Inflammatory exposure drives long-lived impairment of hematopoietic stem cell self-renewal activity and accelerated aging.

Hematopoietic stem cells (HSCs) mediate regeneration of the hematopoietic system following injury, such as following infection or inflammation. These challenges impair HSC function, but whether this functional impairment extends beyond the duration of inflammatory exposure is unknown. Unexpectedly, we observed an irreversible depletion of functional HSCs following challenge with inflammation or bacterial infection, with no evidence of any recovery up to 1 year afterward. HSCs from challenged mice demonstrated multiple cellular and molecular features of accelerated aging and developed clinically relevant blood and bone marrow phenotypes not normally observed in aged laboratory mice but commonly seen in elderly humans. In vivo HSC self-renewal divisions were absent or extremely rare during both challenge and recovery periods. The progressive, irreversible attrition of HSC function demonstrates that temporally discrete inflammatory events elicit a cumulative inhibitory effect on HSCs. This work positions early/mid-life inflammation as a mediator of lifelong defects in tissue maintenance and regeneration.

Pregnancy-specific glycoprotein expression in normal gastrointestinal tract and in tumors detected with novel monoclonal antibodies.

Pregnancy-specific glycoproteins (PSGs) are immunoglobulin superfamily members related to the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family and are encoded by 10 genes in the human. They are secreted at high levels by placental syncytiotrophoblast into maternal blood during pregnancy, and are implicated in immunoregulation, thromboregulation, and angiogenesis. To determine whether PSGs are expressed in tumors, we characterized 16 novel monoclonal antibodies to human PSG1 and used 2 that do not cross-react with CEACAMs to study PSG expression in tumors and in the gastrointestinal (GI) tract using tissue arrays and immunohistochemistry. Staining was frequently observed in primary squamous cell carcinomas and colonic adenocarcinomas and was correlated with the degree of tumor differentiation, being largely absent from metastatic samples. Staining was also observed in normal oesophageal and colonic epithelium. PSG expression in the human and mouse GI tract was confirmed using quantitative RT-PCR. However, mRNA expression was several orders of magnitude lower in the GI tract compared to placenta. Our results identify a non-placental site of PSG expression in the gut and associated tumors, with implications for determining whether PSGs have a role in tumor progression, and utility as tumor biomarkers.

Psg22 expression in mouse trophoblast giant cells is associated with gene inversion and co-expression of antisense long non-coding RNAs.

Pregnancy-specific glycoproteins (PSGs) are secreted carcinoembryonic antigen (CEA)-related cell adhesion molecules-related members of the immunoglobulin superfamily and are encoded by multigene families in species with haemochorial placentation. PSGs may be the most abundant trophoblast-derived proteins in human maternal blood in late pregnancy and there is evidence that dysregulation of PSG expression is associated with gestational pathology. PSGs are produced by syncytiotrophoblast in the human placenta and by trophoblast giant cells (TGCs) and spongiotrophoblast in rodents, and are implicated in immune regulation, angiogenesis and regulation of platelet function. PSGs are encoded by 17 genes in the mouse and ten genes in the human. While functions appear to be conserved, the typical protein domain organisation differs between species. We analysed the evolution of the mouse Psg genomic locus structure and report inversion of the Psg22 gene within the locus. Psg22 is the most abundant Psg transcript detected in the first half of mouse pregnancy and we identified antisense long non-coding RNA (lncRNA) transcripts adjacent to Psg22 associated with an active local chromatin conformation. This suggests that an epigenetic regulatory mechanism may underpin high Psg22 expression relative to the other Psg gene family members in TGCs.

Nutrition-education program improves preschoolers' at-home diet: a group randomized trial.

OBJECTIVE: This study evaluated whether a nutrition-education program in child-care centers improved children's at-home daily consumption of fruits and vegetables, at-home use of low-fat/fat-free milk, and other at-home dietary behaviors. MATERIALS AND METHODS: Twenty-four child-care centers serving low-income families were matched by region, type, and size, and then randomly assigned to either an intervention or control condition. In the 12 intervention centers, registered dietitian nutritionists provided nutrition education to children and parents separately during a 6- to 10-week period. They also held two training sessions for center staff, to educate them on healthy eating and physical activity policies at the centers, and distributed weekly parent newsletters that included activities and recipes. Parents (n=1,143) completed a mail or telephone survey at baseline and follow-up to report information on their child's fruit, vegetable, and milk consumption and other dietary behaviors at home. This study used general and generalized linear mixed models to evaluate program impacts, while accounting for the clustering of children within centers. This study included child age, child sex, household size, respondent race/ethnicity, respondent age, and respondent sex as covariates. RESULTS: The program had a substantial impact on children's at-home daily consumption of vegetables and use of low-fat/fat-free milk. This study also found a significant increase in the frequency of child-initiated vegetable snacking, which might have contributed to the significant increase in vegetable consumption. The program did not have a significant impact on fruit consumption or parental offerings of fruits and vegetables, child-initiated fruit snacking, or child fruit consumption. CONCLUSIONS: This intervention in child-care settings that emphasized children, parents, and teachers significantly increased at-home vegetable and low-fat/fat-free milk consumption among low-income preschoolers.

Effectiveness of educational interventions to improve food safety practices among older adults.

The purpose of the study was to develop and evaluate the effectiveness of using Web-based and print materials for improving food safety practices to reduce the risk of foodborne illness among older adults. The study used a randomized controlled design, with participants assigned to an intervention group or control group. Although we observed small improvements in both groups, the difference in the changes between the two groups was nonsignificant, suggesting the educational materials did not impact participant behavior. We did, however, observe a trend improvement in one measure: the recommendation to avoid eating cold (not reheated) deli meats. The lack of program impact may be attributable to limitations of the evaluation (e.g., measurement effects) or the intervention (e.g., lack of personal contact). Based on the survey findings, improvements in older adults' food safety practices regarding reheating deli meats to steaming hot and cooking eggs until the yolks and whites are firm are needed. The current study and previous research suggest that current cohorts of older adults may be more receptive to print materials than Web-based materials. To improve retention and adoption of recommended food safety practices among older adults, future educational interventions should focus on a limited number of practices and combine print materials with personal contact.

Mouse pregnancy-specific glycoproteins: tissue-specific expression and evidence of association with maternal vasculature.

The pregnancy-specific glycoproteins (Psg) are secreted hormones encoded by multiple genes in rodents and primates, and are thought to act as immune modulators. The only Psg receptor identified is CD9, through which Psg17 induces cytokine production from macrophages cultured in vitro. We examined temporal and spatial aspects of Psg and CD9 expression during mouse pregnancy to determine whether their expression patterns support a role in immune modulation. Using in situ hybridisation, immunohistochemistry and RT-PCR we found Psg expression in trophoblast giant cells and in the spongiotrophoblast. Psg22 is the predominant Psg family member expressed in giant cells. Detectable Psg is associated predominantly with endothelial cells lining vascular channels in the decidua, rather than with maternal immune cell markers. CD9 expression exhibited partial overlap with Psg, but without exclusive co-localisation. CD9 was observed in decidual cells surrounding early implantation sites, and in the endometrium. However, embryo transfer of wild-type embryos to CD9-deficient females indicates that maternal CD9 is not essential for successful pregnancy.

Structure and evolution of the mouse pregnancy-specific glycoprotein (Psg) gene locus.

BACKGROUND: The pregnancy-specific glycoprotein (Psg) genes encode proteins of unknown function, and are members of the carcinoembryonic antigen (Cea) gene family, which is a member of the immunoglobulin gene (Ig) superfamily. In rodents and primates, but not in artiodactyls (even-toed ungulates / hoofed mammals), there have been independent expansions of the Psg gene family, with all members expressed exclusively in placental trophoblast cells. For the mouse Psg genes, we sought to determine the genomic organisation of the locus, the expression profiles of the various family members, and the evolution of exon structure, to attempt to reconstruct the evolutionary history of this locus, and to determine whether expansion of the gene family has been driven by selection for increased gene dosage, or diversification of function. RESULTS: We collated the mouse Psg gene sequences currently in the public genome and expressed-sequence tag (EST) databases and used systematic BLAST searches to generate complete sequences for all known mouse Psg genes. We identified a novel family member, Psg31, which is similar to Psg30 but, uniquely amongst mouse Psg genes, has a duplicated N1 domain. We also identified a novel splice variant of Psg16 (bCEA). We show that Psg24 and Psg30 / Psg31 have independently undergone expansion of N-domain number. By mapping BAC, YAC and cosmid clones we described two clusters of Psg genes, which we linked and oriented using fluorescent in situ hybridisation (FISH). Comparison of our Psg locus map with the public mouse genome database indicates good agreement in overall structure and further elucidates gene order. Expression levels of Psg genes in placentas of different developmental stages revealed dramatic differences in the developmental expression profile of individual family members. CONCLUSION: We have combined existing information, and provide new information concerning the evolution of mouse Psg exon organization, the mouse Psg genomic locus structure, and the expression patterns of individual Psg genes. This information will facilitate functional studies of this complex gene family.