Maternal Imbalance of Vitamin B12 and Folic Acid Alters the Expression of Fetal Growth-related Imprinted Genes in Placenta (P24-033-19)

Abstract

ObjectivesThe present study aimed to elucidate the trans-generational influence of low dietary vitamin B12 with different levels of folic acid in mice model on fetal growth and expression of fetal growth-related imprinted genes in placenta. MethodsC57BL/6 mice (four-week-old) were assigned into four dietary groups: (test groups)-BDFN*, BDFO*, BDFD* & (control group)-BNFN* and were fed diet accordingly for two generations (F0 and F1). Mating was carried out and on 20th day of gestation pregnant mice were sacrificed for fetus collection in both F1 & F2 generation. In F1 generation after weaning period a sub-group of F1 offsprings born to F0 dams were rehabilitated to control diet in each test group (transient) while others were continued on same diet as their mothers (sustained) and further mating was carried out. Vitamins and homocysteine levels in serum were evaluated. Expression of genes, global DNA methylation in placenta and growth-parameters of fetuses were studied. ResultsOur data suggests that deficiency of both vitamins significantly reduced the total body weight and circulating levels of these vitamins in serum. Dietary modulation of vitamins impaired the normal fetal growth as head circumference and crown-rump length was found reduced in BDFO transient & sustained group (P < 0.01), fetal birth weight was reduced in B12 deficient conditions in both F1 & F2 generation and a decrease in placental weight was also found in BDFD & BDFO sustained group (F0 & F1, P < 0.01). Placental expression of imprinted genes were reduced in F0 while it was found to be increased in F1 in all test groups. Over-expression of PHLDA2 in F1 placenta (P < 0.001) can be corelated to the reduced placental weight (BDFD & BDFO sustained group F1, P < 0.01). GRB10 expression was increased in all vitamin B12 deficient sustained groups (F1, P < 0.001 & < 0.01). Enhanced expression of MEST was observed in FO conditions (F1 transient and sustained, P < 0.05) which can be corelated to reduced head circumference, moreover DLK1 was over-expressed in both vitamin deficiency conditions.*Abbreviations: BN: B12 Normal FN: Folate Normal FD: Folate deficient FO: Folate over supplementation BD: B12 deficient. ConclusionsDietary imbalance of vitamin B12 and folic acid levels during the pre-& post-natal development bring about growth anomalies at genetic & phenotypic level in subsequent generation. Funding SourcesThis work is funded by Department of science and technology- Science and Engineering board, New Delhi, India.