Novel cystamine-core dendrimer-formulation rescues ΔF508-CFTR and inhibits Pseudomonas aeruginosa infection by augmenting autophagy

ABSTRACT

Background: Cystic fibrosis (CF) is challenged with pathophysiological barriers for effective airway drug-delivery. Hence, we standardized the therapeutic efficacy of the novel dendrimer-based autophagy-inducing anti-oxidant drug, cysteamine.

Research design and methods: Human primary-CF epithelial-cells, CFBE41o-cells were used to standardize the efficacy of the dendrimer-cystamine in correcting impaired-autophagy, rescuing ΔF508-CFTR and Pseudomonas-aeruginosa (Pa) infection.

Results: We first designed a novel cystamine-core dendrimer formulation (G4-CYS) that significantly increases membrane-ΔF508CFTR expression in CFBE41o-cells (p < 0.05) by forming its reduced-form cysteamine, in vivo. Additionally, G4-CYS treatment corrects ΔF508-CFTR-mediated impaired-autophagy as observed by a significant decrease (p < 0.05) in Ub-LC3-positive aggresome-bodies. Next, we verified that in non-permeabilized CFBE41o-cells, G4-CYS significantly (p < 0.05) induces ΔF508-CFTR’s forward-trafficking to the plasma membrane. Furthermore, cysteamine’s known antibacterial and anti-biofilm properties against Pa were enhanced as our findings demonstrate that both G4-CYS and its control DAB-core dendrimer, G4-DAB, exhibited significant (p < 0.05) bactericidal-activity against Pa. We also found that both G4-CYS and G4-DAB exhibit marked mucolytic-activity against porcine-mucus (p < 0.05). Finally, we demonstrate that G4-CYS not only corrects the autophagy-impairment by rescuing ΔF508-CFTR in CFBE41o-cells but also corrects the intrinsic phagocytosis defect (p < 0.05).

Conclusions: Overall, our data demonstrates the efficacy of novel cystamine-dendrimer formulation in rescuing ΔF508-CFTR to the plasma membrane and inhibiting Pa bacterial-infection by augmenting autophagy.

KEYWORDS:

• Cystic fibrosis
• CFTR
• autophagy
• cystamine
• cysteamine
• dendrimers

Declaration of interest

N Vij is the lead inventor on patent targeting proteostasis mechanisms for rescuing CFTR protein-processing defect and Cystic Fibrosis lung disease. N Vij is also the lead inventor of nano-based selective drug delivery and therapeutic targeting for Cystic Fibrosis. N Vij is a founder of VIJ BIOTECH that focuses on bench-side translation of novel Cystic Fibrosis and Chronic Obstructive Pulmonary Disorder therapeutics. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

Conception, design and protocols: N Vij; Analysis and interpretation: N Vij, J Faraj, M Bodas, G Pehote; Experimental contribution: J Faraj, M Bodas, G Pehote, D Swanson, A Sharma, N Vij; Drafting of the manuscript and/or editing: J Faraj, M Bodas, G Pehote, D Swanson, A Sharma, N Vij.

Additional information

Funding

The study was funded by the National Institute of Health (CTSA RRO25005 and RHL096931), Flight Attendant Medical Research Institute’s (FAMRI), Young Clinical Scientist Award (YCSA_082131) and CFF (FARAJ17HO) grants to N Vij as a Principal Investigator and mentor. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.