Search

Dietary fish oil restores ovarian function in subfertile rats, which is thought to be associated with decreased transcription of follicle-stimulating hormone (FSH) β-subunit. We have previously demonstrated a reduction in early follicular serum FSH levels in normal weight but not obese women after treatment with omega-3 polyunsaturated fatty acids (PUFA). Herein, we report the effect of supplementation with omega-3 PUFA on urinary reproductive hormones across the whole menstrual cycle. This interventional study included 17 eumenorrheic women, aged 24-41 years. One month of daily morning urine was collected before and after 1 month of omega-3 PUFA supplementation with 4 g of eicosapentaenoic acid and docosahexaenoic acid daily. Measurements included urinary FSH, luteinizing hormone (LH) and estrogen and progesterone metabolites, plasma fatty acid composition, and markers of endoplasmic reticulum stress. Compliance with dietary supplementation was verified by significantly reduced ratios of omega-6 to omega-3 PUFA for all subjects after treatment (P < .01). After 1 month of omega-3 PUFA supplementation, urinary FSH was significantly decreased in normal weight, but not obese women, in both follicular and luteal phases (-28.4% and -12.6%, respectively, both P = .04). No significant changes were seen in LH or sex steroids for either weight group. The selective and specific decrease in FSH suggests that omega-3 PUFA supplementation merits further investigation in normal weight women with decreased fertility and/or diminished ovarian reserve.

We dissected the importance of human telomerase biogenesis and trafficking pathways for telomere maintenance. Biological stability of human telomerase RNA (hTR) relies on H/ACA proteins, but other eukaryotes use other RNP assembly pathways. To investigate additional rationale for human telomerase assembly as H/ACA RNP, we developed a minimized cellular hTR. Remarkably, with only binding sites for telomerase reverse transcriptase (TERT), minimized hTR assembled biologically active enzyme. TERT overexpression was required for cellular interaction with minimized hTR, indicating that H/ACA RNP assembly enhances endogenous hTR-TERT interaction. Telomere maintenance by minimized telomerase was unaffected by the elimination of the telomerase holoenzyme Cajal body chaperone TCAB1 or the Cajal body scaffold protein Coilin. Surprisingly, wild-type hTR also maintained and elongated telomeres in TCAB1 or Coilin knockout cells, with distinct changes in telomerase action. Overall, we elucidate trafficking requirements for telomerase biogenesis and function and expand mechanisms by which altered telomere maintenance engenders human disease.

Study hypothesisWe hypothesized that the mitochondria of granulosa cells (GC) and/or oocytes might be abnormal in a mouse model of fragile X premutation (FXPM).Study findingMice heterozygous and homozygous for the FXPM have increased death (atresia) of large ovarian follicles, fewer corpora lutea with a gene dosage effect manifesting in decreased litter size(s). Furthermore, granulosa cells (GC) and oocytes of FXPM mice have decreased mitochondrial content, structurally abnormal mitochondria, and reduced expression of critical mitochondrial genes. Because this mouse allele produces the mutant Fragile X mental retardation 1 (Fmr1) transcript and reduced levels of wild-type (WT) Fmr1 protein (FMRP), but does not produce a Repeat Associated Non-ATG Translation (RAN)-translation product, our data lend support to the idea that Fmr1 mRNA with large numbers of CGG-repeats is intrinsically deleterious in the ovary.What is known alreadyMitochondrial dysfunction has been detected in somatic cells of human and mouse FX PM carriers and mitochondria are essential for oogenesis and ovarian follicle development, FX-associated primary ovarian insufficiency (FXPOI) is seen in women with FXPM alleles. These alleles have 55-200 CGG repeats in the 5' UTR of an X-linked gene known as FMR1. The molecular basis of the pathology seen in this disorder is unclear but is thought to involve either some deleterious consequence of overexpression of RNA with long CGG-repeat tracts or of the generation of a repeat-associated non-AUG translation (RAN translation) product that is toxic.Study design, samples/materials, methodsAnalysis of ovarian function in a knock-in FXPM mouse model carrying 130 CGG repeats was performed as follows on WT, PM/+, and PM/PM genotypes. Histomorphometric assessment of follicle and corpora lutea numbers in ovaries from 8-month-old mice was executed, along with litter size analysis. Mitochondrial DNA copy number was quantified in oocytes and GC using quantitative PCR, and cumulus granulosa mitochondrial content was measured by flow cytometric analysis after staining of cells with Mitotracker dye. Transmission electron micrographs were prepared of GC within small growing follicles and mitochondrial architecture was compared. Quantitative RT-PCR analysis of key genes involved in mitochondrial structure and recycling was performed.Main results and the role of chanceA defect was found in follicle survival at the large antral stage in PM/+ and PM/PM mice. Litter size was significantly decreased in PM/PM mice, and corpora lutea were significantly reduced in mice of both mutant genotypes. Mitochondrial DNA copy number was significantly decreased in GC and metaphase II eggs in mutants. Flow cytometric analysis revealed that PM/+ and PM/PM animals lack the cumulus GC that harbor the greatest mitochondrial content as found in wild-type animals. Electron microscopic evaluation of GC of small growing follicles revealed mitochondrial structural abnormalities, including disorganized and vacuolar cristae. Finally, aberrant mitochondrial gene expression was detected. Mitofusin 2 (Mfn2) and Optic atrophy 1 (Opa1), genes involved in mitochondrial fusion and structure, respectively, were significantly decreased in whole ovaries of both mutant genotypes. Mitochondrial fission factor 1 (Mff1) was significantly decreased in PM/+ and PM/PM GC and eggs compared with wild-type controls.Limitations, reasons for cautionData from the mouse model used for these studies should be viewed with some caution when considering parallels to the human FXPOI condition.Wider implications of the findingsOur data lend support to the idea that Fmr1 mRNA with large numbers of CGG-repeats is intrinsically deleterious in the ovary. FXPM disease states, including FXPOI, may share mitochondrial dysfunction as a common underlying mechanism.Large scale dataNot applicable.Study funding and competing interestsStudies were supported by NIH R21 071873 (J.J./G.H), The Albert McKern Fund for Perinatal Research (J.J.), NIH Intramural Funds (K.U.), and a TUBITAK Research Fellowship Award (B.U.). No conflict(s) of interest or competing interest(s) are noted.

Study hypothesisWe hypothesized that the mitochondria of granulosa cells (GC) and/or oocytes might be abnormal in a mouse model of fragile X premutation (FXPM).Study findingMice heterozygous and homozygous for the FXPM have increased death (atresia) of large ovarian follicles, fewer corpora lutea with a gene dosage effect manifesting in decreased litter size(s). Furthermore, granulosa cells (GC) and oocytes of FXPM mice have decreased mitochondrial content, structurally abnormal mitochondria, and reduced expression of critical mitochondrial genes. Because this mouse allele produces the mutant Fragile X mental retardation 1 (Fmr1) transcript and reduced levels of wild-type (WT) Fmr1 protein (FMRP), but does not produce a Repeat Associated Non-ATG Translation (RAN)-translation product, our data lend support to the idea that Fmr1 mRNA with large numbers of CGG-repeats is intrinsically deleterious in the ovary.What is known alreadyMitochondrial dysfunction has been detected in somatic cells of human and mouse FX PM carriers and mitochondria are essential for oogenesis and ovarian follicle development, FX-associated primary ovarian insufficiency (FXPOI) is seen in women with FXPM alleles. These alleles have 55-200 CGG repeats in the 5' UTR of an X-linked gene known as FMR1. The molecular basis of the pathology seen in this disorder is unclear but is thought to involve either some deleterious consequence of overexpression of RNA with long CGG-repeat tracts or of the generation of a repeat-associated non-AUG translation (RAN translation) product that is toxic.Study design, samples/materials, methodsAnalysis of ovarian function in a knock-in FXPM mouse model carrying 130 CGG repeats was performed as follows on WT, PM/+, and PM/PM genotypes. Histomorphometric assessment of follicle and corpora lutea numbers in ovaries from 8-month-old mice was executed, along with litter size analysis. Mitochondrial DNA copy number was quantified in oocytes and GC using quantitative PCR, and cumulus granulosa mitochondrial content was measured by flow cytometric analysis after staining of cells with Mitotracker dye. Transmission electron micrographs were prepared of GC within small growing follicles and mitochondrial architecture was compared. Quantitative RT-PCR analysis of key genes involved in mitochondrial structure and recycling was performed.Main results and the role of chanceA defect was found in follicle survival at the large antral stage in PM/+ and PM/PM mice. Litter size was significantly decreased in PM/PM mice, and corpora lutea were significantly reduced in mice of both mutant genotypes. Mitochondrial DNA copy number was significantly decreased in GC and metaphase II eggs in mutants. Flow cytometric analysis revealed that PM/+ and PM/PM animals lack the cumulus GC that harbor the greatest mitochondrial content as found in wild-type animals. Electron microscopic evaluation of GC of small growing follicles revealed mitochondrial structural abnormalities, including disorganized and vacuolar cristae. Finally, aberrant mitochondrial gene expression was detected. Mitofusin 2 (Mfn2) and Optic atrophy 1 (Opa1), genes involved in mitochondrial fusion and structure, respectively, were significantly decreased in whole ovaries of both mutant genotypes. Mitochondrial fission factor 1 (Mff1) was significantly decreased in PM/+ and PM/PM GC and eggs compared with wild-type controls.Limitations, reasons for cautionData from the mouse model used for these studies should be viewed with some caution when considering parallels to the human FXPOI condition.Wider implications of the findingsOur data lend support to the idea that Fmr1 mRNA with large numbers of CGG-repeats is intrinsically deleterious in the ovary. FXPM disease states, including FXPOI, may share mitochondrial dysfunction as a common underlying mechanism.Large scale dataNot applicable.Study funding and competing interestsStudies were supported by NIH R21 071873 (J.J./G.H), The Albert McKern Fund for Perinatal Research (J.J.), NIH Intramural Funds (K.U.), and a TUBITAK Research Fellowship Award (B.U.). No conflict(s) of interest or competing interest(s) are noted.

We dissected the importance of human telomerase biogenesis and trafficking pathways for telomere maintenance. Biological stability of human telomerase RNA (hTR) relies on H/ACA proteins, but other eukaryotes use other RNP assembly pathways. To investigate additional rationale for human telomerase assembly as H/ACA RNP, we developed a minimized cellular hTR. Remarkably, with only binding sites for telomerase reverse transcriptase (TERT), minimized hTR assembled biologically active enzyme. TERT overexpression was required for cellular interaction with minimized hTR, indicating that H/ACA RNP assembly enhances endogenous hTR-TERT interaction. Telomere maintenance by minimized telomerase was unaffected by the elimination of the telomerase holoenzyme Cajal body chaperone TCAB1 or the Cajal body scaffold protein Coilin. Surprisingly, wild-type hTR also maintained and elongated telomeres in TCAB1 or Coilin knockout cells, with distinct changes in telomerase action. Overall, we elucidate trafficking requirements for telomerase biogenesis and function and expand mechanisms by which altered telomere maintenance engenders human disease.

Mutations in the human telomerase reverse transcriptase (TERT) promoter are the most frequent non-coding mutations in cancer, but their molecular mechanism in tumorigenesis has not been established. We used genome editing of human pluripotent stem cells with physiological telomerase expression to elucidate the mechanism by which these mutations contribute to human disease. Surprisingly, telomerase-expressing embryonic stem cells engineered to carry any of the three most frequent TERT promoter mutations showed only a modest increase in TERT transcription with no impact on telomerase activity. However, upon differentiation into somatic cells, which normally silence telomerase, cells with TERT promoter mutations failed to silence TERT expression, resulting in increased telomerase activity and aberrantly long telomeres. Thus, TERT promoter mutations are sufficient to overcome the proliferative barrier imposed by telomere shortening without additional tumor-selected mutations. These data establish that TERT promoter mutations can promote immortalization and tumorigenesis of incipient cancer cells.

BackgroundHuman monkeypox is a zoonotic disease endemic to parts of Africa. Similar to other orthopoxviruses, virus and host have considerable interactions through immunomodulation. These interactions likely drive the establishment of a productive infection and disease progression, resulting in the range of disease presentations and case fatality rates observed for members of the Orthopoxvirus genus.ObjectivesMuch of our understanding about the immune response to orthopoxvirus infection comes from either in vitro or in vivo studies performed in small animals or non-human primates. Here, we conducted a detailed assessment of cytokine responses to monkeypox virus using serum from acutely ill humans collected during monkeypox active disease surveillance (2005-2007) in the Democratic Republic of the Congo.Study designNineteen serum samples that were from patients with confirmed monkeypox virus infections were selected for cytokine profiling. Cytokine profiling was performed on the Bio-Rad Bioplex 100 system using a 30-plex human cytokine panel.ResultsCytokine profiling revealed elevated cytokine concentrations in all samples. Overproduction of certain cytokines (interleukin [IL]-2R, IL-10, and granulocyte macrophage-colony stimulating factor were observed in patients with serious disease (defined as >250 lesions based on the World Health Organization scoring system).ConclusionsThe data suggest that cytokine modulation affects monkeypox disease severity in humans.

Mutations in the human telomerase reverse transcriptase (TERT) promoter are the most frequent non-coding mutations in cancer, but their molecular mechanism in tumorigenesis has not been established. We used genome editing of human pluripotent stem cells with physiological telomerase expression to elucidate the mechanism by which these mutations contribute to human disease. Surprisingly, telomerase-expressing embryonic stem cells engineered to carry any of the three most frequent TERT promoter mutations showed only a modest increase in TERT transcription with no impact on telomerase activity. However, upon differentiation into somatic cells, which normally silence telomerase, cells with TERT promoter mutations failed to silence TERT expression, resulting in increased telomerase activity and aberrantly long telomeres. Thus, TERT promoter mutations are sufficient to overcome the proliferative barrier imposed by telomere shortening without additional tumor-selected mutations. These data establish that TERT promoter mutations can promote immortalization and tumorigenesis of incipient cancer cells.

The current lack of an extensive (H2) infrastructure is often cited as a serious barrier to the introduction of H2 as an energy carrier, and to the commercialization of technologies such as H2 vehicles. Because H2 can be made at a wide range of scales (from household to large city) and from a variety of primary sources (fossil, renewable and nuclear), there are many possible pathways for producing and distributing H2 to users. The DOE has identified the need to find viable transition strategies toward widespread use of H2.In this work, we developed and applied simulation tools to evaluate alternative pathways toward widespread use of H2 under various demand scenarios and regional conditions. Geographic information system (GIS) data are utilized as input to analysis, and to visualize results. The use of mathematical programming or other methods to screen the large design space of possible transition pathways for optimum solutions is employed. Using these techniques we carried out a series of regional case studies for H2 infrastructure development. The goal is to understand which factors are most important in finding viable transition strategies under different regional conditions and to develop rules of thumb for future H2 infrastructure development.

Proceedings of the 4th Annual Conference on Carbon Capture and Sequestration DOE/NETL (CCS 2005), Arlington, VA, May 2 - 5, 2005Researchers at the University of California, Davis, in support of the Department of Energy's Fossil Energy programs, are developing engineering/economic/geographic models of fossil hydrogen energy systems with carbon capture and sequestration. In this paper, we present initial results from an ongoing assessment of alternative transition strategies from today's energy system toward widespread use of H2 from fossil fuels as an energy carrier with capture and sequestration of CO2. This study is coordinated with the National Energy Technology Laboratory Carbon Sequestration program and hydrogen modeling efforts at UC Davis and within the USDOE such as H2A. In the future, we plan to utilize data on CO2 sequestration sites from the NATCARB program, and the Regional Sequestration Partnerships. Our model for the design and economics of a fossil H2 energy system with CO2 sequestration considers a number of factors including:* Cost and performance of component technologies making up the system (e.g. fossil energy complex including CO2 capture technology and co-production of hydrogen and electricity, CO2 pipelines and hydrogen storage, distribution and refueling stations). * The location and characteristics of the CO2 sequestration site (storage capacity, permeability, reservoir thickness), * The location, type, size and geographic density of the H2 demand. * Cost, location and availability of primary resources for H2 production such as coal or natural gas. * Location of existing energy infrastructure and rights of way.We have developed techniques for studying regional H2 and CO2 infrastructure development and transition strategies, based on use of Geographic Information System (GIS) data and network optimization techniques. GIS facilitates this analysis by allowing one to use spatially-referenced data, such as existing power plants, coal resources, population distribution, existing rights of way, and CO2 sequestration sites, to calculate the location and magnitude of hydrogen demand and optimize the placement of production facilities and pipeline networks for transporting hydrogen and CO2. We have applied the model to a regional case study of a coal-based hydrogen economy in Ohio with CO2 capture and sequestration. The objective is to model the optimal hydrogen infrastructure design for the entire state under different market penetration scenarios, and find the cost of building the system. In the future, we will extend this work to different regions of the US to conduct a national case study, in coordination with the Department of Energy’s National Energy Technology Laboratory, NATCARB and the Regional Sequestration Partnerships.

Presented at the National Hydrogen Association Annual Hydrogen Conference (NHA 2005), Washington, DC, March 29 - April 1, 2005The use of hydrogen as a light-duty transportation fuel requires the development of a widespread regional hydrogen infrastructure, including production facilities, a distribution network, and refueling stations. In the case of fossil-based hydrogen production with carbon capture and sequestration, additional infrastructure is needed for CO2 disposal. If construction of this infrastructure is to proceed, it is necessary to identify strategies for minimizing the cost while maximizing the utility during the transition. We have developed an infrastructure model that identifies the major parameters that determine infrastructure cost and uses a geographic information system (GIS) to apply these parameters to optimize infrastructure design for a given region.In this paper, the model is applied to a regional case study of a potential coalbased hydrogen economy in Ohio with CO2 capture and sequestration. The objective is to model the optimal hydrogen infrastructure design for the entire state under different market penetration scenarios. GIS facilitates this analysis by allowing one to use existing spatially-referenced data, such as population distribution, coal resources, existing infrastructure, and CO2 sequestration sites, to calculate the location and magnitude of hydrogen demand and optimize the placement of production facilities and pipeline networks for transporting hydrogen and carbon dioxide. Engineering/economic models that identify the costs and technical performance of infrastructure components allow for the calculation of the costs, energy usage and emissions of different hydrogen infrastructure options. Based on these parameters, it is possible to identify the lowest cost infrastructure design for supplying hydrogen to users under multiple scenarios. The goal of this research is to increase understanding of the economics and design issues related to hydrogen infrastructure development under real-world constraints.

Presented at the National Hydrogen Association Annual Hydrogen Conference (NHA 2005), Washington, DC, March 29 - April 1, 2005Understanding the evolution of a hydrogen fuel delivery infrastructure depends on the spatial characteristics of the hydrogen demand. We have developed a GIS-based method to model the magnitude and spatial distribution of hydrogen demand based on exogenously-derived market penetration rates and population data. This approach is applied to a study of the state of Ohio, but can be applied to any region of interest.Our methodology is based upon population density, which is mapped at the census-block level and used to calculate hydrogen demand density based on per-capita vehicle ownership, projections for daily hydrogen use per vehicle, and market penetration levels or profiles. Various methods (including buffers and thresholds) are used to identify and aggregate high demand density areas into demand clusters, since only those areas with sufficient hydrogen demand are assumed to be viable locations for refueling stations. The resulting demand clusters (or demand centers) represent the potential areas in which investment in hydrogen infrastructure may be warranted and can be fed into a supply infrastructure model.Sensitivity analyses were conducted to test the impact on hydrogen demand of different market penetration levels, thresholds, and buffer sizes. (i.e. different scenarios) The results allow one to examine the tradeoff between meeting hydrogen demand and the associated projected infrastructure costs. Although this demand model contains many simplifying assumptions, it provides a means for identifying potentially viable locations for hydrogen infrastructure investment at various scenarios.

Researchers at the Information Center for the Environment (ICE) are using ArcGIS to inventory and monitor environmental risks to California’s north, coastal watersheds. In collaboration with state agencies, ICE has created a comprehensive GIS for selected watersheds in which water quality improvement and endangered species recovery is paramount. ICE has leveraged hyperspectral imagery, extensive field data, and framework datasets to provide resources managers with single source content to make decisions concerning the environmental risk of landslide potential; alterations in aquatic habitat; and land use change, among many. Our results indicate that a geospatial framework for information brokerage is critical for assessing land use decisions at a watershed scale.

The Mattole River Watershed (Figure 1), Humboldt County, California, is listed on the Clean Water Act Section 303(d) list of impaired water bodies, for sediment and temperature. As required by this section and subsequent litigation, the North Coast Regional Water Quality Control Board (NCRWQCB) is under consent decree with the Environmental Protection Agency (EPA) to develop Total Maximum Daily Loads (TMDLs) for these constituents. Sediment and temperature are non-point source pollutants that impair the listed beneficial uses for the river, particularly cold water fisheries for endangered salmonid populations. The Information Center for the Environment (ICE), at the University of California, Davis, has developed analysis procedures for assisting the NCRWQCB in addressing the TMDLs in the Mattole Watershed.To address the sediment TMDL, roads and mass-wasting features were inventoried. The mass-wasting inventory identified all discreet and chronic sediment sources through the use of five sets of stereoscopic aerial photographs spanning five decades. The road inventory focused on contemporary features and was implemented in a similar manner. Current 1:24,000-scale GIS data served as the base for aerial photobased augmentation.To support the temperature TMDL, ICE developed GIS-based inputs for the Stream Segment Temperature Model (SSTEMP), such as location, distance upstream from the mouth, elevation, and average shade for each reach in the stream network. Riparian stream shade was calculated using RipTopo, a GIS-based stream shading model, which incorporated streamside vegetation and topography to calculate the amount of effective shade for a given stream reach.