Lysophosphatidic acid (LPA) acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs) under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG) human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia.
Lysophosphatidic acid (LPA) acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs) under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG) human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia.
The RNA polymerase II transcription cycle is often divided into three major stages: initiation, elongation, and termination. Research over the last decade has blurred these divisions and emphasized the tightly regulated transitions that occur as RNA polymerase II synthesizes a transcript from start to finish. Transcription termination, the process that marks the end of transcription elongation, is regulated by proteins that interact with the polymerase, nascent transcript, and/or chromatin template. The failure to terminate transcription can cause accumulation of aberrant transcripts and interfere with transcription at downstream genes. Here, we review the mechanism, regulation, and physiological impact of a termination pathway that targets small noncoding transcripts produced by RNA polymerase II. We emphasize the Nrd1-Nab3-Sen1 pathway in yeast, in which the process has been extensively studied. The importance of understanding small RNA termination pathways is underscored by the need to control noncoding transcription in eukaryotic genomes.
Background: The Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project is a multiagency and multicountry collaboration that was formed to improve micronutrient assessment and to better characterize anemia.Objectives: The aims of the project were to 1) identify factors associated with inflammation, 2) assess the relations between inflammation, malaria infection, and biomarkers of iron and vitamin A status and compare adjustment approaches, and 3) assess risk factors for anemia in preschool children (PSC) and women of reproductive age (WRA).Design: The BRINDA database inclusion criteria included surveys that 1) were conducted after 2004, 2) had target groups of PSC, WRA, or both, and 3) used a similar laboratory methodology for the measurement of ≥1 biomarker of iron [ferritin or soluble transferrin receptor or vitamin A status (retinol-binding protein or retinol)] and ≥1 biomarker of inflammation (α-1-acid glycoprotein or C-reactive protein). Individual data sets were standardized and merged into a BRINDA database comprising 16 nationally and regionally representative surveys from 14 countries. Collectively, the database covered all 6 WHO geographic regions and contained ∼30,000 PSC and 27,000 WRA. Data were analyzed individually and combined with the use of a meta-analysis.Results: The methods that were used to standardize the BRINDA database and the analytic approaches used to address the project's research questions are presented in this article. Three approaches to adjust micronutrient biomarker concentrations in the presence of inflammation and malaria infection are presented, along with an anemia conceptual framework that guided the BRINDA project's anemia analyses.Conclusions: The BRINDA project refines approaches to interpret iron and vitamin A biomarker values in settings of inflammation and malaria infection and suggests the use of a new regression approach as well as proposes an anemia framework to which real-world data can be applied. Findings can inform guidelines and strategies to prevent and control micronutrient deficiencies and anemia globally.
Vitamin A deficiency (VAD) is an important contributor to child morbidity and mortality. The prevalence of VAD, measured by retinol-binding protein (RBP) or retinol, is overestimated in populations with a high prevalence of inflammation. We aimed to quantify and adjust for the effect of inflammation on VAD prevalence in a nationally representative survey of Liberian children 6 to 35months of age. We compared five approaches to adjust RBP for inflammation and estimate VAD prevalence (defined as RBP<0.7μmol/L): (1) ignoring inflammation; (2) excluding individuals with inflammation (C-reactive protein (CRP) >5mg/L or alpha1-acid glycoprotein (AGP) >1g/)L; (3) multiplying each individual's RBP by an internal correction factor; (4) by an external correction factor; and (5) using regression (corrected RBP=exp(InRBP - β1(lnCRPobs-lnCRPref) - β2(lnAGPobs-lnAGPref)). Corrected RBP was based on a regression model where reference lnCRP and lnAGP were set to the maximum of the lowest decile. The unadjusted prevalence of VAD was 24.7%. Children with elevated CRP and/or AGP had significantly lower RBP concentrations than their apparently healthy peers (geometric mean RBP 0.79μmol/L (95% CI: 0.76, 0.82) vs. 0.95μmol/L (95% CI: 0.92, 0.97), P<0.001). Using approaches 2-5 resulted in a prevalence of VAD of 11.6%, 14.3%, 13.5% and 7.3%, respectively. Depending on the approach, the VAD prevalence is reduced 10-17 percentage points when inflammation is taken into account. Further quantification of the influence of inflammation on biomarkers of vitamin A status from other national surveys is needed to compare and recommend the preferred adjustment approach across populations.
by
Rebecca D. Merrill;
Rachel M. Burke;
Christine A. Northrop-Clewes;
Pura Rayco-Solon;
Rafael Flores-Ayala;
Sorrel M.L. Namaste;
Mary K. Serdula;
Parminder S Suchdev
Background: In many settings, populations experience recurrent exposure to inflammatory agents that catalyze fluctuations in the concentrations of acute-phase proteins and certain micronutrient biomarkers such as C-reactive protein (CRP), α-1-acid glycoprotein (AGP), ferritin, and retinol. Few data are available on the prevalence and predictors of inflammation in diverse settings.Objective: We aimed to assess the relation between inflammation (CRP concentration > 5 mg/L or AGP concentration > 1 g/L) and covariates, such as demographics, reported illness, and anthropometric status, in preschool children (PSC) (age range: 6-59 mo) and women of reproductive age (WRA) (age range: 15-49 y).Design: Cross-sectional data from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project from 29,765 PSC in 16 surveys and 25,731 WRA in 10 surveys were used to model bivariable and multivariable relations.Results: The inflammation prevalence was 6.0-40.2% in PSC and 7.9-29.5% in WRA (elevated CRP) and 21.2-64.3% in PSC and 7.1-26.7% in WRA (elevated AGP). In PSC, inflammation was consistently positively associated with recent fever and malaria but not with other recent illnesses. In multivariable models that were adjusted for age, sex, urban or rural residence, and socioeconomic status, elevated AGP was positively associated with stunting (height-for-age z score < -2) in 7 of 10 surveys. In WRA, elevated CRP was positively associated with obesity [body mass index (in kg/m2) ≥30] in 7 of 9 surveys. Other covariates showed inconsistent patterns of association with inflammation. In a pooled analysis of surveys that measured malaria, stunting was associated with elevated AGP but not CRP in PSC, and obesity was associated with both elevated CRP and AGP in WRA.Conclusions: Recent morbidity and abnormal anthropometric status are consistently associated with inflammation across a range of environments, whereas more commonly collected demographic covariates were not. Because of the challenge of defining a general demographic population or environmental profile that is more likely to experience inflammation, inflammatory markers should be measured in surveys to account for their effects.
Disordered cancer metabolism was described almost a century ago as an abnormal adaptation of cancer cells to glucose utilization especially in hypoxic conditions; the so-called Warburg effect. Greater research interest in this area in the past two decades has led to the recognition of the critical coupling of specific malignant phenotypes such as increased proliferation and resistance to programmed cell death (apoptosis) with altered metabolic handling of key molecules that are essential for normal cellular metabolism. The altered glucose metabolism frequently encountered in cancer cells has already been exploited for cancer diagnosis and treatment. The role of other glycolytic pathway intermediates and alternative pathways for energy generation and macromolecular synthesis in cancer cells has only become recognized more recently. Especially, the important role of altered glutamine metabolism in the malignant behavior of cancer cells and the potential exploitation of this cellular adaptation for therapeutic targeting has now emerged as an important area of cancer research. Expectedly, attempts to exploit this understanding for diagnostic and therapeutic ends are running apace with the elucidation of the complex metabolic alterations that accompany neoplastic transformation. Because lung cancer is a leading cause of cancer death with limited curative therapy options, careful elucidation of the mechanism and consequences of disordered cancer metabolism in lung cancer is warranted. This review provides a concise, systematic overview of the current understanding of the role of altered glutamine metabolism in cancer, and how these findings intersect with current and future approaches to lung cancer management.
The objective of this study was to examine the association between nutritional status and dietary intake in community-dwelling older adults with heart failure (HF). A cross-sectional analysis of NHANES III data was conducted. The analytic sample was comprised of n = 445 individuals aged 50+ years with congestive HF (54.4% male, 22.9% non-Hispanic Black, 43.8% low-income). Nutritional status was measured using the Prognostic Nutritional Index (PNI). Participants were classified by PNI quintiles with lower PNI scores indicating lower nutritional status. Participants in quintile 5 showed significantly greater intakes of energy, protein, vegetables, magnesium, zinc, copper, potassium, red meat, saturated fat, and sodium. In multivariate analyses, increased intake of red meat (β = 0.253, p = 0.040) and vegetables (β = 0.255, p = 0.038) was associated with significantly better nutritional status. In the absence of comprehensive nutritional guidance for HF patients, it appears that small increases in energy, protein (red meat), and vegetable consumption are associated with improved nutritional status.
by
Anne Kopp;
Alexandra Huebner;
Florian Zirkel;
Daniel Hobelsberger;
Alejandro Estrada;
Ingo Jordan;
Thomas R. Gillespie;
Christian Drosten;
Sandra Junglen
The Peribunyaviridae family contains the genera Orthobunyavirus, Herbevirus, Pacuvirus, and Shangavirus. Orthobunyaviruses and pacuviruses are mainly transmitted by blood-feeding insects and infect a variety of vertebrates whereas herbeviruses and shangaviruses have a host range restricted to insects. Here, we tested mosquitoes from a tropical rainforest in Mexico for infections with peribunyaviruses. We identified and characterized two previously unknown viruses, designated Baakal virus (BKAV) and Lakamha virus (LAKV). Sequencing and de novo assembly of the entire BKAV and LAKV genomes revealed that BKAV is an orthobunyavirus and LAKV is likely to belong to a new genus. LAKV was almost equidistant to the established peribunyavirus genera and branched as a deep rooting solitary lineage basal to herbeviruses. Virus isolation attempts of LAKV failed. BKAV is most closely related to the bird-associated orthobunyaviruses Koongol virus and Gamboa virus. BKAV was successfully isolated in mosquito cells but did not replicate in common mammalian cells from various species and organs. Also cells derived from chicken were not susceptible. Interestingly, BKAV can infect cells derived from a duck species that is endemic in the region where the BKAV-positive mosquito was collected. These results suggest a narrow host specificity and maintenance in a mosquito-bird transmission cycle.