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Publication
Journal: Microbiological reviews
December/9/1996
Abstract
Respiratory infections with Pseudomonas aeruginosa and Burkholderia cepacia play a major role in the pathogenesis of cystic fibrosis (CF). This review summarizes the latest advances in understanding host-pathogen interactions in CF with an emphasis on the role and control of conversion to mucoidy in P. aeruginosa, a phenomenon epitomizing the adaptation of this opportunistic pathogen to the chronic chourse of infection in CF, and on the innate resistance to antibiotics of B. cepacia, person-to-person spread, and sometimes rapidly fatal disease caused by this organism. While understanding the mechanism of conversion to mucoidy in P. aeruginosa has progressed to the point where this phenomenon has evolved into a model system for studying bacterial stress response in microbial pathogenesis, the more recent challenge with B. cepacia, which has emerged as a potent bona fide CF pathogen, is discussed in the context of clinical issues, taxonomy, transmission, and potential modes of pathogenicity.
Publication
Journal: Nature
July/30/2006
Abstract
Parkinson's disease is the second most common neurodegenerative disorder and is characterized by the degeneration of dopaminergic neurons in the substantia nigra. Mitochondrial dysfunction has been implicated as an important trigger for Parkinson's disease-like pathogenesis because exposure to environmental mitochondrial toxins leads to Parkinson's disease-like pathology. Recently, multiple genes mediating familial forms of Parkinson's disease have been identified, including PTEN-induced kinase 1 (PINK1; PARK6) and parkin (PARK2), which are also associated with sporadic forms of Parkinson's disease. PINK1 encodes a putative serine/threonine kinase with a mitochondrial targeting sequence. So far, no in vivo studies have been reported for pink1 in any model system. Here we show that removal of Drosophila PINK1 homologue (CG4523; hereafter called pink1) function results in male sterility, apoptotic muscle degeneration, defects in mitochondrial morphology and increased sensitivity to multiple stresses including oxidative stress. Pink1 localizes to mitochondria, and mitochondrial cristae are fragmented in pink1 mutants. Expression of human PINK1 in the Drosophila testes restores male fertility and normal mitochondrial morphology in a portion of pink1 mutants, demonstrating functional conservation between human and Drosophila Pink1. Loss of Drosophila parkin shows phenotypes similar to loss of pink1 function. Notably, overexpression of parkin rescues the male sterility and mitochondrial morphology defects of pink1 mutants, whereas double mutants removing both pink1 and parkin function show muscle phenotypes identical to those observed in either mutant alone. These observations suggest that pink1 and parkin function, at least in part, in the same pathway, with pink1 functioning upstream of parkin. The role of the pink1-parkin pathway in regulating mitochondrial function underscores the importance of mitochondrial dysfunction as a central mechanism of Parkinson's disease pathogenesis.
Publication
Journal: Molecular Biology of the Cell
December/8/1999
Abstract
The unfolded protein response (UPR) controls the levels of molecular chaperones and enzymes involved in protein folding in the endoplasmic reticulum (ER). We recently isolated ATF6 as a candidate for mammalian UPR-specific transcription factor. We report here that ATF6 constitutively expressed as a 90-kDa protein (p90ATF6) is directly converted to a 50-kDa protein (p50ATF6) in ER-stressed cells. Furthermore, we showed that the most important consequence of this conversion was altered subcellular localization; p90ATF6 is embedded in the ER, whereas p50ATF6 is a nuclear protein. p90ATF6 is a type II transmembrane glycoprotein with a hydrophobic stretch in the middle of the molecule. Thus, the N-terminal half containing a basic leucine zipper motif is oriented facing the cytoplasm. Full-length ATF6 as well as its C-terminal deletion mutant carrying the transmembrane domain is localized in the ER when transfected. In contrast, mutant ATF6 representing the cytoplasmic region translocates into the nucleus and activates transcription of the endogenous GRP78/BiP gene. We propose that ER stress-induced proteolysis of membrane-bound p90ATF6 releases soluble p50ATF6, leading to induced transcription in the nucleus. Unlike yeast UPR, mammalian UPR appears to use a system similar to that reported for cholesterol homeostasis.
Publication
Journal: Journal of Biological Chemistry
June/29/2009
Abstract
A major mechanism in the cellular defense against oxidative or electrophilic stress is activation of the Nrf2-antioxidant response element signaling pathway, which controls the expression of genes whose protein products are involved in the detoxication and elimination of reactive oxidants and electrophilic agents through conjugative reactions and by enhancing cellular antioxidant capacity. At the molecular level, however, the regulatory mechanisms involved in mediating Nrf2 activation are not fully understood. It is well established that Nrf2 activity is controlled, in part, by the cytosolic protein Keap1, but the nature of this pathway and the mechanisms by which Keap1 acts to repress Nrf2 activity remain to be fully characterized and are the topics of discussion in this minireview. In addition, a possible role of the Nrf2-antioxidant response element transcriptional pathway in neuroprotection will also be discussed.
Publication
Journal: Behaviour Research and Therapy
May/2/2000
Abstract
Posttraumatic stress disorder (PTSD) is a common reaction to traumatic events. Many people recover in the ensuing months, but in a significant subgroup the symptoms persist, often for years. A cognitive model of persistence of PTSD is proposed. It is suggested that PTSD becomes persistent when individuals process the trauma in a way that leads to a sense of serious, current threat. The sense of threat arises as a consequence of: (1) excessively negative appraisals of the trauma and/or its sequelae and (2) a disturbance of autobiographical memory characterised by poor elaboration and contextualization, strong associative memory and strong perceptual priming. Change in the negative appraisals and the trauma memory are prevented by a series of problematic behavioural and cognitive strategies. The model is consistent with the main clinical features of PTSD, helps explain several apparently puzzling phenomena and provides a framework for treatment by identifying three key targets for change. Recent studies have provided preliminary support for several aspects of the model.
Publication
Journal: Nature
February/11/2003
Abstract
Studies in invertebrates have led to the identification of a number of genes that regulate lifespan, some of which encode components of the insulin or insulin-like signalling pathways. Examples include the related tyrosine kinase receptors InR (Drosophila melanogaster) and DAF-2 (Caenorhabditis elegans) that are homologues of the mammalian insulin-like growth factor type 1 receptor (IGF-1R). To investigate whether IGF-1R also controls longevity in mammals, we inactivated the IGF-1R gene in mice (Igf1r). Here, using heterozygous knockout mice because null mutants are not viable, we report that Igf1r(+/-) mice live on average 26% longer than their wild-type littermates (P < 0.02). Female Igf1r(+/-) mice live 33% longer than wild-type females (P < 0.001), whereas the equivalent male mice show an increase in lifespan of 16%, which is not statistically significant. Long-lived Igf1r(+/-) mice do not develop dwarfism, their energy metabolism is normal, and their nutrient uptake, physical activity, fertility and reproduction are unaffected. The Igf1r(+/-) mice display greater resistance to oxidative stress, a known determinant of ageing. These results indicate that the IGF-1 receptor may be a central regulator of mammalian lifespan.
Publication
Journal: Cell
August/2/2006
Abstract
In metazoans, most microRNAs imperfectly base-pair with the 3' untranslated region (3'UTR) of target mRNAs and prevent protein accumulation by either repressing translation or inducing mRNA degradation. Examples of specific mRNAs undergoing microRNA-mediated repression are numerous, but whether the repression is a reversible process remains largely unknown. Here we show that cationic amino acid transporter 1 (CAT-1) mRNA and reporters bearing its 3'UTR can be relieved from the microRNA miR-122-induced inhibition in human hepatocarcinoma cells subjected to different stress conditions. The derepression of CAT-1 mRNA is accompanied by its release from cytoplasmic processing bodies and its recruitment to polysomes. The derepression requires binding of HuR, an AU-rich-element binding protein, to the 3'UTR of CAT-1 mRNA. We propose that proteins interacting with the 3'UTR will generally act as modifiers altering the potential of miRNAs to repress gene expression.
Publication
Journal: Diabetes
May/5/1991
Abstract
N epsilon-(carboxymethyl)lysine, N epsilon-(carboxymethyl)hydroxylysine, and the fluorescent cross-link pentosidine are formed by sequential glycation and oxidation reactions between reducing sugars and proteins. These compounds, termed glycoxidation products, accumulate in tissue collagen with age and at an accelerated rate in diabetes. Although glycoxidation products are present in only trace concentrations, even in diabetic collagen, studies on glycation and oxidation of model proteins in vitro suggest that these products are biomarkers of more extensive underlying glycative and oxidative damage to the protein. Possible sources of oxidative stress and damage to proteins in diabetes include free radicals generated by autoxidation reactions of sugars and sugar adducts to protein and by autoxidation of unsaturated lipids in plasma and membrane proteins. The oxidative stress may be amplified by a continuing cycle of metabolic stress, tissue damage, and cell death, leading to increased free radical production and compromised free radical inhibitory and scavenger systems, which further exacerbate the oxidative stress. Structural characterization of the cross-links and other products accumulating in collagen in diabetes is needed to gain a better understanding of the relationship between oxidative stress and the development of complications in diabetes. Such studies may lead to therapeutic approaches for limiting the damage from glycation and oxidation reactions and for complementing existing therapy for treatment of the complications of diabetes.
Authors
Publication
Journal: Plant Cell
November/8/2004
Abstract
MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are small noncoding RNAs that have recently emerged as important regulators of mRNA degradation, translational repression, and chromatin modification. In Arabidopsis thaliana, 43 miRNAs comprising 15 families have been reported thus far. In an attempt to identify novel and abiotic stress regulated miRNAs and siRNAs, we constructed a library of small RNAs from Arabidopsis seedlings exposed to dehydration, salinity, or cold stress or to the plant stress hormone abscisic acid. Sequencing of the library and subsequent analysis revealed 26 new miRNAs from 34 loci, forming 15 new families. Two of the new miRNAs from three loci are members of previously reported miR171 and miR319 families. Some of the miRNAs are preferentially expressed in specific tissues, and several are either upregulated or downregulated by abiotic stresses. Ten of the miRNAs are highly conserved in other plant species. Fifty-one potential targets with diverse function were predicted for the newly identified miRNAs based on sequence complementarity. In addition to miRNAs, we identified 102 other novel endogenous small RNAs in Arabidopsis. These findings suggest that a large number of miRNAs and other small regulatory RNAs are encoded by the Arabidopsis genome and that some of them may play important roles in plant responses to environmental stresses as well as in development and genome maintenance.
Publication
Journal: Science
February/16/2006
Abstract
Mice experiencing repeated aggression develop a long-lasting aversion to social contact, which can be normalized by chronic, but not acute, administration of antidepressant. Using viral-mediated, mesolimbic dopamine pathway-specific knockdown of brain-derived neurotrophic factor (BDNF), we showed that BDNF is required for the development of this experience-dependent social aversion. Gene profiling in the nucleus accumbens indicates that local knockdown of BDNF obliterates most of the effects of repeated aggression on gene expression within this circuit, with similar effects being produced by chronic treatment with antidepressant. These results establish an essential role for BDNF in mediating long-term neural and behavioral plasticity in response to aversive social experiences.
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Publication
Journal: Annual Review of Psychology
April/8/2002
Abstract
Socioeconomic status (SES) is one of the most widely studied constructs in the social sciences. Several ways of measuring SES have been proposed, but most include some quantification of family income, parental education, and occupational status. Research shows that SES is associated with a wide array of health, cognitive, and socioemotional outcomes in children, with effects beginning prior to birth and continuing into adulthood. A variety of mechanisms linking SES to child well-being have been proposed, with most involving differences in access to material and social resources or reactions to stress-inducing conditions by both the children themselves and their parents. For children, SES impacts well-being at multiple levels, including both family and neighborhood. Its effects are moderated by children's own characteristics, family characteristics, and external support systems.
Publication
Journal: Physiological Reviews
May/2/2006
Abstract
The heme oxygenases, which consist of constitutive and inducible isozymes (HO-1, HO-2), catalyze the rate-limiting step in the metabolic conversion of heme to the bile pigments (i.e., biliverdin and bilirubin) and thus constitute a major intracellular source of iron and carbon monoxide (CO). In recent years, endogenously produced CO has been shown to possess intriguing signaling properties affecting numerous critical cellular functions including but not limited to inflammation, cellular proliferation, and apoptotic cell death. The era of gaseous molecules in biomedical research and human diseases initiated with the discovery that the endothelial cell-derived relaxing factor was identical to the gaseous molecule nitric oxide (NO). The discovery that endogenously produced gaseous molecules such as NO and now CO can impart potent physiological and biological effector functions truly represented a paradigm shift and unraveled new avenues of intense investigations. This review covers the molecular and biochemical characterization of HOs, with a discussion on the mechanisms of signal transduction and gene regulation that mediate the induction of HO-1 by environmental stress. Furthermore, the current understanding of the functional significance of HO shall be discussed from the perspective of each of the metabolic by-products, with a special emphasis on CO. Finally, this presentation aspires to lay a foundation for potential future clinical applications of these systems.
Publication
Journal: Plant Cell
May/4/2003
Abstract
In Arabidopsis, the induction of a dehydration-responsive gene, rd22, is mediated by abscisic acid (ABA). We reported previously that MYC and MYB recognition sites in the rd22 promoter region function as cis-acting elements in the drought- and ABA-induced gene expression of rd22. bHLH- and MYB-related transcription factors, rd22BP1 (renamed AtMYC2) and AtMYB2, interact specifically with the MYC and MYB recognition sites, respectively, in vitro and activate the transcription of the beta-glucuronidase reporter gene driven by the MYC and MYB recognition sites in Arabidopsis leaf protoplasts. Here, we show that transgenic plants overexpressing AtMYC2 and/or AtMYB2 cDNAs have higher sensitivity to ABA. The ABA-induced gene expression of rd22 and AtADH1 was enhanced in these transgenic plants. Microarray analysis of the transgenic plants overexpressing both AtMYC2 and AtMYB2 cDNAs revealed that several ABA-inducible genes also are upregulated in the transgenic plants. By contrast, a Ds insertion mutant of the AtMYC2 gene was less sensitive to ABA and showed significantly decreased ABA-induced gene expression of rd22 and AtADH1. These results indicate that both AtMYC2 and AtMYB2 proteins function as transcriptional activators in ABA-inducible gene expression under drought stress in plants.
Publication
Journal: Nature Reviews Cancer
September/27/2009
Abstract
Thirty years ago p53 was discovered as a cellular partner of simian virus 40 large T-antigen, the oncoprotein of this tumour virus. The first decade of p53 research saw the cloning of p53 DNA and the realization that p53 is not an oncogene but a tumour suppressor that is very frequently mutated in human cancer. In the second decade of research, the function of p53 was uncovered: it is a transcription factor induced by stress, which can promote cell cycle arrest, apoptosis and senescence. In the third decade after its discovery new functions of this protein were revealed, including the regulation of metabolic pathways and cytokines that are required for embryo implantation. The fourth decade of research may see new p53-based drugs to treat cancer. What is next is anybody's guess.
Publication
Journal: Journal of Pathology
May/10/2010
Abstract
Autophagy is a self-degradative process that is important for balancing sources of energy at critical times in development and in response to nutrient stress. Autophagy also plays a housekeeping role in removing misfolded or aggregated proteins, clearing damaged organelles, such as mitochondria, endoplasmic reticulum and peroxisomes, as well as eliminating intracellular pathogens. Thus, autophagy is generally thought of as a survival mechanism, although its deregulation has been linked to non-apoptotic cell death. Autophagy can be either non-selective or selective in the removal of specific organelles, ribosomes and protein aggregates, although the mechanisms regulating aspects of selective autophagy are not fully worked out. In addition to elimination of intracellular aggregates and damaged organelles, autophagy promotes cellular senescence and cell surface antigen presentation, protects against genome instability and prevents necrosis, giving it a key role in preventing diseases such as cancer, neurodegeneration, cardiomyopathy, diabetes, liver disease, autoimmune diseases and infections. This review summarizes the most up-to-date findings on how autophagy is executed and regulated at the molecular level and how its disruption can lead to disease.
Publication
Journal: Plant Cell
February/18/2017
Publication
Journal: Genome Biology
May/2/2013
Abstract
BACKGROUND
The inflammatory bowel diseases (IBD) Crohn's disease and ulcerative colitis result from alterations in intestinal microbes and the immune system. However, the precise dysfunctions of microbial metabolism in the gastrointestinal microbiome during IBD remain unclear. We analyzed the microbiota of intestinal biopsies and stool samples from 231 IBD and healthy subjects by 16S gene pyrosequencing and followed up a subset using shotgun metagenomics. Gene and pathway composition were assessed, based on 16S data from phylogenetically-related reference genomes, and associated using sparse multivariate linear modeling with medications, environmental factors, and IBD status.
RESULTS
Firmicutes and Enterobacteriaceae abundances were associated with disease status as expected, but also with treatment and subject characteristics. Microbial function, though, was more consistently perturbed than composition, with 12% of analyzed pathways changed compared with 2% of genera. We identified major shifts in oxidative stress pathways, as well as decreased carbohydrate metabolism and amino acid biosynthesis in favor of nutrient transport and uptake. The microbiome of ileal Crohn's disease was notable for increases in virulence and secretion pathways.
CONCLUSIONS
This inferred functional metagenomic information provides the first insights into community-wide microbial processes and pathways that underpin IBD pathogenesis.
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Publication
Journal: Schizophrenia Research
August/8/2001
Abstract
After more than 100 years of research, the neuropathology of schizophrenia remains unknown and this is despite the fact that both Kraepelin (1919/1971: Kraepelin, E., 1919/1971. Dementia praecox. Churchill Livingston Inc., New York) and Bleuler (1911/1950: Bleuler, E., 1911/1950. Dementia praecox or the group of schizophrenias. International Universities Press, New York), who first described 'dementia praecox' and the 'schizophrenias', were convinced that schizophrenia would ultimately be linked to an organic brain disorder. Alzheimer (1897: Alzheimer, A., 1897. Beitrage zur pathologischen anatomie der hirnrinde und zur anatomischen grundlage einiger psychosen. Monatsschrift fur Psychiarie und Neurologie. 2, 82-120) was the first to investigate the neuropathology of schizophrenia, though he went on to study more tractable brain diseases. The results of subsequent neuropathological studies were disappointing because of conflicting findings. Research interest thus waned and did not flourish again until 1976, following the pivotal computer assisted tomography (CT) finding of lateral ventricular enlargement in schizophrenia by Johnstone and colleagues. Since that time significant progress has been made in brain imaging, particularly with the advent of magnetic resonance imaging (MRI), beginning with the first MRI study of schizophrenia by Smith and coworkers in 1984 (Smith, R.C., Calderon, M., Ravichandran, G.K., et al. (1984). Nuclear magnetic resonance in schizophrenia: A preliminary study. Psychiatry Res. 12, 137-147). MR in vivo imaging of the brain now confirms brain abnormalities in schizophrenia. The 193 peer reviewed MRI studies reported in the current review span the period from 1988 to August, 2000. This 12 year period has witnessed a burgeoning of MRI studies and has led to more definitive findings of brain abnormalities in schizophrenia than any other time period in the history of schizophrenia research. Such progress in defining the neuropathology of schizophrenia is largely due to advances in in vivo MRI techniques. These advances have now led to the identification of a number of brain abnormalities in schizophrenia. Some of these abnormalities confirm earlier post-mortem findings, and most are small and subtle, rather than large, thus necessitating more advanced and accurate measurement tools. These findings include ventricular enlargement (80% of studies reviewed) and third ventricle enlargement (73% of studies reviewed). There is also preferential involvement of medial temporal lobe structures (74% of studies reviewed), which include the amygdala, hippocampus, and parahippocampal gyrus, and neocortical temporal lobe regions (superior temporal gyrus) (100% of studies reviewed). When gray and white matter of superior temporal gyrus was combined, 67% of studies reported abnormalities. There was also moderate evidence for frontal lobe abnormalities (59% of studies reviewed), particularly prefrontal gray matter and orbitofrontal regions. Similarly, there was moderate evidence for parietal lobe abnormalities (60% of studies reviewed), particularly of the inferior parietal lobule which includes both supramarginal and angular gyri. Additionally, there was strong to moderate evidence for subcortical abnormalities (i.e. cavum septi pellucidi-92% of studies reviewed, basal ganglia-68% of studies reviewed, corpus callosum-63% of studies reviewed, and thalamus-42% of studies reviewed), but more equivocal evidence for cerebellar abnormalities (31% of studies reviewed). The timing of such abnormalities has not yet been determined, although many are evident when a patient first becomes symptomatic. There is, however, also evidence that a subset of brain abnormalities may change over the course of the illness. The most parsimonious explanation is that some brain abnormalities are neurodevelopmental in origin but unfold later in development, thus setting the stage for the development of the symptoms of schizophrenia. Or there may be additional factors, such as stress or neurotoxicity, that occur during adolescence or early adulthood and are necessary for the development of schizophrenia, and may be associated with neurodegenerative changes. Importantly, as several different brain regions are involved in the neuropathology of schizophrenia, new models need to be developed and tested that explain neural circuitry abnormalities effecting brain regions not necessarily structurally proximal to each other but nonetheless functionally interrelated. (ABSTRACT TRUNCATED)
Publication
Journal: Archives of internal medicine
October/18/1993
Abstract
OBJECTIVE
This article presents a new formulation of the relationship between stress and the processes leading to disease. It emphasizes the hidden cost of chronic stress to the body over long time periods, which act as a predisposing factor for the effects of acute, stressful life events. It also presents a model showing how individual differences in the susceptibility to stress are tied to individual behavioral responses to environmental challenges that are coupled to physiologic and pathophysiologic responses.
METHODS
Published original articles from human and animal studies and selected reviews. Literature was surveyed using MEDLINE.
METHODS
Independent extraction and cross-referencing by us.
RESULTS
Stress is frequently seen as a significant contributor to disease, and clinical evidence is mounting for specific effects of stress on immune and cardiovascular systems. Yet, until recently, aspects of stress that precipitate disease have been obscure. The concept of homeostasis has failed to help us understand the hidden toll of chronic stress on the body. Rather than maintaining constancy, the physiologic systems within the body fluctuate to meet demands from external forces, a state termed allostasis. In this article, we extend the concept of allostasis over the dimension of time and we define allostatic load as the cost of chronic exposure to fluctuating or heightened neural or neuroendocrine response resulting from repeated or chronic environmental challenge that an individual reacts to as being particularly stressful.
CONCLUSIONS
This new formulation emphasizes the cascading relationships, beginning early in life, between environmental factors and genetic predispositions that lead to large individual differences in susceptibility to stress and, in some cases, to disease. There are now empirical studies based on this formulation, as well as new insights into mechanisms involving specific changes in neural, neuroendocrine, and immune systems. The practical implications of this formulation for clinical practice and further research are discussed.
Publication
Journal: Plant Journal
May/1/2003
Abstract
Full-length cDNAs are essential for functional analysis of plant genes in the post-sequencing era of the Arabidopsis genome. Recently, cDNA microarray analysis has been developed for quantitative analysis of global and simultaneous analysis of expression profiles. We have prepared a full-length cDNA microarray containing approximately 7000 independent, full-length cDNA groups to analyse the expression profiles of genes under drought, cold (low temperature) and high-salinity stress conditions over time. The transcripts of 53, 277 and 194 genes increased after cold, drought and high-salinity treatments, respectively, more than fivefold compared with the control genes. We also identified many highly drought-, cold- or high-salinity- stress-inducible genes. However, we observed strong relationships in the expression of these stress-responsive genes based on Venn diagram analysis, and found 22 stress-inducible genes that responded to all three stresses. Several gene groups showing different expression profiles were identified by analysis of their expression patterns during stress-responsive gene induction. The cold-inducible genes were classified into at least two gene groups from their expression profiles. DREB1A was included in a group whose expression peaked at 2 h after cold treatment. Among the drought, cold or high-salinity stress-inducible genes identified, we found 40 transcription factor genes (corresponding to approximately 11% of all stress-inducible genes identified), suggesting that various transcriptional regulatory mechanisms function in the drought, cold or high-salinity stress signal transduction pathways.
Publication
Journal: Physiological Reviews
February/10/1999
Abstract
Mitogen-activated protein kinases (MAPK) are serine-threonine protein kinases that are activated by diverse stimuli ranging from cytokines, growth factors, neurotransmitters, hormones, cellular stress, and cell adherence. Mitogen-activated protein kinases are expressed in all eukaryotic cells. The basic assembly of MAPK pathways is a three-component module conserved from yeast to humans. The MAPK module includes three kinases that establish a sequential activation pathway comprising a MAPK kinase kinase (MKKK), MAPK kinase (MKK), and MAPK. Currently, there have been 14 MKKK, 7 MKK, and 12 MAPK identified in mammalian cells. The mammalian MAPK can be subdivided into five families: MAPKerk1/2, MAPKp38, MAPKjnk, MAPKerk3/4, and MAPKerk5. Each MAPK family has distinct biological functions. In Saccharomyces cerevisiae, there are five MAPK pathways involved in mating, cell wall remodelling, nutrient deprivation, and responses to stress stimuli such as osmolarity changes. Component members of the yeast pathways have conserved counterparts in mammalian cells. The number of different MKKK in MAPK modules allows for the diversity of inputs capable of activating MAPK pathways. In this review, we define all known MAPK module kinases from yeast to humans, what is known about their regulation, defined MAPK substrates, and the function of MAPK in cell physiology.
Publication
Journal: Nature Cell Biology
April/11/2010
Abstract
Impaired selective turnover of p62 by autophagy causes severe liver injury accompanied by the formation of p62-positive inclusions and upregulation of detoxifying enzymes. These phenotypes correspond closely to the pathological conditions seen in human liver diseases, including alcoholic hepatitis and hepatocellular carcinoma. However, the molecular mechanisms and pathophysiological processes in these events are still unknown. Here we report the identification of a novel regulatory mechanism by p62 of the transcription factor Nrf2, whose target genes include antioxidant proteins and detoxification enzymes. p62 interacts with the Nrf2-binding site on Keap1, a component of Cullin-3-type ubiquitin ligase for Nrf2. Thus, an overproduction of p62 or a deficiency in autophagy competes with the interaction between Nrf2 and Keap1, resulting in stabilization of Nrf2 and transcriptional activation of Nrf2 target genes. Our findings indicate that the pathological process associated with p62 accumulation results in hyperactivation of Nrf2 and delineates unexpected roles of selective autophagy in controlling the transcription of cellular defence enzyme genes.
Publication
Journal: Annals of Internal Medicine
March/21/2007
Abstract
BACKGROUND
Anxiety, although as common as depression, has received less attention and is often undetected and undertreated.
OBJECTIVE
To determine the current prevalence, impairment, and comorbidity of anxiety disorders in primary care and to evaluate a brief measure for detecting these disorders.
METHODS
Criterion-standard study performed between November 2004 and June 2005.
METHODS
15 U.S. primary care clinics.
METHODS
965 randomly sampled patients from consecutive clinic patients who completed a self-report questionnaire and agreed to a follow-up telephone interview.
METHODS
7-item anxiety measure (Generalized Anxiety Disorder [GAD]-7 scale) in the clinic, followed by a telephone-administered, structured psychiatric interview by a mental health professional who was blinded to the GAD-7 results. Functional status (Medical Outcomes Study Short Form-20), depressive and somatic symptoms, and self-reported disability days and physician visits were also assessed.
RESULTS
Of the 965 patients, 19.5% (95% CI, 17.0% to 22.1%) had at least 1 anxiety disorder, 8.6% (CI, 6.9% to 10.6%) had posttraumatic stress disorder, 7.6% (CI, 5.9% to 9.4%) had a generalized anxiety disorder, 6.8% (CI, 5.3% to 8.6%) had a panic disorder, and 6.2% (CI, 4.7% to 7.9%) had a social anxiety disorder. Each disorder was associated with substantial impairment that increased significantly (P < 0.001) as the number of anxiety disorders increased. Many patients (41%) with an anxiety disorder reported no current treatment. Receiver-operating characteristic curve analysis showed that both the GAD-7 scale and its 2 core items (GAD-2) performed well (area under the curve, 0.80 to 0.91) as screening tools for all 4 anxiety disorders.
CONCLUSIONS
The study included a nonrandom sample of selected primary care practices.
CONCLUSIONS
Anxiety disorders are prevalent, disabling, and often untreated in primary care. A 2-item screening test may enhance detection.
Publication
Journal: Science
August/31/1994
Abstract
Mammalian cells respond to endotoxic lipopolysaccharide (LPS) by activation of protein kinase cascades that lead to new gene expression. A protein kinase, p38, that was tyrosine phosphorylated in response to LPS, was cloned. The p38 enzyme and the product of the Saccharomyces cerevisiae HOG1 gene, which are both members of the mitogen-activated protein (MAP) kinase family, have sequences at and adjacent to critical phosphorylation sites that distinguish these proteins from most other MAP kinase family members. Both HOG1 and p38 are tyrosine phosphorylated after extracellular changes in osmolarity. These findings link a signaling pathway in mammalian cells with a pathway in yeast that is responsive to physiological stress.
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