ABSTRACT
Parkinson's disease (PD), multisystem atrophy (MSA), and progressive supranuclear palsy (PSP) present similarly with bradykinesia, tremor, rigidity, and cognitive impairments. Neuroimaging studies have found differential changes in the nigrostriatal pathway in these disorders, however whether the volume and shape of specific regions within this pathway can distinguish between atypical Parkinsonian disorders remains to be determined. This paper investigates striatal and thalamic volume and morphology as distinguishing biomarkers, and their relationship to neuropsychiatric symptoms. Automatic segmentation to calculate volume and shape analysis of the caudate nucleus, putamen, and thalamus were performed in 18 PD patients, 12 MSA, 15 PSP, and 20 healthy controls, then correlated with clinical measures. PSP bilateral thalami and right putamen were significantly smaller than controls, but not MSA or PD. The left caudate and putamen significantly correlated with the Neuropsychiatric Inventory total score. Bilateral thalamus, caudate, and left putamen had significantly different morphology between groups, driven by differences between PSP and healthy controls. This study demonstrated that PSP patient striatal and thalamic volume and shape are significantly different when compared with controls. Parkinsonian disorders could not be differentiated on volumetry or morphology, however there are trends for volumetric and morphological changes associated with PD, MSA, and PSP.
Subject(s)
Multiple System Atrophy , Parkinson Disease , Parkinsonian Disorders , Supranuclear Palsy, Progressive , Humans , Parkinson Disease/diagnostic imaging , Supranuclear Palsy, Progressive/diagnostic imaging , Multiple System Atrophy/diagnostic imaging , Parkinsonian Disorders/diagnostic imaging , Thalamus/diagnostic imaging , Thalamus/metabolismABSTRACT
The neoplastic tumour suppressors, Scribble, Dlg and Lgl, originally discovered in the vinegar fly Drosophila melanogaster, are currently being actively studied for their potential role in mammalian tumourigenesis. In Drosophila, these tumour suppressors function in a common genetic pathway to regulate apicobasal cell polarity and also play important roles in the control of cell proliferation, survival, differentiation and in cell migration/invasion. The precise mechanism by which Scribble, Dlg and Lgl function is not clear; however, they have been implicated in the regulation of signalling pathways, vesicle trafficking and in the Myosin II-actin cytoskeleton. We review the evidence for the involvement of Scribble, Dlg, and Lgl in cancer, and how the various functions ascribed to these tumour suppressors in Drosophila and mammalian systems may impact on the process of tumourigenesis.
Subject(s)
Cell Polarity/genetics , Drosophila Proteins/physiology , Membrane Proteins/physiology , Neoplasms/genetics , Tumor Suppressor Proteins/physiology , Animals , Cell Adhesion/genetics , Cell Adhesion/physiology , Disease Progression , Drosophila/genetics , Drosophila Proteins/genetics , Humans , Membrane Proteins/genetics , Models, Biological , Neoplasm Metastasis/genetics , Neoplasms/pathology , Tumor Suppressor Proteins/geneticsABSTRACT
Cytokinesis ensures the successful completion of the cell cycle and distribution of chromosomes, organelles, and cytoplasm between daughter cells. It is accomplished by formation and constriction of an actomyosin contractile ring that drives the progression of a cleavage furrow. Microinjection experiments and in vitro transfection assays have suggested a requirement for small GTPases of the Rho family in cytokinesis. Yet, the identity of proteins regulating Rho signaling pathways during cytokinesis remains unknown. Here we show that in Drosophila, Pebble (Pbl), a putative exchange factor for Rho GTPases (RhoGEF), is required for the formation of the contractile ring and initiation of cytokinesis. The dynamics of Pbl expression and its distribution during mitosis, as well as structure-function analysis, indicate that it is a key regulatory component of the pathway. pbl interacts genetically with Rho1, but not with Rac1 or Cdc42, and Pbl and Rho1 proteins interact in vivo in yeast. Similar to mutations in pbl, loss of Rho1 or expression of a dominant-negative Rho1 blocks cytokinesis. Our results identify Pbl as a RhoGEF specifically required for cytokinesis and linked through Rho1 activity to the reorganization of the actin cytoskeleton at the cleavage furrow.
Subject(s)
Cell Cycle/physiology , Drosophila melanogaster/physiology , GTP Phosphohydrolases/metabolism , GTP-Binding Proteins/metabolism , Proteins/genetics , Proteins/metabolism , rho GTP-Binding Proteins , Amino Acid Sequence , Animals , Animals, Genetically Modified , Cell Division , Chromosomes/physiology , Chromosomes/ultrastructure , Cloning, Molecular , Cytoplasm/physiology , Cytoplasm/ultrastructure , Drosophila Proteins , Drosophila melanogaster/cytology , Drosophila melanogaster/genetics , Microscopy, Electron, Scanning , Mitosis , Molecular Sequence Data , Organelles/physiology , Organelles/ultrastructure , Proteins/chemistry , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Signal TransductionABSTRACT
The tum gene of coliphage 186, encoded on a LexA controlled operon, is essential for UV induction of a 186 prophage. Primer extension analysis is used to confirm that Tum is the sole phage function required for prophage induction and that it acts against the maintenance repressor, CI, to relieve repression of the lytic promoters, pR and pB, and thereby bring about lytic development. In vitro experiments with purified proteins demonstrate that Tum prevents CI binding to its operator sites. Tum does not compete with CI for binding sites on DNA, and unlike RecA mediated induction of lambda prophage, the action of Tum on CI is reversible. Mechanisms by which Tum may act against CI are discussed.
Subject(s)
Repressor Proteins/antagonists & inhibitors , Viral Proteins/physiology , Bacterial Proteins/genetics , DNA-Binding Proteins/metabolism , Dimerization , Gene Expression Regulation, Viral/genetics , Isopropyl Thiogalactoside/pharmacology , Operator Regions, Genetic/genetics , Protein Conformation , SOS Response, Genetics/genetics , Serine Endopeptidases/genetics , Ultraviolet Rays/adverse effects , Viral Proteins/chemistry , Viral Proteins/metabolism , Viral Regulatory and Accessory Proteins , Virus Activation/geneticsABSTRACT
We have sequenced the LexA-controlled operon of coliphage 186 that carries the tum gene, whose product is necessary for UV induction of the 186 prophage. The operon consists of orf95 and orf97, and we have identified orf95 as the tum gene. The major translation products from orf95 result from internal initiations and modulate Tum activity. Tum is the product of the full-length Orf95 protein. The second gene of the operon, orf97, is of unknown function but, while it has little effect on prophage induction, its presence in the cell totally blocks infection of that cell by 186.
Subject(s)
Coliphages/genetics , Operon , SOS Response, Genetics , Viral Proteins/genetics , Amino Acid Sequence , Base Sequence , DNA, Viral , Escherichia coli/genetics , Escherichia coli/virology , Genes, Viral , Molecular Sequence Data , Open Reading FramesABSTRACT
Our results show that UV induction of the 186 prophage depends upon the phage function Tum, with the mutant phenotype of turbid plaques on mitomycin plates and the expression of which is controlled by the host LexA protein. Tum function, encoded near the right-hand end of the coliphage 186 chromosome, is under the control of promoter p95. This promoter is overlapped by a sequence closely related to the consensus sequence of the LexA-binding site. It is proposed that inactivation of LexA after UV irradiation (or by genetic means) leads to prophage induction by permitting expression of Tum which, by unknown means, induces prophage. This mechanism is basically different from that seen with the UV-inducible lambdoid coliphages, which are not regulated by LexA.
Subject(s)
Coliphages/radiation effects , DNA Repair , Genes, Viral , SOS Response, Genetics , Ultraviolet Rays , Virus Activation/radiation effects , Base Sequence , Coliphages/genetics , Coliphages/growth & development , Escherichia coli/genetics , Escherichia coli/radiation effects , Kinetics , Molecular Sequence Data , Mutation , Temperature , Time FactorsABSTRACT
The outcome of 103 enuretics after a mean follow-up of 2.7 years showed remission of wetting in 63%. The figures varied considerably for different subgroups. Enuresis in association with conduct disorders had the worst outcome. Girls showed better response to treatment. A high score of behaviour abnormalities was related to poor outcome. A global outcome measure at follow-up added further information to remission rates.