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1.  Alcohol Abuse, Endoplasmic Reticulum Stress and Pancreatitis 
Alcohol abuse is a common cause of both acute and chronic pancreatitis. There is a wide spectrum of pancreatic manifestations in heavy drinkers from no apparent disease in most individuals to acute inflammatory and necrotizing pancreatitis in a minority of individuals with some progressing to chronic pancreatitis characterized by replacement of the gland by fibrosis and chronic inflammation. Both smoking and African-American ethnicity are associated with increased risk of alcoholic pancreatitis. In this review we describe how our recent studies demonstrate that ethanol feeding in rodents causes oxidative stress in the endoplasmic reticulum (ER) of the digestive enzyme synthesizing acinar cell of the exocrine pancreas. This ER stress is attenuated by a robust unfolded protein response (UPR) involving X-box binding protein-1 (XBP1) in the acinar cell. When the UPR activation is prevented by genetic reduction in XBP1, ethanol feeding causes significant pathological responses in the pancreas. These results suggest that the reason most individuals who drink alcohol heavily do not get significant pancreatic disease is because the pancreas mounts an adaptive UPR to attenuate the ER stress that ethanol causes. We hypothesize that disease in the pancreas results when the UPR is insufficiently robust to alleviate the ER stress caused by alcohol abuse.
doi:10.1159/000327212
PMCID: PMC3211518  PMID: 21525762
Pancreas; Pancreatitis; Unfolded protein response; Alcohol; Smoking
2.  Cholinergic Mediation of Alcohol-Induced Experimental Pancreatitis 
Objectives
The mechanisms initiating pancreatitis in patients with chronic alcohol abuse are poorly understood. Although alcohol feeding has been previously suggested to alter cholinergic pathways, the effects of these cholinergic alterations in promoting pancreatitis have not been characterized. For the present study, we determined the role of the cholinergic system in ethanol-induced sensitizing effects on cerulein pancreatitis.
Methods
Rats were pair fed control and ethanol-containing Lieber-DeCarli diets for 6 weeks followed by parenteral administration of four hourly intraperitoneal injections of the cholecystokinin analogue, cerulein at 0.5 μg/Kg. This dose of cerulein was selected because it caused pancreatic injury in ethanol-fed but not in control-fed rats. Pancreatitis was preceded by treatment with the muscarinic receptor antagonist atropine or by bilateral subdiaphragmatic vagotomy. Measurement of pancreatic pathology included serum lipase activity, pancreatic trypsin and caspase-3 activities, and markers of pancreatic necrosis, apoptosis and autophagy. In addition, we measured the effects of ethanol feeding on pancreatic acetylcholinesterase activity and pancreatic levels of the muscarinic acetylcholine receptors m1 and m3. Finally, we examined the synergistic effects of ethanol and carbachol on inducing acinar cell damage.
Results
We found that atropine blocked almost completely pancreatic pathology caused by cerulein administration in ethanol fed rats, while vagotomy was less effective. Ethanol feeding did not alter expression levels of cholinergic muscarinic receptors in the pancreas but significantly decreased pancreatic acetylcholinesterase activity, suggesting that acetylcholine levels and cholinergic input within the pancreas can be higher in ethanol fed rats. We further found that ethanol treatment of pancreatic acinar cells augmented pancreatic injury responses caused by the cholinergic agonist, carbachol.
Conclusion
These results demonstrate key roles for the cholinergic system in the mechanisms of alcoholic pancreatitis.
doi:10.1111/j.1530-0277.2010.01264.x
PMCID: PMC2950903  PMID: 20626730
Pancreas; alcohol feeding; cerulein; cholinergic pathways; acetylcholinesterase
3.  Adaptive Unfolded Protein Response Attenuates Alcohol-induced Pancreatic Damage 
Gastroenterology  2010;140(3):987-997.e8.
BACKGROUND & AIMS
Endoplasmic reticulum (ER) stress responses (collectively known the unfolded protein response, UPR) have important roles in several human disorders, but their contribution to alcoholic pancreatitis is not known. We investigated the role of X box-binding protein 1 (XBP1), an UPR regulator, in prevention of alcohol-induced ER stress in the exocrine pancreas.
METHODS
Wild-type and Xbp1+/− mice were fed control or ethanol diets for 4 weeks. Pancreatic tissue samples were then examined by light and electron microscopy to determine pancreatic alterations; UPR regulators were analyzed biochemically.
RESULTS
In wild-type mice, ethanol activated a UPR, increasing pancreatic levels of XBP1 and XBP1 targets such as protein disulfide isomerase (PDI). In these mice, pancreatic damage was minor. In ethanol-fed Xbp1+/− mice, XBP1 and PDI levels were significantly lower than in ethanol-fed, wild-type mice. The combination of XBP1 deficiency and ethanol feeding reduced expression of regulators of ER function and the upregulation of pro-apoptotic signals. Moreover, ethanol feeding induced oxidation of PDI, which might compromise PDI-mediated disulfide bond formation during ER protein folding. In ethanol-fed Xbp1+/− mice, ER stress was associated with disorganized and dilated ER, loss of zymogen granules, accumulation of autophagic vacuoles, and increased acinar cell death.
CONCLUSIONS
Chronic ethanol feeding causes oxidative ER stress, which activates a UPR and increases XBP1 levels and activity. A defective UPR, due to XBP1 deficiency, results in ER dysfunction and acinar cell pathology.
doi:10.1053/j.gastro.2010.11.038
PMCID: PMC3057335  PMID: 21111739
alcohol disease; transcription factors; ER protein folding; organelle
4.  The Absence of MIST1 Leads to Increased Ethanol Sensitivity and Decreased Activity of the Unfolded Protein Response in Mouse Pancreatic Acinar Cells 
PLoS ONE  2011;6(12):e28863.
Background
Alcohol abuse is a leading cause of pancreatitis in humans. However, rodent models suggest that alcohol only sensitizes the pancreas to subsequent insult, indicating that additional factors play a role in alcohol-induced pancreatic injury. The goal of this study was to determine if an absence of MIST1, a transcription factor required for complete differentiation of pancreatic acinar cells in mice, increased the sensitivity to alcohol.
Methods
Two to four month-old mice lacking MIST1 (Mist1−/−) or congenic C57 Bl6 mice were placed on a Lieber-DeCarli diet (36% of total kcal from ethanol and fat), a control liquid diet (36% kcal from fat) or a regular breeding chow diet (22% kcal from fat). After six weeks, pancreatic morphology was assessed. Biochemical and immunofluorescent analysis was used to assess mediators of the unfolded protein response (UPR).
Results
Ethanol-fed Mist1−/− mice developed periductal accumulations of inflammatory cells that did not appear in wild type or control-fed Mist1−/− mice. Wild type mice fed diets high in ethanol or fat showed enhancement of the UPR based on increased accumulation of peIF2α and spliced XBP1. These increases were not observed in Mist1−/− pancreatic tissue, which had elevated levels of UPR activity prior to diet exposure. Indeed, exposure to ethanol resulted in a reduction of UPR activity in Mist1−/− mice.
Conclusions
Our findings suggest that an absence of MIST1 increases the sensitivity to ethanol that correlated with decreased activity of the UPR. Therefore, events that affect the expression and/or function of MIST1 may be confounding factors in pancreatitis.
doi:10.1371/journal.pone.0028863
PMCID: PMC3247225  PMID: 22216129
5.  Molecular mechanisms of alcohol associated pancreatitis 
Alcohol abuse is commonly associated with the development of both acute and chronic pancreatitis. Despite this close association, the fact that only a small percentage of human beings who abuse alcohol develop pancreatitis indicates that alcohol abuse alone is not sufficient to initiate clinical pancreatitis. This contention is further supported by the fact that administration of ethanol to experimental animals does not cause pancreatitis. Because of these findings, it is widely believed that ethanol sensitizes the pancreas to injury and additional factors trigger the development of overt pancreatitis. How ethanol sensitizes the pancreas to pancreatitis is not entirely known. Numerous studies have demonstrated that ethanol and its metabolites have a number of deleterious effects on acinar cells. Important acinar cells properties that are affected by ethanol include: calcium signaling, secretion of zymogens, autophagy, cellular regeneration, the unfolded protein response, and mitochondrial membrane integrity. In addition to the actions of ethanol on acinar cells, it is apparent that ethanol also affects pancreatic stellate cells. Pancreatic stellate cells have a critical role in normal tissue repair and the pathologic fibrotic response. Given that ethanol and its metabolites affect so many pancreatic functions, and that all of these effects occur simultaneously, it is likely that none of these effects is “THE” effect. Instead, it is most likely that the cumulative effect of ethanol on the pancreas predisposes the organ to pancreatitis. The focus of this article is to highlight some of the important mechanisms by which ethanol alters pancreatic functions and may predispose the pancreas to disease.
doi:10.4291/wjgp.v5.i3.147
PMCID: PMC4133514  PMID: 25133017
Pancreatitis; Alcoholic pancreatitis; Alcoholic acute pancreatitis; Alcoholic chronic pancreatitis
6.  Role of Alcohol Metabolism in Chronic Pancreatitis 
Alcohol Research & Health  2007;30(1):48-54.
Alcohol abuse is the major cause of chronic inflammation of the pancreas (i.e., chronic pancreatitis). Although it has long been thought that alcoholic pancreatitis is a chronic disease from the outset, evidence is accumulating to indicate that chronic damage in the pancreas may result from repeated attacks of acute tissue inflammation and death (i.e., necroinflammation). Initially, research into the pathogenesis of alcoholic pancreatitis was related to ductular and sphincteric abnormalities. In recent years, the focus has shifted to the type of pancreas cell that produces digestive juices (i.e., acinar cell). Alcohol now is known to exert a number of toxic effects on acinar cells. Notably, acinar cells have been shown to metabolize alcohol (i.e., ethanol) via both oxidative (i.e., involving oxygen) and nonoxidative pathways. The isolation and study of pancreatic stellate cells (PSCs)—the key effectors in the development of connective tissue fibers (i.e., fibrogenesis) in the pancreas—has greatly enhanced our understanding of the pathogenesis of chronic pancreatitis. Pancreatic stellate cells become activated in response to ethanol and acetaldehyde, a toxic byproduct of alcohol metabolism. In addition, PSCs have the capacity to metabolize alcohol via alcohol dehydrogenase (the major oxidizing enzyme for ethanol). The fact that only a small percentage of heavy alcoholics develop chronic pancreatitis has led to the search for precipitating factors of the disease. Several studies have investigated whether variations in ethanol-metabolizing enzymes may be a trigger factor for chronic pancreatitis, but no definite relationship has been established so far.
PMCID: PMC3860433  PMID: 17718401
Alcohol abuse; ethanol metabolism; ethanol-to-acetaldehyde metabolism; alcohol dehydrogenase (ADH); acetaldehyde; cytochrome P4502E1 (CYP2E1); reactive oxygen species (ROS); oxidation; pancreas; chronic pancreatitis; acute pancreatitis; alcoholic pancreatitis; acinar cell; pancreatic stellate cells (PSCs); fatty acid ethyl esters (FAEEs); genetic factors; genetic polymorphisms
7.  Organellar Dysfunction in the Pathogenesis of Pancreatitis 
Antioxidants & Redox Signaling  2011;15(10):2699-2710.
Abstract
Significance
Acute pancreatitis is an inflammatory disease of exocrine pancreas that carries considerable morbidity and mortality; its pathophysiology remains poorly understood. During the past decade, new insights have been gained into signaling pathways and molecules that mediate the inflammatory response of pancreatitis and death of acinar cells (the main exocrine pancreas cell type). By contrast, much less is known about the acinar cell organellar damage in pancreatitis and how it contributes to the disease pathogenesis.
Recent Advances
This review summarizes recent findings from our group, obtained on experimental in vivo and ex vivo models, which reveal disordering of key cellular organelles, namely, mitochondria, autophagosomes, and lysosomes, in pancreatitis. Our results indicate a critical role for mitochondrial permeabilization in determining the balance between apoptosis and necrosis in pancreatitis, and thus the disease severity. We further investigate how the mitochondrial dysfunction (and hence acinar cell death) is regulated by Ca2+, reactive oxygen species, and Bcl-xL, in relation to specific properties of pancreatic mitochondria. Our results also reveal that autophagy, the principal cellular degradative, lysosome-driven pathway, is impaired in pancreatitis due to inefficient lysosomal function, and that impaired autophagy mediates two key pathological responses of pancreatitis—accumulation of vacuoles in acinar cells and the abnormal, intra-acinar activation of digestive enzymes such as trypsinogen.
Critical Issues and Future Directions
The findings discussed in this review indicate critical roles for mitochondrial and autophagic/lysosomal dysfunctions in the pathogenesis of pancreatitis and delineate directions for detailed investigations into the molecular events that underlie acinar cell organellar damage. Antioxid. Redox Signal. 15, 2699–2710.
doi:10.1089/ars.2011.4068
PMCID: PMC3183656  PMID: 21834686
8.  Investigating the Pathobiology of Alcoholic Pancreatitis 
Summary
Alcohol abuse is one of the most common causes of pancreatitis. The risk of developing alcohol-induced pancreatitis is related to the amount and duration of drinking. However, only a small portion of heavy drinkers develop disease, indicating that other factors (genetic, environmental or dietary) contribute to disease initiation. Epidemiologic studies suggest roles for cigarette smoking and dietary factors in the development of alcoholic pancreatitis. The mechanisms underlying alcoholic pancreatitis are starting to be understood. Studies from animal models are revealing that alcohol sensitizes the pancreas to key pathobiologic processes that are involved in pancreatitis. Current studies are focused on the mechanisms responsible for the sensitizing effect of alcohol; recent findings reveal disordering of key cellular organelles including endoplasmic reticulum, mitochondria, and lysosomes. As our understanding of alcohol’s effects continue to advance to the level of molecular mechanisms, insights into potential therapeutic strategies will emerge providing opportunities for clinical benefit.
doi:10.1111/j.1530-0277.2010.01408.x
PMCID: PMC3083481  PMID: 21284675
9.  Ethanol consumption as inductor of pancreatitis 
Alcohol abuse is a major cause of pancreatitis, a condition that can manifest as both acute necroinflammation and chronic damage (acinar atrophy and fibrosis). Pancreatic acinar cells can metabolize ethanol via the oxidative pathway, which generates acetaldehyde and involves the enzymes alcohol dehydrogenase and possibly cytochrome P4502E1. Additionally, ethanol can be metabolized via a nonoxidative pathway involving fatty acid ethyl ester synthases. Metabolism of ethanol by acinar and other pancreatic cells and the consequent generation of toxic metabolites, are postulated to play an important role in the development of alcohol-related acute and chronic pancreatic injury. This current work will review some recent advances in the knowledge about ethanol actions on the exocrine pancreas and its relationship to inflammatory disease and cancer.
doi:10.4292/wjgpt.v1.i1.3
PMCID: PMC3091140  PMID: 21577288
Pancreas; Calcium; Ethanol; Reactive oxygen species; Pancreatitis
10.  Alcohol consumption on pancreatic diseases 
Although the association between alcohol and pancreatic diseases has been recognized for a long time, the impact of alcohol consumption on pancreatitis and pancreatic cancer (PC) remains poorly defined. Nowadays there is not consensus about the epidemiology and the beverage type, dose and duration of alcohol consumption causing these diseases. The objective of this study was to review the epidemiology described in the literature for pancreatic diseases as a consequence of alcoholic behavior trying to understand the association between dose, type and frequency of alcohol consumption and risk of pancreatitis and PC. The majority of the studies conclude that high alcohol intake was associated with a higher risk of pancreatitis (around 2.5%-3% between heavy drinkers and 1.3% between non drinkers). About 70% of pancreatitis are due to chronic heavy alcohol consumption. Although this incidence rate differs between countries, it is clear that the risk of developing pancreatitis increases with increasing doses of alcohol and the average of alcohol consumption vary since 80 to 150 g/d for 10-15 years. With regard to PC, the role of alcohol consumption remains less clear, and low to moderate alcohol consumption do not appear to be associated with PC risk, and only chronic heavy drinking increase the risk compared with lightly drinkers. In a population of 10%-15% of heavy drinkers, 2%-5% of all PC cases could be attributed to alcohol consumption. However, as only a minority (less than 10% for pancreatitis and 5% for PC) of heavily drinkers develops these pancreatic diseases, there are other predisposing factors besides alcohol involved. Genetic variability and environmental exposures such as smoking and diet modify the risk and should be considered for further investigations.
doi:10.3748/wjg.v19.i5.638
PMCID: PMC3574589  PMID: 23429423
Acute pancreatitis; Chronic pancreatitis; Alcohol consumption; Alcohol metabolism; Genetic variability; Pancreatic cancer; Risk
11.  Extensive Pancreas Regeneration Following Acinar-Specific Disruption of Xbp1 in Mice 
Gastroenterology  2011;141(4):1463-1472.
Background & Aims
Progression of diseases of the exocrine pancreas, which include pancreatitis and cancer, is associated with increased levels of cell stress. Pancreatic acinar cells are involved in development of these diseases and, because of their high level of protein output, they require an efficient, unfolded protein response (UPR), which mediates recovery from endoplasmic reticulum (ER) stress following the accumulation of misfolded proteins.
Methods
To study recovery from ER stress in the exocrine organ, we generated mice with conditional disruption of Xbp1 (a principle component of the UPR) in most adult pancreatic acinar cells (Xbp1fl/fl). We monitored the effects of constitutive ER stress in the exocrine pancreas of these mice.
Results
Xbp1-null acinar cells underwent extensive apoptosis, followed by a rapid phase of recovery in the pancreas that included expansion of the centroacinar cell compartment, formation of tubular complexes that contained Hes1- and Sox9-expressing cells, and regeneration of acinar cells that expressed Mist1 from the residual, surviving Xbp1+ cell population.
Conclusions
XBP1 appears to be required for homeostatisis of acinar cells in mice; ER stress induces a regenerative response in the pancreas that involves acinar and centroacinar cells and promotes organ recovery from exocrine pancreas disease.
doi:10.1053/j.gastro.2011.06.045
PMCID: PMC3186847  PMID: 21704586
endoplasmic reticulum stress; pancreatic progenitor cells; protein folding; tissue regeneration
12.  Acute pancreatitis: The stress factor 
Acute pancreatitis is an inflammatory disorder of the pancreas that may cause life-threatening complications. Etiologies of pancreatitis vary, with gallstones accounting for the majority of all cases, followed by alcohol. Other causes of pancreatitis include trauma, ischemia, mechanical obstruction, infections, autoimmune, hereditary, and drugs. The main events occurring in the pancreatic acinar cell that initiate and propagate acute pancreatitis include inhibition of secretion, intracellular activation of proteases, and generation of inflammatory mediators. Small cytokines known as chemokines are released from damaged pancreatic cells and attract inflammatory cells, whose systemic action ultimately determined the severity of the disease. Indeed, severe forms of pancreatitis may result in systemic inflammatory response syndrome and multiorgan dysfunction syndrome, characterized by a progressive physiologic failure of several interdependent organ systems. Stress occurs when homeostasis is threatened, and stressors can include physical or mental forces, or combinations of both. Depending on the timing and duration, stress can result in beneficial or harmful consequences. While it is well established that a previous acute-short-term stress decreases the severity of experimentally-induced pancreatitis, the worsening effects of chronic stress on the exocrine pancreas have received relatively little attention. This review will focus on the influence of both prior acute-short-term and chronic stress in acute pancreatitis.
doi:10.3748/wjg.v20.i19.5801
PMCID: PMC4024789  PMID: 24914340
Pancreatitis; Acute stress; Chronic stress; Heat shock proteins; Tumor necrosis factor alpha
13.  Bile and pancreatic juice exclusion activates acinar stress kinases and exacerbates gallstone pancreatitis 
Surgery  2007;143(3):434-440.
Hypothesis: Bile and pancreatic juice exclusion from gut activates acinar stress kinases and exacerbates gallstone pancreatitis as evidenced by ameliorating effects of replacement therapy in an experimental model of duct ligation-induced acute pancreatitis. In early stages of gallstone pancreatitis, bile-pancreatic juice cannot enter the gut. Enteral exclusion worsens pancreatitis by causing feedback hyperstimulation of the exocrine pancreas that activates acinar cell stress kinases. Investigations using a unique surgical model, the Donor Rat Model, showed that duodenal replacement of bile-pancreatic juice in rats with duct ligation attenuates pancreatic stress kinase activation, reduces pancreatic cytokine production, and ameliorates pancreatic morphologic changes. These findings suggest that exclusion-induced acinar hyperstimulation, in the presence of duct obstruction, exacerbates acute pancreatitis via stress kinase activation. Although acinar hyperstimulation has often been implicated in acute pancreatitis pathogenesis, the lack of supporting evidence remains a conspicuous lacuna. The proposed hypothesis draws on fresh evidence to present a new paradigm that re-examines the role of exocrine pancreatic hyperstimulation in gallstone pancreatitis pathogenesis.
doi:10.1016/j.surg.2007.06.004
PMCID: PMC2278165  PMID: 18291265
14.  Increased serum pancreatitis associated protein (PAP) concentration after longterm alcohol consumption: further evidence for regular subclinical pancreatic damage after heavy drinking? 
Gut  1995;36(1):117-120.
It has been shown recently that longterm but not short term heavy drinking of alcohol frequently results in increased serum activities of pancreatic enzymes suggesting subclinical pancreatic injury. Serum pancreatitis associated protein (PAP) is a novel protein, whose synthesis in the acinar cells and release into serum is specifically induced by acute pancreatic damage. This study was performed to further characterise the alcohol induced subclinical pancreatic injury by using serum PAP measurements. Three groups were studied: (1) control group (n = 25), (2) short term drinking group (n = 20), who consumed 2.0 g of ethanol per kg body weight during four hours, and (3) longterm drinking group (n = 32), who were admitted to withdrawal clinic after a median 30 months heavy drinking period. Serum PAP concentration was low in the control group (8 (5 to 12) micrograms/l, geometric mean (95% confidence intervals)). In the short term drinking group serum PAP was in the range of the control group values during 56 hours after drinking. Longterm drinking induced at least a 10-fold increase in serum PAP, the highest concentrations being seen on day 2 after drinking had ended (106 (61 to 184) micrograms/l). The patients did not develop abdominal symptoms, increased blood white cell count, or increased serum C reactive protein concentration. These results further support the suggestion that heavy longterm drinking often induces subclinical pancreatic damage, but not clinical pancreatitis.
PMCID: PMC1382364  PMID: 7890213
15.  Alcohol Use and Risk of Pancreatic Cancer 
American Journal of Epidemiology  2009;169(9):1043-1051.
The epidemiologic evidence for the role of alcohol use in pancreatic cancer development is equivocal. The authors prospectively examined the relation between alcohol use and risk of pancreatic cancer among 470,681 participants who were aged 50–71 years in 1995–1996 in the US National Institutes of Health-AARP Diet and Health Study. The authors identified 1,149 eligible exocrine pancreatic cancer cases through December 2003. Multivariate Cox proportional hazards regression models were used to calculate relative risks and 95% confidence intervals with the referent group being light drinkers (<1 drink/day). The relative risks of developing pancreatic cancer were 1.45 (95% confidence interval (CI): 1.17, 1.80; Ptrend = 0.002) for heavy total alcohol use (≥3 drinks/day, ∼40 g of alcohol/day) and 1.62 (95% CI: 1.24, 2.10; Ptrend = 0.001) for heavy liquor use, compared with the respective referent group. The increased risk with heavy total alcohol use was seen in never smokers (relative risk = 1.35, 95% CI: 0.79, 2.30) and participants who quit smoking 10 or more years ago before baseline (relative risk = 1.41, 95% CI: 1.01, 2.00). These findings suggest a moderately increased pancreatic cancer risk with heavy alcohol use, particularly liquor; however, residual confounding by cigarette smoking cannot be completely excluded.
doi:10.1093/aje/kwp034
PMCID: PMC2727241  PMID: 19299403
alcohol drinking; cohort studies; pancreatic neoplasms; risk; smoking
16.  Alcohol Consumption at Midlife and Successful Ageing in Women: A Prospective Cohort Analysis in the Nurses' Health Study 
PLoS Medicine  2011;8(9):e1001090.
Using the Nurses' Health Study, Qi Sun and colleagues examine whether moderate alcohol intake is associated with overall health and well-being among women who survive to older age.
Background
Observational studies have documented inverse associations between moderate alcohol consumption and risk of premature death. It is largely unknown whether moderate alcohol intake is also associated with overall health and well-being among populations who have survived to older age. In this study, we prospectively examined alcohol use assessed at midlife in relation to successful ageing in a cohort of US women.
Methods and Findings
Alcohol consumption at midlife was assessed using a validated food frequency questionnaire. Subsequently, successful ageing was defined in 13,894 Nurses' Health Study participants who survived to age 70 or older, and whose health status was continuously updated. “Successful ageing” was considered as being free of 11 major chronic diseases and having no major cognitive impairment, physical impairment, or mental health limitations. Analyses were restricted to the 98.1% of participants who were not heavier drinkers (>45 g/d) at midlife. Of all eligible study participants, 1,491 (10.7%) achieved successful ageing. After multivariable adjustment of potential confounders, light-to-moderate alcohol consumption at midlife was associated with modestly increased odds of successful ageing. The odds ratios (95% confidence interval) were 1.0 (referent) for nondrinkers, 1.11 (0.96–1.29) for ≤5.0 g/d, 1.19 (1.01–1.40) for 5.1–15.0 g/d, 1.28 (1.03–1.58) for 15.1–30.0 g/d, and 1.24 (0.87–1.76) for 30.1–45.0 g/d. Meanwhile, independent of total alcohol intake, participants who drank alcohol at regular patterns throughout the week, rather than on a single occasion, had somewhat better odds of successful ageing; for example, the odds ratios (95% confidence interval) were 1.29 (1.01–1.64) and 1.47 (1.14–1.90) for those drinking 3–4 days and 5–7 days per week in comparison with nondrinkers, respectively, whereas the odds ratio was 1.10 (0.94–1.30) for those drinking only 1–2 days per week.
Conclusions
These data suggest that regular, moderate consumption of alcohol at midlife may be related to a modest increase in overall health status among women who survive to older ages.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
People have always drunk alcoholic beverages but throughout history there have been arguments about the risks and benefits of beer, wine, and spirits. It is clear that excessive alcohol use—heavy drinking (an average of more than two drinks per day for men or more than one drink per day for women; in the US, a “drink” is defined as 15 g of alcohol or, roughly speaking, a can of beer or a small glass of wine) or binge drinking (five or more drinks on a single occasion for men; 4 or more drinks at one time for women)—is harmful. It causes liver damage and increases the risk of developing some types of cancer. It contributes to depression and violence and interferes with relationships. And it is often implicated in fatal traffic accidents. However, in contrast to these and other harms associated with excessive alcohol use, moderate alcohol consumption seems to reduce the risk of specific diseases such as heart disease, stroke, and cognitive decline (deterioration in learning, reasoning, and perception).
Why Was This Study Done?
Although people who drink moderate amounts of alcohol have a reduced risk of premature death compared to abstainers or heavy drinkers, it is not known whether moderate alcohol consumption is associated with overall health among ageing populations. In many countries, elderly people are an increasingly large part of the population, so it is important to know how moderate alcohol consumption affects their well-being. In this study, the researchers examine the effect of alcohol consumption at midlife on successful ageing among the participants of the Nurses' Health Study. The researchers study the effect of midlife alcohol consumption because the chronic conditions that affect elderly people develop slowly and it is likely that factors in earlier life determine health in later life. Successful ageing is defined as being free of major chronic diseases such as cancer and heart disease, and having no major cognitive impairment, physical impairment, or mental health problems. The Nurses' Health Study enrolled 121,700 female registered nurses in 1976 to investigate the long-term effects of oral contraceptive use but has provided insights into many aspects of health and disease.
What Did the Researchers Do and Find?
The researchers assessed the alcohol consumption of the study participants at midlife (average age 58 years) from food frequency questionnaires completed in 1980 and 1984. Successful ageing for 13,984 participants who survived past 70 years was assessed by analyzing biennial health status questionnaires and cognitive function test results. One tenth of the women achieved successful ageing. After allowing for other factors that might affect their health such as smoking, women who drank light or moderate amounts of alcohol had a modestly increased chance of successful ageing compared to nondrinkers. For example, compared to nondrinkers, women who drank 5–15 g of alcohol per day (between one-third and one drink per day) had about a 20% higher chance of successful ageing. Independent of total alcohol intake, women who drank alcohol regularly had a better chance of successful ageing than occasional drinkers. Thus, compared to nondrinkers, women who drank five to seven days a week had nearly a 50% greater chance of successful ageing whereas women who drank only one or two days a week had a similar likelihood of successful ageing.
What Do These Findings Mean?
These findings suggest that regular, moderate consumption of alcohol at midlife may be related to a modest increase in overall health among women who survive to older ages. Because this is an observational study, it is possible that the women who drank moderately share other unknown characteristics that are actually responsible for their increased chance of successful ageing. Moreover, because all the study participants were women and most had European ancestry, these findings cannot be applied to men or to other ethnic groups. Nevertheless, these findings provide support for the 2010 US Department of Agriculture dietary guidelines, which state that consumption of up to one alcoholic drink per day for women and up to two alcoholic drinks per day for men may provide health benefits. Importantly, they also suggest that drinking alcohol regularly in moderation rather than occasional heavy drinking may be associated with a greater likelihood of successful ageing.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001090.
The US National Institute on Alcohol Abuse and Alcoholism has detailed information about alcohol and its effects on health, including a fact sheet on women and alcohol and a booklet entitled Alcohol, a woman's health issue
The US Centers for Disease Control and Prevention has a website on alcohol and public health
The UK National Health Service Choices website provides detailed information about drinking and alcohol, including how to calculate consumption
The Nutrition Source, a website maintained by the Department of Nutrition at Harvard School of Public Health, has an article entitled Alcohol: balancing risks and benefits
MedlinePlus provides links to many other resources on alcohol and on seniors' health
Details of the Nurses' Health Study are available
The 2010 US Department of Agriculture dietary guidelines are available
doi:10.1371/journal.pmed.1001090
PMCID: PMC3167795  PMID: 21909248
17.  VAMP8 is the v-SNARE that mediates basolateral exocytosis in a mouse model of alcoholic pancreatitis 
The Journal of Clinical Investigation  2008;118(7):2535-2551.
In rodents and humans, alcohol exposure has been shown to predispose the pancreas to cholinergic or viral induction of pancreatitis. We previously developed a rodent model in which exposure to an ethanol (EtOH) diet, followed by carbachol (Cch) stimulation, redirects exocytosis from the apical to the basolateral plasma membrane of acinar cells, resulting in ectopic zymogen enzyme activation and pancreatitis. This redirection of exocytosis involves a soluble NSF attachment receptor (SNARE) complex consisting of syntaxin-4 and synapse-associated protein of 23 kDa (SNAP-23). Here, we investigated the role of the zymogen granule (ZG) SNARE vesicle-associated membrane protein 8 (VAMP8) in mediating basolateral exocytosis. In WT mice, in vitro EtOH exposure or EtOH diet reduced Cch-stimulated amylase release by redirecting apical exocytosis to the basolateral membrane, leading to alcoholic pancreatitis. Further reduction of zymogen secretion, caused by blockade of both apical and basolateral exocytosis and resulting in a more mild induction of alcoholic pancreatitis, was observed in Vamp8–/– mice in response to these treatments. In addition, although ZGs accumulated in Vamp8–/– acinar cells, ZG-ZG fusions were reduced compared with those in WT acinar cells, as visualized by electron microscopy. This reduction in ZG fusion may account for reduced efficiency of apical exocytosis in Vamp8–/– acini. These findings indicate that VAMP8 is the ZG-SNARE that mediates basolateral exocytosis in alcoholic pancreatitis and that VAMP8 is critical for ZG-ZG homotypic fusion.
doi:10.1172/JCI34672
PMCID: PMC2413188  PMID: 18535671
18.  Effects of Oxidative Alcohol Metabolism on the Mitochondrial Permeability Transition Pore and Necrosis in a Mouse Model of Alcoholic Pancreatitis 
Gastroenterology  2012;144(2):10.1053/j.gastro.2012.10.037.
BACKGROUND & AIMS
Opening of the mitochondrial permeability transition pore (MPTP) causes loss of the mitochondrial membrane potential (ΔΨm) and, ultimately, adenosine triphosphate depletion and necrosis. Cells deficient in cyclophilin D (CypD), a component of the MPTP, are resistant to MPTP opening, loss of ΔΨm, and necrosis. Alcohol abuse is a major risk factor for pancreatitis and is believed to sensitize the pancreas to stressors, by poorly understood mechanisms. We investigated the effects of ethanol on the pancreatic MPTP, the mechanisms of these effects, and their role in pancreatitis.
METHODS
We measured ΔΨm in mouse pancreatic acinar cells incubated with ethanol alone and in combination with physiologic and pathologic concentrations of cholecystokinin-8 (CCK). To examine the role of MPTP, we used ex vivo and in vivo models of pancreatitis, induced in wild-type and CypD−/− mice by a combination of ethanol and CCK.
RESULTS
Ethanol reduced basal ΔΨm and converted a transient depolarization, induced by physiologic concentrations of CCK, into a sustained decrease in ΔΨm, resulting in reduced cellular adenosine triphosphate and increased necrosis. The effects of ethanol and CCK were mediated by MPTP because they were not observed in CypD−/− acinar cells. Ethanol and CCK activated MPTP through different mechanisms— ethanol by reducing the ratio of oxidized nicotinamide adenine dinucleotide to reduced nicotinamide adenine dinucleotide, as a result of oxidative metabolism, and CCK by increasing cytosolic Ca2+. CypD−/− mice developed a less-severe form of pancreatitis after administration of ethanol and CCK.
CONCLUSIONS
Oxidative metabolism of ethanol sensitizes pancreatic mitochondria to activate MPTP, leading to mitochondrial failure; this makes the pancreas susceptible to necrotizing pancreatitis.
doi:10.1053/j.gastro.2012.10.037
PMCID: PMC3841074  PMID: 23103769
Tissue Damage; Ethanol Toxicity; Cell Death; Exocrine Pancreas
19.  Ethanol Administration Impairs Pancreatic Repair Following Injury 
Pancreas  2012;41(8):1272-1279.
Objectives
Alcohol abuse is one of the most common factors associated with acute and chronic pancreatitis. Although it is evident that alcohol abuse can have an important role in the development of pancreatitis, it does not appear that alcohol abuse alone is responsible for this disease. We investigated the involvement of ethanol in impairment of pancreatic repair after induction of pancreatitis.
Methods
A biologically relevant mouse model of alcoholic pancreatitis, combining chronic ethanol consumption and coxsackievirus infection, was used to investigate the effects of ethanol on pancreatic regeneration. Tissues were harvested and analyzed by RT-PCR and immunoblot.
Results
These studies demonstrate that chronic ethanol consumption impairs the structural repair of the exocrine pancreas. This is accompanied by a delay in the restitution of lipase expression. Additionally, impaired expression of the critical pancreatic transcription factors, PDX1 and PTF1, and the mediator of Notch signaling, HES1, were observed.
Conclusions
Chronic ethanol consumption impairs the structural repair and functional restitution of the pancreas after severe injury. These impairments may, in part, be explained by impaired expression of factors important in the development and maintenance of the exocrine pancreas. Impaired pancreatic regeneration may have a role in the pathogenesis of alcoholic pancreatitis.
doi:10.1097/MPA.0b013e31824bde37
PMCID: PMC3479327  PMID: 22617711
Acute Pancreatitis; Coxsackievirus; Ethanol; Tissue Repair; Alcoholic Pancreatitis; Developmental Factors
20.  Persistent Salmonellosis Causes Pancreatitis in a Murine Model of Infection 
PLoS ONE  2014;9(4):e92807.
Pancreatitis, a known risk factor for the development of pancreatic ductal adenocarcinoma, is a serious, widespread medical condition usually caused by alcohol abuse or gallstone-mediated ductal obstruction. However, many cases of pancreatitis are of an unknown etiology. Pancreatitis has been linked to bacterial infection, but causality has yet to be established. Here, we found that persistent infection of mice with the bacterial pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) was sufficient to induce pancreatitis reminiscent of the human disease. Specifically, we found that pancreatitis induced by persistent S. Typhimurium infection was characterized by a loss of pancreatic acinar cells, acinar-to-ductal metaplasia, fibrosis and accumulation of inflammatory cells, including CD11b+ F4/80+, CD11b+ Ly6Cint Ly6G+ and CD11b+ Ly6Chi Ly6G− cells. Furthermore, we found that S. Typhimurium colonized and persisted in the pancreas, associated with pancreatic acinar cells in vivo, and could invade cultured pancreatic acinar cells in vitro. Thus, persistent infection of mice with S. Typhimurium may serve as a useful model for the study of pancreatitis as it relates to bacterial infection. Increased knowledge of how pathogenic bacteria can cause pancreatitis will provide a more integrated picture of the etiology of the disease and could lead to the development of new therapeutic approaches for treatment and prevention of pancreatitis and pancreatic ductal adenocarcinoma.
doi:10.1371/journal.pone.0092807
PMCID: PMC3981665  PMID: 24717768
21.  Pancreatic stellate cells: a starring role in normal and diseased pancreas 
While the morphology and function of cells of the exocrine and endocrine pancreas have been studied over several centuries, one important cell type in the gland, the pancreatic stellate cell (PSC), had remained undiscovered until as recently as 20 years ago. Even after its first description in 1982, it was to be another 16 years before its biology could begin to be studied, because it was only in 1998 that methods were developed to isolate and culture PSCs from rodent and human pancreas. PSCs are now known to play a critical role in pancreatic fibrosis, a consistent histological feature of two major diseases of the pancreas—chronic pancreatitis and pancreatic cancer. In health, PSCs maintain normal tissue architecture via regulation of the synthesis and degradation of extracellular matrix (ECM) proteins. Recent studies have also implied other functions for PSCs as progenitor cells, immune cells or intermediaries in exocrine pancreatic secretion in humans. During pancreatic injury, PSCs transform from their quiescent phase into an activated, myofibroblast-like phenotype that secretes excessive amounts of ECM proteins leading to the fibrosis of chronic pancreatitis and pancreatic cancer. An ever increasing number of factors that stimulate and/or inhibit PSC activation via paracrine and autocrine pathways are being identified and characterized. It is also now established that PSCs interact closely with pancreatic cancer cells to facilitate cancer progression. Based on these findings, several therapeutic strategies have been examined in experimental models of chronic pancreatitis as well as pancreatic cancer, in a bid to inhibit/retard PSC activation and thereby alleviate chronic pancreatitis or reduce tumor growth in pancreatic cancer. The challenge that remains is to translate these pre-clinical developments into clinically applicable treatments for patients with chronic pancreatitis and pancreatic cancer.
doi:10.3389/fphys.2012.00344
PMCID: PMC3428781  PMID: 22973234
pancreatic fibrosis; stellate cells; chronic pancreatic; desmoplastic reaction; pancreatic cancer; review
22.  Origin and development of exocrine pancreatic insufficiency in experimental renal failure. 
Gut  1994;35(3):401-407.
Chronic renal failure affects the physiological function of many organ systems. One of them is the exocrine pancreas. Although varying degrees of pancreatic insufficiency are the dominating clinical characteristic of uraemic pancreatic disease, it remains unclear whether this disease should be regarded as a manifestation of chronic pancreatitis, arising from recurring attacks of acute pancreatitis, or represents a distinct entity. The exocrine pancreas was studied in a model of experimental renal failure. The pancreas was removed from each rat at selected time points over eight weeks after subtotal nephrectomy and from a standard rat model of pancreatitis for comparison. The data show that the in vitro secretory response is considerably changed in renal failure (increased during early acute and decreased during chronic renal failure). While the pancreatic content of digestive enzymes progressively declines, DNA and protein synthesis increase over time. Acinar cell deletion is increased and accompanied by an increased rate of mitosis. This increased cellular turnover is not associated with tissue oedema, pancreatic fibrosis, inflammatory changes, autophagocytosis or subcellular redistribution of lysosomal hydrolases, all of which are characteristic for pancreatitis. The ultrastructural changes of uraemic pancreatic disease bear no resemblance to the changes seen in pancreatitis. It is concluded that the morphological and biochemical changes in early uraemic pancreatic disease are quite distinct, correspond with toxic damage of the pancreas, and are dominated by functional impairment and an increased cellular turnover.
Images
PMCID: PMC1374599  PMID: 7512063
23.  Bmi1 is Required for Regeneration of the Exocrine Pancreas in Mice 
Gastroenterology  2012;143(3):821-31.e1-2.
Background & Aims
Bmi1 is a member of the Polycomb protein family and represses transcription by modifying chromatin organization at specific promoters. Bmi1 is implicated in the control of stem cell self-renewal and has been shown to regulate cell proliferation, tissue homeostasis, and differentiation. Bmi1 is present in a subpopulation of self-renewing pancreatic acinar cells and is expressed in response to pancreatic damage. We investigated the role of Bmi1 in exocrine pancreas regeneration.
Methods
Acute pancreatitis was induced in Bmi1−/− mice with caerulein; pancreatic cell regeneration, differentiation, and apoptosis were assessed. Cultured Bmi1−/− and wild-type primary acini were analyzed in vitro, to determine acinar-specific consequences of Bmi1 deletion. To investigate cell-autonomous vs non–cell-autonomous roles for Bmi1 in vivo, pancreatitis was induced in Bmi1−/− mice reconstituted with a wild-type hematopoietic system.
Results
Bmi1 expression was upregulated in the exocrine pancreas during regeneration after caerulein-induced pancreatitis. Exocrine regeneration was impaired following caerulein administration to Bmi1−/− mice. Pancreata of Bmi1−/− mice were hypoplastic, and the exocrine pancreas was replaced with ductal metaplasia that had increased apoptosis and decreased cell proliferation, compared to that of wild-type mice. Expression of Cdkn2a and p53-dependent apoptotic genes were markedly upregulated in Bmi1−/− pancreas, compared to wild-type mice, after injury. Furthermore, after transplantation of bone marrow from wild-type to Bmi1−/− mice, the chimeric mice had intermediate levels of pancreatic hypoplasia and significant, but incomplete, rescue of impaired exocrine regeneration after caerulein injury.
Conclusions
Bmi1 contributes to regeneration of the exocrine pancreas after caerulein-induced injury through cell-autonomous mechanisms—in part by regulating Cdkn2a expression—and non-cell-autonomous mechanisms.
doi:10.1053/j.gastro.2012.05.009
PMCID: PMC3485080  PMID: 22609312
pancreatitis; polycomb proteins; tissue regeneration; mouse model
24.  A Population-Based Study on Alcohol and High-Risk Sexual Behaviors in Botswana 
PLoS Medicine  2006;3(10):e392.
Background
In Botswana, an estimated 24% of adults ages 15–49 years are infected with HIV. While alcohol use is strongly associated with HIV infection in Africa, few population-based studies have characterized the association of alcohol use with specific high-risk sexual behaviors.
Methods and Findings
We conducted a cross-sectional, population-based study of 1,268 adults from five districts in Botswana using a stratified two-stage probability sample design. Multivariate logistic regression was used to assess correlates of heavy alcohol consumption (>14 drinks/week for women, and >21 drinks/week for men) as a dependent variable. We also assessed gender-specific associations between alcohol use as a primary independent variable (categorized as none, moderate, problem and heavy drinking) and several risky sex outcomes including: (a) having unprotected sex with a nonmonogamous partner; (b) having multiple sexual partners; and (c) paying for or selling sex in exchange for money or other resources. Criteria for heavy drinking were met by 31% of men and 17% of women. Adjusted correlates of heavy alcohol use included male gender, intergenerational relationships (age gap ≥10 y), higher education, and living with a sexual partner. Among men, heavy alcohol use was associated with higher odds of all risky sex outcomes examined, including unprotected sex (AOR = 3.48; 95% confidence interval [CI], 1.65 to 7.32), multiple partners (AOR = 3.08; 95% CI, 1.95 to 4.87), and paying for sex (AOR = 3.65; 95% CI, 2.58 to 12.37). Similarly, among women, heavy alcohol consumption was associated with higher odds of unprotected sex (AOR = 3.28; 95% CI, 1.71 to 6.28), multiple partners (AOR = 3.05; 95% CI, 1.83 to 5.07), and selling sex (AOR = 8.50; 95% CI, 3.41 to 21.18). A dose-response relationship was seen between alcohol use and risky sexual behaviors, with moderate drinkers at lower risk than both problem and heavy drinkers.
Conclusions
Alcohol use is associated with multiple risks for HIV transmission among both men and women. The findings of this study underscore the need to integrate alcohol abuse and HIV prevention efforts in Botswana and elsewhere.
Alcohol use is associated with multiple risks for HIV transmission in men and women. The findings underscore the need to integrate alcohol abuse and HIV prevention efforts in Botswana and elsewhere.
Editors' Summary
Background.
Human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS), is most commonly spread through unprotected sex with an infected partner. HIV enters the body through the lining of the sex organs, rectum, or mouth, and destroys immune system cells, leaving the infected person susceptible to other viruses and bacteria. Although HIV education and prevention campaigns emphasize the importance of safe sex in reducing HIV transmission, people continue to become infected by having unprotected sex (that is, not using a condom) with either a nonmonogamous partner or multiple sexual partners, or in situations where they are paying for or selling sex. Research in different populations suggested that heavy alcohol use is associated with risky sexual behaviors. This is because alcohol relaxes the brain and body, reduces inhibitions, and diminishes risk perception. Drinking alcohol may further increase the risk of becoming infected with HIV through its suppressive effects on the immune system.
Why Was This Study Done?
Alcohol abuse is widespread in sub-Saharan Africa where most HIV infections occur and has been associated with risky sexual behaviors. It may therefore be one of the most common, potentially modifiable HIV risk factors in this region. However, research to date has concentrated on the association between alcohol consumption and risky sex in people attending HIV-treatment clinics or recruited at beer halls, and these populations may not be representative of the general population of sub-Saharan Africa. In this study, the researchers have investigated the potential role of alcohol in perpetuating the HIV epidemic by undertaking a population-based study on alcohol use and high-risk sexual behaviors in Botswana. Nearly a quarter of adults are infected with HIV here, and alcohol abuse is also common, particularly in the townships.
What Did the Researchers Do and Find?
The researchers recruited a random cross-section of people from the five districts of Botswana with the highest number of HIV-infected individuals and interviewed all 1,268 participants using a questionnaire. This included general questions about the participants (for example, their age and marital status) and questions about alcohol use, sexual behavior, and knowledge of HIV. Overall, 31% of the men in the study and 17% of the women were heavy drinkers—more than 21 drinks/week for men, 14 for women; a drink is half a pint of beer or a glass of wine. Heavy alcohol use was associated with being male, being in an intergenerational relationship (at least 10 years age difference between partners; intergenerational sex facilitates the continued spread of HIV in sub-Saharan Africa), having had more education, and living with a sexual partner. Among men, those who drank heavily were three to four times more likely to have unprotected sex or multiple partners or to pay for sex than nondrinkers. Among women, there was a similar association between heavy drinking and having unprotected sex or multiple partners, and heavy drinkers were eight times as likely to sell sex as nondrinkers. For both men and women, the more they drank, the more likely they were to have risky sex. The study did not address behavior among same-sex partnerships.
What Do These Findings Mean?
This study indicates that heavy alcohol consumption is strongly and consistently associated with sexual risk behaviors in both men and women in Botswana. Because of the study design, it does not prove that heavy alcohol use is the cause of such behaviors but provides strong circumstantial evidence that this is the case. It is possible that these results may not apply to neighboring African countries—Botswana is unique in being relatively wealthy and in its government being strongly committed to tackling HIV. Nevertheless, taken together with the results of other studies, this research strongly argues for the need to deal with alcohol abuse within HIV prevention programs in sub-Saharan Africa. Strategies to do this could include education campaigns that target both alcohol use and HIV in schools and in social venues, including beer halls. But, stress the researchers, any strategy that is used must consider the cultural and social significance of alcohol use (in Botswana, alcohol use is a symbol of masculinity and high socioeconomic status) and must simultaneously tackle not only the overlap between alcohol use and risky sexual behavior but also the overlap between alcohol and other risk behaviors such as intergenerational sex.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030392.
US National Institute of Allergy and Infectious Diseases factsheet on HIV infection and AIDS
US Department of Health and Human Services information on AIDS
US Centers for Disease Control and Prevention information on HIV/AIDS
US National Institute on Alcohol Abuse and Alcoholism patient information on alcohol and HIV/AIDS]
Aidsmap, information on HIV and AIDS provided by the charity NAM,which includes some information on HIV infections and alcohol
AVERT information on HIV and AIDS in Botswana
doi:10.1371/journal.pmed.0030392
PMCID: PMC1592342  PMID: 17032060
25.  Impaired Autophagy and Organellar Dysfunction in Pancreatitis 
Recent findings from our group, obtained on experimental in vivo and ex vivo models of pancreatitis, reveal that this disease causes a profound dysfunction of key cellular organelles, lysosomes and mitochondria. We found that autophagy, the main cellular degradative, lysosome-driven process, is activated but also impaired in acute pancreatitis because of its’ inefficient progression/resolution (flux) resulting from defective function of lysosomes. One mechanism underlying the lysosomal dysfunction in pancreatitis is abnormal processing (maturation) and activation of cathepsins, major lysosomal hydrolases; another is a decrease in pancreatic levels of key lysosomal membrane proteins LAMP-1 and LAMP-2. Our data indicate that lysosomal dysfunction plays an important initiating role in pancreatitis pathobiology. The impaired autophagy mediates vacuole accumulation in acinar cells; furthermore, the abnormal maturation and activation of cathepsins leads to increase in intra-acinar trypsin, the hallmark of pancreatitis; and LAMP-2 deficiency causes inflammation and acinar cell necrosis. Thus, the autophagic and lysosomal dysfunctions mediate key pathologic responses of pancreatitis. On the other hand, we showed that pancreatitis causes acinar cell mitochondria depolarization, mediated by the permeability transition pore (PTP). Genetic (via deletion of cyclophilin D) inactivation of PTP prevents mitochondrial depolarization and greatly ameliorates the pathologic responses of pancreatitis. Further, our data suggest that mitochondrial damage, by stimulating autophagy, increases the demand for efficient lysosomal degradation and therefore aggravates the pathologic consequences of lysosomal dysfunction. Thus, the combined autophagic, lysosomal and mitochondrial dysfunctions are key to the pathogenesis of pancreatitis.
doi:10.1111/j.1440-1746.2011.07004.x
PMCID: PMC3281514  PMID: 22320913
lysosome; cathepsin; LAMP protein; permeability transition pore; pancreatic mitochondria

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