A New Paradigm for Bladder Outlet Obstruction

Transcription

1 A New Paradigm for Bladder Outlet Obstruction J Todd Purves MD, PhD Division of Urology Duke University Medical Center Disclosures: None

2 5yo Male Healthy. Presents with some urinary straining and weaker urinary stream. History and Exam suggestive of early BPH Offer alpha blockers, 5α reductase inhibitor, deobstructing procedure He chooses medical therapy Obstruction persists 1 1 Jiang YH, Wang CC and Kuo HC PLoS One 13(2): E1974

3 Functional/Anatomic Bladder Outlet Obstruction Anatomic: Benign Prostatic Hyperplasia Functional: Detrusor/Sphincter Dyssynergia Elevated Denervation Fibrosis Chronic pressure, stretch Inflammation and hypoxia Irritative voiding 3

4 Ten year later: 6M Medical Management of BPH with Flowmax, Finasteride Now prevents with urinary urgency, frequency, difficulty emptying bladder and 2 UTI in past 3 months Considering surgical therapy Has 1 years of damage jeopardized surgical success?

5 Inflammasomes in the Bladder NLRP3 Hughes et al., AmJPhysiol-Renal (214) 36:F299

6 Inflammation TLRs PAMP PAMP DAMP DAMP DAMPs (ATP) PAMPs (LPS) NLRP3 IL-1β IL-18 DAMPS Pyroptosis camp MyD88 NLRP3 PKA TRAF6 NLRP3 Inflammasome ASC Adaptor CREB NF-κB Pro-IL-1β Casp-1 Pro-Casp-1 IL-1β Pro-IL-18 IL-18

7 Exposure to hydrostatic pressure increases extracellular ATP release and caspase-1 activity Data are mean +/- S.E.M. statistically analyzed by one-way ANOVA with post-hoc Tukey HSD test (n=2). * P value <.5, ** P value <.1

8 MYP3 cells display a ATP dosedependent increase in caspase-1 activity Data are mean +/- S.E.M. (n=6).

9 Inhibition of purinergic receptors reduces pressure induced extracellular ATP concentration and caspase-1 activation Data are mean +/- S.E.M. statistically analyzed by one-way ANOVA with post-hoc Tukey HSD test (n=14). * P value <.5, ** P value <.1

10 Caspase-1 activation via direct stimulation with ATP is abolished in the presence of P2X 4 but not P2X 7 antagonists Data are mean +/- S.E.M. statistically analyzed by one-way ANOVA with post-hoc Tukey HSD test (n=6). * P value <.5, ** P value <.1

11 Pressure Activates Urothelial NLRP3 Via ATP Dependent Mechanism Illustrated by Megan Llewellyn, MSMI; copyright Duke University with permission under a CC-BY 4. license

12 Mechanism of BOO Obstruction Repeated bouts of High pressure Stretch hypoxia/reperfusion DAMPs ) ) ) ) Pro-IL-1β NLRP3 X Glyburide IL-1β Casp-1 Inflammation (sterile) Chronic Decompensation (Decrease in voiding efficiency) 4 groups of rats: Early 1. Control 2. Sham operated 3. BOO 4. BOO + glyburide (NLRP3 inhibitor) Urinary Stasis Overflow incontinence UTIs Stones renal failure irritative symptoms (OAB) Denervation Frequency Fibrosis Urgency 12 days BOO Gotta go RIGHT NOW!

13 Surgical BOO Model

14 BOO Activates the NLRP3 Inflammasome Urothelial Caspase-1 Activity (pg AFC/min/mg) * * * Con Sham Veh Gly BOO BOO Hughes et al., J. Urol (216) 195:1568

15 BOO Stimulates Inflammation Through NLRP3 * Inflammation * * Evan s Blue Extravasation Assay Control Inflamed Evans Blue Extravasation (ng dye/mg tissue) mg Bladder Weight * Con Sham Veh Gly BOO ng dye/mg tissue Evan s Blue * Con Sham Veh Gly BOO Hughes et al., J. Urol (216) 195:1568

16 Mechanism of BOO Obstruction Repeated bouts of High pressure Stretch hypoxia/reperfusion DAMPs ) ) ) ) NLRP3 X Casp-1 Inflammation (sterile) Early Irritative symptoms (OAB) Denervation Frequency Fibrosis Urgency 12 days BOO

17 Urodynamics Awake, restrained rats Suprapubic catheter implanted at time of BOO surgery Schneider et al. BJU Int (215) 115:8

18 BOO Triggers Urinary Frequency Through NLRP3 -Urodynamics Control Sham BOO + Vehicle Bladder Pressure (cm H 2 ) BOO = High Pressure, Low Flow Flow rate 197 ± 22 µl/s 16 ± 15 µl/s 43 ± 6 µl/s 12 BOO + Glyburide ± 7 µl/s Hughes et al., J. Urol (216), PMID Time (sec)

19 BOO Increases Frequency ( ICI) and Void Volume Through NLRP3 ICI Void Volume * * ICI (seconds) * * Con Sham Veh Gly Void Volume (µl) * Con Sham Veh Gly BOO BOO Hughes et al., J. Urol (216) 195:1568

20 Blocking NLRP3 Lengthens the Voiding Contraction Duration of Contraction Duration of void seconds *** * *** * * Con Sham Veh Gly seconds *** * *** * * Con Sham Veh Gly BOO BOO Hughes et al., J. Urol (216) 195:1568

21 Mechanism of BOO Obstruction Repeated bouts of High pressure Stretch hypoxia/reperfusion DAMPs ) ) ) ) NLRP3 X Casp-1 Inflammation (sterile) Early Irritative symptoms (OAB) Denervation Frequency Fibrosis 12 days BOO

22 Quantitation of nerve density Stain for PGP9.5 Scan whole transverse cross sections Count nerves SHAM BOO+Veh Divide by bladder wall area

23 NLRP3 Mediates Denervation during BOO Nerve Density (# nerves x 1-6 )/µm 2 ) IL-1bb * The NLRP3/IL-1β pathway mediates denervation during BOO * Nerve Density 3 High pressure Stretch 2 Hypoxia/reperfusion * * * Control Sham Veh Pelvic Ganglion Nerves Apoptosis IL-1β Induces Apoptosis in 2 Pelvic Neurons in vitro DAMPs (ATP) Gly BOO Conclusion Ana Pro-IL-1β Apoptotic/Total cells (%) Inflammasome Casp-1 NLR Adaptor Total number of Nerves Bladder Area (x1 6 µm 2 ) # Nerves * Control Sham Veh * Control Sham Veh ** Apoptosis Gly Ana BOO Bladder Area IL-1β IL-1β Pyroptosis IL-1β (ng/ml) Gly BOO Ana

24 Mechanism of BOO Obstruction Masson s Trichrome Stain Control BOO Repeated bouts of High pressure Stretch hypoxia/reperfusion DAMPs ) ) ) ) Collagen deposition = NLRP3 X Casp-1 Early irritative symptoms (OAB) Denervation Fibrosis Inflammation (sterile) 12 days BOO

25 Fibrosis during BOO is mediated through NLRP3 Collagen Area (Yellow) Total Area (Purple) % collagen area ** * ** * Control Sham Vehicle Glyburide BOO

26 Source of increased collagen? Urothelia Detrusor Control 1. More urothelia Staining: Prolyl 4-hydroxylase (modifies collagen prior to secretion) BOO

27 Source of more collagen 2. More Collagen per cell pg collagen / per cell Control * BOO Cumulative collagen production after 48 hours of culture (Sirius Red)

28 IL-1β stimulates pro-collagen secretion from control urothelia in vitro IL-1β IL-1R1 Prolyl 4-OHase Synthesis & Modification Collagen secretion OH pg collagen / per cell *** 25 IL-1β (ng/ml) 24 h culture followed by 24 h treatment and collagen quantitation (Sirius Red)

29 Mechanism of BOO Obstruction Chronic Decompensation (Decrease Decompensation in voiding efficiency) Urinary 42 days Stasis BOO Overflow incontinence UTIs Stones renal failure Repeated bouts of High pressure Stretch hypoxia/reperfusion DAMPs ) ) ) ) NLRP3 X Casp-1 Early irritative symptoms (OAB) Denervation Frequency Fibrosis Glyburide Inflammation (sterile) 12 days BOO

30 The Decrease in Voiding Efficiency (Decompensation) is Blocked with Glyburide Voiding Efficiency (%) *** Control Sham No Treat Glyburide BOO

31 Mechanism of BOO Obstruction Chronic Decompensation (Decrease in voiding efficiency) Repeated bouts of High pressure Stretch hypoxia/reperfusion NLRP3 X Casp-1 Early irritative symptoms (OAB) Denervation Frequency Fibrosis Glyburide Inflammation (sterile) Urinary 42 days Stasis BOO Overflow incontinence UTIs Stones renal failure <5% Effective TURP VERY Effective Urgency 12 days BOO Gotta go RIGHT NOW!

32 Immunocentric Model of LUTS secondary to BOO PRESSURE UROTHELIUM DETRUSOR ATP AFFERENT NERVES NLRP3 CYTOKINES META-INFLAMMATION FIBROSIS Lower Urinary Tract Symptoms

33 NLRP3-mediated bladder inflammatory disorders Sterile Cyclophosphamide-induced Hemorrhagic Cystitis Bladder Outlet Obstruction Diabetes Stones Infectious UTI Irritative voiding Fibrosis IL-1R Denervation Possible Therapeutics IL-1β Anakinra Rilonacept canakinumab DAMPS - FDA - - Intermediate approved Small molecule for in diabetes glyburide inhibitor synthesis of NLRP3 - Effective --pathway Being Β-hydroxybutyrate rodent developed model by Avistron - Hypoglycemic - -Does (Cornwall, A ketone not effects body UK) glucose may prohibit metab use No extensive An In development endogenic black licorice publications NLRP3 since 214 inhibitor (48 on PubMed - - from 14 Used pubs as Nature on an Ped anti-inflammatory Med med for 215 to four in - Jan Uesfulness 4, years 218) studied in China in human - migraines Cheap and and widely blood available flow DAMPS Pro-Casp-1 NLRP3 Glyburide MCC95 BHB Isoliquirtigenin Casp-1 Pro-IL-1β - Mostly useful in research Anakinra - IL-1R antagonist studies Rilonacept decoy receptor - Herbal extracts Canakinumab neutralizing antibody - Efficacy and solubility issues - FDA approved - Expensive - Injectable - Immunocompromise VX-765 Ac-YVAD-CMK Z-VAD-FMK Parthenolide shikonin

34 Duke University Urinary Dysfunction Lab Funding Source: R1-DK (P.I. Purves)