Perspective: Human Milk Composition and Related Data for National Health and Nutrition Monitoring and Related Research.

National health and nutrition monitoring is an important federal effort in the United States and Canada, and the basis for many of their nutrition and health policies. Understanding of child exposures through human milk (HM) remains out of reach due to lack of current and representative data on HM's composition and intake volume. This article provides an overview of the current national health and nutrition monitoring activities for HM-fed children, HM composition (HMC) and volume data used for exposure assessment, categories of potential measures in HM, and associated variability factors. In this Perspective, we advocate for a framework for collection and reporting of HMC data for national health and nutrition monitoring and programmatic needs, including a shared vision for a publicly available Human Milk Composition Data Repository (HMCD-R) to include essential metadata associated with HMC. HMCD-R can provide a central, integrated platform for researchers and public health officials for compiling, evaluating, and sharing HMC data. The compiled compositional and metadata in HMCD-R would provide pertinent measures of central tendency and variability and allow use of modeling techniques to approximate compositional profiles for subgroups, providing more accurate exposure assessments for purposes of monitoring and surveillance. HMC and related metadata could facilitate understanding the complexity and variability of HM composition, provide crucial data for assessment of infant and maternal nutritional needs, and inform public health policies, food and nutrition programs, and clinical practice guidelines.

Understanding childhood obesity in the US: the NIH environmental influences on child health outcomes (ECHO) program.

BACKGROUND: Few resources exist for prospective, longitudinal analysis of the relationships between early life environment and later obesity in large diverse samples of children in the United States (US). In 2016, the National Institutes of Health launched the Environmental influences on Child Health Outcomes (ECHO) program to investigate influences of environmental exposures on child health and development. We describe demographics and overweight and obesity prevalence in ECHO, and ECHO's potential as a resource for understanding how early life environmental factors affect obesity risk. METHODS: In this cross-sectional study of 70 extant US and Puerto Rico cohorts, 2003-2017, we examined age, race/ethnicity, and sex in children with body mass index (BMI) data, including 28,507 full-term post-birth to <2 years and 38,332 aged 2-18 years. Main outcomes included high BMI for age <2 years, and at 2-18 years overweight (BMI 85th to <95th percentile), obesity (BMI ≥ 95th percentile), and severe obesity (BMI ≥ 120% of 95th percentile). RESULTS: The study population had diverse race/ethnicity and maternal demographics. Each outcome was more common with increasing age and varied with race/ethnicity. High BMI prevalence (95% CI) was 4.7% (3.5, 6.0) <1 year, and 10.6% (7.4, 13.7) for 1 to <2 years; overweight prevalence increased from 13.9% (12.4, 15.9) at 2-3 years to 19.9% (11.7, 28.2) at 12 to <18 years. ECHO has the statistical power to detect relative risks for 'high' BMI ranging from 1.2 to 2.2 for a wide range of exposure prevalences (1-50%) within each age group. CONCLUSIONS: ECHO is a powerful resource for understanding influences of chemical, biological, social, natural, and built environments on onset and trajectories of obesity in US children. The large sample size of ECHO cohorts adopting a standardized protocol for new data collection of varied exposures along with longitudinal assessments will allow refined analyses to identify drivers of childhood obesity.

Advances, challenges, and opportunities in extracellular RNA biology: insights from the NIH exRNA Strategic Workshop.

Extracellular RNA (exRNA) has emerged as an important transducer of intercellular communication. Advancing exRNA research promises to revolutionize biology and transform clinical practice. Recent efforts have led to cutting-edge research and expanded knowledge of this new paradigm in cell-to-cell crosstalk; however, gaps in our understanding of EV heterogeneity and exRNA diversity pose significant challenges for continued development of exRNA diagnostics and therapeutics. To unravel this complexity, the NIH convened expert teams to discuss the current state of the science, define the significant bottlenecks, and brainstorm potential solutions across the entire exRNA research field. The NIH Strategic Workshop on Extracellular RNA Transport helped identify mechanistic and clinical research opportunities for exRNA biology and provided recommendations on high priority areas of research that will advance the exRNA field.

Definition of a high-affinity Gag recognition structure mediating packaging of a retroviral RNA genome.

All retroviral genomic RNAs contain a cis-acting packaging signal by which dimeric genomes are selectively packaged into nascent virions. However, it is not understood how Gag (the viral structural protein) interacts with these signals to package the genome with high selectivity. We probed the structure of murine leukemia virus RNA inside virus particles using SHAPE, a high-throughput RNA structure analysis technology. These experiments showed that NC (the nucleic acid binding domain derived from Gag) binds within the virus to the sequence UCUG-UR-UCUG. Recombinant Gag and NC proteins bound to this same RNA sequence in dimeric RNA in vitro; in all cases, interactions were strongest with the first U and final G in each UCUG element. The RNA structural context is critical: High-affinity binding requires base-paired regions flanking this motif, and two UCUG-UR-UCUG motifs are specifically exposed in the viral RNA dimer. Mutating the guanosine residues in these two motifs--only four nucleotides per genomic RNA--reduced packaging 100-fold, comparable to the level of nonspecific packaging. These results thus explain the selective packaging of dimeric RNA. This paradigm has implications for RNA recognition in general, illustrating how local context and RNA structure can create information-rich recognition signals from simple single-stranded sequence elements in large RNAs.

Translation initiation factor a/eIF2(-gamma) counteracts 5' to 3' mRNA decay in the archaeon Sulfolobus solfataricus.

The trimeric translation initiation factor a/eIF2 of the crenarchaeon Sulfolobus solfataricus is pivotal for binding of initiator tRNA to the ribosome. Here, we present in vitro and in vivo evidence that the a/eIF2 gamma-subunit exhibits an additional function with resemblance to the eukaryotic cap-complex. It binds to the 5'-triphosphate end of mRNA and protects the 5' part from degradation. This unprecedented capacity of the archaeal initiation factor further indicates that 5' --> 3' directional mRNA decay is a pathway common to all domains of life.

Translational activation by the noncoding RNA DsrA involves alternative RNase III processing in the rpoS 5'-leader.

The intricate regulation of the Escherichia coli rpoS gene, which encodes the stationary phase sigma-factor sigmaS, includes translational activation by the noncoding RNA DsrA. We observed that the stability of rpoS mRNA, and concomitantly the concentration of sigmaS, were significantly higher in an RNase III-deficient mutant. As no decay intermediates corresponding to the in vitro mapped RNase III cleavage site in the rpoS leader could be detected in vivo, the initial RNase III cleavage appears to be decisive for the observed rapid inactivation of rpoS mRNA. In contrast, we show that base-pairing of DsrA with the rpoS leader creates an alternative RNase III cleavage site within the rpoS/DsrA duplex. This study provides new insights into regulation by small regulatory RNAs in that the molecular function of DsrA not only facilitates ribosome loading on rpoS mRNA, but additionally involves an alternative processing of the target.

RNA processing in Aquifex aeolicus involves RNase E/G and an RNase P-like activity.

To assess the evolutionary conservation of RNA processing pathways in Aquifex aeolicus, we characterized the products of rRNA and tRNA processing that originated from polycistronic transcripts encoded by the A. aeolicus tufA2 and rRNA operons. We found that, similar to its Escherichia coli counterpart, A. aeolicus RNase E/G is involved in rRNA processing and maturation of tRNAs, thus indicating that RNA processing pathways in E. coli and A. aeolicus include common steps and some of them are dependent on RNase E/G. Moreover, although recent biochemical approaches failed to detect an RNase P-like activity in A. aeolicus, our results suggest that such an activity exists in this organism. Accordingly, we show that this activity requires the presence of an RNA component and magnesium ions in order to be detectable in vitro and therefore shares common properties with bacterial RNase P.

Functional analysis of the small subunit of the putative homoaconitase from Pyrococcus horikoshii in the Thermus lysine biosynthetic pathway.

An in vivo disruption-integration vector system for Thermus thermophilus was developed and used for the functional analysis of an evolutionary-related archaeal protein for lysine biosynthesis. In contrast to fungal one, the putative homoaconitase of T. thermophilus consists of two subunits and catalyzes the second and third steps of lysine biosynthesis. ORFs from hyperthermophilic archaeon Pyrococcus horikoshii, PH1726 and PH1724, share a high degree of amino acid identity with the T. thermophilus subunits LysT and LysU, respectively. In the present report, gene encoding the putative small subunit of archaeal homoaconitase, PH1724, was integrated into the lysU locus of T. thermophilus. The archaeal gene was expressed under the control of PslpA promoter and functional analyses were performed. Transformants were able to grow on minimal medium without lysine when PH1724 ORF was integrated, whereas the lysU disruption led to lysine auxotrophy. Chromosomal integration was verified by PCR analysis, and homoaconitase assay showed that the archaeal gene product functions as a small subunit of homoaconitase, possibly by forming a heterodimer with the LysT subunit of T. thermophilus. These results strongly suggest the functional relation of P. horikoshii PH1724 with LysU in the Thermus lysine biosynthetic pathway, together with functional assignment of LysU as small subunit of homoaconitase. In addition, the provided results indicate that archaeal genes products from hyperthermophiles can be studied in a thermophilic eubacterium such as T. thermophilus.

Expression, polymorphism analysis, reticulocyte binding and serological reactivity of two Plasmodium vivax MSP-1 protein recombinant fragments.

Among the four parasite species causing malaria in humans, Plasmodium vivax prevails on both the Asian and the American continents. Several antigens from this parasite's erythrocytic stages have been characterised and some of them are considered to be good vaccine candidates. The P. vivax merozoite surface protein-1 (PvMSP-1) is a 200 kDa antigen, thought to mediate the initial contact between the merozoite and the erythrocyte. An effective blockage of this interaction could be important in anti-malarial vaccine design. This study analyses the genetic polymorphism, binding to both reticulocytes and erythrocytes, antigenicity and immunogenicity of two recombinant proteins belonging to the 33 kDa PvMSP-1 proteolytic fragment. Both regions showed very low genetic variation, bound reticulocytes with higher affinity than erythrocytes, were recognised by naturally P. vivax-infected patient sera and were immunogenic when used to immunise rabbits, making them good vaccine candidates against P. vivax, to be further preclinically tested in the Aotus monkey model.