Cholecystokinin fails to promote pancreatic regeneration in diabetic rats following the induction of experimental pancreatitis

Acute pancreatitis induces a transient hypercoagulable state in murine models

BACKGROUND/OBJECTIVES

Although understudied, risk of venous thromboembolism (VTE) appears to be increased during acute pancreatitis (AP). We aimed to further characterize a hypercoagulable state associated with AP utilizing thromboelastography (TEG), a readily available, point of care test.

METHODS

AP was induced in C57/Bl6 mice using l-arginine and caerulein. TEG was performed with citrated native samples. The maximum amplitude (MA) and coagulation index (CI), a composite marker of coagulability, were evaluated. Platelet aggregation was assessed using whole blood collagen-activated platelet impedance aggregometry. Circulating tissue factor (TF), the initiator of extrinsic coagulation, was measured with ELISA. A VTE model using IVC ligation followed by measurement of clot size and weight was evaluated. After IRB approval and consent, blood samples from patients hospitalized with a diagnosis of AP were evaluated by TEG.

RESULTS

Mice with AP displayed a significant increase in MA and CI, consistent with hypercoagulability. Hypercoagulability peaked at 24 h after induction of pancreatitis, then returned to baseline by 72 h. AP resulted in significantly increased platelet aggregation and elevated circulating TF. Increased clot formation with AP was observed in an in vivo model of deep vein thrombosis. In a proof of concept, correlative study, over two thirds of patients with AP demonstrated an elevated MA and CI compared to the normal range, consistent with hypercoagulability.

CONCLUSIONS

Murine acute pancreatitis results in a transient hypercoagulable state that can be assessed by TEG. Correlative evidence for hypercoagulability was also demonstrated in human pancreatitis. Further study to correlate coagulation measures to incidence of VTE in AP is warranted.

Mechanisms of Post-Pancreatitis Diabetes Mellitus and Cystic Fibrosis-Related Diabetes: A Review of Preclinical Studies

Anatomical proximity and functional correlations between the exocrine and endocrine pancreas warrant reciprocal effects between the two parts. Inflammatory diseases of the exocrine pancreas, such as acute or chronic pancreatitis, or the presence of cystic fibrosis disrupt endocrine function, resulting in diabetes of the exocrine pancreas. Although novel mechanisms are being increasingly identified, the intra- and intercellular pathways regulating exocrine-endocrine interactions are still not fully understood, making the development of new and more effective therapies difficult. Therefore, this review sought to accumulate current knowledge regarding the pathogenesis of diabetes in acute and chronic pancreatitis, as well as cystic fibrosis.

Experimental Acute Pancreatitis Models: History, Current Status, and Role in Translational Research

Acute pancreatitis is a potentially severe inflammatory disease that may be associated with a substantial morbidity and mortality. Currently there is no specific treatment for the disease, which indicates an ongoing demand for research into its pathogenesis and development of new therapeutic strategies. Due to the unpredictable course of acute pancreatitis and relatively concealed anatomical site in the retro-peritoneum, research on the human pancreas remains challenging. As a result, for over the last 100 years studies on the pathogenesis of this disease have heavily relied on animal models. This review aims to summarize different animal models of acute pancreatitis from the past to present and discuss their main characteristics and applications. It identifies key studies that have enhanced our current understanding of the pathogenesis of acute pancreatitis and highlights the instrumental role of animal models in translational research for developing novel therapies.

Multiple Hits in Acute Pancreatitis: Components of Metabolic Syndrome Synergize Each Other's Deteriorating Effects

Introduction

The incidence of acute pancreatitis (AP) and the prevalence of metabolic syndrome (MetS) are growing worldwide. Several studies have confirmed that obesity (OB), hyperlipidemia (HL), or diabetes mellitus (DM) can increase severity, mortality, and complications in AP. However, there is no comprehensive information on the independent or joint effect of MetS components on the outcome of AP. Our aims were (1) to understand whether the components of MetS have an independent effect on the outcome of AP and (2) to examine the joint effect of their combinations.

Methods

From 2012 to 2017, 1435 AP cases from 28 centers were included in the prospective AP Registry. Patient groups were formed retrospectively based on the presence of OB, HL, DM, and hypertension (HT). The primary endpoints were mortality, severity, complications of AP, and length of hospital stay. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated.

Results

1257 patients (55.7 ± 17.0 years) were included in the analysis. The presence of OB was an independent predictive factor for renal failure [OR: 2.98 (CI: 1.33–6.66)] and obese patients spent a longer time in hospital compared to non-obese patients (12.1 vs. 10.4 days, p = 0.008). HT increased the risk of severe AP [OR: 3.41 (CI: 1.39–8.37)], renal failure [OR: 7.46 (CI: 1.61–34.49)], and the length of hospitalization (11.8 vs. 10.5 days, p = 0.020). HL increased the risk of local complications [OR: 1.51 (CI: 1.10–2.07)], renal failure [OR: 6.4 (CI: 1.93–21.17)], and the incidence of newly diagnosed DM [OR: 2.55 (CI: 1.26–5.19)]. No relation was found between the presence of DM and the outcome of AP. 906 cases (mean age ± SD: 56.9 ± 16.7 years) had data on all four components of MetS available. The presence of two, three, or four MetS factors increased the incidence of an unfavorable outcome compared to patients with no MetS factors.

Conclusion

OB, HT, and HL are independent risk factors for a number of complications. HT is an independent risk factor for severity as well. Components of MetS strongly synergize each other’s detrimental effect. It is important to search for and follow up on the components of MetS in AP.

Preexisting Diabetes Elevates Risk of Local and Systemic Complications in Acute Pancreatitis: Systematic Review and Meta-analysis

The prevalence of diabetes mellitus (DM) and acute pancreatitis (AP) increases continuously, therefore, to understand the effects of preexisting diabetes on AP is crucially needed. Here, we performed a systematic review and meta-analysis in which AP patients including DM and non-DM groups were sorted. Several outcome parameters were analyzed, and the odds ratio (OR) and standardized mean difference with 95% confidence intervals (CIs) were calculated.We found 1417 articles, of which 9 articles involving 354,880 patients were analyzed. More complications were seen in diabetic patients than in non-DM patients (OR, 1.553 [95% CI, 1.266-1.904]; P < 0.001). Intensive care unit admission (OR, 1.799 [95% CI, 1.442-2.243]; P < 0.001) and renal failure (OR, 1.585 [95% CI, 1.278-1.966]; P < 0.001) were more frequent in DM patients. There was a tendency of higher mortality and local complications (OR, 1.276 [95% CI, 0.991-1.643]; P = 0.059; and OR, 1.267 [95% CI, 0.964-1.659]; P = 0.090, respectively) in preexisting DM. Length of hospitalization was longer in DM patients (standardized mean difference, 0.217 [95% CI, 0.075-0.360]; P = 0.003). Preexisting DM negatively influences the outcome of AP and increases the risk of renal failure, local complications, and mortality.

Relationship between the exocrine and endocrine pancreas after acute pancreatitis

AIM: To determine the prevalence and time course of pancreatic exocrine insufficiency in individuals with newly diagnosed prediabetes or diabetes mellitus after acute pancreatitis.

METHODS: Relevant literature cited in three major biomedical journal databases (EMBASE, MEDLINE, and Scopus) was reviewed independently by two authors. There were no language constraints but the search was limited to human studies. Studies included were cohort studies of adult patients who were discharged after an attack of acute pancreatitis. Patients were excluded if they were under 18 years of age or had a previous diagnosis of prediabetes or diabetes mellitus, pancreatic exocrine insufficiency, or chronic pancreatitis. The main outcome measure was the prevalence of concomitant pancreatic exocrine insufficiency in patients who were diagnosed with prediabetes and diabetes mellitus after an attack of acute pancreatitis. Subgroup analysis was conducted for patients who were diagnosed with prediabetes only and those who were diagnosed with diabetes mellitus only. Subgroup analysis looking at the time course of concomitant pancreatic exocrine and endocrine insufficiency was also conducted. Pooled prevalence and corresponding 95% confidence intervals were calculated for all outcome measures and P-values < 0.05 were deemed statistically significant.

RESULTS: Eight clinical studies comprising of 234 patients met all eligibility criteria. The pooled prevalence of newly diagnosed prediabetes or diabetes in individuals after acute pancreatitis was 43% (95%CI: 30%-56%). The pooled prevalence of pancreatic exocrine insufficiency in individuals after acute pancreatitis was 29% (95%CI: 19%-39%). The prevalence of concomitant pancreatic exocrine insufficiency in individuals with newly diagnosed prediabetes or diabetes was 40% (95%CI: 25%-55%). The prevalence of concomitant pancreatic exocrine insufficiency among individuals with prediabetes alone and diabetes mellitus alone was 41% (95%CI: 12%-75%) and 39% (95%CI: 28%-51%), respectively. Further analysis showed that the prevalence of concomitant pancreatic exocrine insufficiency in individuals with prediabetes or diabetes decreases over time after an attack of acute pancreatitis.

CONCLUSION: Pancreatic exocrine insufficiency occurs in 40% of individuals with newly diagnosed prediabetes or diabetes mellitus after acute pancreatitis. Further studies are needed to investigate the pathogenesis of diabetes in this setting.

Insulin protects pancreatic acinar cells from palmitoleic acid-induced cellular injury

Acute pancreatitis is a serious and sometimes fatal inflammatory disease where the pancreas digests itself. The non-oxidative ethanol metabolites palmitoleic acid (POA) and POA-ethylester (POAEE) are reported to induce pancreatitis caused by impaired mitochondrial metabolism, cytosolic Ca²⁺ ([Ca²⁺]_i) overload and necrosis of pancreatic acinar cells. Metabolism and [Ca²⁺]_i are linked critically by the ATP-driven plasma membrane Ca²⁺-ATPase (PMCA) important for maintaining low resting [Ca²⁺]_i. The aim of the current study was to test the protective effects of insulin on cellular injury induced by the pancreatitis-inducing agents, ethanol, POA, and POAEE. Rat pancreatic acinar cells were isolated by collagenase digestion and [Ca²⁺]_i was measured by fura-2 imaging. An in situ [Ca²⁺]_i clearance assay was used to assess PMCA activity. Magnesium green (MgGreen) and a luciferase-based ATP kit were used to assess cellular ATP depletion. Ethanol (100 mm) and POAEE (100 μm) induced a small but irreversible Ca²⁺ overload response but had no significant effect on PMCA activity. POA (50–100 μm) induced a robust Ca²⁺ overload, ATP depletion, inhibited PMCA activity, and consequently induced necrosis. Insulin pretreatment (100 nm for 30 min) prevented the POA-induced Ca²⁺ overload, ATP depletion, inhibition of the PMCA, and necrosis. Moreover, the insulin-mediated protection of the POA-induced Ca²⁺ overload was partially prevented by the phosphoinositide-3-kinase (PI3K) inhibitor, LY294002. These data provide the first evidence that insulin directly protects pancreatic acinar cell injury induced by bona fide pancreatitis-inducing agents, such as POA. This may have important therapeutic implications for the treatment of pancreatitis.

Insulin protects pancreatic acinar cells from cytosolic calcium overload and inhibition of plasma membrane calcium pump

Acute pancreatitis is a serious and sometimes fatal inflammatory disease of the pancreas without any reliable treatment or imminent cure. In recent years, impaired metabolism and cytosolic Ca(2+) ([Ca(2+)](i)) overload in pancreatic acinar cells have been implicated as the cardinal pathological events common to most forms of pancreatitis, regardless of the precise causative factor. Therefore, restoration of metabolism and protection against cytosolic Ca(2+) overload likely represent key therapeutic untapped strategies for the treatment of this disease. The plasma membrane Ca(2+)-ATPase (PMCA) provides a final common path for cells to "defend" [Ca(2+)](i) during cellular injury. In this paper, we use fluorescence imaging to show for the first time that insulin treatment, which is protective in animal models and clinical studies of human pancreatitis, directly protects pancreatic acinar cells from oxidant-induced cytosolic Ca(2+) overload and inhibition of the PMCA. This protection was independent of oxidative stress or mitochondrial membrane potential but appeared to involve the activation of Akt and an acute metabolic switch from mitochondrial to predominantly glycolytic metabolism. This switch to glycolysis appeared to be sufficient to maintain cellular ATP and thus PMCA activity, thereby preventing Ca(2+) overload, even in the face of impaired mitochondrial function.

Epidemiological study of pancreatic diabetes in Japan in 2005: a nationwide study

OBJECTIVES

There have been few epidemiological studies on pancreatic diabetes. In this study, we determined the incidence and pathology of pancreatic diabetes in Japan.

METHODS

We examined the epidemiology of pancreatic diabetes in Japan in 2005 by using a nationwide stratified random-sampling method. Especially, we focused on newly developed diabetes in association with the occurrence of pancreatic disease (true pancreatic diabetes).

RESULTS

A total of 19,500 individuals received treatment for true pancreatic diabetes, accounting for 0.8% of patients with diabetes. Prevalence was estimated to be 15.2 per 100,000 with an annual onset incidence of 1.1 per 100,000. With regard to the complications in true pancreatic diabetes, the incidence of retinopathy was lower than that in types 1 and 2 diabetes. Among true pancreatic diabetes with chronic pancreatitis, alcoholic pancreatitis was found in the largest sector. Furthermore, as many as 53.7% were continuous drinkers, and 66.7% received insulin therapy. The frequency of hypoglycemia was high in regular drinkers treated with insulin. Hypoglycemia was a major cause of death in patients who were on insulin and continuous drinkers.

CONCLUSION

We clarified the epidemiology of pancreatic diabetes in Japan. Patients with chronic pancreatitis-associated pancreatic diabetes should receive lifestyle guidance focused on drinking cessation.

Interactions between the endocrine and exocrine pancreas and their clinical relevance

In consequence of the close anatomical and functional links between the exocrine and endocrine pancreas, any disease affecting one of these parts will inevitably affect the other. Pancreatic conditions which might cause diabetes mellitus include acute and chronic pancreatitis, pancreatic surgery, cystic fibrosis and pancreatic cancer. The development of diabetes greatly influences the prognosis and quality of life of patients with exocrine pancreatic diseases. It may cause life-threatening complications, such as hypoglycemia, due to the lack of glucagon and the impaired absorption of nutrients, or the micro- and macrovascular complications may impair the organ functions. Diabetes mellitus is an independent risk factor of mortality in those with exocrine pancreatic diseases. The treatment of pancreatic diabetes, a distinct metabolic and clinical form of diabetes, requires special knowledge. Diet and pancreatic enzyme replacement therapy may be sufficient in the early stages. Oral antidiabetic drugs are not recommended. If the diet proves inadequate to reach the glycemic goals, insulin treatment with multiple injections is required. Impairments of the exocrine pancreatic function and morphology in diabetic patients are frequent and well known. Atrophy of the exocrine tissue may be caused by the lack of trophic insulin, whereas pancreatic fibrosis can result from activation of stellate cells by hyperglycemia, or from microangiopathy and neuropathy. The regulation of the exocrine pancreatic function is also damaged because of the impaired effect of islet hormones. In the event of a proven impairment of the pancreatic exocrine function in diabetes mellitus, pancreatic enzyme replacement therapy is indicated. This may improve the nutritional condition of the patient and decrease the metabolic instability.

Insulin is necessary for the hypertrophic effect of cholecystokinin-octapeptide following acute necrotizing experimental pancreatitis

AIM: In previous experiments we have demonstrated that by administering low doses of cholecystokinin-octapeptide (CCK-8), the process of regeneration following L-arginine (Arg)-induced pancreatitis is accelerated. In rats that were also diabetic (induced by streptozotocin, STZ), pancreatic regeneration was not observed. The aim of this study was to deduce whether the administration of exogenous insulin could in fact restore the hypertrophic effect of CCK-8 in diabetic-pancreatitic rats.

METHODS: Male Wistar rats were used for the experiments. Diabetes mellitus was induced by administering 60 mg/kg body mass of STZ intraperitoneally (i.p.), then, on d 8, pancreatitis was induced by 200 mg/100 g body mass Arg i.p. twice at an interval of 1 h. The animals were injected subcutaneously twice daily (at 7 a.m. and 7 p.m.) with 1 μg/kg of CCK-8 and/or 2 IU mixed insulin (300 g/L short-action and 700 g/L intermediate-action insulin) for 14 d after pancreatitis induction. Following this the animals were killed and the serum amylase, glucose and insulin levels as well as the plasma glucagon levels, the pancreatic mass/body mass ratio (pm/bm), the pancreatic contents of DNA, protein, amylase, lipase and trypsinogen were measured. Pancreatic tissue samples were examined by light microscopy on paraffin-embedded sections.

RESULTS: In the diabetic-pancreatitic rats treatment with insulin and CCK-8 significantly elevated pw/bm and the pancreatic contents of protein, amylase and lipase vs the rats receiving only CCK-8 treatment. CCK- 8 administered in combination with insulin also elevated the number of acinar cells with mitotic activities, whereas CCK- 8 alone had no effect on laboratory parameters or the mitotic activities in diabetic-pancreatitic rats.

CONCLUSION: Despite the hypertrophic effect of CCK-8 being absent following acute pancreatitis in diabetic-rats, the simultaneous administration of exogenous insulin restored this effect. Our results clearly demonstrate that insulin is necessary for the hypertrophic effect of low-doses of CCK-8 following acute pancreatitis.

L-arginine-induced experimental pancreatitis

Despite medical treatment, the lethality of severe acute pancreatitis is still high (20%-30%). Therefore, it is very important to find good animal models to characterise the events of this severe disease. In 1984, Mizunuma et al^[1] developed a new type of experimental necrotizing pancreatitis by intraperitoneal administration of a high dose of L-arginine in rats. This non-invasive model is highly reproducible and produces selective, dose-dependent acinar cell necrosis. Not only is this a good model to study the pathomechanisms of acute necrotizing pancreatitis, but it is also excellent to observe and influence the time course changes of the disease. By writing this review we iluminate some new aspects of cell physiology and pathology of acute necrotizing pancreatitis. Unfortunately, the reviews about acute experimental pancreatitis usually did not discuss this model. Therefore, the aim of this manuscript was to summarise the observations and address some challenges for the future in L-arginine-induced pancreatitis.