Protease-Activated Receptor 4 Induces Bladder Pain through High Mobility Group Box-1.
Protease-Activated Receptor 4 Induces Bladder Pain through High Mobility Group Box-1.
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DOI：
10.1371/journal.pone.0152055
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Vera PL
中科院分区：
文献类型：
--
作者：
Kouzoukas DE;Ma F;Meyer-Siegler KL;Westlund KN;Hunt DE;Vera PL
疼痛是间质性膀胱炎/疼痛性膀胱综合征（IC/PBS）的重要临床表现。尿路上皮蛋白酶激活受体4（PAR 4）的激活通过释放尿路上皮巨噬细胞迁移抑制因子（MIF）引起疼痛。高迁移率族蛋白-1（HMGB 1）是一种染色质结合蛋白，在膀胱炎实验模型（环磷酰胺）中介导膀胱疼痛（但不介导炎症）。为了确定PAR 4诱导的膀胱超敏反应是否依赖于HMGB 1下游，我们测试了：1）膀胱PAR 4刺激是否影响尿路上皮HMGB 1释放; 2）阻断MIF是否抑制尿路上皮HMGB 1释放;以及3）阻断HMGB 1是否预防PAR 4诱导的膀胱超敏反应。在暴露于PAR 4激活肽（PAR 4-AP; 100 μM; 2小时）或乱序对照肽的永生化人尿路上皮培养物（UROtsa）中检查HMGB 1释放。雌性C57 BL/6小鼠，用HMGB 1抑制剂（HMGB 1抑制剂：50 mg/kg; ip）或溶剂预处理，接受膀胱内PAR 4-AP或对照肽（100 μM; 1小时），以测定1）1小时时膀胱内液（释放的HMGB 1）和尿路刺激中的HMGB 1水平，以及2）24小时后对von Frey细丝刺激的腹部超敏反应。我们还测试了用MIF阻断剂（ISO-1：20 mg/kg; ip）预处理的小鼠，以确定MIF是否介导PAR 4诱导的尿路上皮HMGB 1释放。PAR 4-AP触发人（体外）和小鼠（体内）尿路上皮细胞释放HMGB 1。膀胱内PAR 4激活引起小鼠腹部超敏反应，通过阻断HMGB 1来预防。MIF抑制可阻止PAR 4介导的HMGB 1从小鼠尿路上皮中释放。尿路上皮MIF和HGMB 1代表了膀胱疼痛疾病治疗干预的新靶点。
Pain is the significant presenting symptom in Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS). Activation of urothelial protease activated receptor 4 (PAR4) causes pain through release of urothelial macrophage migration inhibitory factor (MIF). High Mobility Group Box-1 (HMGB1), a chromatin-binding protein, mediates bladder pain (but not inflammation) in an experimental model (cyclophosphamide) of cystitis. To determine if PAR4-induced bladder hypersensitivity depends on HMGB1 downstream, we tested whether: 1) bladder PAR4 stimulation affected urothelial HMGB1 release; 2) blocking MIF inhibited urothelial HMGB1 release; and 3) blocking HMGB1 prevented PAR4-induced bladder hypersensitivity. HMGB1 release was examined in immortalized human urothelial cultures (UROtsa) exposed to PAR4-activating peptide (PAR4-AP; 100 μM; 2 hours) or scrambled control peptide. Female C57BL/6 mice, pretreated with a HMGB1 inhibitor (glycyrrhizin: 50 mg/kg; ip) or vehicle, received intravesical PAR4-AP or a control peptide (100 μM; 1 hour) to determine 1) HMGB1 levels at 1 hour in the intravesical fluid (released HMGB1) and urothelium, and 2) abdominal hypersensitivity to von Frey filament stimulation 24 hours later. We also tested mice pretreated with a MIF blocker (ISO-1: 20 mg/kg; ip) to determine whether MIF mediated PAR4-induced urothelial HMGB1 release. PAR4-AP triggered HMGB1 release from human (in vitro) and mice (in vivo) urothelial cells. Intravesical PAR4 activation elicited abdominal hypersensitivity in mice that was prevented by blocking HMGB1. MIF inhibition prevented PAR4-mediated HMGB1 release from mouse urothelium. Urothelial MIF and HGMB1 represent novel targets for therapeutic intervention in bladder pain conditions.