Gelsolin Amyloidogenesis Is Effectively Modulated by Curcumin and Emetine Conjugated PLGA Nanoparticles

PLoS One. 2015 May 21;10(5):e0127011. doi: 10.1371/journal.pone.0127011. eCollection 2015.

Abstract

Small molecule based therapeutic intervention of amyloids has been limited by their low solubility and poor pharmacokinetic characteristics. We report here, the use of water soluble poly lactic-co-glycolic acid (PLGA)-encapsulated curcumin and emetine nanoparticles (Cm-NPs and Em-NPs, respectively), as potential modulators of gelsolin amyloidogenesis. Using the amyloid-specific dye Thioflavin T (ThT) as an indicator along with electron microscopic imaging we show that the presence of Cm-NPs augmented amyloid formation in gelsolin by skipping the pre-fibrillar assemblies, while Em-NPs induced non-fibrillar aggregates. These two types of aggregates differed in their morphologies, surface hydrophobicity and secondary structural signatures, confirming that they followed distinct pathways. In spite of differences, both these aggregates displayed reduced toxicity against SH-SY5Y human neuroblastoma cells as compared to control gelsolin amyloids. We conclude that the cytotoxicity of gelsolin amyloids can be reduced by either stalling or accelerating its fibrillation process. In addition, Cm-NPs increased the fibrillar bulk while Em-NPs defibrillated the pre-formed gelsolin amyloids. Moreover, amyloid modulation happened at a much lower concentration and at a faster rate by the PLGA encapsulated compounds as compared to their free forms. Thus, besides improving pharmacokinetic and biocompatible properties of curcumin and emetine, PLGA conjugation elevates the therapeutic potential of both small molecules against amyloid fibrillation and toxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amyloidogenic Proteins / chemistry
  • Amyloidogenic Proteins / metabolism*
  • Cell Line
  • Curcumin / administration & dosage*
  • Curcumin / chemistry
  • Emetine / administration & dosage*
  • Emetine / chemistry
  • Gelsolin / chemistry
  • Gelsolin / metabolism*
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Kinetics
  • Lactic Acid* / chemistry
  • Models, Molecular
  • Molecular Sequence Data
  • Nanoparticles* / chemistry
  • Particle Size
  • Polyglycolic Acid* / chemistry
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Protein Aggregation, Pathological
  • Protein Conformation

Substances

  • Amyloidogenic Proteins
  • Gelsolin
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • Curcumin
  • Emetine

Grants and funding

The work was supported by funding from The Indian Council of Medical Research, Government of India. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.