Phytoestrogens genistein and daidzein affect immunity in the nematode Caenorhabditis elegans via alterations of vitellogenin expression.
METHODS
Phytoestrogens, such as the soy isoflavones genistein and daidzein, are suggested to beneficially affect lipid metabolism in humans and thereby contribute to healthy ageing. New evidences show that phytoestrogens might slow ageing processes also by affecting immune processes.


RESULTS
We tested in the nematode Caenorhabditis elegans the effects of 17β-estradiol, genistein, and daidzein on resistance versus the nematode pathogen Photorhabdus luminescens with focus on vitellogenins, which are invertebrate estrogen-responsive genes that encode homologues to ApoB100 with impact on immune functions. Here, we show that the estrogen 17β-estradiol increases the resistance of C. elegans versus P. luminescens by enhancing vitellogenin-expression at the mRNA and protein level. Knockdown of single out of five functional vits by RNA-interference blunted the life-extending effects under heat-stress of 17β-estradiol, demonstrating a lack of redundancy for the vitellogenins. RNAi for nhr-14, a suggested nuclear hormone receptor for estrogens, displayed no influence on 17β-estradiol effects. The soy isoflavone genistein reduced vitellogenin-expression and also resistance versus P. luminescens whereas daidzein increased resistance versus the pathogen in a vitellogenin-dependent manner.


CONCLUSIONS
Our studies show that induction of estrogen-responsive vitellogenin(s) by the phytoestrogen daidzein potently increases resistance of C. elegans versus pathogenic bacteria and heat whereas genistein acts in an antiestrogenic manner.
Molecular Nutrition Research, Interdisciplinary Research Center, Justus-Liebig-University of Giessen, Giessen, Germany.
Malaika
M
Fischer
Charlotte
C
Regitz
Mareike
M
Kahl
Michael
M
Werthebach
Michael
M
Boll
Uwe
U
Wenzel
D000818:Animals; D017173:Caenorhabditis elegans / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D004032:Diet; D015536:Down-Regulation; D019833:Genistein / Q000008:administration & dosage*; D018869:Heat-Shock Response; D006801:Humans; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000008:administration & dosage; D007529:Isoflavones / Q000008:administration & dosage*; D020637:Photorhabdus / Q000502:physiology*; D048789:Phytoestrogens / Q000008:administration & dosage*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D014819:Vitellogenins / Q000235:genetics* / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D007155:Immunologic Factors; D007529:Isoflavones; D048789:Phytoestrogens; D020033:Protein Isoforms; D012333:RNA, Messenger; D011960:Receptors, Estrogen; C575683:VIT-6 protein, C elegans; D014819:Vitellogenins; C004742:daidzein; D019833:Genistein