Human detrusor smooth muscle cells release interleukin-6, interleukin-8, and RANTES in response to proinflammatory cytokines interleukin-1beta and tumor necrosis factor-alpha.
OBJECTIVE
Recently, we have demonstrated that human detrusor smooth muscle cells in culture secrete the chemokine monocyte chemoattractant protein 1. In the present study, we extended these studies to include the effect of the proinflammatory cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta on IL-8, IL-6, and RANTES (regulated on activation, normal T cell expressed and secreted) release by human detrusor smooth muscle cells (HDSMCs) and examined their regulation.


METHODS
With ethical approval, detrusor muscle biopsies were obtained from patients with benign noninvasive bladder diseases undergoing control cystoscopy. HDSMCs were cultured using an explant technique and used at maximum third passage. HDSMCs were cultured in the presence or absence of TNF-alpha and IL-1beta. Supernatants were collected after 6, 12, and 24 hours. IL-8, IL-6, and RANTES were measured using enzyme-linked immunosorbent assays.


RESULTS
TNF-alpha and IL-1beta (0.01 to 100 ng/mL) induced secretion of IL-8, IL-6, and RANTES in a dose and time-dependent manner. The production of chemokines reached a maximum after 24 hours of incubation. In nonstimulated HDSMCs, the basal secretion of IL-8, IL-6, and RANTES was detectable. Induction of cytokine release by IL-1beta was synergistic with TNF-alpha.


CONCLUSIONS
These findings for the first time demonstrate that HDSMCs release IL-8, IL-6, and RANTES in response to IL-1beta and TNF-alpha. The constitutive and cytokine-stimulated production of chemokines and cytokines suggest that the human detrusor may contribute to mast cell infiltration into the bladder interstitium. The new evidence that HDSMCs secrete immunomodulatory proteins makes the detrusor muscle cell a target for anti-inflammatory therapy.
Bouchelouche
Kirsten
K
Smooth Muscle Laboratory, Herlev Hospital, University of Copenhagen, Herlev, Denmark. Bouchelouche@mail.tele.dk
Alvarez
Susana
S
Horn
Thomas
T
Nordling
Jorgen
J
Bouchelouche
Pierre
P
D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology*; D015850:Interleukin-6 / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D009130:Muscle, Smooth / Q000166:cytology* / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D001743:Urinary Bladder / Q000166:cytology* / Q000378:metabolism*
D018946:Chemokine CCL5; D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha