Cao J, Boucher W, Kempuraj D, Donelan J M, Theoharides T C
Department of Biochemistry, Tufts University School of Medicine, Tufts-New England Medical Center, 136 Harrison Avenue, Boston, MA 02111, USA.
J Urol. 2006 Sep;176(3):1208-13. doi: 10.1016/j.juro.2006.04.026.
Corticotropin-releasing hormone is typically released from the hypothalamus but it has proinflammatory effects outside of the brain, possibly through the activation of mast cells. These cells express corticotropin-releasing hormone receptors with selective secretion of vascular endothelial growth factor, which may be involved in the pathogenesis of painful bladder syndrome/interstitial cystitis. This condition is characterized by bladder inflammation and worsened by stress. We investigated the effect of intravesical corticotropin-releasing hormone and acute restraint stress on vascular endothelial growth factor release from mouse bladder explants and the role of mast cells.
The bladder of C57BL/6 mast cell deficient (W/W(v)) and normal congenic (+/+) female mice (Jackson Laboratories, Bar Harbor, Maine) at ages 10 to 12 weeks was catheterized using anesthesia. After emptying urine 1) normal saline or corticotropin-releasing hormone was introduced for 45 minutes, urine was collected and the mice were allowed to recover for 4 hours before sacrifice or 2) the mice were stressed by placing them in a restrainer for 4 hours before sacrifice and urine was collected 2 hours after stress. The bladder was removed 4 hours after stress and processed for corticotropin-releasing hormone immunohistochemical staining. In other experiments the bladder was removed, minced into 1 mm(2) pieces and cultured with or without corticotropin-releasing hormone overnight. Urine and medium were frozen for histamine, interleukin-6, tumor necrosis factor-alpha and vascular endothelial growth factor assay.
Corticotropin-releasing hormone (100 nM) or acute restraint stress (4 hours) increased histamine release in urine and vascular endothelial growth factor release in medium without increasing interleukin-6 or tumor necrosis factor-alpha in the bladder explants of C57BL/6 or +/+ but not W/W(v) mice. No vascular endothelial growth factor, interleukin-6 or tumor necrosis factor-alpha was detected in urine before or after stimulation. Corticotropin-releasing hormone immunoreactivity was present in control bladders but it increased dramatically in the bladder of stressed mice.
Intravesical corticotropin-releasing hormone and acute restraint stress induced mast cell dependent vascular endothelial growth factor release from bladder explants. These findings suggest that stress, corticotropin-releasing hormone, mast cells and vascular endothelial growth factor might participate in the pathogenesis of painful bladder syndrome/interstitial cystitis, which is worsened by stress, and provide for new therapeutic targets.
促肾上腺皮质激素释放激素通常由下丘脑释放,但它在脑外具有促炎作用,可能是通过激活肥大细胞实现的。这些细胞表达促肾上腺皮质激素释放激素受体,并选择性分泌血管内皮生长因子,这可能参与了疼痛性膀胱综合征/间质性膀胱炎的发病机制。这种疾病以膀胱炎症为特征,并会因压力而加重。我们研究了膀胱内注射促肾上腺皮质激素释放激素和急性束缚应激对小鼠膀胱外植体中血管内皮生长因子释放的影响以及肥大细胞的作用。
对10至12周龄的C57BL/6肥大细胞缺陷型(W/W(v))和正常同基因(+/+)雌性小鼠(杰克逊实验室,缅因州巴尔港)的膀胱进行麻醉插管。排空尿液后,1)注入生理盐水或促肾上腺皮质激素释放激素45分钟,收集尿液,小鼠恢复4小时后处死;或2)在处死前将小鼠置于束缚器中应激4小时,应激2小时后收集尿液。应激4小时后取出膀胱,进行促肾上腺皮质激素释放激素免疫组化染色。在其他实验中,取出膀胱,切成1mm²的小块,在有或无促肾上腺皮质激素释放激素的条件下过夜培养。将尿液和培养基冷冻用于组胺、白细胞介素-6、肿瘤坏死因子-α和血管内皮生长因子检测。
促肾上腺皮质激素释放激素(100 nM)或急性束缚应激(4小时)增加了C57BL/6或+/+小鼠(而非W/W(v)小鼠)尿液中的组胺释放和培养基中的血管内皮生长因子释放,而未增加膀胱外植体中的白细胞介素-6或肿瘤坏死因子-α。刺激前后尿液中均未检测到血管内皮生长因子、白细胞介素-6或肿瘤坏死因子-α。对照膀胱中存在促肾上腺皮质激素释放激素免疫反应性,但在应激小鼠的膀胱中其显著增加。
膀胱内注射促肾上腺皮质激素释放激素和急性束缚应激诱导了膀胱外植体中肥大细胞依赖性血管内皮生长因子的释放。这些发现表明,压力、促肾上腺皮质激素释放激素、肥大细胞和血管内皮生长因子可能参与了疼痛性膀胱综合征/间质性膀胱炎的发病机制,该疾病会因压力而加重,并提供了新的治疗靶点。