Captopril, an Angiotensin-converting enzyme inhibitor, attenuates the severity of acute pancreatitis in rats by reducing expression of matrix metalloproteinase 9

A Fatal Case of Lisinopril-Induced Acute Necrotizing Pancreatitis

Angiotensin-converting enzyme inhibitors (ACE-I), such as lisinopril, are used as first-line therapy in the treatment of hypertension, heart failure with reduced ejection fraction, and proteinuric chronic kidney disease due to their beneficial effects on reducing morbidity and mortality. Commonly cited adverse effects of lisinopril include hyperkalemia, acute kidney injury, and angioedema, and while uncommon, there have been reports of lisinopril-induced necrotizing pancreatitis in the literature. The true incidence of drug-induced pancreatitis is unknown since establishing a causal relationship between medication's adverse effects and disease occurrence is difficult; however, there are validated tools such as the Adverse Drug Reaction Probability Scale that can aid in determining causality. Here, we present a case of a 63-year-old man with a history of hypertension who was being treated with lisinopril for eight months and developed a fatal case of lisinopril-induced severe necrotizing pancreatitis.

Cytokines and inflammatory mediators: Markers involved in interstitial damage to the pancreas in two dengue fever cases associated with acute pancreatitis

Dengue viral (DENV) infections can lead to acute pancreatitis and associated tissue damage. This study examined the pancreas from two fatal cases of DENV for histopathological changes as well as for the detection of cytokines, and other inflammatory mediators. Tissue sections were prepared for examination by ultrastructural and histopathological techniques. Sections from the pancreas of non-infected individuals were prepared in parallel as a control. The presence of viral replication in macrophages was detected by co-staining for the proteins NS3 and CD68 by immunofluorescence. Immunohistochemistry was used to detect cells that expressed cytokines and inflammatory mediators to characterize the inflammatory response. Edema, acinar necrosis and fibrosis areas associated with a mononuclear infiltrate were found in infected tissues. The major site of virus replication appeared to be macrophages based on their exclusive presentation of the viral protein NS3. Pancreatic tissues from the infected individuals also displayed increased levels of high mobility group box-1, caspase-3, gelatinase B and tumor necrosis factor alpha compared to controls. The presence of virus replicating macrophages in the pancreas was associated with multiple changes in tissue structure that included elevated levels of cytokines and inflammatory markers that may differentiate acute pancreatitis due to DENV infections from other causes.

Lisinopril-Induced Acute Necrotizing Pancreatitis

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor that is used as one of the first-line antihypertensive medications. Necrotizing pancreatitis induced by the use of ACE inhibitors is an extremely rare occurrence. Although an uncommon risk factor, our aim is to further highlight that patients with chronic use of lisinopril can develop such complications and should be considered among the list of differential diagnoses for pancreatitis. A 53-year-old Caucasian male with a history of hypertension treated with lisinopril presented with a one-day history of nausea, vomiting, and severe epigastric pain. On physical examination, there was tenderness to palpation in the epigastric region and left lower quadrant without rebound tenderness or guarding. A complete blood count showed a slight increase in white blood cell count to 12,000 cells/mm³ and serum lipase level was elevated at 1028 U/L. A subsequent CT scan of the abdomen with contrast revealed findings supporting necrotizing pancreatitis. The patient was treated with conservative medical management with goal-directed intravenous fluid support, early enteral feeding, and pain control. His condition resolved, and he was found doing well on follow-up visits.

The potential therapeutic use of renin-angiotensin system inhibitors in the treatment of inflammatory diseases

Inflammation is a normal part of the immune response to injury or infection but its dysregulation promotes the development of inflammatory diseases, which cause considerable human suffering. Nonsteroidal anti-inflammatory agents are the most commonly prescribed agents for the treatment of inflammatory diseases, but they are accompanied by a broad range of side effects, including gastrointestinal and cardiovascular events. The renin-angiotensin system (RAS) is traditionally known for its role in blood pressure regulation. However, there is increasing evidence that RAS signaling is also involved in the inflammatory response associated with several disease states. Angiotensin II increases blood pressure by binding to angiotensin type 1 (AT₁ ) receptor, and direct renin inhibitors, angiotensin-converting enzyme (ACE) inhibitors and AT₁ receptor blockers (ARBs) are clinically used as antihypertensive agents. Recent data suggest that these drugs also have anti-inflammatory effects. Therefore, this review summarizes these recent findings for the efficacy of two of the most widely used antihypertensive drug classes, ACE inhibitors and ARBs, to reduce or treat inflammatory diseases such as atherosclerosis, arthritis, steatohepatitis, colitis, pancreatitis, and nephritis.

The effect of renin angiotensin system genetic variants in acute pancreatitis

OBJECTIVES

We sought association of genetic variants in the renin-angiotensin system (RAS) and vitamin D system with acute pancreatitis (AP) development and severity.

BACKGROUND

The endocrine RAS is involved in circulatory homeostasis through the pressor action of angiotensin II at its AT1 receptor. However, local RAS regulate growth and inflammation in diverse cells and tissues, and their activity may be suppressed by vitamin D. Intrapancreatic angiotensin II generation has been implicated in the development of AP.

METHODS

Five hundred forty-four white patients with AP from 3 countries (United Kingdom, 22; Germany, 136; and The Netherlands 386) and 8487 control subjects (United Kingdom 7833, The Netherlands 717) were genotyped for 8 polymorphisms of the RAS/vitamin D systems, chosen on the basis of likely functionality.

RESULTS

The angiotensin-converting enzyme I (rather than D) allele was significantly associated with alcohol-related AP when all cohorts were combined (P = 0.03). The renin rs5707 G (rather than A) allele was associated with AP (P = 0.002), infected necrosis (P = 0.025) and mortality (P = 0.046).

CONCLUSIONS

The association of 2 RAS polymorphisms with AP suggests the need for further detailed analysis of the role of RAS/vitamin D in the genesis or severity of AP, particularly given the ready potential for pharmacological manipulation of this system using existing marketed agents. However, further replication studies will be required before any such association is considered robust, particularly given the significant heterogeneity of AP causation and clinical course.

Fractalkine upregulates inflammation through CX3CR1 and the Jak-Stat pathway in severe acute pancreatitis rat model

Based on the function of chemokine fractalkine (FKN), acting as both adhesion and chemoattractant, FKN plays a role in acute inflammatory response. In this study, we investigated the mechanism of FKN mediated upregulation inflammation in severe acute pancreatitis (SAP) rat models. Western blot, reverse transcriptase-polymerase chain reaction, and immunofluorescence demonstrated that FKN and its receptor CX3CR1 were overexpressed in cerulein-stimulated AR42J cells. AG490 and FKN-siRNA inhibited activation of Janus kinase/signal transducers and activators of transcription (Jak/Stat) in cerulein-stimulated AR42J cells. Following exposure AG490 and FKN-siRNA inhibited tumor necrosis factor-alpha expression by enzyme-linked immunosorbent assay and immunohistochemistry in vivo the SAP rat models. These results showed FKN and CX3CR1 were involved inflammatory response in cerulein-stimulated AR42J cells. FKN upregulates inflammation through CX3CR1 and the Jak/Stat pathway in SAP rat models.

Inhibition of gelatinase B (matrix metalloprotease-9) activity reduces cellular inflammation and restores function of transplanted pancreatic islets

Islet transplantation provides an approach to compensate for loss of insulin-producing cells in patients with type 1 diabetes. However, the intraportal route of transplantation is associated with instant inflammatory reactions to the graft and subsequent islet destruction as well. Although matrix metalloprotease (MMP)-2 and -9 are involved in both remodeling of extracellular matrix and leukocyte migration, their influence on the outcome of islet transplantation has not been characterized. We observed comparable MMP-2 mRNA expressions in control and transplanted groups of mice, whereas MMP-9 mRNA and protein expression levels increased after islet transplantation. Immunostaining for CD11b (Mac-1)-expressing leukocytes (macrophage, neutrophils) and Ly6G (neutrophils) revealed substantially reduced inflammatory cell migration into islet-transplanted liver in MMP-9 knockout recipients. Moreover, gelatinase inhibition resulted in a significant increase in the insulin content of transplanted pancreatic islets and reduced macrophage and neutrophil influx compared with the control group. These results indicate that the increase of MMP-9 expression and activity after islet transplantation is directly related to enhanced leukocyte migration and that early islet graft survival can be improved by inhibiting MMP-9 (gelatinase B) activity.

siRNA-based targeting of fractalkine overexpression suppresses inflammation development in a severe acute pancreatitis rat model

Fractalkine (FKN), a chemokine that acts as both an adhesion molecule and a chemoattractant, is expressed in many inflammatory diseases. Chemokines play a crucial role in severe acute pancreatitis (SAP). This study used adenovirus-mediated siRNA to target FKN overexpression and assessed its ability to suppress inflammation development in a SAP rat model. Adenovirus-mediated FKN siRNA was transfected into cerulein-stimulated AR42J cells. The growth of cerulein-stimulated AR42J cells was determined by colony formation and MTT assays. The inhibitory effect of the FKN siRNA was studied in a SAP rat model in vivo and detected by ELISA, RT-PCR, western blot analysis and immunohistochemistry. FKN, IL-8 and TNF-α were found to be overexpressed in cerulein-stimulated AR42J cells by ELISA and western blot analysis (P<0.05). The animal experiments confirmed that FKN siRNA could inhibit inflammation development in SAP. The values of serum FKN, TNF-α and IL-8 levels were decreased after FKN siRNA treatment (P<0.05). Furthermore, western blotting and RT-PCR analysis showed that FKN protein and mRNA levels were decreased after injection with FKN siRNA (P<0.05). Immunohistochemistry also showed that inflammation was decreased after injection with FKN-siRNA in the SAP rat model. Treatment with siRNA can inhibit FKN overexpression and also suppresses inflammation development in a SAP rat model. More importantly, this study indicated that FKN, which is overexpressed in the SAP rat model, may serve as a novel and effective therapeutic target for SAP.

Fractalkine as a marker for assessment of severe acute pancreatitis

OBJECTIVE

The aim of this study was to study the role of fractalkine (FKN) in the development of severe acute pancreatitis (SAP) in animal model.

METHODS

Serum FKN levels in rat model (control, SAP6 h, 16 h, 24 h and 48 h) were determined by enzyme-linked immunosorbent assay. FKN mRNA and protein levels in the pancreas tissue were measured by reverse transcription polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry.

RESULTS

Serum FKN level in the SAP rat increased significantly (P < 0.05 compared with the control group). FKN mRNA and protein levels in pancreas and lung increased significantly and reached the peak at 16 h after the induction of SAP, while those in kidney reached the peak at 48 h. Immunohistochemistry showed the overexpression of FKN in pancreas, lung and kidney tissue.

CONCLUSION

FKN involves in the progression of SAP and might be a valuable marker for the assessment of SAP.

The Renin-angiotensin system and reactive oxygen species: implications in pancreatitis

SIGNIFICANCE

The renin-angiotensin system (RAS) is a circulating hormonal system involved in the regulation of blood pressure and circulating fluid electrolytes. Recent findings have revealed that locally generated angiotensin (Ang) II plays a pivotal role in normal physiology as well as pathophysiology in various tissues and organs, including the pancreas. This review article summarizes current progress that has been made in elucidating the putative roles of Ang II in both acute and chronic pancreatitis.

RECENT ADVANCES

A convergence of evidence suggests that the underlying mechanism may involve reactive oxygen species (ROS)-generating systems, such as nicotinamide adenine dinucleotide phosphate oxidase, and subsequent elevation of proinflammatory and profibrogenic gene expression as well as protein activity. More importantly, Ang II-induced ROS interacts with other ROS-generating systems to positively feed-forward the ROS-induced signaling.

CRITICAL ISSUES AND FUTURE DIRECTIONS

Advances in basic research indicate that RAS blockers may provide potential therapeutic role for the management of pancreatic inflammation and, more importantly, pancreatitis-associated complications. Genetic alterations resulting from a malfunction in the epigenetic control of pancreatic RAS could be a causative factor in the development of pancreatitis.

Review article: pancreatic renin-angiotensin systems in health and disease

BACKGROUND

In addition to the circulating (endocrine) renin-angiotensin system (RAS), local renin-angiotensin systems are now known to exist in diverse cells and tissues. Amongst these, pancreatic renin-angiotensin systems have recently been identified and may play roles in the physiological regulation of pancreatic function, as well as being implicated in the pathogenesis of pancreatic diseases including diabetes, pancreatitis and pancreatic cancer.

AIM

To review and summarise current knowledge of pancreatic renin-angiotensin systems.

METHODS

We performed an extensive PubMed, Medline and online review of all relevant literature.

RESULTS

Pancreatic RAS appear to play various roles in the regulation of pancreatic physiology and pathophysiology. Ang II may play a role in the development of pancreatic ductal adenocarcinoma, via stimulation of angiogenesis and prevention of chemotherapy toxicity, as well as in the initiation and propagation of acute pancreatitis (AP); whereas, RAS antagonism is capable of preventing new-onset diabetes and improving glycaemic control in diabetic patients. Current evidence for the roles of pancreatic RAS is largely based upon cell and animal models, whilst definitive evidence from human studies remains lacking.

CONCLUSIONS

The therapeutic potential for RAS antagonism, using cheap and widely available agents, and may be untapped and such roles are worthy of active investigation in diverse pancreatic disease states.

Activated NHE1 is required to induce early cardiac hypertrophy in mice

The Na+/H+ exchanger isoform 1 (NHE1) has been implicated as being causal in cardiac hypertrophy and the protein level and activity are elevated in the diseased myocardium. However, it is unclear whether mere elevation of the protein is sufficient for cardiac pathology, or whether activation of the protein is required. In this study, we examined the comparative effects of elevation of wild type and activated NHE1. Two mouse transgenic models that expressed either a wild type NHE1 protein or an activated NHE1 protein were characterized. Expression of activated NHE1 caused significant increases in heart weight to body weight, apoptosis, cross-sectional area, interstitial fibrosis and decreased cardiac performance. Expression of wild type NHE1 caused a much milder pathology. When we examined 2 or 10-week-old mouse hearts, there was neither elevation of calcineurin levels nor increased phosphorylation of ERK or p38 in either NHE1 transgenic mouse line. Expression of activated NHE1 in intact mice caused an increased sensitivity to phenylephrine-induced hypertrophy. Our results show that expression of activated NHE1 promotes cardiac hypertrophy to a much greater degree than elevated levels of wild type NHE1 alone. In addition, expression of activated NHE1 promotes greater sensitivity to neurohormonal stimulation. The results suggest that activation of NHE1 is a key component that accentuates NHE1-induced myocardial pathology.

Chronic angiotensin-converting enzyme inhibition up-regulates mouse kidney growth arrest specific-6 protein and the AXL subfamily of receptor tyrosine kinases

INTRODUCTION

Growth arrest specific-6 (GAS-6), a vitamin K-dependent protein, is a potential mediator in progressive and chronic renal disease, specifically as a mediator of abnormal mesangial cell proliferation. Nitric oxide and angiotensin II affect mesangial cell proliferation. However, an association between nitric oxide synthase or angiotensin II on GAS-6 expression in the kidney has not previously been examined. Thus, our aim was to examine the effects of antihypertensive angiotensin-converting enzyme inhibitors and chronic nitric oxide synthase inhibition on the kidney expression of GAS-6 and its receptors AXL, MER and RSE.

METHODS

Four groups of adult male C57BL/6J mice were studied: group 1, untreated controls (tap water for six weeks); group 2, treated orally with a nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 0.325 mg/ml for six weeks); group 3, treated orally with captopril (0.6875 mg/ml for six weeks); group 4, co-treated orally with L-NAME and captopril (same doses for six weeks). At the end of the study, kidneys were placed in fixative and processed to paraffin for immunohistochemical staining.

RESULTS

GAS-6 and its receptors were not present in control and L-NAME-treated mice. Positive GAS-6 staining was detectable only in those mice receiving some form of chronic dosing with captopril, whether they were treated with captopril only or with captopril and L-NAME. Immunohistochemical detection across cases for MER and RSE was rare, whereas AXL-positive staining in the kidney mirrored GAS-6 staining/expression. The staining of GAS6 and AXL was predominantly localised to the renal tubular cells.

CONCLUSIONS

These findings suggest that GAS-6 may not be a final common pathway for nitric oxide synthase inhibition-induced renal disease. Renal tubular GAS-6 expression following captopril treatment was unexpected and could be beneficial in preventing tubular atrophy following the onset of persistent systemic hypertension.

Short term effects of doxycycline on matrix metalloproteinases 2 and 9

PURPOSE

To investigate the short term effects of Doxycycline on MMP-2 and MMP-9.

METHODS

Short term effects of Doxycycline (100 mg B.I.D.) on plasma levels of MMP-2 and MMP-9 were investigated in 20 healthy subjects; the effects of Doxy, Acetylsalicylic acid, Nitrates, and Enalapril on MMP-9 release from were assessed in isolated polymorphonuclear cells.

RESULTS

In plasma, MMP-9 activity was reduced (-22%, 95% CI -32/-11; P = 0.002) starting at 12 h after doxy; in vitro, MMP-9 released from stimulated neutrophils was reduced by Doxy (-28%, 95% CI -43/-14; P = 0.001), inhibiting degranulation, and by nitrates (-52%, 95% CI -76/-28 P = 0.005), increasing three times both pro- and active-MMP-9 bound to neutrophils (P = 0.007 and 0.040, respectively).

CONCLUSIONS

Doxy decreases MMP-9 plasma levels by around 20%, within the first 12 h. The mechanism leading to such reduction seems due to the inhibition of PMN degranulation.

Cardiovascular homeostasis in hypotension associated with initial stages of severe acute pancreatitis

OBJECTIVES

To identify the mechanisms underlying hypotension during the early phase of severe acute pancreatitis (SAP) by analyzing whether an impaired response to vasoactive substances occurs in this pathological process.

METHODS

Experimental SAP was induced by infusing 5% sodium taurocholate through the main pancreatic duct in rats. Once mean arterial pressure (MAP) in animals with pancreatitis was reduced, different vasoactive substances and inhibitors were administered.

RESULTS

Administration of the nonspecific nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester caused a similar increase in MAP in rats with pancreatitis and control rats, whereas inducible nitric oxide synthase inhibition did not cause changes in MAP. Moreover, the hypertensive response to endothelin and angiotensin II was lower in pancreatitis. Inhibition of angiotensin II synthesis by the angiotensin-converting enzyme inhibitor perindopril in animals with pancreatitis caused severe hypotension, causing death in 40% of them. Finally, pressor hyporesponsiveness to angiotensin II in animals with pancreatitis was avoided by previous administration of perindopril and N omega-nitro-L-arginine methyl ester.

CONCLUSIONS

The SAP-induced hypotension is associated with a deficient pressor responsiveness to angiotensin II and endothelin-1. The renin-angiotensin system plays an important role in the control of MAP in animals with pancreatitis.