Cyclooxygenase-2 protein and prostaglandin E(2) production are up-regulated in a rat bladder inflammation model

Prostaglandin E2 and F2alpha Modulate Urinary Bladder Urothelium, Lamina Propria and Detrusor Contractility via the FP Receptor

Current pharmacological treatment options for many bladder contractile dysfunctions are not suitable for all patients, thereby bringing interest to the investigation of therapies that target a combination of receptors. This study aimed to compare responses of PGE₂ on the urinary bladder urothelium with lamina propria (U&LP, also called the bladder mucosa) or detrusor smooth muscle and attempt to identify the receptor subtypes mediating PGE₂ contractile responses in these tissues. In the presence of selective EP1 – 4 receptor antagonists, varying concentrations of PGE₂ were applied to isolated strips of porcine U&LP and detrusor that were mounted in organ baths filled with Krebs-bicarbonate solution and gassed with carbogen. The addition of PGE₂ (1 and 10 μM) and PGF_2α (10 μM) to U&LP preparations caused significant increases in the baseline tension and in the spontaneous phasic contractile frequency. In detrusor preparations, significant increases in the baseline tension were observed in response to PGE₂ (1 and 10 μM) and PGF_α (10 μM), and spontaneous phasic contractions were initiated in 83% of preparations. None of the selective PGE₂ receptor antagonists inhibited the increases in baseline tension in both U&LP and detrusor. However, the antagonism of PGF_2α receptor showed significantly inhibited contractile responses in both layers of the bladder. This study presents prostaglandin receptor systems as a potential regulator of urinary bladder contractility. The main contractile effects of PGE₂ in both U&LP and detrusor are mediated via the FP receptor with no observed contribution from any of the four EP receptors.

Receptors involved in the modulation of guinea pig urinary bladder motility by prostaglandin D2

BACKGROUND AND PURPOSE

We have described a urothelium-dependent release of PGD2 -like activity which had inhibitory effects on the motility of guinea pig urinary bladder. Here, we have pharmacologically characterized the receptors involved and localized the sites of PGD2 formation and of its receptors.

EXPERIMENTAL APPROACH

In the presence of selective DP and TP receptor antagonists alone or combined, PGD2 was applied to urothelium-denuded diclofenac-treated urinary bladder strips mounted in organ baths. Antibodies against PGD2 synthase and DP1 receptors were used with Western blots and for histochemistry.

KEY RESULTS

PGD2 inhibited nerve stimulation -induced contractions in strips of guinea pig urinary bladder with estimated pIC50 of 7.55 ± 0.15 (n = 13), an effect blocked by the DP1 receptor antagonist BW-A868C. After blockade of DP1 receptors, PGD2 enhanced the contractions, an effect abolished by the TP receptor antagonist SQ-29548. Histochemistry revealed strong immunoreactivity for PGD synthase in the urothelium/suburothelium with strongest reaction in the suburothelium. Immunoreactive DP1 receptors were found in the smooth muscle of the bladder wall with a dominant localization to smooth muscle membranes.

CONCLUSIONS AND IMPLICATIONS

In guinea pig urinary bladder, the main effect of PGD2 is an inhibitory action via DP1 receptors localized to the smooth muscle, but an excitatory effect via TP receptors can also be evoked. The urothelium with its suburothelium might signal to the smooth muscle which is rich in PGD2 receptors of the DP1 type. The results are important for our understanding of regulation of bladder motility.

Prostaglandin E(2) mediates acid-induced heartburn in healthy volunteers

Prostaglandin E(2) (PGE(2)) plays a major role in pain processing and hypersensitivity. This study investigated whether PGE(2) levels are increased in the esophageal mucosa after acid infusion and whether increases in PGE(2) are associated with heartburn. Furthermore, expression of the PGE(2) receptor EP1 was investigated in human esophageal mucosa. Fourteen healthy male volunteers were randomized to 30-min lower esophageal acid (1% HCl) or saline perfusion. Before and after acid perfusion, endoscopic biopsies were taken from the distal esophagus. PGE(2) concentration (pg/mg protein) and EP1 mRNA and protein in biopsy samples were measured by ELISA, RT-PCR, and Western blotting. Symptom status of heartburn was evaluated with a validated categorical rating scale with a higher values corresponding to increasing intensity. PGE(2) levels in the esophageal mucosa significantly increased after acid infusion (before vs. after acid infusion: 23.2 ± 8.6 vs. 68.6 ± 18.3, P < 0.05), but not after saline infusion (before vs. after saline infusion: 9.3 ± 2.5 vs. 9.0 ± 3.2, NS). Time to first sensation (min) after acid infusion was less than after saline (saline vs. acid infusion: 22.1 ± 4.1 vs. 5.4 ± 1.5, P < 0.05). Intensity of heartburn in the acid-infusion group was also significantly greater compared with saline (saline vs. acid infusion: 54.3 ± 13.1 vs. 178.5 ± 22.8, P < 0.01). Changes in PGE(2) levels in the esophagus correlated with symptom intensity score (r = 0.80, P = 0.029). EP1 mRNA and protein expression were observed in the normal human esophageal mucosa. Esophageal PGE(2) expression is associated with mucosal acid exposure and heartburn.

Evaluating the role of curcum powder as a protective factor against bladder cancer--an experimental study

Throughout human history, plant products have been used for many purposes including as medicines. Herbal products and spices can be used as preventive agents against cancer due to their antimicrobial, antioxidant and antitumorigenic properties. This study was designed to evaluate the potential protective effect of curcum in rats administered nitrosamine precursors; dibutylamine (DBA) and sodium nitrate (NaNO3); and infected with Escherichia coli (E. coli) and also to monitor changes in nuclear factor the Kappa B p65 (NF-κB p56) pathway and its downstream products, Bcl-2 and interleukin-6 (IL-6), in parallel with nitrosamine precursors, E. coli and curcum treatment. Rats were divided into three groups (n=25 each; except of control group, n+20). Group I a normal control group, group II administered DBA/NaNO3 in drinking water and infected with E. coli and group III was administered DBA/NaNO3 in drinking water, infected with E. coli and receiving standard diet containing 1% curcum powder. Histopathological examination reflected that the curcum treated group featured a lower incidence of urinary bladder lesions,and lower levels of NF-κB, Bcl-2 and IL-6, than the group receiving nitrosamine precursor and infected with E. coli. These findings suggested that curcum may have a protective role during the process of bladder carcinogenesis by inhibiting the NF-κB pathway and its downstream products.

ONO-8130, a selective prostanoid EP1 receptor antagonist, relieves bladder pain in mice with cyclophosphamide-induced cystitis

Given the previous evidence for involvement of prostanoid EP1 receptors in facilitation of the bladder afferent nerve activity and micturition reflex, the present study investigated the effect of ONO-8130, a selective EP1 receptor antagonist, on cystitis-related bladder pain in mice. Cystitis in mice was produced by intraperitoneal administration of cyclophosphamide at 300mg/kg. Bladder pain-like nociceptive behavior and referred hyperalgesia were assessed in conscious mice. Phosphorylation of extracellular signal-regulated kinase (ERK) in the L6 spinal cord was determined by immunohistochemistry in anesthetized mice. Cyclophosphamide treatment caused bladder pain-like nociceptive behavior and referred hyperalgesia accompanying cystitis symptoms, including increased bladder weight and vascular permeability and upregulation of cyclooxygenase-2 in the bladder tissue. Oral preadministration of ONO-8130 at 0.3-30 mg/kg strongly prevented both the bladder pain-like behavior and referred hyperalgesia in a dose-dependent manner, but had slight effect on the increased bladder weight and vascular permeability. Oral ONO-8130 at 30 mg/kg also reversed the established cystitis-related bladder pain. Intravesical administration of prostaglandin E2 caused prompt phosphorylation of ERK in the L6 spinal cord, an effect blocked by ONO-8130. Our findings strongly suggest that the prostaglandin E2/EP1 system participates in processing of cystitis-related bladder pain, and that EP1 antagonists including ONO-8130 are useful for treatment of bladder pain, particularly in interstitial cystitis. Prostaglandin E2 contributes to cystitis-related bladder pain via EP1 receptors in mice, indicating possible therapeutic usefulness of selective EP1 antagonists.

Role of mast cells and protease-activated receptor-2 in cyclooxygenase-2 expression in urothelial cells

Mast cells have been shown to play a role in development and persistence of various inflammatory bladder disorders. Mast cell-derived tryptase specifically activates protease-activated receptor-2 (PAR-2), and PAR-2 is known to be involved in inflammation. We investigated whether mast cells participate in increase of cyclooxygenase-2 (COX-2) protein abundance in urothelium/suburothelium of bladders of mice subsequent to cyclophosphamide (CYP)-induced bladder inflammation. We also used primary cultures of human urothelial cells to investigate cellular mechanisms underlying activation of PAR-2 resulting in increased COX-2 expression. We found that treatment of mice with CYP (150 mg/kg ip) increased COX-2 protein abundance in bladder urothelium/suburothelium 3, 6, and 24 h after CYP (P < 0.01), and increased COX-2 protein abundance was prevented by treatment of mice with the mast cell stabilizer sodium cromolyn (10 mg/kg ip) for 4 consecutive days before CYP treatment. Incubation of freshly isolated mouse urothelium/suburothelium with a selective PAR-2 agonist, 2-furoyl-LIGRLO-amide (3 microM), also increased COX-2 protein abundance (P < 0.05). We further demonstrated that 2-furoyl-LIGRLO-amide (3 microM) increased COX-2 mRNA expression and protein abundance in primary cultures of human urothelial cells (P < 0.01), and the effects of PAR-2 activation were mediated primarily by the ERK1/2 MAP kinase pathway. These data indicate that there are functional interactions among mast cells, PAR-2 activation, and increased expression of COX-2 in bladder inflammation.

Intravesical botulinum toxin A administration inhibits COX-2 and EP4 expression and suppresses bladder hyperactivity in cyclophosphamide-induced cystitis in rats

BACKGROUND

Cyclooxygenase 2 (COX-2) elevation and subsequent prostaglandin E(2) (PGE(2)) production play a major role in bladder inflammation and hyperactivity. EP4 receptor, a subtype of PGE(2) receptors, mediates tissue inflammation and hypersensitivity.

OBJECTIVE

To investigate the effect of intravesical botulinum toxin A (BoNT-A) on COX-2 and EP4 expression in cyclophosphamide (CYP)-induced cystitis in rats.

DESIGN, SETTING, AND PARTICIPANTS

Experimental (N=40) and control animals (N=20) were injected with CYP (75 mg/kg intraperitoneally) or saline on days 1, 4, and 7. BoNT-A (1 ml, 20 unit/ml) or saline were administered into the bladder and retained for 1 h on day 2.

INTERVENTION

Waking cystometrograms (CMGs) were performed. Bladder and L6 and S1 spinal cord were harvested on day 8.

MEASUREMENTS

CMG parameters, histology, and COX-2 and EP4 expression by immunostaining or western blotting were measured.

RESULTS AND LIMITATIONS

CYP induced increased bladder inflammatory reaction, bladder hyperactivity, and COX-2 and EP4 expression in the bladder and spinal cord. The CYP effects were suppressed by BoNT-A treatment. BoNT-A treatment decreased inflammatory reaction (56.5% decrease), COX-2 expression (77.8%, 61.7%, and 54.8% decrease for bladder, L6, and S1 spinal cord, respectively), EP4 expression (56.8%, 26.9%, and 84.2% decrease for bladder, L6, and S1 spinal cord, respectively), and suppressed bladder hyperactivity (intercontraction interval, 107% increase and contraction amplitude, 43% decrease).

CONCLUSIONS

CYP injection activated COX2 and EP4 expression in the bladder and spinal cord and induced bladder inflammation and hyperactivity, which effects were suppressed by BoNT-A treatment. These findings suggest a potential benefit of EP4-targeted pharmacotherapy and BoNT-A treatment for bladder inflammatory conditions.

Loss of prostaglandin E2 release from immortalized urothelial cells obtained from interstitial cystitis patient bladders

Interstitial cystitis (IC) is associated with increased activated mast cell numbers in the bladder and impairment of the barrier function of the urothelium. We stimulated immortalized urothelial cells derived from the inflamed region of IC bladders (SR22A or SM28 abn) or from healthy bladders (PD07i or PD08i) with tryptase and measured phospholipase A(2) (PLA(2)) activity and the resultant release of arachidonic acid and prostaglandin E(2) (PGE(2)). Tryptase stimulation of either PD07i or SR22A resulted in similar increases in PLA(2) activity and arachidonic acid release. However, tryptase stimulation of SR22A and SM28 abn did not result in a significant increase in PGE(2) release compared with the increase in PGE(2) release from tryptase-stimulated PD07i and PD08i cells. Expression of mRNA for cyclooxygenase-2 and PGE synthase was lower and mRNA for 15-hydroxyprostaglandin dehydrogenase was higher in SR22A compared with PD07i, suggesting that both decreased synthesis and increased metabolism are responsible for the lack of a PGE(2) response in tryptase-stimulated SR22A cells. Since PGE(2) is a cytoprotective eicosanoid, the failure to produce this metabolite in cells isolated from the IC bladder may represent an increased susceptibility to damage by proinfammatory stimuli.

Cyclophosphamide Induced Cystitis: Role of Nitric Oxide Synthase, Cyclooxygenase-1 and 2, and NK1Receptors

PURPOSE

The role of substance P, inducible nitric oxide synthase, and cyclooxygenase-1 and 2 on the pathogenesis of cyclophosphamide induced cystitis was investigated in rats.

MATERIALS AND METHODS

Sprague-Dawley male rats received 1 of certain treatments, including 1) 0.9 weight per volume saline (0.10 ml/100 gm intraperitoneally), 2) cyclophosphamide (75 mg/kg intraperitoneally), 3) cyclophosphamide plus the NK(1) receptor antagonist Win-51.708 (20 mg/kg intraperitoneally), 4) cyclophosphamide plus the inducible nitric oxide synthase inhibitor S-methylthiourea (20 mg/kg intraperitoneally), 5) cyclophosphamide plus the highly selective cyclooxygenase-2 inhibitor rofecoxib (15 mg/kg intraperitoneally), 6) cyclophosphamide plus the selective cyclooxygenase-2 inhibitor meloxicam (15 mg/kg intraperitoneally), 7) cyclophosphamide plus the nonselective cyclooxygenase inhibitor ketoprofen (20 mg/kg intraperitoneally) or 8) cyclophosphamide plus methylthiourea plus meloxicam. Parameters were evaluated 6 hours after cyclophosphamide administration, including plasma protein extravasation, histological changes, myeloperoxidase and inducible nitric oxide synthase activities in the bladder, plasmatic nitric oxide metabolites and urinary nitric oxide metabolites, and prostaglandin E(2) levels.

RESULTS

Cyclophosphamide produced inflammatory and cytotoxic changes in the bladder, accompanied by increased nitric oxide metabolites, urinary prostaglandins, myeloperoxidase and inducible nitric oxide synthase activity. Pretreatment with Win-51.708 and with methylthiourea prevented all of these effects except myeloperoxidase activity, which was only prevented by Win-51.708. All inducible cyclooxygenases were able to prevent prostaglandin synthesis and increases in myeloperoxidase activity. Combined inhibition of inducible nitric oxide synthase and cyclooxygenase-2/cyclooxygenase-1 (methylthiourea plus meloxicam) did not provide any additional protection against bladder damage, increased inducible nitric oxide synthase activity or prostaglandin E(2) synthesis. Additionally, this combination was unable to prevent increased myeloperoxidase activity.

CONCLUSIONS

The results of this study suggest that there is crosstalk between nitric oxide and the cyclooxygenase enzyme with cyclooxygenase-1/cyclooxygenase-2 isoforms having an important role in this relationship. Augmented myeloperoxidase activity seems to be associated with NK(1) receptor activation and low levels of nitric oxide with cyclooxygenase-1 having an important role.

Neural Upregulation in Interstitial Cystitis

Interstitial cystitis (IC) is a syndrome of bladder hypersensitivity with symptoms of urgency, frequency, and chronic pelvic pain. Although no consensus has been reached on the underlying cause of IC, several pathophysiologic mechanisms, including epithelial dysfunction, mast cell activation, and neurogenic inflammation, have been proposed. Despite multiple different causes of urinary cystitis, the bladder's response to cystitis is limited and typical. Animal experiments have shown upregulation of proteinase-activated receptors, tryptase, beta-nerve growth factor, inducible nitric oxide synthase, nuclear transcription factor-kappaB, c-Fos, phosphodiesterase 1C, cyclic adenosine monophosphate (cAMP)-dependent protein kinase, and proenkephalin B. After the noxious stimulus has abated, downregulation of genes appears to follow. Distention of the bladder results in the release of adenosine triphosphate (ATP) from urothelial cells, which activates purinergic P2X3 receptors. Activation by ATP of P2X3-expressing afferents is a fundamental signaling factor in bladder sensation and appears to play a role in bladder reflexes. Fos proteins present in spinal cord neurons have been shown to be upregulated in animals that have undergone cyclophosphamide-induced chemical cystitis. These and other findings suggest that neural upregulation occurs both peripherally and centrally in subjects with chronic cystitis. It is unclear whether neural mechanisms and inflammation are the cause of IC or the result of other initiating events. Neural upregulation is known to play a role in the chronicity of pain, urgency, and frequency and represents an exciting area of research that may lead to additional treatments and a better understanding of IC.

The role of the prostacyclin receptor antagonist RO3244019 in treating neurogenic detrusor overactivity after spinal cord injury in rats

OBJECTIVE

To determine the effects of the prostacyclin receptor (IP) antagonist RO3244019 on neurogenic detrusor overactivity (NDO) in spinal cord-injured (SCI) neurogenic bladder of the rat.

MATERIALS AND METHODS

Female Sprague-Dawley rats with SCI were divided into four treatment groups of eight each: vehicle (200 mm Tris base), indomethacin (3 mg/kg), RO3244019 (at 1 and 5 mg/kg). The conscious rats were assessed by cystometry, by slowly infusing the bladder with physiological normal saline at 0.04 mL/min. After 1 h of cystometry one of the four compounds was administered intravenously to the rats and changes in cystometrogram tracings recorded. Seven voiding variables were calculated before and after administering each compound: the intercontractile interval (ICI) for all contractions, voiding ICI, amplitude of all contractions, amplitude of voiding contractions, time to first void (TFV), voided volumes (VVs), and first VV. Data were analysed using a paired t-test for each of the experiments.

RESULTS

At 1 mg/kg, the RO compound was associated with a statistically significant difference in the voiding ICI and VVs (both P < 0.05). The mean (sd) voiding ICI increased from 621 (140) to 889 (119) s (43% increase) and the VVs from 0.53 (0.13) to 0.72 (0.09) mL (36% increase). However, there was no statistically significant difference in the TFV or the first VVs. Increasing the dose to 5 mg/kg was more effective in improving the voiding ICI and the VVs (both P < 0.01). The voiding ICI increased from 716 (130) to 1346 (159) s (88% increase) and the VVs from 0.60 (0.11) to 1.05 (0.12) mL (75% increase). In addition, the higher dose had a statistically significant difference in the TFV (P < 0.05). There was more than a four-fold increase in the TFV, from 807 (138) to 3239 (883) s. At 5 mg/kg, the difference in the first VV before and after administering the compound was also almost statistically significant (P = 0.057); the first VV increased from 0.56 (0.14) to 1.01 (0.21) mL. There were no statistically significant differences in the amplitude of contractions or the ICI for all contractions for either of the dosages. Indomethacin at 3 mg/kg was the most effective compound for improving all of the voiding variables and was the only one to show a significant difference in the first VV. However, the IP antagonist at 5 mg/kg was almost as effective as indomethacin when comparing other variables, e.g. the voiding ICI and the VV. There was no statistically significant difference in any of the seven voiding variables before and after administering the vehicle.

CONCLUSION

The IP antagonist RO3244019 was effective in treating NDO in SCI bladders. While RO3244019 at 1 mg/kg significantly increased the voiding ICI and VVs, 5 mg/kg appeared to be more effective, suggesting a dose-dependent effect of the drug. The RO compound at 5 mg/kg was almost as effective as indomethacin in improving all of the voiding variables.

Dual, but not selective, COX-1 and COX-2 inhibitors, attenuate acetic acid-evoked bladder irritation in the anaesthetised female cat

Non-selective cyclooxygenase (COX) inhibitors exert effects on lower urinary tract function in several species. The exact contributions of COX-1 and COX-2 isozymes have not been studied much. The present studies investigated the effects of non- and selective COX inhibitors on bladder irritation in the cat.Chloralose-anaesthetised female cats were catheterised through the bladder dome for cystometric evaluation of bladder responses to intravesical infusion of saline or acetic acid. Bladder capacity, voiding efficiency, threshold pressure, and reflex-evoked bladder contraction amplitude and duration were measured. The cat COX selectivity of the doses of inhibitors examined was determined using an in vitro whole-blood assay and analysis of plasma levels. Pretreatment with indomethacin or ketoprofen (non-selective COX inhibitors; 0.3 mg kg(-1) i.v.) inhibited acetic acid-evoked irritation (characterised by a decrease in bladder capacity in vehicle pretreated animals). FR-122047 (selective COX-1 inhibitor), NS-398 and nimesulide (selective COX-2 inhibitors; 1 and 3 mg kg(-1) i.v.) had no effects on bladder irritation. Analysis of plasma levels of the doses examined and determination of COX-1 and COX-2 inhibition in cat whole blood confirmed the reported selectivity of these compounds in this species. The present studies suggest that dual COX inhibition is required to attenuate acetic acid-evoked bladder irritation in the cat.

Effects of intravesical instillation of cyclooxygenase-2 inhibitor on the expression of inducible nitric oxide synthase and nerve growth factor in cyclophosphamide-induced overactive bladder

OBJECTIVE

To examine the effects of intravesical cyclooxygenase-2 (COX-2) inhibitors on the expression of inducible nitric oxide synthase (iNOS) and nerve growth factor (NGF) in cyclophosphamide (CYP)-induced overactive bladder (OAB).

MATERIALS AND METHODS

In all, 40 Sprague-Dawley rats were divided into control, OAB, and COX-2 inhibitor-treated groups. OAB was induced by an intraperitoneal injection with CYP. Cystometry was performed in all rats and, in half of the OAB rats, a COX-2 inhibitor was administered intravesically. The bladders of all rats were stained immunohistochemically for iNOS and NGF.

RESULTS

In the OAB rats, the contraction interval and intercontraction interval were significantly shorter than in control rats, and the contraction time and pressure were significantly greater. In the COX-2 inhibitor-treated rats, the contraction interval and intercontraction interval were significantly longer than in the OAB rats, and the contraction time was significantly shorter. On immunohistochemical staining, there was no iNOS activity and NGF activity was minimally localized in the mucosa and submucosa in the control group. In the OAB rats, NGF activity in the mucosa and submucosa were increased, and there was greater expression of iNOS in all layers and of NGF in detrusor; in the COX-2 inhibitor-treated rats, their expression was less in all layers.

CONCLUSIONS

Intravesical instillation with COX-2 inhibitors can reduce CYP-induced bladder hyperactivity and expression of iNOS and NGF. Intravesical instillation with COX-2 inhibitors can be considered as a possible treatment for OAB.

A role for Akt in the rapid regulation of inflammatory and apoptotic pathways in mouse bladder

Akt is linked to both inflammatory and neoplastic pathways. Akt activation is dependent on the phosphatidylinositol-3 kinase (PI3K) signaling pathways. Upon phosphorylation by PI3K, Akt can phosphorylate nuclear factor kappa B (NF-kappaB) and members of the forkhead family of transcription factors, which includes AFX. Our goal is to examine the effect of Escherichia coli lipopolysaccharide (LPS) on early cellular signaling in inflammatory (NF-kappaB) and apoptotic pathways (AFX) in a mouse-bladder model and in T-24 urothelial cancer cells. Female C57BL/6 mice were given an intraperitoneal (IP) injection of LPS or LPS free water and sacrificed 0-120 minutes later. Bladders were harvested, and immunohistochemistry (IHC) and/or immunoblotting performed using antibodies to PI3K, inhibitor kappa B-alpha (IkappaB-alpha), and total and phosphorylated Akt, NF-kappaB and AFX. Levels of IkappaB-alpha and total and phosphorylated Akt and NF-kappaB were determined in T-24 cells treated with LPS for 0-120 minutes. Bladders and T-24 cells were treated with PI3K inhibitors in some experiments. Protein amounts in different samples were normalized to immunoreactive actin. Phosphorylated and non-phosphorylated species of Akt, NF-kappaB, and AFX were localized to the urothelium. IP LPS injection rapidly (within 30 minutes) increased Akt phosphorylation. IP LPS injection decreased IkappaB-alpha levels, and increased NF-kappaB and AFX phosphorylation. Wortmannin effectively blocked phosphorylation of Akt in LPS-treated mice, and also reduced phosphorylation of AFX and, to a lesser extent, NF-kappaB. After treatment with LPS, Akt and NF-kappaB phosphorylation was rapidly increased in T-24 cells. Akt phosphorylation, and to a lesser extent NF-kappaB phosphorylation, were blocked by LY-294,002. LPS/PI3K/Akt is a cellular signaling pathway which rapidly activates downstream pathways of inflammation and neoplasia in bladder urothelium.

Lipid signaling changes in smooth muscle remodeling associated with partial urinary bladder outlet obstruction

AIMS

Hypertrophy of the urinary bladder smooth muscle (detrusor) is associated with partial bladder outlet obstruction (PBOO). Hypertrophied detrusor smooth muscle (DSM) reveals altered contractile characteristics. In this study, we analyzed the lipid-dependent signaling system that includes phospholipase A2 in PBOO-induced DSM remodeling and hypertrophy to determine whether the release of arachidonic acid (AA) from phospholipid is altered in the detrusor.

METHODS

Partial bladder outlet obstruction (PBOO) was produced by partial ligation of the urethra in New Zealand white rabbits. Two weeks after the surgery, the bladder function was studied by keeping the rabbits in metabolic cages for 24 hr. Bladders were removed from rabbits that had bladder dysfunction (increased urinary frequency and decreased void volume) and the DSM separated from mucosa and serosa. The isolated smooth muscle was incubated with [3H] AA to equilibrate the cytoplasmic AA. The level of AA release was compared with the level obtained with 2-week sham-operated rabbits.

RESULTS

The rate of AA release was high in DSM from bladders with PBOO-induced hypertrophy. Carbachol stimulated AA release in control DSM but DSM from obstructed rabbits revealed no further increase from the elevated basal AA release. The half-maximal concentration of carbachol that was required to stimulate AA release from control samples of detrusor was 35 microM.

CONCLUSIONS

The increased levels of AA release that are observed in this tissue after PBOO indicate the activation of phospholipase A2. The finding that carbachol could induce contraction, but not an increase in AA, indicates that the carbachol-induced contraction in the obstructed bladders is independent of lipid signaling pathways that involve AA. It is possible that the increased rate of arachidonic acid release from obstructed bladders correlates with the enhanced rates of prostaglandin production reported by other investigators from the same tissue.

Inflammation of the rat prostate evokes release of macrophage migration inhibitory factor in the bladder: evidence for a viscerovisceral reflex

PURPOSE

Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is found in preformed stores in bladder epithelium. We examined the effects of prostatic inflammation on micturition frequency, bladder histology and bladder MIF content as a model in which to study viscerovisceral reflexes mediating pelvic visceral inflammation.

MATERIALS AND METHODS

Cystometry was performed in urethane anesthetized male rats. Formalin or saline was injected into the ventral lobe of the prostate to induce inflammation. Cystometry continued 1 hour after injection. The bladder, ventral lobes of the prostates and lumbosacral spinal cord were then removed, and protein levels and gene expression of MIF, cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) were examined. Edema was verified histologically in the bladder and prostate.

RESULTS

Intraprostatic formalin produced almost immediate bladder hyperreflexia, which was maintained during the observation period. Bladder edema was noted during histological examination. Bladder MIF protein amounts decreased, while COX-2 and NGF increased after prostatic injection. Bladder MIF, COX-2 and NGF mRNA increased. In the lumbosacral spinal cord protein and mRNA amounts increased for all factors examined in animals that received intraprostatic formalin. No changes were observed in the cervical cord. Rats injected with formalin mixed with dye showed restriction of the dye to the prostate.

CONCLUSIONS

A viscerovisceral reflex in the rat, probably mediated by the lumbosacral spinal cord, produced bladder hyperreflexia and bladder edema, and evoked MIF release from the bladder and the induction of other inflammatory mediators. This supports our hypothesis that MIF is involved in neurogenic inflammation in the pelvic viscera and it may represent an interesting therapeutic target.

Prostasin attenuates inducible nitric oxide synthase expression in lipopolysaccharide-induced urinary bladder inflammation

Prostasin is a glycosylphosphatidylinositol-anchored serine protease, with epithelial sodium channel activation and tumor invasion suppression activities. We identified the bladder as an expression site of prostasin. In the mouse, prostasin mRNA expression was detected by reverse transcription and real-time polymerase chain reaction in the bladder, and the prostasin protein was localized by immunohistochemistry in the urothelial cells. In mice injected intraperitoneally with bacterial lipopolysaccharide (LPS), bladder prostasin mRNA expression was downregulated, whereas the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interferon-gamma (IFN-gamma), TNF-alpha, IL-1beta, and IL-6 was upregulated. Viral promoter-driven expression of the human prostasin homolog in the bladder of transgenic mice attenuated the LPS induction of iNOS but did not abolish the induction. LPS induction of COX-2, TNF-alpha, IL-1beta, and IL-6 expression, however, was not reduced by prostasin transgene expression. Liposome-mediated delivery of prostasin-expressing plasmid into mouse bladder produced similar attenuation effects on LPS-induced iNOS expression, while not affecting COX-2 or cytokine induction. Mice receiving plasmid expressing a catalytic mutant prostasin did not manifest the iNOS induction attenuation phenotype. We propose a proteolytic mechanism for prostasin to intercept cytokine signaling during LPS-induced bladder inflammation.

Time course of COX-1 and COX-2 expression during ischemia-reperfusion in rat skeletal muscle

The aim of this study was to assess cyclooxygenase (COX)-1 and COX-2 expression in skeletal muscle after an ischemia-reperfusion (I/R). Male Sprague-Dawley rats were subjected to unilateral hindlimb ischemia for 2 h and then euthanized after 0, 1, 2, 4, 6, 10, 24, and 72 h of reperfusion. The COX protein and mRNA were assessed in control and injured gastrocnemius muscle. Muscle damage was indirectly determined by plasma creatine kinase activity and edema by weighing wet muscle. Creatine kinase activity in plasma increased as early as 1 h after reperfusion and returned to control levels by 72 h of reperfusion. Edema was observed at 6 and 10 h of reperfusion, but histological investigations showed an absence of tissular inflammatory cell infiltration. COX-1 mRNA was expressed in control muscle and was increased at 72 h of reperfusion, but the levels of associated COX-1 protein detected in control and injured gastrocnemius muscle were similar. COX-2 mRNA was not, or only slightly, detectable in control muscle and after I/R. In contrast, I/R induced major overexpression of COX-2 immunoreactivity at 6 and 10 h of reperfusion with a maximum at 10 h, whereas COX-2 protein was undetectable in control muscle. In conclusion, hindlimb I/R induced a large overexpression of COX-2 but not COX-1 protein between 6 and 10 h after injury. These results suggest a role for COX-2 enzyme in such pathophysiological conditions of the skeletal muscle.

Prostaglandin facilitates afferent nerve activity via EP1 receptors during urinary bladder inflammation in rats

We examined the effects of loxoprofen, a cyclooxygenase inhibitor, and ONO-8711, an EP1-receptor antagonist, on afferent nerve activity during acetic acid (AA, 0.1% v/v)-induced inflammation of the rat urinary bladder. Distension stimulation was performed (vesical pressure of 30 cm H2O) for 2 min. The neuronal discharge was recorded from L6 dorsal root filaments. The discharge was observed just after the beginning of distension and increased gradually thereafter. When the vesical pressure returned to control value, the discharge diminished abruptly. AA infusion increased the total number of spikes to 198 +/- 38.8% of control values. AA infusion also produced asynchronous discharge in 39% of the animals. Loxoprofen administration (1 mg/kg, i.v.) reduced the number of spikes to 40.3 +/- 14.8% of control values. ONO-8711 administration (1 and 3 mg/kg, i.v.) reduced the number of spikes to 81.6 +/- 1.6% and 32.2 +/- 7.4% of control values, respectively. These data indicate that loxoprofen or EP1-receptor antagonist inhibit the inflammation-related neuronal activity. EP1 receptors in the peripheral afferent nerve terminal and/or urothelium may facilitate the primary afferent nerve activity, which elicits the inflammation-induced micturition reflex.

Loxoprofen inhibits facilitated micturition reflex induced by acetic acid urinary bladder infusion of the rats

Prostaglandins (PGs) are well known as one of the chemical mediators of inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs), PG synthesis inhibitors, are used for anti-nociception and/or anti-inflammation. We examine the effect of loxoprofen, an NSAID, on micturiton in acetic acid-induced bladder inflammation of the rats. In cystometrogram study with saline infusion into the urinary bladder, loxoprofen did not alter the interval of bladder contraction (IC, 107% of the control). IC was shortened by acetic acid infusion (65% of the control) and loxoprofen prolonged the IC (162% of acetic acid infused period). This prolonged IC was approximately same as the control. Loxoprofen did not alter the threshold pressure and the maximal voiding pressure. These data suggest that PGE2 might not play a part of normal micturition and may play a part of the micturition reflex during acetic acid infusion. That is, loxoprofen might be useful for pathological hyperreflex of the micturition.

INTRALUMINAL ANTIBODIES TO MACROPHAGE MIGRATION INHIBITORY FACTOR DECREASE SUBSTANCE P INDUCED INFLAMMATORY CHANGES IN THE RAT BLADDER AND PROSTATE

PURPOSE

Noxious stimuli induce substance P (SP) secretion from nerve terminals, resulting in plasma extravasation, edema and hyperalgesia, commonly referred to as neurogenic inflammation. Since SP is a short-lived molecule, additional proinflammatory mediators maintain continued inflammation. The bladder contains stores of preformed macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, which is released into the lumen in response to SP. MIF may act in an amplifying manner to maintain or increase inflammation. Inducing inflammatory changes with SP, while sequestering released luminal MIF with an antibody, tested this hypothesis.

MATERIALS AND METHODS

In anesthetized rats the ureters were cut to isolate the bladder and the bladder contents were replaced with saline or antiMIF antibody (5 or 15 microg/ml), immediately followed by systemic SP or saline. Changes in the expression of inflammatory cytokines, and histological changes in the bladder and prostate were evaluated 1 hour later.

RESULTS

: Targeted array analysis identified increases in proinflammatory gene expression in the bladder and prostate as a result of SP. SP induced changes in MIF, cyclooxygenase-2, nerve growth factor, c-fos and edema were decreased by intraluminal anti-MIF.

CONCLUSIONS

SP increased MIF amounts in the bladder lumen. Sequestering luminal MIF with an antiMIF antibody decreased SP induced inflammatory changes in the bladder and prostate, suggesting that MIF is involved in acute pelvic visceral neurogenic inflammation. These data indicate that MIF released from the bladder sustains or amplifies SP induced inflammation, a possibility that agrees with known MIF proinflammatory functions. These data continue to support our hypothesis that MIF is a new target for intervention in pelvic viscera inflammation.

Detrusor responses to prostaglandin E2 and bladder outlet obstruction in wild-type and Ep1 receptor knockout mice

PURPOSE

Prostaglandins (PGs) are suggested to be involved in the pathophysiology of different bladder disorders and it has been demonstrated that cyclooxygenase-2 expression is increased as a consequence of bladder outflow obstruction. We investigated whether the PGE2 receptor EP1 is involved in the regulation of normal micturition, the response to intravesical PGE2 administration, and the development of bladder hypertrophy and overactivity due to bladder outlet obstruction (BOO).

MATERIALS AND METHODS

Moderate BOO was created in EP1 receptor knockout (EP1KO) mice and their WT counterparts. After 1 week cystometry was performed in conscious animals before and after PGE2 instillation. Findings were compared to those in unobstructed control animals. Bladder wet weight was measured to document the degree of hypertrophy after BOO.

RESULTS

There was no difference between unobstructed EP1KO and WT mice in urodynamic parameters but EP1KO mice did not respond to intravesical PGE2 instillation, while WT mice showed detrusor overactivity. The lack of EP1 receptor did not prevent bladder hypertrophy due to BOO. After BOO WT mice had pronounced detrusor overactivity, while this was negligible in EP1KO mice.

CONCLUSIONS

The EP1 receptor appears not to be essential for normal micturition or the mediation of bladder hypertrophy due to BOO but it seems to have a role in the development of detrusor overactivity caused by PGE2 and outlet obstruction.

Rapid Up-Regulation of Endothelial Nitric-Oxide Synthase in a Mouse Model ofEscherichia coliLipopolysaccharide-Induced Bladder Inflammation

Increases in the signaling molecule nitric oxide (NO) during inflammation may be linked not only to inducible nitric-oxide synthase (iNOS) but also to endothelial (e)NOS. Escherichia coli lipopolysaccharide (LPS) induces an inflammatory response in the bladder and rapidly increases phosphorylation of Akt/protein kinase B (Akt), a key enzyme regulating proliferation, apoptosis, and inflammation. Activated Akt phosphorylates human eNOS at serine 1177 and subsequently increases NOS activity. Because Akt and eNOS are both localized in the bladder urothelium, phosphorylation of eNOS by Akt provides an attractive mechanism for rapid increases in urinary NO production. Female mice were intraperitoneally injected with LPS (25 mg/kg) or pyrogen-free water (control). Four hours before LPS injection, some mice were injected with wortmannin, which inhibits Akt phosphorylation. Levels of urinary cyclic GMP, a downstream product of NO, increase 75% within 1 h after intraperitoneal injection of LPS, and this increase is blocked by wortmannin. Bladder eNOS and phosphorylated eNOS protein increase 94 and 151%, respectively, 1 h after LPS treatment, whereas iNOS was not detected. Wortmannin decreases eNOS phosphorylation by 60%. Furthermore, bladder Ca(2+)-dependent NOS activity (eNOS, neuronal NOS) is increased 79 +/- 20% 1 h after LPS treatment, whereas there is no increase in Ca(2+)-independent (iNOS) activity (n = 4). Increases in urinary cyclic GMP, NOS activity, and eNOS protein and phosphorylation 1 h after induction of inflammation with LPS, indicate that eNOS plays a role in the early response to bladder inflammation.

Macrophage Migration Inhibitory Factor Is Upregulated in an Endotoxin-Induced Model of Bladder Inflammation in Rats

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine found in epithelial cells as preformed stores, such that MIF release can activate innate immune responses. Our identification of MIF stores in the urothelium suggests that MIF may function in the bladder's initial response to infectious stimuli, such as lipopolysaccharide (LPS). To test this hypothesis, we observed changes in MIF, cyclooxygenase-2 (COX-2) and c-fos in the bladder, L6-S1 spinal cord, dorsal root ganglion (DRG), and major pelvic ganglion (MPG) and MIF changes in the prostate following intravesical LPS. Intravesical LPS induced bladder edema and leukocyte infiltration, as well as increased MIF protein and mRNA in the bladder and lumbosacral spinal cord. Expression of immediate-early gene c-fos, a transcription factor used as a marker of neuronal activation, increased in the L6-S1 spinal cord and L6-S1 DRG of rats that received LPS. We conclude that significant increases in bladder MIF expression and protein in response to intravesical LPS may represent part of this organ's initial innate immune response. In addition, MIF upregulation may represent a neural response to visceral inflammation. Finally, changes in prostate MIF content after intravesical LPS suggest that MIF may be involved in viscerovisceral interactions associated with chronic pelvic pain syndromes.

Protease-activated receptor-2-mediated contraction of urinary bladder is enhanced in cyclophosphamide-treated rats

Protease-activated receptor-2 (PAR-2) is activated by serine proteases, such as trypsin and mast cell tryptase. Recently, we have shown that activators of PAR-2 contract the rat urinary bladder mainly by stimulating release of prostaglandins (PGs) from the mucosal layer. In the present study, we investigated how the PAR-2-mediated responses are altered in rats with cyclophosphamide (CYP)-induced cystitis. The contractile responses to trypsin and PAR-2 activating peptide (PAR-2 AP; SLIGRL-NH2) in the urinary bladders were augmented by treatment of rats with CYP. The contractile effects of these PAR-2 activators on the smooth muscles of the urinary bladder were also potentiated after induction of cystitis by CYP. On the other hand, CYP-induced cystitis significantly attenuated contractions produced by PGE2 in the smooth muscles of the urinary bladder. The PAR-2-mediated contractions were significantly prevented by indomethacin or NS-398, an inhibitor of cyclooxygenase-2. Both trypsin and PAR-2 AP increased the release of PGE2 from the urinary bladder mucosa and smooth muscle. CYP-induced cystitis enhanced the PAR-2 activators-induced PGE2 releases from the urinary mucosa without affecting those from the smooth muscle of the urinary bladder. The PGE2 releases were prevented by indomethacin or NS-398. The mRNAs for PAR-2 in the urinary bladder mucosa and smooth muscle preparations were not altered in CYP-induced cystitis. These results suggest that PAR-2-mediated responses were enhanced in bladders from CYP-treated rats. The enhancement of PAR-2-mediated contraction might be ascribed to the increased production of PGs and the altered sensitivity of smooth muscle to PAR-2 activators.

Hydrochloric acid induced changes in macrophage migration inhibitory factor in the bladder, peripheral and central nervous system of the rat

PURPOSE

We established the presence of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) in the bladder and in nervous system structures innervating the bladder, and evaluated changes in MIF and cyclooxygenase-2 (COX-2) protein levels and expression following chemical cystitis.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized and a catheter was introduced into the bladder dome. Cystitis was induced by infusing 0.4 N HCl into the bladder. Control rats received a similar volume of saline. Two hours later the bladder, major pelvic ganglia (MPG), L6/S1 dorsal root ganglia (DRG) and L6/S1 spinal cord were removed and assayed for MIF and COX-2 protein, and mRNA using Western blot and quantitative reverse transcriptase-polymerase chain reaction techniques.

RESULTS

Immunohistochemistry showed MIF located mainly in the urothelium of saline treated rats. Instillation of HCl into the bladder resulted in marked epithelial denudation, moderate edema and vasodilatation in the submucosa. MIF protein levels decreased but MIF mRNA expression remained unchanged in bladders treated with HCl compared with controls. However, MIF protein and mRNA levels increased in the MPG, L6/S1 DRG and L6/S1 spinal cord of HCl treated animals. COX-2 protein was not detected in the bladder, DRG or MPG of saline-treated rats. However, a small amount was present in the L6/S1 cord. On the other hand, HCl treated rats showed marked increases in COX-2 protein levels in all tissues examined. Similarly although cox-2 mRNA was constitutively expressed in all tissues examined, expression increased following HCl treatment.

CONCLUSIONS

Chemical cystitis induced by intravesical HCl in rats increases the protein levels and mRNA expression of MIF and COX-2 in central and peripheral nervous system tissues that are involved in innervating the bladder. This finding suggests that MIF may be involved in bladder inflammation and may have a role in the peripheral and central nervous system pathways that regulate bladder reflexes in response to bladder inflammation.

Gene expression profiling of inflammatory bladder disorders

Inflammation underlies all major bladder pathologies including malignancy and represents a defense reaction to injury caused by physical damage, chemical substances, micro-organisms or other agents. During acute inflammation, activation of specific molecular pathways leads to an increased expression of selected genes whose products attack the insult, but ultimately should protect the tissue from the noxious stimulus. However, once the stimulus ceases, gene-expression should return to basal levels to avoid tissue damage, fibrosis, loss of function, and chronic inflammation. If this down-regulation does not occur, tissue fibrosis occurs as a serious complication of chronic inflammation. Although sensory nerve and most cells products are known to be key parts of the inflammatory puzzle, other key molecules are constantly being described that have a role in bladder inflammation. Therefore, as the database describing the repertoire of inflammatory mediators implicated in bladder inflammation increases, the central mechanisms by which injury can induce inflammation, cell damage, and repair often becomes less rather than more clear. To make sense of the vast knowledge of the genes involved in the inflammatory response may require analysis of the patterns of change and the elucidation of gene networks far more than definition of additional members of inflammatory cascades. This review discuss the appropriate use of microarray technology, which promises to solve both of these problems as well as identifying key molecules and mechanisms involved in the transition between acute and chronic inflammation.

COX-2 and prostanoid expression in micturition pathways after cyclophosphamide-induced cystitis in the rat

The purpose of this study was to determine the role of cyclooxygenase-2 (COX-2) and its metabolites in lower urinary tract function after induction of acute (4 h), intermediate (48 h), or chronic (10 day) cyclophosphamide (CYP)-induced cystitis. Bladders were harvested from euthanized female rats for analyses. Conscious cystometry was used to assess the effects of a COX-2-specific inhibitor, 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl2(5H)-furanone (DFU, 5 mg/kg sc), a disubstituted furanone, in CYP-induced cystitis. COX-2 mRNA was increased in inflamed bladders after acute (12-fold) and chronic (9-fold) treatment. COX-2 protein expression in inflamed bladders paralleled COX-2 mRNA expression. Prostaglandin D2-methoxime expression in the bladder was significantly (P < or = 0.01) increased in acute (3-fold) and chronic (5.5-fold) cystitis. Prostaglandin E2 was significantly (P < or = 0.01) increased (2-fold) in the bladder with intermediate (1.7-fold) and chronic (2.6-fold) cystitis. COX-2-immunoreactive cell profiles were distributed throughout the inflamed bladder and coexpressed histamine immunoreactivity. Conscious cystometry in rats treated with CYP + DFU showed increased micturition intervals 4 and 48 h after CYP treatment and decreased intravesical pressures during filling and micturition compared with rats treated with CYP + vehicle. These studies suggest an involvement of urinary bladder COX-2 and its metabolites in altered micturition reflexes with CYP-induced cystitis.

PGE2 action in human coronary artery smooth muscle: role of potassium channels and signaling cross-talk

Cyclic AMP-stimulating agents are powerful vasodilators, but our knowledge of the signal transduction mechanisms of these agents, particularly in human arteries, is limited. We now report direct molecular effects of prostaglandin E(2) (PGE(2)) on cultured human coronary artery smooth muscle cells (HCASMC). Patch-clamp studies revealed that 10 microM PGE(2) opens a high-conductance (approximately 200 pS), calcium-stimulated potassium (BK(Ca)) channel in intact HCASMC. In contrast, PGE(2) had no direct effect on channels in cell-free patches, indicating involvement of a soluble second messenger. Enzyme immunoassay demonstrated that PGE(2) enhances production of cAMP in HCASMC, but does not increase [cGMP]. Furthermore, forskolin, CPT-cAMP, or CPT-cGMP mimicked the stimulatory effect of PGE(2) on BK(Ca) channel activity. Interestingly, the response to PGE(2) was unaffected by inhibiting the cAMP-dependent protein kinase, but was antagonized by inhibitors of the cGMP-dependent protein kinase (PKG). Furthermore, cAMP-stimulated PKG activity mimicked the effect of PGE(2). These studies suggest a novel PGE(2) action in human arteries: opening of BK(Ca) channels via cAMP cross-activation of PKG in HCASMC. It is proposed that this signaling mechanism may mediate the vasodilatory response to cAMP-dependent agents in the human coronary and other vascular beds.

Prostaglandin E2 production and cyclooxygenase-2 induction in human urinary tract infections and bladder cancer

PURPOSE

Increased prostaglandin production correlates positively with cancer risk and cyclooxygenase (COX)-2, the inducible rate limiting enzyme for prostaglandin synthesis, is elevated in bladder cancer cases. Urinary prostaglandin levels and COX-2 expression in urine particulates may increase in urogenital cancer, including bladder cancer, and with infectious and inflammatory processes, including urinary tract infections and that resulting from bacillus Calmette-Guerin (BCG) treatment for bladder cancer.

MATERIALS AND METHODS

Urinary prostaglandin E2 levels were measured in patients with a urinary tract infection before and after treatment, urogenital cancer (including bladder cancer), bladder cancer in remission and bladder cancer with BCG treatment. COX-1 and COX-2 mRNA and protein were assessed in the human ureter, in normal human bladder muscle and urothelium, and in urine particulates from patients with urinary tract infections, bladder cancer and bladder cancer with BCG treatment.

RESULTS

COX-1 protein, and mRNA and COX-2 mRNA were expressed in the ureter, and bladder muscle and urothelium. Urinary prostaglandin E2 levels and COX-2 protein expression in urine particulates were elevated in patients with urinary tract infections and with bladder cancer compared with age matched controls. Successful treatment for urinary tract infections and bladder cancer lowers urinary prostaglandin E2 levels. Urinary prostaglandin E2 and COX-2 protein levels are elevated during BCG treatment.

CONCLUSIONS

Increased urinary prostaglandin E2 production and COX-2 protein expression correlate with urogenital cancer, urinary tract infections and inflammatory processes, such as those induced by BCG. Patients in whom urinary tract infection was treated with antibiotics or in whom bladder cancer is in remission have reduced urinary prostaglandin E2 compared with those who have active disease.

Gene expression profiling of mouse bladder inflammatory responses to LPS, substance P, and antigen-stimulation

Inflammatory bladder disorders such as interstitial cystitis (IC) deserve attention since a major problem of the disease is diagnosis. IC affects millions of women and is characterized by severe pain, increased frequency of micturition, and chronic inflammation. Characterizing the molecular fingerprint (gene profile) of IC will help elucidate the mechanisms involved and suggest further approaches for therapeutic intervention. Therefore, in the present study we used established animal models of cystitis to determine the time course of bladder inflammatory responses to antigen, Escherichia coli lipopolysaccharide (LPS), and substance P (SP) by morphological analysis and cDNA microarrays. The specific aim of the present study was to compare bladder inflammatory responses to antigen, LPS, and SP by morphological analysis and cDNA microarray profiling to determine whether bladder responses to inflammation elicit a specific universal gene expression response regardless of the stimulating agent. During acute bladder inflammation, there was a predominant infiltrate of polymorphonuclear neutrophils into the bladder. Time-course studies identified early, intermediate, and late genes that were commonly up-regulated by all three stimuli. These genes included: phosphodiesterase 1C, cAMP-dependent protein kinase, iNOS, beta-NGF, proenkephalin B and orphanin, corticotrophin-releasing factor (CRF) R, estrogen R, PAI2, and protease inhibitor 17, NFkB p105, c-fos, fos-B, basic transcription factors, and cytoskeleton and motility proteins. Another cluster indicated genes that were commonly down-regulated by all three stimuli and included HSF2, NF-kappa B p65, ICE, IGF-II and FGF-7, MMP2, MMP14, and presenilin 2. Furthermore, we determined gene profiles that identify the transition between acute and chronic inflammation. During chronic inflammation, the urinary bladder presented a predominance of monocyte/macrophage infiltrate and a concomitant increase in the expression of the following genes: 5-HT 1c, 5-HTR7, beta 2 adrenergic receptor, c-Fgr, collagen 10 alpha 1, mast cell factor, melanocyte-specific gene 2, neural cell adhesion molecule 2, potassium inwardly-rectifying channel, prostaglandin F receptor, and RXR-beta cis-11-retinoic acid receptor. We conclude that microarray analysis of genes expressed in the bladder during experimental inflammation may be predictive of outcome. Further characterization of the inflammation-induced gene expression profiles obtained here may identify novel biomarkers and shed light into the etiology of cystitis.