Maturity-onset diabetes of the young (MODY) is a form of non-insulin-dependent (type 2) diabetes mellitus (NIDDM) which is characterized by an early age at onset and an autosomal dominant mode of inheritance. Except for these features, the clinical characteristics of patients with MODY are similar to those with the more common late-onset form(s) of NIDDM. Previously we observed tight linkage between DNA polymorphisms in the glucokinase gene on the short arm of chromosome 7 and NIDDM in a cohort of sixteen French families having MODY. Glucokinase is an enzyme that catalyses the formation of glucose-6-phosphate from glucose and may be involved in the regulation of insulin secretion and integration of hepatic intermediary metabolism. Because the glucokinase gene was a candidate for the site of the genetic lesion in these families, we scanned this gene for mutations. Here we report the identification of a nonsense mutation in the gene encoding glucokinase and its linkage with early-onset diabetes in one family. To our knowledge, this result is the first evidence implicating a mutation in a gene involved in glucose metabolism in the pathogenesis of NIDDM.
We have identified a novel cDNA encoding a protein highly homologous to the mammalian brown fat uncoupling protein (UCP). Unlike the known UCP, which is expressed specifically in brown adipose tissue, the UCP homolog (UCPH) mRNA is expressed in a variety of tissues, with predominant expression in human white adipose tissue and skeletal muscle. In the white adipose tissue of ob/ob and db/db mice, the UCPH transcript is induced approximately fivefold relative to lean littermate controls. Expression of murine UCPH in yeast results in growth inhibition under conditions that require aerobic respiration, but does not affect growth under anaerobic conditions. Furthermore, UCPH expression in yeast causes a decrease in the mitochondrial membrane potential, as judged by staining with the potential-sensitive dye DiOC 6 . These observations suggest that UCPH, like UCP, uncouples oxidative phosphorylation. The possibility that the UCPH protein is an important mediator of human thermogenesis is discussed. Diabetes 46:900-906, 1997
Natural outbreaks of multidrug-resistant microorganisms can cause widespread devastation, and several can be used or engineered as agents of bioterrorism. From a biosecurity standpoint, the capacity to detect and then efficiently control, within hours, the spread and the potential pathological effects of an emergent outbreak, for which there may be no effective antibiotics or vaccines, become key challenges that must be met. We turned to phage engineering as a potentially highly flexible and effective means to both detect and eradicate threats originating from emergent (uncharacterized) bacterial strains. To this end, we developed technologies allowing us to (1) concurrently modify multiple regions within the coding sequence of a gene while conserving intact the remainder of the gene, (2) reversibly interrupt the lytic cycle of an obligate virulent phage (T4) within its host, (3) carry out efficient insertion, by homologous recombination, of any number of engineered genes into the deactivated genomes of a T4 wild-type phage population, and (4) reactivate the lytic cycle, leading to the production of engineered infective virulent recombinant progeny. This allows the production of very large, genetically engineered lytic phage banks containing, in an E. coli host, a very wide spectrum of variants for any chosen phage-associated function, including phage host-range. Screening of such a bank should allow the rapid isolation of recombinant T4 particles capable of detecting (ie, diagnosing), infecting, and destroying hosts belonging to gram-negative bacterial species far removed from the original E. coli host.
To explore the mechanisms whereby estrogen and antiestrogen (tamoxifen (TAM)) can regulate breast cancer cell growth, we investigated gene expression changes in MCF7 cells treated with 17 -estradiol (E 2 ) and/or with 4-OH-TAM. The patterns of differential expression were determined by the ValiGen Gene IDentification (VGID) process, a subtractive hybridization approach combined with microarray validation screening. Their possible biologic consequences were evaluated by integrative data analysis. Over 1000 cDNA inserts were isolated and subsequently cloned, sequenced and analyzed against nucleotide and protein databases (NT/NR/EST) with BLAST software. We revealed that E 2 induced differential expression of 279 known and 28 unknown sequences, whereas TAM affected the expression of 286 known and 14 unknown sequences. Integrative data analysis singled out a set of 32 differentially expressed genes apparently involved in broad cellular mechanisms. The presence of E 2 modulated the expression patterns of 23 genes involved in anchors and junction remodeling; extracellular matrix (ECM) degradation; cell cycle progression, including G 1 /S check point and S-phase regulation; and synthesis of genotoxic metabolites. In tumor cells, these four mechanisms are associated with the acquisition of a motile and invasive phenotype. TAM partly reversed the E 2 -induced differential expression patterns and consequently restored most of the biologic functions deregulated by E 2 , except the mechanisms associated with cell cycle progression. Furthermore, we found that TAM affects the expression of nine additional genes associated with cytoskeletal remodeling, DNA repair, active estrogen receptor formation and growth factor synthesis, and mitogenic pathways. These modulatory effects of E 2 and TAM upon the gene expression patterns identified here could explain some of the mechanisms associated with the acquisition of a more aggressive phenotype by breast cancer cells, such as E 2 -independent growth and TAM resistance.
Autism Spectrum Disorder (ASD) affects approximately 1 child in 54, with a 35-fold increase since 1960. Selected studies suggest that part of the recent increase in prevalence is likely attributable to an improved awareness and recognition, and changes in clinical practice or service availability. However, this is not sufficient to explain this epidemiological phenomenon. Research points to a possible link between ASD and intestinal microbiota because many children with ASD display gastro-intestinal problems. Current large-scale datasets of ASD are limited in their ability to provide mechanistic insight into ASD because they are predominantly cross-sectional studies that do not allow evaluation of perspective associations between early life microbiota composition/function and later ASD diagnoses. Here we describe GEMMA (Genome, Environment, Microbiome and Metabolome in Autism), a prospective study supported by the European Commission, that follows at-risk infants from birth to identify potential biomarker predictors of ASD development followed by validation on large multi-omics datasets. The project includes clinical (observational and interventional trials) and pre-clinical studies in humanized murine models (fecal transfer from ASD probands) and in vitro colon models. This will support the progress of a microbiome-wide association study (of human participants) to identify prognostic microbiome signatures and metabolic pathways underlying mechanisms for ASD progression and severity and potential treatment response.
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