Intermittent restraint stress induces circadian misalignment in the mouse bladder, leading to nocturia

Sci Rep. 2019 Jul 11;9(1):10069. doi: 10.1038/s41598-019-46517-w.

Abstract

Intermittent stress disrupts the circadian rhythm in clock genes such as Per2 only in peripheral organs without any effect on the central circadian clock in the suprachiasmatic nucleus. Here, the effect of restraint stress (RS) on circadian bladder function was investigated based on urination behavior and gene expression rhythms. Furthermore, PF670462 (PF), a Per2 phosphorylation enzyme inhibitor, was administered to investigate the effects on circadian bladder re-alignment after RS. Two-hour RS during the light (sleep) phase was applied to mice (RS mice) for 5 days. The following parameters were then examined: urination behaviors; clock gene expression rhythms and urinary sensory-related molecules such as piezo type mechanosensitive ion channel component 1 (Piezo1), transient receptor potential cation channel subfamily V member 4 (TRPV4), and Connexin26 (Cx26) in the bladder mucosa; Per2 expression in the excised bladder of Per2luciferase knock-in mice (Per2::luc); in vivo Per2 expression rhythms in the bladder of Per2::luc mice. Control mice did not show altered urination behavior in the light phase, whereas RS mice exhibited a higher voiding frequency and lower bladder capacity. In the bladder mucosa, RS mice also showed abrogated or misaligned Piezo1, TRPV4, Connexin26, and clock gene expression. The rhythmic expression of Per2 was also altered in RS mice both in excised- and in vivo bladder, compared with control mice. After PF administration, voiding frequency was reduced and bladder capacity was increased during the light phase in RS mice; the in vivo Per2 expression rhythm was also fully restored. Therefore, RS can alter circadian gene expression in the bladder during the light phase and might cause nocturia via changes in circadian bladder function due the dysregulation of clock genes. Amending the circadian rhythm therapeutically could be applied for nocturia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Circadian Rhythm / physiology*
  • Connexin 26
  • Connexins / genetics
  • Connexins / metabolism
  • Gene Expression Regulation
  • Humans
  • Ion Channels / genetics
  • Ion Channels / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nocturia / genetics
  • Nocturia / metabolism*
  • Period Circadian Proteins / antagonists & inhibitors
  • Period Circadian Proteins / genetics
  • Period Circadian Proteins / metabolism*
  • Pyrimidines / administration & dosage
  • Pyrimidines / pharmacology
  • Restraint, Physical / physiology*
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism
  • Urinary Bladder / physiology*
  • Urination

Substances

  • Connexins
  • Gjb2 protein, mouse
  • Ion Channels
  • Per2 protein, mouse
  • Period Circadian Proteins
  • Piezo1 protein, mouse
  • Pyrimidines
  • TRPV Cation Channels
  • Trpv4 protein, mouse
  • Connexin 26
  • PF-670462