Porcine ZBED6 regulates growth of skeletal muscle and internal organs via multiple targets

PLoS Genet. 2021 Oct 28;17(10):e1009862. doi: 10.1371/journal.pgen.1009862. eCollection 2021 Oct.

Abstract

ZBED6 (zinc finger BED domain containing protein 6) is a transcription factor unique to placental mammals and its interaction with the IGF2 (insulin-like growth factor 2) locus plays a prominent role in the regulation of postnatal skeletal muscle growth. Here, we generated lean Bama miniature pigs by generating ZBED6-knockout (ZBED6-/-) and investigated the mechanism underlying ZBED6 in growth of muscle and internal organs of placental mammals. ZBED6-/- pigs show markedly higher lean mass, lean mass rate, larger muscle fiber area and heavier internal organs (heart and liver) than wild-type (WT) pigs. The striking phenotypic changes of ZBED6-/- pigs coincided with remarkable upregulation of IGF2 mRNA and protein expression across three tissues (gastrocnemius muscle, longissimus dorsi, heart). Despite a significant increase in liver weight, ZBED6-/- pigs show comparable levels of IGF2 expression to those of WT controls. A mechanistic study revealed that elevated methylation in the liver abrogates ZBED6 binding at the IGF2 locus, explaining the unaltered hepatic IGF2 expression in ZBED6-/- pigs. These results indicate that a ZBED6-IGF2-independent regulatory pathway exists in the liver. Transcriptome analysis and ChIP-PCR revealed new ZBED6 target genes other than IGF2, including cyclin dependent kinase inhibitor 1A (CDKN1A) and tsukushi, small leucine rich proteoglycan (TSKU), that regulates growth of muscle and liver, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Gene Expression Regulation / physiology
  • Insulin-Like Growth Factor II / metabolism
  • Liver / metabolism
  • Male
  • Muscle Development / physiology
  • Muscle Fibers, Skeletal / metabolism
  • Muscle, Skeletal / metabolism*
  • Placenta / metabolism
  • Pregnancy
  • Repressor Proteins / metabolism*
  • Swine
  • Transcription Factors / metabolism
  • Transcriptome / physiology
  • Up-Regulation / physiology

Substances

  • Repressor Proteins
  • Transcription Factors
  • Insulin-Like Growth Factor II

Grants and funding

This work was supported by the National Key R & D Program of China grant 2020YFA0509500 to LJ, the Agricultural Science and Technology Innovation Program of China grant ASTIP-IAS01 to YM and National High-tech R&D Program of China grant 2017YFC1103702 and 2017YFC1103700 to DP. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.