting (k) and time discounting (r) values used to estimate health and economic burden of NCC in India. The data for the scenario without any age weighting and time discounting are presented in “Estimation of the health and economic burden of neurocysticercosis in India” [1]
Constitutional Cases (Pt 3) | Access to Justice (Panel A)
No full textThe 26th iteration of the Constitutional Cases conference was held on Friday, April 14, 2023. Osgoode Hall Law School’s Annual Constitutional Cases Conference, recognized as the leading constitutional law conference in Canada, brings together many highly respected constitutional scholars, lawyers, students, and experts for an insightful and practical analysis of the Supreme Court’s significant constitutional judgments of the past year.
Panel A | Access to Justice Panelists will consider issues of public interest standing, including questions of justiciability, genuine interest, and reasonable and effective means. They will consider broader issues on the intersection between rules of civil procedure and the administration of justice, and access to the justice through a disability rights lens.
Panelists:
00:03:03 Professor Gerard Kennedy, UManitoba Faculty of Law
00:18:30 Elin Sigurdson, Mandell Pinder LLP
00:36:50 Professor Tess Sheldon, UWindsor Faculty of Law, Karen R. Spector, Barrister & Solicitor, and Professor Ruby Dhand, Faculty of Law, Thompson Rivers University
Chair: Professor Faisal Bhabha, Osgoode Hall Law Schoo
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