(080) Exploring the Effects of Actinidin as a Novel Collagenase on Human Peyronie’s Disease Cells
Authors: Feng K , Kiattiburut W , Hickling D , Burton J , Campbell J 
Published: May 2023

Abstract

Introduction
Peyronie’s Disease (PD) is a connective tissue disorder of the penile tunica albuginea that affects approximately 10% of men. The plaques that hallmark PD contain excessive amounts of collagen and can result in penile curvature, painful erections, and/or erectile dysfunction. Intralesional Collagenase Clostridium histolyticum injection for PD are no longer available in Canada, making treatment options limited. Hayward kiwi fruit are rich in natural actinidin, a soluble enzyme that has the unique ability to hydrolyze various types of collagen and fibrinogen. Actinidin is considered a collagenase alternative; however, there have been no studies evaluating the application of actinidin on in vitro cellular PD models.

Objective
To determine the effectiveness of actinidin at reducing the collagen component of a 2D human PD cell model. Secondly, to determine the cytotoxicity of kiwifruit extract on human PD cells.

Methods
Human PD tissues obtained during penile prosthesis implantation were isolated for fibroblast cells and cultured using complete media. The cells were plated on a 96-well plate and treated with one of 4 treatment groups: media, saline, and low and high concentration actinidin treatment (0.5 mg/ml to 37.5 mg/ml). The actinidin treatments were prepared by dissolving freeze-dried kiwi powder in saline and then filtered; the low concentration was further diluted with saline. Cells were incubated at 37°C for 24 hours and then collagen was extracted and measured using a soluble collagen quantification assay kit and a fluorescent microplate reader. To measure cytotoxicity, cells were stained for the nucleus and actin filaments using DAPI and Phalloidin-conjugated FITC, respectively. A twelve-hour timelapse capturing images of FITC and DAPI fluorescein were carried through using a fluorescent confocal microscope. The total fluorescent area of each well was measured using ImageJ. Actin signals were normalized by DAPI signals, and all values were analyzed using Python and Prism10.

Results
The higher concentration of actinidin treatment significantly reduced cellular collagen of human PD fibroblasts compared to the media treatment (P &lt; 0.05). The high concentration actinidin treatment had a significantly higher normalized actin signal than other treatment groups (P &lt; 0.0001). This ratio allows us to observe the treated cells with compromised plasma membranes. The low concentration of actinidin did not have any significant difference from media and saline treatment groups. A significant increased level of normalized actin indicated that actinidin may have mechanisms to disturb the plasma membrane.

Conclusions
Our preliminary study suggests that the natural collagenase actinidin can break down PD cells by reducing the extracellular collagen content and compromising the cellular membrane. Further studies are underway to investigate treatment in 3D models and to determine the optimal actinidin concentration that can further reduce the collagen composition in human PD cell models. Actinidin has the potential to be a novel treatment option for patients suffering from PD.

Disclosure
Yes, this is sponsored by industry/sponsor: KiwiEnzyme.com Ltd

Clarification
No industry support in study design or execution