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INFLAMMATION AND IMMUNOPHARMACOLOGY
Okazaki City Medical Association, Public Health Center (T.Y.), Okazaki, Japan; and Departments of Internal Medicine and Bioregulation (A.K., S.N., T.A., T.O., H.O., T.N, T.J., M.I.), Experimental Pathophysiology and Tumor Biology (K.O., M.T., T.S.), and Gastroenterological Surgery (K.M.), Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
Received September 14, 2004; accepted December 13, 2004.
| Abstract |
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-smooth muscle actin, and gene expression of cytokine and growth factors were assessed, as well as circulating renin-angiotensin system components. Dose-dependent effects of combination therapy were also investigated. Only combination therapy attenuated gross alterations in the pancreas, as quantitatively confirmed by increases in pancreatic weights and decreases in myeloperoxidase activity, hydroxyproline content, histologic scores, relative fibrosis area, and relative area of
-smooth muscle actin-positive cells. Combination therapy suppressed up-regulation of tumor necrosis factor-
, platelet-derived growth factor-receptor
, and transforming growth factor-
1 mRNA in the pancreas. Dose dependence of combination therapy was recognized with reference to improvement in these parameters. The conclusions are that combination therapy synergistically alleviated pancreatic inflammation and fibrosis in male WBN/Kob rats. This effect may be related to suppression of tumor necrosis factor-
, platelet-derived growth factor-receptor
, and transforming growth factor-
1 mRNA. Compared with the either therapy alone, combination therapy with an angiotensin-converting enzyme inhibitor and an angiotensin II type 1 receptor blocker may be more beneficial for treating chronic pancreatitis.
There is a growing body of evidence that the renin-angiotensin system (RAS) plays a crucial role in the pathophysiology of fibrosis in the heart, kidney, and liver (Kagami et al., 1994
; Bataller et al., 2000
; Ostrom et al., 2003
). Both angiotensin-converting enzyme (ACE) inhibitors (ACEIs) and angiotensin II (AT-II) type 1 receptor blockers (ARBs) attenuate hepatic fibrosis by suppressing activation of hepatic stellate cells and reducing their production of transforming growth factor (TGF)-
1 in experimental animals, suggesting that AT-II and its type 1 receptor interaction may be intimately involved in hepatic fibrosis (Jonsson et al., 2001
; Yoshiji et al., 2001
). Furthermore, it has been demonstrated that anti-aldosteronic drugs suppress cardiac and renal fibrosis in experimental animals, so that aldosterone, the last product of the RAS, may also be involved in fibrosis in these organs (Epstein, 2001
; Rocha and Funder, 2002
).
Pancreatic stellate cells (PSCs), which have some similar properties to their counterparts in liver are involved in the pathogenesis of pancreatic fibrosis in both experimental animals and humans (Apte et al., 1999
; Haber et al., 1999
). Furthermore, the RAS is present intrinsically in the pancreas, and its gene expression is elevated during acute pancreatitis and chronic pancreatic hypoxia in experimental animals, suggesting an important role of RAS in the pathogenesis of pancreatic injury (Leung et al., 2000
; Chan et al., 2000
). We recently demonstrated that both lisinopril, an ACEI, and candesartan, an ARB, in drinking water attenuate pancreatic inflammation and fibrosis by suppressing induction of TGF-
1 mRNA and blocking activation of PSCs in male WBN/Kob rats (Kuno et al., 2003
; Yamada et al., 2003
). However, the effective doses of ACEI and ARB observed in the previous studies are too high for the clinical use.
It is well documented that addition of ARB to ACEI and combination therapy with both drugs can either additively or synergistically exert cardio- and renoprotection in experimental animals and humans (McKelvie et al., 1999
; Mogensen et al., 2000
; Rossing et al., 2003
). These findings strongly suggested the possibility that combination therapy with ACEI and ARB may exert an additive or synergistic effect on pancreatic fibrosis and to test this hypothesis the present study was performed with our WBN/Kob rats. The purposes were to 1) determine whether ineffective doses of lisinopril and candesartan might in combination reduce pancreatic inflammation and fibrosis; 2) assess the effects of combination therapy on circulating components of the RAS and cytokine and growth factors mRNA in the pancreas to clarify mechanisms; and 3) investigate dose dependence of combination therapy in the model.
| Materials and Methods |
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Groups of Animals and Treatment. Twenty-three WBN/Kob (10-week-old) rats were randomly divided into the four groups, receiving no treatment (n = 6; untreated group), lisinopril (20 mg/l in drinking water) (n = 5, lisinopril group), candesartan (10.5 mg/l) (n = 5; candesartan group), and the combination of lisinopril (20 mg/l) and candesartan (10.5 mg/l) (n = 7; combination group). In a second experiment, 21 animals (10-week-old) were divided into untreated (n = 6; untreated group), and three combination therapy groups, the latter receiving lisinopril (20 mg/l) plus candesartan (10.5 mg/l) (n = 5; combination group), lisinopril (6 mg/l) plus candesartan (8.4 mg/l) (n = 5; medium combination group), and lisinopril (3 mg/l) plus candesartan (4.2 mg/l) (n = 5; low combination group).
The concentrations of lisinopril and candesartan in drinking water, 20 and 10.5 mg/l, and more than twice of those were earlier found to be ineffective for attenuating pancreatic inflammation and fibrosis in the present model (Kuno et al., 2003
; Yamada et al., 2003
). The estimated doses in the single therapy groups were 2 and 1 mg/kg/day, respectively (Kuno et al., 2003
; Yamada et al., 2003
). In the present experiments, lisinopril was dissolved in drinking water, and candesartan was dissolved in 1:1 mix of ethanol and polyethylene glycol, warmed to 60 centigrade, and then 1 N sodium carbonate solution was added before being dissolved in drinking water (Yamada et al., 2003
). Untreated group was given water containing equal volume of ethanol, polyethylene glycol, and sodium carbonate solution without lisinopril and candesartan. Fresh solutions were given three times a week, for a total of 10 weeks, and the amount consumed was calculated. Body weights were recorded weekly. Five male Wistar rats (20 week old) were used as nonpancreatitis controls.
Tissue Sampling. All WBN/Kob rats treated for 10 weeks were killed with an overdose of pentobarbital sodium (Abbott Laboratories, North Chicago, IL) after taking blood from the abdominal aorta. Each pancreas was immediately removed and samples were stored at 80 centigrade for determination of myeloperoxidase (MPO) activity and hydroxyproline content, or in liquid nitrogen for eventual determination of cytokine and growth factors mRNA levels by reverse transcription-polymerase chain reaction (RT-PCR). Tissue was also fixed in 10% buffered formalin for histological assessment and immunohistochemistry. Serum and plasma containing ethylenediamine tetraacetic acid sodium were kept at 80 centigrade for eventual determination of ACE (serum), AT-II (plasma), and aldoseterone (serum). In addition, pancreases from 20-week-old Wistar rats were immediately placed in liquid nitrogen for RT-PCR analyses.
Histological Analyses. Pancreas tissues, obtained from both duodenal and splenic lobes, were fixed with 10% buffered formalin and routinely processed for embedding in paraffin, sectioned, and stained with hematoxylin and eosin and Azan. Histological observation was performed using a microscope having the object lens of 10x, intermittent lens of 4x, and eyepiece lens of 10x (Olympus BH-2, Olympus Co., Tokyo, Japan). The histological status of inflammation in each animal was evaluated by a pathologist who was unaware of the groups, with reference to the grades of inflammatory cell infiltration, interstitial edema, acinar cell necrosis, hemorrhage, and fibrosis, as reported previously (Yamada et al., 2001
, 2003
; Kuno et al., 2003
). Each factor was graded as none, mild, moderate, and severe, scored as 0, 1, 2, and 3, respectively. Quantity of fibrosis was analyzed under the microscope (Olympus BH-2, Olympus Co., Tokyo, Japan) connected with the 3CCD color video camera (DXC-950, Sony Co., Tokyo, Japan) with the aid of an image processor (Image Processor for Analytical Pathology; Sumica Technoservise, Osaka, Japan). The percentage of aniline-blue positive fibrous tissue per total area in whole Azan-stained pancreas section was measured except lymph nodes and major vessels, if included (Kuno et al., 2003
; Yamada et al., 2003
). The results were then used to calculate values relative to the control cases, set at 100%.
Immunohistochemistry for
-Smooth Muscle Actin. Tissues were stained with mouse anti-human
-smooth muscle actin (
-SMA) monoclonal antibody (DakoCytomation California Inc., Carpiteria, CA), which can detect rat
-SMA as described previously (Kuno et al., 2003
; Yamada et al., 2003
). The relative area of
-SMA-positive cells per total area was also evaluated as described for "Histological Analyses".
Measurement of Pancreatic Myeloperoxidase Activity. Pancreatic MPO activity, an indirect quantitative index of granulocyte infiltration, was determined as described previously (Yamada et al., 2001
, 2003
; Kuno et al., 2003
). MPO activity was determined by measuring H2O2-dependent oxidation of 3,3',5,5' tetramethylbenzidine and expressed as units per gram wet weight of pancreas.
Measurement of Pancreatic Hydroxyproline Content. Hydroxyproline content, an indicator of collagen deposition, was determined as reported previously (Kuno et al., 2003
; Yamada et al., 2003
). Hydroxyproline levels were calculated using a standard curve made with 4-hydroxy-1-proline and expressed as micrograms per gram of tissue.
Measurement of Serum Angiotensin-Converting Enzyme Activity, Plasma Angiotensin II Levels, and Serum Aldosterone Levels. Serum ACE activity was determined by using a commercially available kit, ACE color (Fujirebio Co., Tokyo, Japan), and expressed as IU per liter.
AT-II in the plasma containing ethylenediamine tetraacetic acid sodium was determined by radioimmunoassay as reported previously (Iwahana et al., 1996
). Briefly, plasma was incubated with a rabbit anti-AT-II antibody and 125I-labeled AT-II and then a goat antibody for rabbit immunoglobulin. After adding polyethylene glycol, the radioactivity of the pellet was measured using a counter. The amount of AT-II was calculated using a standard curve generated using angiotensin II human.
Serum aldosterone was determined with a commercially available aldosterone radioimmunoassay kit II (Dinabott Co., Tokyo, Japan) and expressed as picograms per milliliter.
Reverse Transcription-Polymerase Chain Reaction. Total RNA was extracted from frozen pancreatic tissue with TRIzol reagent (Invitrogen, Carlsbad, CA), and 2 mg was reverse transcribed into cDNA using an oligo(dT)1218 primer (Invitrogen), Superscript II RNase H-Reverse transcriptase (Invitrogen), and an RNase inhibitor (Toyobo Co., Ltd., Osaka, Japan). The polymerase chain reaction was performed with reaction mixtures containing 2.5 mM dNTP, 10 mM sense and anti-sense primers, and 5 units/ml TaqDNA polymerase (Takara Shuzo Co. Otsu, Japan) in a thermal cycler for 1 min at 94°C, 1 min at 55°C [tumor necrosis factor (TNF)-
, platelet-derived growth factor (PDGF)-B, PDGF-receptor
(PDGF-R
),
-actin] or 62°C [transforming growth factor (TGF)-
1], and 2 min at 72°C, for 34 (TNF-
), 28 (PDGF-B), 30 (PDGF-R
), 32 (TGF-
1), and 22 (
-actin) cycles, and then an extension reaction was carried out at 72°C for 5 min.
Sequences of primers for TNF-
, PDGF-B, PDGF-R
, TGF-
1, and
-actin were listed in Table 1. PCR products were electrophoresed on 1% agarose gels, visualized by ethidium bromide staining and photographed under ultraviolet light.
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The relative expression intensity of each mRNA band was determined with an image analyzer (NIH Image), and semiquantitative analyses relative to
-actin were preformed.
Statistics. Data are expressed as arithmetic means ± standard deviations. Statistical differences among groups were identified using the one-way analysis of variance, followed by multiple comparisons using the least significance difference method. The Mann-Whitney's U test was used for statistical analyses of the histologic scores, relative fibrosis area, and relative area of
-SMA-positive cells.
| Results |
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Macroscopic Findings. The pancreases in the untreated, lisinopril, and candesartan groups had widespread brown and red foci (Fig. 1, AC, respectively). In sharp contrast, the pancreases in the combination group had almost intact appearances (Fig. 1D) as observed in the pancreas in Wistar rat (not shown).
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Histological Analyses. Focal severe inflammation in the pancreas was evident in the untreated group (Fig. 2A). This was characterized by neutrophil and lymphocyte infiltration, interstitial edema, hemorrhage, and occasional acinar cell necrosis. Fibrosis was noted as replacing acini, being also found between remaining acini. Neither lisinopril nor candesartan had any significant effects on these inflammatory changes (Fig. 2, B and C). However, the combination therapy dramatically reduced the inflammatory changes, resulting in limited foci of lymphocyte infiltration with slight fibrosis (Fig. 2D). No histological alteration in the pancreas was present in Wistar rat (Fig. 2E). Significant reduction of inflammatory scores was observed for almost all parameters in the combination group compared with the untreated, lisinopril, and candesartan groups (Table 3). Relative fibrosis area calculated by Azan-stained area in the pancreas tended to be decreased to 55.6 ± 19.0% in the combination group compared with 100% set for the untreated group.
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Immunohistochemistry for
-Smooth Muscle Actin.
-SMA-positive cells with the morphology of activated PSCs were localized in the peri-acinar fibrotic areas and vascular walls in the untreated, lisinopril, and candesartan groups (not shown). In contrast,
-SMA-positive cells were observed only in the vascular walls in the combination group. Decrease in the relative area of
-SMA-positive cells was noted, although it did not reach statistical significance (Table 3).
Pancreatic Myeloperoxidase Activity. Pancreatic MPO activity, an indirect index of granulocyte infiltration, was significantly suppressed in the combination group compared with those in the untreated and candesartan groups (Table 2).
Pancreatic Hydroxyproline Content. The combination therapy significantly suppressed the increase in pancreatic hydroxyproline content, an indirect index of collagen deposition, compared with those in untreated, lisinopril, and candesartan groups (Table 2).
Serum Angiotensin-Converting Enzyme Activity, Plasma Angiotensin II Levels, and Serum Aldosterone Levels. Serum ACE activity and plasma AT-II levels were significantly decreased in the lisinopril and combination groups compared with those in untreated and candesartan groups, respectively. Serum aldosterone levels were not significantly decreased in the combination group compared with those of other groups (Table 4).
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Expression of Tumor Necrosis Factor-
, Platelet-Derived Growth Factor-B, Platelet-Derived Growth Factor-Receptor
, and Transforming Growth Factor-
1 mRNA. RT-PCR revealed TNF-
, PDGF-R
, and TGF-
1 mRNA to be overexpressed in the pancreas in the untreated group, whereas they were detected at only low levels in male Wistar rats (Fig. 3). However, PDGF-B mRNA was not up-regulated in the untreated groups compared with that in male Wistar rats. Although lisinopril and candesartan alone did not alter TNF-
, PDGF-R
, and TGF-
1 mRNA levels, the combination therapy suppressed up-regulation of all three mRNAs. Semiquantitative analysis of each mRNA relative to
-actin revealed that TNF-
, PDGF-R
, and TGF-
1 mRNA were significantly up-regulated in the untreated group compared with Wistar rats and they were suppressed in the combination group (Table 5).
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Doses of Lisinopril and Candesartan, Body Weights, and Pancreas Weights in the Dose-Dependence Study. Next, the dose-dependent effects of the combination therapy were assessed. The average doses of lisinopril in the low and medium combination and combination groups were 0.29 ± 0.01, 0.62 ± 0.06, and 2.27 ± 0.12 mg/kg/day, respectively. Those of candesartan were 0.41 ± 0.01, 0.87 ± 0.08, and 1.19 ± 0.06 mg/kg/day, respectively. The body weights were significantly lower in all three combination groups than in the untreated group, and the pancreas weights were significantly higher (Table 6).
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Dose Dependence of the Combination Therapy Effects on Histological Findings. In line with earlier studies, untreated animals showed severe inflammation and fibrosis in the pancreas (Fig. 4A). Limited foci of severe and moderate focal inflammation remained in the low and medium combination groups, respectively (Fig. 4, B and C), so that protective effects assessed by histologic scores were observed with regard to acinar cell necrosis in the low combination group and acinar cell necrosis and fibrosis in the medium combination group, respectively (Table 7). In contrast, significant reduction was noted for all histologic scores in the combination group (Fig. 4D; Table 7). The relative fibrosis areas were significantly decreased in all three combination groups compared with the untreated group. The relative area of
-SMA-positive cells was significantly decreased in the medium combination group and tended to be decreased in the low combination and combination groups (Table 7).
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Dose Dependence of the Combination Therapy Effects on Pancreatic Myeloperoxidase Activity and Pancreatic Hydroxyproline Content. Pancreatic MPO activity and pancreatic hydroxyproline content were significantly decreased in the three combination groups compared with those in the untreated group (Table 6).
| Discussion |
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-SMA-positive cells (an index of stellate cell activation), and relative fibrosis area. Furthermore, the combination therapy suppressed up-regulation of TNF-
, PDGF-R
, and TGF-
1 mRNAs in the pancreas. We speculate that suppression of TNF-
mRNA may lead to decreased production of cytokine and reduced inflammatory response. Furthermore, suppression of PDGF-R
and TGF-
1 mRNA might account for prevention of pancreatic stellate cell activation and pancreatic fibrosis. We additionally demonstrated dose dependence of the protective effects of combination therapy.
We recently reported that lisinopril, an ACEI, and candesartan, an ARB, in drinking water suppress pancreatic inflammation and fibrosis in the present model (Kuno et al., 2003
; Yamada et al., 2003
). However, the doses were much higher than the maximal clinical doses (lisinopril, 21.3 mg/kg/day, 65-fold; and candesartan, 13.9 mg/kg/day, 70-fold). Since ACEI and ARB suppress the RAS by pharmacologically different mechanisms, the combination therapy with ACEI and ARB might be expected to be safer and more effective in inhibiting AT-II function than single therapy with twice doses of either agent. It was well documented that the combination therapy with ACEI and ARB has advantages over either therapy alone at low doses for treating heart and kidney diseases in the experimental models and humans (McKelvie et al., 1999
; Mogensen et al., 2000
; Nakamura et al., 2003
; Rossing et al., 2003
). These findings prompted us to explore the effect of the combination therapy on chronic pancreatitis. Since the single therapies with more than twice of the present single doses were reported to be ineffective for treating chronic pancreatitis (lisinopril, 5.1 ± 0.5 mg/kg/day, Kuno et al., 2003
; candesartan, 4.3 ± 0.3 mg/kg/day, Yamada et al., 2003
), we defined the protective effect of the combination therapy as synergistic.
The serum levels of lisinopril and candesartan in the combination therapy are estimated to be around 18 and 55 ng/ml, respectively, from the data of the previous studies (Kuno et al., 2003
; Yamada et al., 2003
). Since pancreatic weights were increased and pancreatic MPO activity, pancreatic hydroxyproline content, and some histologic scores were decreased in the low and medium combination groups compared with the untreated group in the study of dose dependence, the combination therapy with lower doses of both drugs could still exert protective effects. Considering that the calculated doses of lisinopril and candesartan were 0.29 ± 0.01 and 0.41 ± 0.01 mg/kg/day in the low combination group, it is possible that combination therapy with the maximal clinical doses of both drugs (lisinopril, 0.33 mg/kg/day and candesartan, 0.20 mg/kg/day) may alleviate pancreatic inflammation and fibrosis in cases of human chronic pancreatitis.
Since both lisinopril and candesartan are widely used as antihypertensive drugs in humans, one might speculate that they may decrease blood pressure in the present model. However, the combination therapy with much higher doses of ACEI and ARB did not cause significant decrease in blood pressure in rats with myocardial infarction (Nakamura et al., 2003
). It has been well documented that the combination therapy with ACEI and ARB did not cause excessive decrease in blood pressure in human (McKelvie et al., 1999
; Mogensen et al., 2000
; Rossing et al., 2003
). Together, it was speculated that the combination therapy may not cause excessive decrease in blood pressure in the present study.
TNF-
, a proinflammatory cytokine, is expressed in acinar cells and infiltrating macrophages in acute pancreatitis (Gukovskaya et al., 1997
). It is reported that TNF-
released from acinar cells is involved in the development of pancreatitis by mediating early inflammatory reactions (Gukovskaya et al., 1997
; Xie et al., 2001a
). Its inhibition reduces acute pancreatic damage and improves survival with acute pancreatitis in rats (Hughes et al., 1996
). Moreover, tissue expression of TNF-
is involved in the onset of chronic pancreatitis in the present model (Xie et al., 2001b
). Thus, we assessed tissue TNF-
mRNA levels and confirmed up-regulation in the untreated group. Only combination therapy suppressed this.
PDGF, a dimerized protein secreted by infiltrated inflammatory cells, including macrophages and platelets, induces proliferation of PSCs (Apte et al., 1999
; Luttenberger et al., 2000
). It consists of two polypeptide chains linked via disulfide bonds and has three isoforms, PDGF-A, PDGF-B, and PDGF-AB, with PDGF-B having the most potent effects in vitro (Apte et al., 1999
). The PDGF receptor is composed of two types,
and
, which recognize all three types of PDGF and PDGF-B, respectively. PDGF-B and PDGF-R
, but not PDGF-R
, are closely associated with fibrosis in human and experimental pancreatitis (Ebert et al., 1998
; Haber et al., 1999
). Furthermore, PDGF-B mRNA is up-regulated in dibutyltin dichloride-induced chronic pancreatitis (Inoue et al., 2002
). We here found PDGF-R
mRNA to be up-regulated in the present model, whereas PDGF-B mRNA was unchanged. Again, only combination therapy suppressed this up-regulation of PDGF-R
mRNA.
It is well established that TGF-
1, a multifunctional cytokine, mediates fibrosis in various organs (Waltenberger et al., 1993
; Yoshioka et al., 1993
; Bedossa et al., 1995
), and TGF-
1 precursors and its latent binding protein are observed in inflamed lesions with fibrosis in human chronic pancreatitis (Van Laethem et al., 1995
). TGF-
1 promotes pancreatic fibrosis and inhibition of its expression results in reduction of extracellular matrix protein in experimental animals (Van Laethem et al., 1996
; Menke et al., 1997
). As reported previously, TGF-
1 mRNA was here found to be up-regulated and the combination therapy suppressed this.
AT-II directly induces proliferation of pancreatic stellate cells as well as digestive enzyme secretion by acinar cells in vitro, both of which were abolished in the presence of ARBs (Reinehr et al., 2004
; Hama et al., 2004
; Tsang et al., 2004
). We speculate that inhibition of AT-II by the combination therapy may have similar effects in the present model. Moreover, AT-II is a potent vasoconstrictor, and ACEIs increase vasodilatory factors, including bradykinin, nitric oxide, and prostaglandin (Campbell et al., 1994
). The combination therapy could thus increase pancreatic blood flow by both blocking AT-II function and increasing vasodilatory factors, thereby improving pancreatic ischemia, which was reported to be one element in the pathogenesis of chronic pancreatitis (Mori et al., 1988
). Moreover, interaction between AT-II and its type 1 receptor may result in secretion of aldosterone, which may be involved in cardiac and renal fibrosis in the experimental animals (Epstein, 2001
; Rocha and Funder, 2002
). In fact, combination therapy with an ACEI and an ARB resulted in greater decrease in circulating aldosterone levels than the either agent alone in the RESOLVD study (McKelvie et al., 1999
). To our knowledge, no reports are available regarding the role of aldosterone in chronic pancreatitis. We hypothesized that protection might be related to its decrease, but contrary to expectation, the combination therapy did not cause further depress of serum aldosterone levels compared with single lisinopril therapy, suggesting that aldosterone may not be involved in the pathogenesis of pancreatic fibrosis.
There are sporadic reports demonstrating that ACEIs caused acute pancreatitis in humans (Madsen and Jacobsen, 1995
; Muchnick and Mehta, 1999
). Although we were able to reduce the effective dose of lisinopril by combined administration with candesartan, caution may be necessary when lisinopril is used for treating chronic pancreatitis in humans.
In conclusion, the combination therapy with lisinopril and candesartan may synergistically alleviate chronic pancreatic inflammation and fibrosis in male WBN/Kob rats by suppressing up-regulation of TNF-
, PDGF-R
, and TGF-
1 mRNA, resulting in the prevention of pancreatic stellate cell activation and pancreatic fibrosis. We propose that combination therapy with an ACEI and an ARB may allow reduction of effective doses so that treatment of chronic pancreatitis with such agents will become possible. Further studies in this area are clearly warranted.
| Footnotes |
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ABBREVIATIONS: WBN/Kob, Wistar Bonn/Kobori; RAS, renin-angiotensin system; ACE, angiotensin-converting enzyme; ACEI, angiotensin-converting enzyme inhibitor; AT-II, angiotensin II; ARB, angiotensin II receptor blocker; MPO, myeloperoxidase; PSC, pancreatic stellate cell; RT-PCR, reverse transcription-polymerase chain reaction;
-SMA,
-smooth muscle actin; TNF-
, tumor necrosis factor-
; PDGF, platelet-derived growth factor; PDGF-R
, platelet-derived growth factor-receptor
; TGF-
1, transforming growth factor-
1.
Address correspondence to: Dr. Tamaki Yamada, Okazaki City Medical Association, Public Health Center, 1-9-1 Tatsumi-nishi, Okazaki, Aichi, Japan, 444-0875. E-mail: t-yamada{at}okazaki-med.or.jp
| References |
|---|
|
|
|---|
Apte MV, Haber PS, Darby SJ, Rodgers SC, McCaughan GW, Korsten MA, Pirola RC, and Wilson JS (1999) Pancreatic stellate cells are activated by proinflammatory cytokines: implications for pancreatic fibrogenesis. Gut 44: 534541.
Bataller R, Gines P, Nicolas JM, Gorbig MN, Garcia-Ramallo E, Gasull X, Bosch J, Arroyo V, and Rodes J (2000) Angiotensin II induces contraction and proliferation of human hepatic stellate cells. Gastroenterology 118: 11491156.[CrossRef][Medline]
Bedossa P, Peltier E, Terris B, Franco D, and Poynard T (1995) Transforming growth factor-
1 (TGF-
1) and TGF-
1 receptors in normal, cirrhotic and neoplastic livers. Hepatology 21: 760766.[CrossRef][Medline]
Campbell DJ, Kladis A, and Dunkan AM (1994) Effects of converting enzyme inhibitors on angiotensin and bradykinin. Hypertension 23: 439449.
Chan WP, Fung ML, Nobiling R, and Leung PS (2000) Activation of local renin-angiotensin system by chronic hypoxia in rat pancreas. Mol Cell Endocrinol 160: 107114.[CrossRef][Medline]
Ebert M, Kasper HU, Hernberg S, Friess H, Büchler MW, Roessner A, Korc M, and Malfertheiner P (1998) Overexpression of platelet-derived growth factor (PDGF) B chain and type
PDGF receptor in human chronic pancreatitis. Dig Dis Sci 43: 567574.[CrossRef][Medline]
Epstein M (2001) Aldosterone as a mediator of progressive renal dysfunction. Intern Med 40: 573583.[Medline]
Gukovskaya AS, Gukovsky I, Zaninovic V, Song M, Sandoval D, Gukovsky S, and Pandol SJ (1997) Pancreatic acinar cells produce, release and respond to tumor necrosis factor-
. Role in regulating cell death and pancreatitis. J Clin Investig 100: 18531862.[Medline]
Haber PS, Keogh QW, Apte MV, Moran CS, Stewart NL, Crawford DHG, Pirola RC, McCaughan GW, Ramm GA, and Wilson JS (1999) Activation of pancreatic stellate cells in human and experimental pancreatic fibrosis. Am J Pathol 155: 10871095.
Hama K, Ohnishi H, Yasuda H, Ueda N, Mashima H, Satoh Y, Hanatsuka K, Kita H, Ohashi A, Tamada K, et al. (2004) Angiotensin II stimulates DNA synthesis of rat pancreatic stellate cells by activating ERK through EGF receptor. Biochem Biophys Res Commun 315: 905911.[CrossRef][Medline]
Hughes CB, Grewal HP, Gaber LW, Kotb M, El-din AB, Mann L, and Gaber AO (1996) Anti-TNF
therapy improves survival and ameliorates the pathophysiologic sequelae in acute pancreatitis in the rat. Am J Surg 171: 274280.[CrossRef][Medline]
Inoue M, Ino Y, Gibo J, Ito T, Hisano T, Arita Y, and Nawata H (2002) The role of monocyte chemoattractant protein-1 in experimental chronic pancreatitis model induced by dibutyltin dichloride in rats. Pancreas 25: e64e70.[CrossRef][Medline]
Iwahana M, Tokumoto M, Maikishi N, Takatori O, and Miyazaki N (1996) Fundamental evaluation of no-extraction method of angiotensin II by radioimmuno assay. Igaku Yakugaku 36: 297303.
Jonsson JR, Clouston AD, Ando Y, Kelemen LI, Horn MJ, Adamson MD, Purdie DM, and Powell EE (2001) Angiotensin-converting enzyme inhibition attenuates the progression of rat hepatic fibrosis. Gastroenterology 121: 148155.[CrossRef][Medline]
Kagami S, Border WA, Miller DE, and Noble NA (1994) Angiotensin II stimulates extracellular matrix protein synthesis through induction of transforming growth factor-
expression in rat glomerular mesangial cells. J Clin Investig 93: 24312437.
Kuno A, Yamada T, Masuda K, Ogawa K, Sogawa M, Nakamura S, Nakazawa T, Ohara H, Nomura T, Joh T, et al. (2003) Angiotensin-converting enzyme inhibitor attenuates pancreatic inflammation and fibrosis in male Wistar Bonn/Kobori rats. Gastroenterology 124: 10101019.[CrossRef][Medline]
Leung PS, Chan WP, and Nobiling R (2000) Regulated expression of the pancreatic renin-angiotensin system in experimental pancreatitis. Mol Cell Endocrinol 166: 121128.[CrossRef][Medline]
Luttenberger T, Schmid-Kotsas A, Menke A, Siech M, Beger H, Adler G, Grünert A, and Bachem MG (2000) Platelet-derived growth factors stimulate proliferation and extracellular matrix synthesis of pancreatic stellate cells: implications in pathogenesis of pancreatic fibrosis. Lab Investig 80: 4755.[Medline]
Madsen JS and Jacobsen IA (1995) Angiotensin converting enzyme inhibitor therapy and acute pancreatitis. Blood Press 4: 369371.[Medline]
McKelvie RS, Yusuf S, Pericak D, Avezum A, Burns RJ, Probstfield J, Tsuyuki RT, White M, Rouleau J, Latini R, et al. (1999) Comparisons of candesartan, enalapril and their combination in congestive heart failure: randomized evaluation of strategies for left ventricular dysfunction (RESOLVD) pilot study. Circulation 100: 10561064.
Menke A, Yamaguchi H, Gress TM, and Adler G (1997) Extracellular matrix protein is reduced by inhibition of TGF-
1 in pancreatitis in the rat. Gastroenterology 113: 295303.[CrossRef][Medline]
Mogensen CE, Neldam S, Tikkanen I, Oren S, Viskoper R, Watts RW, and Copper ME (2000) Randomized controlled trial of dual blockade of renin-angiotensin system in patients with hypertension, microalbuminuria and non-insulin dependent diabetes: the candesartan and lisinopril microalbuminuria (CALM) study. BMJ 321: 14401444.
Mori Y, Yokoyama J, Nishimura M, and Ikeda Y (1988) A new diabetic strain of rat with exocrine pancreatic insufficiency, in Diabetes Secondary to Pancreatopathy (Tiengo A, Del Prato S, Alberti KG, and Vanic M eds) pp 107112, Elsevier Science, Amsterdam.
Muchnick JS and Mehta JL (1999) Angiotensin-converting enzyme inhibitor-induced panceratitis. Clin Cardiol 22: 5051.[Medline]
Nakamura Y, Yoshiyama M, Omura T, Yoshida K, Izumi Y, Takeuchi K, Kim S, Iwao H, and Yoshikawa J (2003) Beneficial effects of combination of ACE inhibitor and angiotensin II type 1 receptor blocker on cardiac remodeling in rat myocardial infarction. Cardiovasc Res 57: 4854.
Okazaki K, Uchida K, Ohana M, Nakase H, Uose S, Inai M, Matsushima Y, Katamura K, Ohmori K, and Chiba T (2000) Autoimmune-related pancreatitis is associated with autoantibodies and a Th1/Th2-type cellular immune response. Gastroenterology 118: 573581.[CrossRef][Medline]
Ostrom RS, Naugle JE, Hase M, Gregorian C, Swaney JS, Insel PA, Brunton LL, and Meszaros JG (2003) Angiotensin II enhances adenylyl cyclase signaling via Ca2+/calmodulin Gp-Gs cross-talk regulates collagen production in cardiac fibroblasts. J Biol Chem 278: 2446124468.
Reinehr R, Zoller S, Klonowski-Stumpe H, Kordes C, and Hössinger D (2004) Effects of angiotensin II on rat pancreatic stellate cells. Pancreas 28: 129137.[CrossRef][Medline]
Rocha R and Funder JW (2002) The pathophysiology of aldosterone in the cardiovascular system. Ann NY Acad Sci 970: 89100.[Medline]
Rossing K, Pietraszek L, Jacobsen P, and Parving H-H (2003) Renoprotective effects of adding angiotensin II receptor blocker to maximal recommended doses of ACE inhibitor in diabetic nephropathy: a randomized double-blind crossover trial. Diabetes Care 26: 22682274.
Tsang SW, Cheng CH, and Leung PS (2004) The role of the pancreatic renin-angiotensin system in acinar digestive enzyme secretion and in acute pancreatitis. Regul Pept 119: 213219.[CrossRef][Medline]
Van Laethem JL, Deviere J, Resibois A, Rickaert F, Vertongen P, Ohtani H, Cremer M, Miyazono K, and Robberecht P (1995) Localization of transforming growth factor-
1 expression and its binding protein in human chronic pancreatitis. Gastroenterology 108: 18731881.[CrossRef][Medline]
Van Laethem JL, Robberecht P, Resibois A, and Deviere J (1996) Transforming growth factor-
promotes development of fibrosis after repeated courses of acute pancreatitis in mice. Gastroenterology 110: 576582.[CrossRef][Medline]
Waltenberger J, Lundin L, Oberg K, Wilander E, Miyazono K, Heldin C-H, and Funa K (1993) Involvement of transforming growth factor-
in the formation of fibrotic lesions in carcinoid heart disease. Am J Pathol 142: 7178.[Abstract]
Xie MJ, Motoo Y, Su SB, and Sawabu N (2001a) Expression of clusterin in pancreatic acinar cell injuries in vivo and in vitro. Pancreas 22: 126134.[CrossRef][Medline]
Xie MJ, Motoo Y, Su SB, and Sawabu N (2001b) Expression of tumor necrosis factor-
, interleukin-6 and interferon-
in spontaneous chronic pancreatitis in the WBN/Kob rat. Pancreas 22: 400408.[CrossRef][Medline]
Yamada T, Hashimoto T, Sogawa M, Kobayashi S, Kaneda K, Nakamura S, Kuno A, Sano H, Ando T, Kobayashi S, et al. (2001) Involvement of T cells in development of chronic pancreatitis in male Wistar Bonn/Kobori rats: protective effects of tacrolimus. Am J Physiol 281: G1397G1404.
Yamada T, Kuno A, Masuda K, Ogawa K, Sogawa M, Nakamura S, Ando T, Sano H, Nakazawa T, Ohara H, et al. (2003) Candesartan, an angiotensin II receptor antagonist, suppresses pancreatic inflammation and fibrosis in rats. J Pharmacol Exp Ther 307: 1723.
Yoshiji H, Kuriyama S, Yoshii J, Ikenaka Y, Noguchi R, Nakatani T, Tsujinoue H, and Fukui H (2001) Angiotensin-II type 1 receptor interaction is a major regulator for liver fibrosis development in rats. Hepatology 34: 745750.[CrossRef][Medline]
Yoshioka K, Takemura T, Murakami K, Okada M, Hino S, Miyamoto H, and Maki S (1993) Transforming growth factor-
protein and mRNA in glomeruli in normal and diseased human kidney. Lab Investig 68: 154163.[Medline]
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