Diosgenin Promotes Bacterial Clearance in Bladder Epithelial Cells by Regulating Rab27b Expression: A Study Based on...

Area of Science:

• Microbiology
• Pharmacology
• Biochemistry

Background:

• Antimicrobial resistance (AMR) necessitates novel non-antibiotic therapies for infectious diseases.
• Urinary tract infections (UTIs), often caused by uropathogenic Escherichia coli (UPEC), involve intracellular bacterial survival within bladder epithelial cells (BECs).
• Rab27b facilitates the expulsion of intracellular bacteria, with its upregulation shown to reduce bacterial loads.

Purpose of the Study:

• To identify compounds that bind to Rab27b using virtual screening.
• To investigate the therapeutic potential of diosgenin (DSG) in treating UPEC-induced UTIs by modulating Rab27b.
• To elucidate the mechanism by which DSG affects intracellular bacterial clearance and bladder tissue integrity.

Main Methods:

• Virtual screening and molecular dynamics simulations for compound identification.
• Surface plasmon resonance (SPR) to confirm direct binding of DSG to Rab27b.
• Cellular assays (CCK-8, Western blot, immunofluorescence, colony counting, siRNA) and in vivo mouse models (HE staining, SEM) to assess DSG's effects.

Main Results:

• Diosgenin (DSG) and ST5330591 (ST) were identified as stable binders of Rab27b.
• DSG upregulated Rab27b protein expression post-transcriptionally, enhancing intracellular UPEC clearance in BECs.
• DSG treatment in a mouse UTI model reduced intracellular bacterial CFU, alleviated inflammation, and protected bladder epithelial integrity.

Conclusions:

• DSG directly binds to Rab27b and upregulates its protein expression via a post-transcriptional mechanism.
• This upregulation promotes the clearance of intracellular UPEC from BECs, demonstrating therapeutic potential for UTIs.
• DSG represents a promising non-antibiotic therapeutic agent for managing UPEC-induced UTIs.