Pantothenic acid status of free living adolescent and young adults

Manipulation of pantothenate kinase in Anopheles stephensi suppresses pantothenate levels with minimal impacts on mosquito fitness

Pantothenate (Pan) is an essential nutrient required by both the mosquito vector and malaria parasite. We previously demonstrated that increasing pantothenate kinase (PanK) activity and co-enzyme A (CoA) biosynthesis led to significantly decreased parasite infection prevalence and intensity in the malaria mosquito Anopheles stephensi. In this study, we demonstrate that Pan stores in A. stephensi are a limited resource and that manipulation of PanK levels or activity, via small molecule modulators of PanK or transgenic mosquitoes, leads to the conversion of Pan to CoA and an overall reduction in Pan levels with minimal to no effects on mosquito fitness. Transgenic A. stephensi lines with repressed insulin signaling due to PTEN overexpression or repressed c-Jun N-terminal kinase (JNK) signaling due to MAPK phosphatase 4 (MKP4) overexpression exhibited enhanced PanK levels and significant reductions in Pan relative to non-transgenic controls, with the PTEN line also exhibiting significantly increased CoA levels. Provisioning of the PTEN line with the small molecule PanK modulator PZ-2891 increased CoA levels while provisioning Compound 7 decreased CoA levels, affirming chemical manipulation of mosquito PanK. We assessed effects of these small molecules on A. stephensi lifespan, reproduction and metabolism under optimized laboratory conditions. PZ-2891 and Compound 7 had no impact on A. stephensi survival when delivered via bloodmeal throughout mosquito lifespan. Further, PZ-2891 provisioning had no impact on egg production over the first two reproductive cycles. Finally, PanK manipulation with small molecules was associated with minimal impacts on nutritional stores in A. stephensi mosquitoes under optimized rearing conditions. Together with our previous data demonstrating that PanK activation was associated with significantly increased A. stephensi resistance to Plasmodium falciparum infection, the studies herein demonstrate a lack of fitness costs of mosquito Pan depletion as a basis for a feasible, novel strategy to control parasite infection of anopheline mosquitoes.

Plasma B Vitamers: Population Epidemiology and Parent-Child Concordance in Children and Adults

Scope: B vitamers are co-enzymes involved in key physiological processes including energy production, one-carbon, and macronutrient metabolism. Studies profiling B vitamers simultaneously in parent–child dyads are scarce. Profiling B vitamers in parent–child dyads enables an insightful determination of gene–environment contributions to their circulating concentrations. We aimed to characterise: (a) parent–child dyad concordance, (b) generation (children versus adults), (c) age (within the adult subgroup (age range 28–71 years)) and (d) sex differences in plasma B vitamer concentrations in the CheckPoint study of Australian children. Methods and Results: 1166 children (11 ± 0.5 years, 51% female) and 1324 parents (44 ± 5.1 years, 87% female) took part in a biomedical assessment of a population-derived longitudinal cohort study: The Growing Up in Australia’s Child Health CheckPoint. B vitamer levels were quantified by UHPLC/MS-MS. B vitamer levels were weakly concordant between parent–child pairs (10–31% of variability explained). All B vitamer concentrations exhibited generation-specificity, except for flavin mononucleotide (FMN). The levels of thiamine, pantothenic acid, and 4-pyridoxic acid were higher in male children, and those of pantothenic acid were higher in male adults compared to their female counterparts. Conclusion: Family, age, and sex contribute to variations in the concentrations of plasma B vitamers in Australian children and adults.

Roles of vitamins in stem cells

Stem cells can differentiate to diverse cell types in our body, and they hold great promises in both basic research and clinical therapies. For specific stem cell types, distinctive nutritional and signaling components are required to maintain the proliferation capacity and differentiation potential in cell culture. Various vitamins play essential roles in stem cell culture to modulate cell survival, proliferation and differentiation. Besides their common nutritional functions, specific vitamins are recently shown to modulate signal transduction and epigenetics. In this article, we will first review classical vitamin functions in both somatic and stem cell cultures. We will then focus on how stem cells could be modulated by vitamins beyond their nutritional roles. We believe that a better understanding of vitamin functions will significantly benefit stem cell research, and help realize their potentials in regenerative medicine.

[Pantothenic acid levels in blood of athletes at rest and after aerobic exercise]

Ninety-six high-performance athletes of various disciplines were available for this investigation. All athletes had many years of training and competition experience. The pantothenic acid contents in the blood were determined by means of microbiological measurements. In addition to the pantothenic acid level at rest, measurements were made resp. physical exertion in 14 marathon runners and nine body builders. Blood was collected for determination of pantothenic acid before (a), after (b) and 2 h after exercise. Compared to the reference values for untrained persons (1.34 +/- 0.13 nmol/mL), the marathon runners with 0.76 (0.31-0.94) nmol/mL and soccer players with 1.19 (0.37-2.64) nmol/mL were below the reference values. According to relative frequencies, more than 30% of all athletes were below the lower limit (< 1.20 nmol/mL). The values in body builders/racing cyclists differed significantly from those in marathon racers (p < 0.001), which is presumably due to unallowed supplementation. During exercise, there was a significant increase in the pantothenic acid level in marathon runners (p < 0.01).

Pantothenic acid in health and disease

In summary, the vitamin pantothenic acid is an integral part of the acylation carriers, CoA and acyl carrier protein (ACP). The vitamin is readily available from diverse dietary sources, a fact which is underscored by the difficulty encountered in attempting to induce pantothenate deficiency. Although pantothenic acid deficiency has not been linked with any particular disease, deficiency of the vitamin results in generalized malaise clinically. In view of the fact that pantothenate is required for the synthesis of CoA, it is surprising that tissue CoA levels are not altered in pantothenate deficiency. This suggests that the cell is equipped to conserve its pantothenate content, possibly by a recycling mechanism for utilizing pantothenate obtained from degradation of pantothenate-containing molecules. Although the steps involved in the conversion of pantothenate to CoA have been characterized, much remains to be done to understand the regulation of CoA synthesis. In particular, in view of what is known about the in vitro regulation of pantothenate kinase, it is surprising that the enzyme is active in vivo, since factors that are known to inhibit the enzyme are present in excess of the concentrations known to inhibit the enzyme. Thus, other physiological regulatory factors (which are largely unknown) must counteract the effects of these inhibitors, since the pantothenate-to-CoA conversion is operative in vivo. Another step in the biosynthetic pathway that may be rate limiting is the conversion of 4'-phosphopantetheine (4'-PP) to dephospho-CoA, a step catalyzed by 4'-phosphopantetheine adenylyl-transferase. In mammalian systems, this step may occur in the mitochondria or in the cytosol. The teleological significance of these two pathways remains to be established, particularly since mitochondria are capable of transporting CoA from the cytosol. Altered homeostasis of CoA has been observed in diverse disease states including starvation, diabetes, alcoholism, Reye syndrome (RS), medium-chain acyl CoA dehydrogenase deficiency, vitamin B12 deficiency, and certain tumors. Hormones, such as glucocorticoids, insulin, and glucagon, as well as drugs, such as clofibrate, also affect tissue CoA levels. It is not known whether the abnormal metabolism observed in these conditions is the result of altered CoA metabolism or whether CoA levels change in response to hormonal or nonhormonal perturbations brought about in these conditions. In other words, a cause-effect relation remains to be elucidated. It is also not known whether the altered CoA metabolism (be it cause or result of abnormal metabolism) can be implicated in the manifestations of a disease. Besides CoA, pantothenic acid is also an integral part of the ACP molecule.(ABSTRACT TRUNCATED AT 400 WORDS)

The nutrient intakes of pregnant and lactating mothers of good socio-economic status in Cambridge, UK: some implications for recommended daily allowances of minor nutrients

1. Forty-two mothers from social classes I, II and III non-manual and twenty-one from social classes III manual M), IV and V were studied longitudinally. The mean daily nutrient intakes in months 4-9 of pregnancy, months 2-4 of lactation and 3 and 6 months post-lactation are presented and are compared with the UK and the US recommended daily allowances (RDA). 2. The quality of the diets (nutrients per 4184 kJ (1000 kcal] was found to be better than that of other adult female populations studied in the UK, except for a group of dietitians. 3. The mean daily intakes of nutrients for which there are UK RDA were almost all greater than 100% of the RDA. The exceptions were iron, which in the manual group (social classes IIIM, IV and V) was 85% of the RDA in pregnancy and 75% post-lactation, and vitamin D. 4. Among the nutrients for which there are US, but not UK RDA, only phosphorus and vitamin B12 intakes were greater than 100% of the RDA in both groups at all stages of the study. Intakes of other nutrients were below the RDA: pantothenate 70-91, vitamin B6, zinc, vitamin E and copper 40-72, folate 21-44, and biotin less than 20% of the RDA. 5. The bases of the RDA for adult women were examined; for most nutrients the information is limited. It was concluded that the RDA for magnesium, vitamin E and pantothenate are probably higher than necessary and that deficiency is unlikely; that zinc, copper, vitamin B6 and folate are probably 'marginal' nutrients for 'at risk' groups; and that information on biotin is insufficient even roughly to assess the dietary requirement.