Nature of bacterial colonization influences transcription of mucin genes in mice during the first week of life

TY - JOUR

T1 - Nature of bacterial colonization influences transcription of mucin genes in mice during the first week of life

AU - Bergström, Anders

AU - Kristensen, Matilde Bylov

AU - Bahl, Martin Iain

AU - Metzdorff, Stine Broeng

AU - Fink, Lisbeth Nielsen

AU - Frøkiær, Hanne

AU - Licht, Tine Rask

PY - 2012

Y1 - 2012

N2 - Postnatal regulation of the small intestinal mucus layer is potentially important in the development of adult gut functionality. We hypothesized that the nature of bacterial colonization affects mucus gene regulation in early life. We thus analyzed the influence of the presence of a conventional microbiota as well as two selected monocolonizing bacterial strains on the transcription of murine genes involved in mucus layer development during the first week of life. Mouse pups (N = 8/group) from differently colonized dams: Germ-free (GF), conventional specific pathogen free (SPF), monocolonized with either Lactobacillus acidophilus NCFM (Lb) or Escherichia coli Nissle (Ec) were analyzed by qPCR on isolated ileal tissue sections from postnatal days 1 and 6 (PND1, PND6) after birth with respect to: (i) transcription of specific genes involved in mucus production (Muc1-4, Tff3) and (ii) amounts of 16S rRNA of Lactobacillus and E. coli. Quantification of 16S rRNA genes was performed to obtain a measure for amounts of colonized bacteria. Results: We found a microbiota-independent transcriptional increase of all five mucus genes from PND1 to PND6. Furthermore, the relative level of transcription of certain mucus genes on PND1 was increased by the presence of bacteria. This was observed for Tff3 in the SPF, Ec, and Lb groups; for Muc2 in SPF; and for Muc3 and Muc4 in Ec and Lb, respectively. Detection of bacterial 16S rRNA genes levels above the qPCR detection level occurred only on PND6 and only for some of the colonized animals. On PND6, we found significantly lower levels of Muc1, Muc2 and Muc4 gene transcription for Lb animals with detectable Lactobacillus levels as compared to animals with Lactobacillus levels below the detection limit. Conclusions: In summary, our data show that development of the expression of genes encoding secreted (Muc2/Tff3) and membrane-bound (Muc1/Muc3/Muc4) mucus regulatory proteins, respectively, is distinct and that the onset of this development may be accelerated by specific groups of bacteria present or absent at the mucosal site.

AB - Postnatal regulation of the small intestinal mucus layer is potentially important in the development of adult gut functionality. We hypothesized that the nature of bacterial colonization affects mucus gene regulation in early life. We thus analyzed the influence of the presence of a conventional microbiota as well as two selected monocolonizing bacterial strains on the transcription of murine genes involved in mucus layer development during the first week of life. Mouse pups (N = 8/group) from differently colonized dams: Germ-free (GF), conventional specific pathogen free (SPF), monocolonized with either Lactobacillus acidophilus NCFM (Lb) or Escherichia coli Nissle (Ec) were analyzed by qPCR on isolated ileal tissue sections from postnatal days 1 and 6 (PND1, PND6) after birth with respect to: (i) transcription of specific genes involved in mucus production (Muc1-4, Tff3) and (ii) amounts of 16S rRNA of Lactobacillus and E. coli. Quantification of 16S rRNA genes was performed to obtain a measure for amounts of colonized bacteria. Results: We found a microbiota-independent transcriptional increase of all five mucus genes from PND1 to PND6. Furthermore, the relative level of transcription of certain mucus genes on PND1 was increased by the presence of bacteria. This was observed for Tff3 in the SPF, Ec, and Lb groups; for Muc2 in SPF; and for Muc3 and Muc4 in Ec and Lb, respectively. Detection of bacterial 16S rRNA genes levels above the qPCR detection level occurred only on PND6 and only for some of the colonized animals. On PND6, we found significantly lower levels of Muc1, Muc2 and Muc4 gene transcription for Lb animals with detectable Lactobacillus levels as compared to animals with Lactobacillus levels below the detection limit. Conclusions: In summary, our data show that development of the expression of genes encoding secreted (Muc2/Tff3) and membrane-bound (Muc1/Muc3/Muc4) mucus regulatory proteins, respectively, is distinct and that the onset of this development may be accelerated by specific groups of bacteria present or absent at the mucosal site.

KW - Animals

KW - Animals, Newborn

KW - Escherichia coli

KW - Gene Expression Regulation, Developmental

KW - Germ-Free Life

KW - Intestine, Small

KW - Lactobacillus acidophilus

KW - Metagenome

KW - Mice

KW - Microbial Consortia

KW - Mucin-1

KW - Mucin-2

KW - Mucin-3

KW - Mucin-4

KW - Mucins

KW - Mucus

KW - RNA, Ribosomal, 16S

KW - Real-Time Polymerase Chain Reaction

KW - Transcription, Genetic

KW - Germ free mice

KW - Monocolonized

KW - qPCR

KW - LinRegPCR

KW - Postnatal transcription onset

KW - Probiotics

KW - Lactobacillus acidophilus NCFM

KW - Escherichia coli Nissle

KW - 16S rRNA

U2 - 10.1186/1756-0500-5-402

DO - 10.1186/1756-0500-5-402

M3 - Journal article

C2 - 22857743

SN - 1756-0500

VL - 5

JO - BMC Research Notes

JF - BMC Research Notes

IS - 402

ER -