Biomedical subjects

Salvatore Cuzzocrea

Publications and source records attributed to Salvatore Cuzzocrea.

At least 73 records · Page 4Linked to original sources

PubMed2005

Green tea polyphenol extract attenuates ischemia/reperfusion injury of the gut.

Various studies have clearly demonstrated that green tea catechins possess potent antioxidative properties, and the preventive effects against various oxidative diseases have been reported. The aim of this study was to investigate the effect of green tea extract on the tissue injury caused by ischemia/reperfusion (I/R) of the gut. I/R injury of the intestine was caused by clamping both the superior mesenteric artery and the celiac trunk for 45 min followed by release of the clamp allowing reperfusion for 1 h or 4 h. This procedure results in splanchnic artery occlusion (SAO) shock. Rats subjected to SAO developed a significant fall in mean arterial blood pressure, and only 10% of the animals survived for the entire 4-h reperfusion period. Surviving animals were sacrificed for histological examination and biochemical studies. Rats subjected to SAO displayed a significant increase in tissue myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels, significant increases in plasma tumor necrosis factor (TNF)-alpha levels and marked injury to the distal ileum. Increased immunoreactivity to nitrotyrosine was observed in the ileum of rats subjected to SAO. Staining of sections of the ileum obtained from SAO rats with anti-intercellular adhesion molecule (ICAM-1) antibody and with anti-P-selectin antibody resulted in diffuse staining. Administration of green tea extract (20 and 10 mg kg(-1) i.v.) 15 min prior to the onset of gut reperfusion significantly reduced in a dose-dependent manner the fall in mean arterial blood pressure, the mortality rate, infiltration of the reperfused intestine with polymorphonuclear neutrophils (MPO activity), lipid peroxidation (MDA levels), production of TNF-alpha, and histological evidence of gut injury. Administration of green tea extract also markedly reduced nitrotyrosine formation and the up-regulation of ICAM-1 and P-selectin during reperfusion. In order to clarify that green tea extract might be useful in the therapy of I/R injury, we also investigated the effect of green tea extract (20 mg kg(-1) i.v.) when administered 5 min after the onset of gut reperfusion. Similar to the pretreatment approach, the post-treatment also significantly reduced the gut injury induced by I/R. These results demonstrate that green tea extract significantly reduces I/R injury of the intestine.

Animals↗

PubMed2005

5-Arylidene-2-imino-4-thiazolidinones: design and synthesis of novel anti-inflammatory agents.

The synthesis and pharmacological activity of 5-arylidene-2-imino-4-thiazolidinones (3a-8a) are described. All derivatives exhibited significant activity levels in models of acute inflammation such as carrageenan-induced paw and pleurisy edema in rats. In particular, 5-(3-methoxyphenylidene)-2-phenylimino-3-propyl-4-thiazolidinone (3a) displayed high levels of carrageenan-induced paw edema inhibition comparable to those of indomethacin. In addition the ability of such a new class of anti-inflammatory agents to inhibit COX isoforms was assessed in murine monocyte/macrophage J774 cell line assay. 5-(4-Methoxyphenylidene)-2-phenylimino-3-propyl-4-thiazolidinone (6a), the most interesting compound in such an experiment, was docked in the known active site of COX-2 protein and showed that its 4-methoxyarylidene moiety can easily occupy the COX-2 secondary pocket considered as the critical interaction for COX-2 selectivity.

Animals↗

PubMed2005

Green tea polyphenol extract attenuates lung injury in experimental model of carrageenan-induced pleurisy in mice.

Here we investigate the effects of the green tea extract in an animal model of acute inflammation, carrageenan-induced pleurisy. We report here that green tea extract (given at 25 mg/kg i.p. bolus 1 h prior to carrageenan), exerts potent anti-inflammatory effects in an animal model of acute inflammation in vivo. Injection of carrageenan (2%) into the pleural cavity of mice elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity that contained many neutrophils (PMNs), an infiltration of PMNs in lung tissues and increased production of nitrite/nitrate, tumour necrosis factor alpha. All parameters of inflammation were attenuated by green tea extract treatment. Furthermore, carrageenan induced an up-regulation of the adhesion molecule ICAM-1, as well as nitrotyrosine and poly (ADP-ribose) synthetase (PARS) formation, as determined by immunohistochemical analysis of lung tissues. Staining for the ICAM-1, nitrotyrosine, and PARS was reduced by green tea extract. Our results clearly demonstrate that treatment with green tea extract exerts a protective effect and offers a novel therapeutic approach for the management of lung injury.

Animals↗

PubMed2005

Inhibition or knock out of inducible nitric oxide synthase result in resistance to bleomycin-induced lung injury.

BACKGROUND: In the present study, by comparing the responses in wild-type mice (WT) and mice lacking (KO) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the role played by iNOS in the development of on the lung injury caused by bleomycin administration. When compared to bleomycin-treated iNOSWT mice, iNOSKO mice, which had received bleomycin, exhibited a reduced degree of the (i) lost of body weight, (ii) mortality rate, (iii) infiltration of the lung with polymorphonuclear neutrophils (MPO activity), (iv) edema formation, (v) histological evidence of lung injury, (vi) lung collagen deposition and (vii) lung Transforming Growth Factor beta1 (TGF-beta1) expression. METHODS: Mice subjected to intratracheal administration of bleomycin developed a significant lung injury. Immunohistochemical analysis for nitrotyrosine revealed a positive staining in lungs from bleomycin-treated iNOSWT mice. RESULTS: The intensity and degree of nitrotyrosine staining was markedly reduced in tissue section from bleomycin-iNOSKO mice. Treatment of iNOSWT mice with of GW274150, a novel, potent and selective inhibitor of iNOS activity (5 mg/kg i.p.) also significantly attenuated all of the above indicators of lung damage and inflammation. CONCLUSION: Taken together, our results clearly demonstrate that iNOS plays an important role in the lung injury induced by bleomycin in the mice.

Animals↗

PubMed2005

Reduced development of experimental periodontitis by treatment with M40403, a superoxide dismutase mimetic.

M40403, [manganese(II)dichloro[(4R,9R,14R,19R)-3,10,13,20,26 pentaazatetracyclo[20.3.1.0.(4,9)0(14,19)]hexacosa-1(26),-22(23),24-triene]], is a low-molecular-weight, synthetic, manganese-containing superoxide dismutase mimetic that removes superoxide anions without interfering with other reactive species known to be involved in inflammatory responses (e.g., nitric oxide, NO and peroxynitrite, ONOO-). As such, M40403 represents an important pharmacological tool to dissect the roles of superoxide anion in acute and chronic inflammation. For this purpose, the pharmacological profile of M40403 was evaluated in a rat model of periodontitis. Periodontitis was induced in rats by placing a 2/0 braided silk around the lower left first molar. On day 8 the gingivomucosal tissue encircling the first molar was removed for biochemical and histological analysis. Ligation significantly increased inducible nitric oxide synthase activity and expression, and gingival tissue revealed increased neutrophil infiltration, lipid peroxidation and positive staining for nitrotyrosine formation and poly (ADP-ribose) polymerase activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction. Intraperitoneal injection of M40403 (10 mg/kg daily for 8 days) significantly decreased all of the above-described markers of inflammation. This suggests compounds that inhibit the generation of superoxide anion, such as M40403 may be potentially useful for the treatment of periodontitis.

Alveolar Bone Loss↗

PubMed2005

Inhibitors of calpain activation (PD150606 and E-64) and renal ischemia-reperfusion injury.

Calpain activation has been implicated in the development of ischemia-reperfusion (I-R) injury. Here we investigate the effects of two inhibitors of calpain activity, PD150606 and E-64, on the renal dysfunction and injury caused by I-R of rat kidneys in vivo. Male Wistar rats were administered PD150606 or E-64 (3mg/kg i.p.) or vehicle (10%, v/v, DMSO) 30min prior to I-R. Rats were subjected to bilateral renal ischemia (45min) followed by reperfusion (6h). Serum and urinary biochemical indicators of renal dysfunction and injury were measured; serum creatinine (for glomerular dysfunction), fractional excretion of Na(+) (FE(Na), for tubular dysfunction) and urinary N-acetyl-beta-d-glucosaminidase (NAG, for tubular injury). Additionally, kidney tissues were used for histological analysis of renal injury, immunohistochemical analysis of intercellular adhesion molecule-1 (ICAM-1) expression and nitrotyrosine formation. Renal myeloperoxidase (MPO) activity (for polymorphonuclear leukocyte infiltration) and malondialdehyde (MDA) levels (for tissue lipid peroxidation) were determined. Both PD150606 and E-64 significantly reduced the increases in serum creatinine, FE(Na) and NAG caused by renal I-R, indicating attenuation of renal dysfunction and injury and reduced histological evidence of renal damage caused by I-R. Both PD150606 and E-64 markedly reduced the evidence of oxidative stress (ICAM-1 expression, MPO activity, MDA levels) and nitrosative stress (nitrotyrosine formation) in rat kidneys subjected to I-R. These findings provide the first evidence that calpain inhibitors can reduce the renal dysfunction and injury caused by I-R of the kidney and may be useful in enhancing the tolerance of the kidney against renal injury associated with aortovascular surgery or renal transplantation.

Acrylates↗

PubMed2005

The cyclopentenone prostaglandin 15-deoxydelta(12,14)-prostaglandin J2 attenuates the development of zymosan-induced shock.

OBJECTIVE: Multiple-organ failure (MOF) is defined as the progressive deterioration in function which occurs in several organs or systems in patients with septic shock, multiple trauma, severe burns, or pancreatitis. This study investigated the effect of 15-deoxy-delta(12,14)-PGJ2 (15d-PGJ2), a PPAR-gamma ligand, in a model of zymosan-induced nonseptic shock in mice. MATERIALS AND METHODS: Mice were randomly assigned to one of four groups (n=10 each) and treated i.p. as follows: group 1, zymosan (500 mg/kg suspended in saline solution) and vehicle (10% DMSO); group 2, zymosan (500 mg/kg suspended in saline solution) plus 15d-PGJ2 (30 microg/kg, suspended in 10% DMSO) 1 h before and 6 h after zymosan administration; group 3, 15d-PGJ2 (30 microg/kg, suspended in 10% DMSO; group 4, vehicle for PGJ2 (10% DMSO) always 1 h before and 6 h after saline administration. After 18 h mice were killed and tissues and biological fluids used for biochemical, immunohistochemical, and histological analysis. MEASUREMENTS AND RESULTS: 15d-PGJ2 inhibited the inflammatory response and significantly reduced peritoneal mononuclear cell infiltration and histological injury in mice. A significant protection was demonstrated in kidney, liver, and pancreas injury by the reduction in amylase, lipase, creatinine, AST, ALT, bilirubin, and alkaline phosphatase levels. 15d-PGJ2 also reduced the appearance of nitrotyrosine in the inflamed intestinal tissues. Histological examination revealed a significant reduction in zymosan-induced intestinal damage in 15d-PGJ2 treated mice. CONCLUSIONS: Our findings demonstrate that 15d-PGJ2 exerts potent anti-inflammatory effects on zymosan-induced shock.

Analysis of Variance↗

PubMed2005

Uric acid protects against secondary damage after spinal cord injury.

Peroxynitrite contributes to the pathogenesis of various neurodegenerative disorders through multiple mechanisms and is thought to mediate secondary neuronal cell death after spinal cord injury (SCI). Here we establish that physiologically relevant levels of uric acid (UA), a selective inhibitor of certain peroxynitrite-mediated reactions, block the toxic effects of peroxynitrite on primary spinal cord neurons in vitro. Furthermore, administration of UA at the onset of SCI in a mouse model inhibits several pathological changes in the spinal cord including general tissue damage, nitrotyrosine formation, lipid peroxidation, activation of poly(ADP-ribose) polymerase, and neutrophil invasion. More importantly, UA treatment improves functional recovery from the injury. Taken together, our findings support the concept that peroxynitrite contributes to the pathophysiology of secondary damage after SCI. They also raise the possibility that elevating UA levels may provide a therapeutic approach for the treatment of SCI as well as other neurological diseases with a peroxynitrite-mediated pathological component.

Animals↗

PubMed2005

Mice lacking the 110-kD isoform of poly(ADP-ribose) glycohydrolase are protected against renal ischemia/reperfusion injury.

The role of poly(ADP-ribose) (PAR) glycohydrolase (PARG) in the pathophysiology of renal ischemia/reperfusion (I/R) injury is not known. Poly(ADP-ribosyl)ation is rapidly stimulated in cells after DNA damage caused by the generation of reactive oxygen and nitrogen species during I/R. Continuous or excessive activation of poly(ADP-ribose) polymerase-1 produces extended chains of ADP-ribose on nuclear proteins and results in a substantial depletion of intracellular NAD(+) and subsequently, ATP, leading to cellular dysfunction and, ultimately, cell death. The key enzyme involved in polymer turnover is PARG, which possesses mainly exoglycosidase activity but can remove olig(ADP-ribose) fragments via endoglycosidic cleavage. Thus, the aim of this study was to investigate whether the absence of PARG(110) reduced the renal dysfunction, injury, and inflammation caused by I/R of the mouse kidney. Here, the renal dysfunction and injury caused by I/R (bilateral renal artery occlusion [30 min] followed by reperfusion [24 h]) in mice lacking PARG(110), the major nuclear isoform of PARG, was investigated. The following markers of renal dysfunction and injury were measured: Plasma urea, creatinine, aspartate aminotransferase, and histology. The following markers of inflammation were also measured: Myeloperoxidase activity, malondialdehyde levels, and plasma nitrite/nitrate. The degree of renal injury and dysfunction caused by I/R was significantly reduced in PARG(110)-deficient mice when compared with their wild-type littermates, and there were no differences in any of the biochemical parameters measured between sham-operated PARG(110)(-/-) mice and sham-operated wild-type littermates. Thus, it is proposed that endogenous PARG(110) plays a pivotal role in the pathophysiology of I/R injury of the kidney.

Animals↗

PubMed2005

Inhibitors of poly(ADP-ribose) polymerase modulate signal transduction pathways and the development of bleomycin-induced lung injury.

Poly(ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA, plays an important role in the tissue injury associated with inflammation. The aim of our study was to evaluate the therapeutic efficacy of in vivo inhibition of PARP in an experimental model of lung injury caused by bleomycin administration. Mice subjected to intratracheal administration of bleomycin developed significant lung injury and apoptosis (measured by Annexin V coloration). An increase of immunoreactivity to nitrotyrosine and PARP, as well as a significant loss of body weight and mortality, was observed in the lung of bleomycin-treated mice. Administration of the two PARP inhibitors 3-aminobenzamide (3-AB) or 5-aminoisoquinolinone (5-AIQ) significantly reduced the 1) loss of body weight, 2) mortality rate, 3) infiltration of the lung with polymorphonuclear neutrophils (myeloperoxidase activity), 4) edema formation, and 5) histological evidence of lung injury. Administration of 3-AB and 5-AIQ also markedly reduced nitrotyrosine formation and PARP activation. These results demonstrate that treatment with PARP inhibitors reduces the development of inflammation and tissue injury events induced by bleomycin administration in the mice.

Animals↗

PubMed2005

Erythropoietin reduces the degree of arthritis caused by type II collagen in the mouse.

OBJECTIVE: Erythropoietin (EPO) is a potent stimulator of erythroid progenitor cells, and its expression is enhanced by hypoxia. The aim of this study was to investigate the effect of EPO on collagen-induced arthritis (CIA) in the mouse. METHODS: CIA was induced by intradermal injection of bovine type II collagen (CII) and Freund's complete adjuvant. Starting on day 25, some of the mice with CIA received daily subcutaneous injections of EPO (1,000 units/kg). Two other groups of mice received sham treatment alone or sham treatment followed by EPO treatment, respectively. Arthritis was assessed clinically, radiologically, and histologically. Cytokine and chemokine levels were measured, and neutrophil infiltration into inflamed joints was quantitated. Immunohistochemistry studies were performed to measure protein nitrosylation. Chondrocyte apoptosis was assessed by TUNEL assay. RESULTS: Macroscopic clinical evidence of CIA first appeared as periarticular erythema and edema in the hind paws. The incidence of CIA was 100% by day 27 in the CII-challenged mice, and the severity of CIA progressed over a 35-day period, with radiographic evaluation revealing focal resorption of bone. Histopathologic features of CIA included erosion of the cartilage at the joint margins. Treatment with EPO starting at the onset of arthritis (day 25) ameliorated the clinical signs on days 26-35 and improved histologic status in the joints and paws. The degree of oxidative and nitrosative damage was significantly reduced in EPO-treated mice as indicated by decreased nitrotyrosine formation and poly(ADP-ribose) polymerase activation. Plasma levels of the proinflammatory cytokine tumor necrosis factor alpha were also significantly reduced by EPO treatment. In addition, EPO reduced the levels of apoptosis in chondrocytes in articular cartilage, as indicated by decreased TUNEL staining. CONCLUSION: These findings demonstrate that EPO exerts an antiinflammatory effect during chronic inflammation and is able to ameliorate the tissue damage associated with CIA.

Animals↗

PubMed2005

Effects of combination M40403 and dexamethasone therapy on joint disease in a rat model of collagen-induced arthritis.

OBJECTIVE: To investigate the effects of combination therapy with M40403, a superoxide dismutase mimetic (SODm), and dexamethasone (DEX) on collagen-induced arthritis (CIA) in rats. METHODS: CIA was elicited in Lewis rats by an intradermal injection of 100 mul of an emulsion of bovine type II collagen (CII) in Freund's incomplete adjuvant (IFA) at the base of the tail. On day 21, a second injection of CII in IFA was administered at the base of the tail. RESULTS: Lewis rats developed erosive arthritis of the hind paw when immunized with an emulsion of CII in IFA. The histopathology of CIA included erosion of the articular cartilage at the joint margins and subchondral bone resorption. Immunohistochemical analysis for nitrotyrosine, poly(ADP-ribose) polymerase (PARP), inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2) revealed positive staining in inflamed joints of collagen-treated rats. The combination therapy with M40403 2 mg/kg and DEX 0.01 mg/kg significantly reduced the development of the inflammatory process and reduced the degree of staining for iNOS, COX-2, nitrotyrosine, and PARP. No significant difference in the degree of staining between the combination therapy and the higher dose of DEX (0.1 mg/kg) was found. Furthermore, radiographic evidence of protection from bone resorption was apparent in the tibiotarsal joints of rats that received the combination therapy. CONCLUSION: This study shows that combination therapy with M40403 and DEX reduced the degree of chronic inflammation and tissue and bone damage associated with CIA in the rat. It supports the possible use of SODm in combination with steroids to reduce the dose necessary and the side effects related to the use of steroids in the management of chronic diseases such as rheumatoid arthritis.

Animals↗

PubMed2005

Synergistic interaction between methotrexate and a superoxide dismutase mimetic: pharmacologic and potential clinical significance.

OBJECTIVE: To investigate the effects of combination therapy with M40403 and methotrexate (MTX) on collagen-induced arthritis (CIA) in rats. METHODS: CIA was elicited in Lewis rats that had been assigned to different experimental groups, and the rats were treated daily, starting at the onset of arthritis (day 26), with M40403 2 mg/kg intraperitoneally, MTX 0.15 mg/kg orally, or combination therapy (M40403 2 mg/kg plus MTX 0.015 mg/kg). RESULTS: The histopathologic features of CIA in type II collagen-challenged rats included erosion of the articular cartilage and bone resorption. Treatment of rats with MTX 0.15 mg/kg orally delayed the development of clinical signs (days 26-35) and improved histologic status in the knee and paw, as clearly demonstrated by a significant reduction in erosion of the articular cartilage at the joint margins and subchondral bone resorption. Furthermore, radiographic evidence of protection against bone resorption and soft tissue swelling was apparent in the tibiotarsal joints of rats treated with MTX 0.15 mg/kg daily. Furthermore, combination therapy with M40403 2 mg/kg plus MTX 0.015 mg/kg exerted significant protection against the development of arthritis, similar to that observed with MTX alone at a dose of 0.15 mg/kg. In contrast, no significant protection was observed in animals treated with M40403 2 mg/kg alone or with MTX 0.015 mg/kg alone. CONCLUSION: This study provides the first evidence that M40403, a potent superoxide dismutase mimetic, exerts a significant synergistic effect with MTX in rats with CIA.

Animals↗

PubMed2005

Role of endogenous ligands for the peroxisome proliferators activated receptors alpha in the secondary damage in experimental spinal cord trauma.

The peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors related to retinoid, steroid, and thyroid hormone receptors. The aim of the present study was to examine the effects of endogenous PPAR-alpha ligand in an experimental model of spinal cord trauma. Spinal cord injury was induced in PPAR-alpha wild-type (WT) mice and PPAR-alpha knock out mice (PPAR-alpha KO) mice by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration (measured as an increase in myeloperoxidase activity) and apoptosis (measured by Annexin 5 staining). An increase of immunoreactivity to TNF-alpha was observed in the spinal cord of spinal cord-injured PPAR-alpha WT mice. Absence of a functional PPAR-alpha gene in PPAR-alphaKO mice resulted in a significant augmentation of all the above described parameters. In a separate set of experiments, we have also demonstrated that the absence of PPAR-alpha gene in PPAR-alphaKO mice significantly worsened the recovery of limb function (evaluated by motor recovery score). Thus, endogenous PPAR-alpha ligands reduce the degree of development of inflammation and tissue injury events associated with spinal cord trauma in the mice.

Age Factors↗

PubMed2005

Involvement of 5-lipoxygenase in spinal cord injury.

A traumatic spinal cord injury (SCI) induces a sequelae of events which conduce biochemical and cellular alterations. Here we compare the degree of spinal cord injury caused by the application of vascular clips, in mice lacking the 5-lipoxygenase and in the corresponding wild-type mice. Biochemical, immunohistochemical and functional studies revealed respectively an increase of neutrophils infiltration, of IL-1beta, TNF-alpha immunoreactivity, apoptosis (measured by Annexin-V staining) and loss of hind legs movement in SCI operated 5-LO wild-type mice. In contrast, the degree of (1) neutrophil infiltration at different time points, (2) cytokine expression (TNF-alpha and IL-1beta), (3) histological damage, (4) apoptosis, was markedly reduced in the tissues obtained from SCI operated 5-LO deficient mice and (5) the motor recovery was ameliorated.

Animals↗

PubMed2005

Role of poly(ADP-ribose) glycohydrolase (PARG) in shock, ischemia and reperfusion.

Poly(ADP-ribosyl)ation is regulated by the synthesizing enzyme poly(ADP-ribose) polymerase-1 (PARP-1) and the degrading enzyme poly(ADP-ribose) glycohydrolase (PARG). Homeostasis of poly(ADP-ribosyl)ation has been proposed to be an important regulator for pathogenesis in multi-cellular organisms. Although the role of PARP-1 in tissue damage, inflammation and ischemia has been extensively studied, the function of PARG in various cellular processes is largely unknown. Recent studies using chemical inhibitors of PARG and genetically engineered Drosophila and mouse models that carry a disrupted PARG gene have started to shed new light on the biological function of PARG in vivo. These animal models and cells isolated from them will be useful for further validation of PARG as a potential pharmaceutical target to intervene the pathogenesis induced by acute tissue injury, ischemia and inflammation.

Animals↗

PubMed2005

Shock, inflammation and PARP.

The activation of poly(ADP-ribose) polymerase (PARP) is well considered to play an important role in various patho-physiological conditions like inflammation and shock. A vast amount of circumstantial evidence implicates oxygen-derived free radicals (especially, superoxide and hydroxyl radical) and high-energy oxidants (such as peroxynitrite) as mediators of inflammation and shock. ROS (e.g., superoxide, peroxynitrite, hydroxyl radical and hydrogen peroxide) are all potential reactants capable of initiating DNA single strand breakage, with subsequent activation of the nuclear enzyme poly(ADP-ribose) synthetase (PARS), leading to eventual severe energy depletion of the cells, and necrotic-type cell death. During the last years, numerous experimental studies have clearly demonstrated the beneficial effects of PARP inhibition in cell cultures through rodent models and more recently in pre-clinical large animal models of acute and chronic inflammation. The aim of this review is to describe recent experimental evidence implicating PARP as a pathophysiological modulator of acute and chronic inflammation.

Animals↗

PubMed2005

Inhibition of tyrosine-kinase-mediated cellular signaling by tyrphostins AG 126 and AG556 modulates murine experimental acute pancreatitis.

BACKGROUND: The effects of the tyrosine kinase inhibitors, tyrphostin AG126 and AG556 in a murine model of acute pancreatitis are investigated. METHODS: Intraperitoneal injection of cerulein in mice resulted in a severe, acute pancreatitis, which was characterized by edema, neutrophil infiltration, tissue hemorrhage, and cell necrosis as well as elevation in the serum activities of amylase or lipase. RESULTS: Infiltration of the pancreatic tissue of these animals with neutrophils (measured as increase in myeloperoxidase activity) was associated with signs of enhanced lipid peroxidation (increased tissue levels of malondialdehyde). Immunohistochemical examination showed a marked increase in immunoreactivity for nitrotyrosine and poly (ADP-ribose) polymerase (PARP) in the pancreas of cerulein-treated mice. Pretreatment or posttreatment with tyrphostin AG126 and AG556, 2 different tyrosine kinase inhibitors, significantly reduced the degree of pancreatic inflammation and tissue injury (histologic score). In particular, the treatment with the 2 tyrosine kinase inhibitors reduced the cerulein-induced nitrotyrosine formation and PARP activation in the pancreas as well as the systemic release of tumor necrosis factor alpha. CONCLUSIONS: This study provides the first evidence that (1) prevention of the activation of protein tyrosine kinases reduces the development of acute pancreatitis, and (2) inhibition of the activity of certain tyrosine kinases may represent a novel approach for the therapy of acute pancreatitis.

Acute Disease↗