Improvement of glymphatic-lymphatic drainage of beta-amyloid by focused ultrasound in Alzheimer's disease model

Sci Rep. 2020 Sep 30;10(1):16144. doi: 10.1038/s41598-020-73151-8.

Abstract

Drainage of parenchymal waste through the lymphatic system maintains brain homeostasis. Age-related changes of glymphatic-lymphatic clearance lead to the accumulation beta-amyloid (Aβ) in dementia models. In this study, focused ultrasound treatment in combination with microbubbles (FUS-MB) improved Aβ drainage in early dementia model mice, 5XFAD. FUS-MB enhanced solute Aβ clearance from brain, but not plaques, to cerebrospinal fluid (CSF) space and then deep cervical lymph node (dCLN). dCLN ligation exaggerated memory impairment and progress of plaque formation and also the beneficial effects of FUS-MB upon Aβ removal through CSF-lymphatic routes. In this ligation model, FUS-MB improved memory despite accumulation of Aβ in CSF. In conclusion, FUS-MB enhances glymphatic-lymphatic clearance of Aβ mainly by increasing brain-to-CSF Aβ drainage. We suggest that FUS-MB can delay dementia progress in early period and benefits of FUS-MB depend on the effect of Aβ disposal through CSF-lymphatics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / immunology
  • Alzheimer Disease / therapy*
  • Amyloid beta-Peptides / metabolism
  • Animals
  • Brain / metabolism
  • Disease Models, Animal
  • Glymphatic System / drug effects*
  • Glymphatic System / metabolism
  • Humans
  • Lymphatic System / metabolism
  • Male
  • Mice
  • Mice, Transgenic
  • Microbubbles / therapeutic use*
  • Parenchymal Tissue
  • Plaque, Amyloid / pathology
  • Ultrasonic Therapy / methods

Substances

  • Amyloid beta-Peptides