Effect of nicotine on exocytotic pancreatic secretory response: role of calcium signaling

A dose-response correlation between smoking and severity of acute pancreatitis: a propensity score-matched study

Background

Acute pancreatitis, among the most prevalent gastrointestinal disorders, exhibits a continual rise in its incidence recent years. This study endeavor to explore the correlation between smoking exposure and the severity of acute pancreatitis (AP).

Methods

Five hundred and eight patients diagnosed as acute pancreatitis (AP) were included in our data analysis. Patients were categorized based on their smoking pack-years into four groups: light, moderate, heavy, and non-smokers. Outcomes were classified as two: "mild acute pancreatitis (MAP)" and "moderately severe acute pancreatitis (MSAP) or severe acute pancreatitis (SAP)". We conducted propensity score matching (PSM) to adjust confounding factors and multivariable logistic regression analysis to determine adjusted odds ratios and 95% confidence intervals. Additionally, a dose-dependent association analysis between smoking exposure and the incidence rate of "MSAP or SAP" was performed.

Results

Smokers exhibited a higher risk of "MSAP or SAP" compared to non-smokers, both before (17.1 vs. 54.9%, p < 0.001) and after (9.4 vs. 24.7%, p < 0.001) PSM. With an area under the ROC curve of 0.708, smoking showed a moderate level of predictive ability. Furthermore, propensity score matching analysis showed that patients who smoked compared to non-smokers had significantly higher risks of "MSAP or SAP" for light smoking (OR 3.76, 95% CI 1.40-10.07, p = 0.008), moderate smoking (OR 4.94, 95% CI 2.23-10.92, p < 0.001), and heavy smoking (OR 8.08, 95% CI 3.39-19.25, p < 0.001).

Conclusion

Smoking is an independent risk factor that can raise the severity of pancreatitis. Moreover, the severity of acute pancreatitis escalates in tandem with the accumulation of pack-years of smoking.

Recurrence rates and risk factors for recurrence after first episode of acute pancreatitis: A systematic review and meta-analysis

BACKGROUND

There are a certain number of acute pancreatitis (AP) patients who may suffer from multiple episodes and develop recurrent acute pancreatitis (RAP), but recurrence rates and associated risk factors for RAP vary significantly in the published literature.

METHODS

We searched PubMed, Web of Science, Scopus, and Embase databases to identify all publications reporting AP recurrence until October 20th, 2022. Meta-analysis and meta-regression were performed to calculate the pooled estimates using the random-effects model.

RESULTS

A total of 36 studies met the inclusion criteria and all were used in pooled analyses. The overall rate of recurrence after first-time AP was 21% (95% CI, 18%- 24%), and pooled rates in biliary, alcoholic, idiopathic, and hypertriglyceridemia etiology patients were 12%, 30%, 25%, and 30%, respectively. After managing underlying causes post-discharge, the recurrence rate decreased (14% versus 4% for biliary, 30% versus 6% for alcoholic, and 30% versus 22% for hypertriglyceridemia AP). An increased risk of recurrence was reported in patients with a smoking history (odds ratio [OR] = 1.99), alcoholic etiology (OR = 1.72), male sex (hazard ratio [HR] = 1.63), and local complications (HR = 3.40), while biliary etiology was associated with lower recurrence rates (OR = 0.38).

CONCLUSION

More than one-fifth of AP patients experienced recurrence after discharge, with the highest recurrence rate in alcoholic and hypertriglyceridemia etiologies, and managing underlying causes post-discharge was related to decreased incidence. In addition, smoking history, alcoholic etiology, male gender, and presence of local complications were independent risks for the recurrence.

Tobacco smoking and the risk of pancreatitis: A systematic review and meta-analysis of prospective studies

BACKGROUND

Tobacco smoking has been associated with increased risk of pancreatitis in several studies, however, not all studies have found an association and it is unclear whether there is a dose-response relationship between increasing amount of tobacco smoked and pancreatitis risk. We conducted a systematic review and meta-analysis of prospective studies on tobacco smoking and pancreatitis to clarify the association.

METHODS

PubMed and Embase databases were searched for relevant studies up to April 13th^, 2019. Prospective studies that reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for the association between tobacco smoking and pancreatitis were included and summary RRs were calculated using a random effects model.

RESULTS

Ten prospective studies were included. The summary RR for acute pancreatitis was 1.49 (95% CI: 1.29-1.72, I² = 68%, n = 7) for current smokers, 1.24 (95% CI: 1.15-1.34, I² = 0%, n = 7) for former smokers, and 1.39 (95% CI: 1.25-1.54, I² = 69%, n = 7) for ever smokers compared to never smokers. Similar results were observed for chronic pancreatitis and acute/chronic pancreatitis combined. The summary RR per 10 cigarettes per day was 1.30 (95% CI: 1.18-1.42, I² = 42%, n = 3) and per 10 pack-years in current smokers was 1.13 (95% CI: 1.08-1.17, I² = 14%, n = 4) for acute pancreatitis and results were similar for chronic pancreatitis and acute/chronic pancreatitis combined.

CONCLUSIONS

These results suggest that tobacco smoking increases the risk of acute and chronic pancreatitis and acute and chronic pancreatitis combined and that there is a dose-response relationship between increasing number of cigarettes and pack-years and pancreatitis risk.

Pathophysiological Events Associated With Pancreatitis in Response to Tobacco: An In Vitro Comparative Study With Ethanol in Primary Acinar Cell Culture

OBJECTIVES

The aim of this study was to comparatively analyze the effects of different concentrations of cigarette smoke condensate (CSC, a standardized tobacco extract) and ethanol on intracellular enzyme activation, cell necrosis, alteration of cytosolic calcium concentration ([Ca]c), and amylase secretion in pancreatic acinar cells.

METHODS

The effects of CSC (1 μg/mL to 0.4 mg/mL) and ethanol (10-100 mM) on intracellular enzyme activity, cell necrosis, and [Ca]c were measured by fluorescence assays in isolated pancreatic acinar cells. Amylase secretion was evaluated by spectrophotometry. Supramaximal concentrations of cholecystokinin (10-100 nM) were used as positive control.

RESULTS

Neither CSC nor ethanol induced trypsin or elastase activation. Both CSC (0.1-0.4 mg/mL) and ethanol (10-75 mM) significantly increased [Ca]c. Amylase secretion was increased only in CSC-treated cells (0.3 and 0.4 mg/mL). After 60 minutes, CSC (0.3 and 0.4 mg/mL) significantly increased acinar cell necrosis at a similar percentage to that induced by cholecystokinin. Ethanol did not induce any significant cell necrosis.

CONCLUSIONS

Cigarette smoke condensate induces acinar cell injury and increases [Ca]c and amylase secretion, independently of intracellular enzyme activation, suggesting that tobacco could induce several main early events of pancreatitis in pancreatic acinar cells. However, ethanol only induces increases [Ca]c, having no effect on cell injury, amylase secretion, or intracellular enzyme activation.

Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells

Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes.

How does cigarette smoking cause acute pancreatitis?

INTRODUCTION

Acute Pancreatitis (AP) is an emerging health problem world-wide and it is a major cause of admissions for gastrointestinal disease in many countries. Amongst the more common causes (alcohol and gallstones), recent evidence has emerged indicating that smoking is an independent risk factor for AP. However, the mechanisms involved in smoking-induced AP have not been completely elucidated. This review puts together all the published evidence in literature to present the clinical and laboratory evidence relating smoking to the causation of AP.

DISCUSSION

The two main metabolites from cigarette smoke, namely nicotine and NNK are able to induce functional and histological changes within the pancreas consistent with AP. The major mechanisms involved include their action on acinar cells and zymogen secretion through pathways involving CCK and the nicotinic preganglionic receptors. Effects on the pancreatic microvasculature may be mediated through the nitric oxide pathway. There is indirect evidence to suggest that nicotine and acrolein may lead to CFTR dysfunction thereby influencing ductal secretion. However, direct evidence for this effect is needed. The effect of cigarette smoke metabolites on stellate cells and the islets warrants further investigation in the context of pathogenesis of AP.

CONCLUSION

Using a step-wise approach, the review revisits the effects of the various metabolites of cigarette smoke on the constituents of the pancreas (exocrine, endocrine, neurohormonal, stellate cells, ductal system) and highlights their proven, and potential, mechanisms in triggering off an attack of AP.

Epidemiologic and Mechanistic Associations Between Smoking and Pancreatitis

OPINION STATEMENT

Alcohol has long been associated with pancreatitis. Although first described more than three decades ago, smoking has been widely accepted as an important risk factor for all forms of pancreatitis only in the past few years. Empiric data has confirmed smoking as an independent and dose-dependent risk for both acute and chronic pancreatitis. Smoking also increases the risk of recurrences and progression of established chronic pancreatitis. The effects of smoking are enhanced in the presence of alcohol consumption. Indirect evidence suggests that smoking cessation may be beneficial in preventing disease progression. Smoking cessation can therefore be an important strategy for primary as well as secondary prevention of pancreatitis. Therefore, in addition to alcohol, physicians should routinely counsel patients for the benefits of smoking cessation. The mechanisms through which cigarette smoke triggers pathological cellular events, resulting in pancreatitis, are unresolved. Although cigarette smoke contains greater than 4000 compounds, principally nicotine and the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) have been broadly studied with regard to pancreatic diseases. Both nicotine and NNK have been shown to induce morphological changes in the pancreas consistent with those seen in pancreatitis. Furthermore, nicotine affects pancreatic secretion and NNK induces premature zymogen activation, two well-known features of pancreatitis. These cigarette toxins may mediate both pro- and anti-inflammatory pathways and can induce changes in pancreatic acinar cell function at the level of transcription, leading to conditions such as thiamin deficiency and mitochondrial dysfunction. Such circumstances could leave the pancreas prone to the development of pancreatitis. This review summarizes relevant research findings and focuses on the epidemiologic links between smoking and pancreatitis, and the cellular pathways that may be significant in induction and evolution of smoking-related pancreatitis.

Pathologic cellular events in smoking-related pancreatitis

Pancreatitis, a debilitating inflammatory disorder, results from pancreatic injury. Alcohol abuse is the foremost cause, although cigarette smoking has recently surfaced as a distinct risk factor. The mechanisms by which cigarette smoke and its toxins initiate pathological cellular events leading to pancreatitis, have not been clearly defined. Although cigarette smoke is composed of more than 4000 compounds, it is mainly nicotine and the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which have been extensively studied with respect to pancreatic diseases. This review summarizes these research findings and highlights cellular pathways which may be of relevance in initiation and progression of smoking-related pancreatitis.

Nicotine alters the proteome of two human pancreatic duct cell lines

CONTEXT

Cigarette smoking is a known risk factor of pancreatic disease. Nicotine--a major cigarette tobacco component--can traffic through the circulatory system and may induce fibrosis and metastasis, hallmarks of chronic pancreatitis and pancreatic adenocarcinoma, respectively. However, at the biomolecular level, particularly in pancreatic research, the effects of nicotine remain unresolved.

METHODS

The effects of nicotine on the proteomes of two pancreatic duct cell lines-an immortalized normal cell line (HPNE) and a cancer cell line (PanC1)- were investigated using mass spectrometry-based proteomics. For each cell line, the global proteomes of cells exposed to nicotine for 24 hrs were compared with untreated cells in triplicate using 6-plex tandem mass tag-based isobaric labeling techniques.

RESULTS

Over 5,000 proteins were detected per cell line. Of these, over 900 proteins were differentially abundant with statistical significance (corrected P-value <0.01) upon nicotine treatment, 57 of which were so in both cell lines. Amyloid precursor protein, previously observed to increase expression in pancreatic stellate cells when exposed to nicotine, was also up-regulated in both cell lines.In general, the two cell lines varied in the classes of proteins altered by nicotine treatment, supporting published evidence that nicotine may play different roles in the initiation and progression of pancreatic disease.

CONCLUSIONS

Understanding the underlying mechanisms associating nicotine with pancreatic function is paramount to intervention aiming to retard, arrest, or ameliorate pancreatic disease.

Social determinants of tobacco consumption among Nepalese men: findings from Nepal Demographic and Health Survey 2011

Background

In the 20th century, 100 million people across the globe lost their lives due to consumption of tobacco. Every year 15,000 deaths in Nepal are attributable to tobacco smoking and using other products of tobacco. This study aimed to establish the proportion and the social determinants of tobacco use among Nepalese men based on the Nepal Demographic and Health Survey (NDHS), 2011.

Methods

This study used the NDHS 2011 data. The prevalence of cigarette smoking, other forms of tobacco 16 smoking and use of tobacco in any form is reported as a percentage (%). The significance of association of the statistically significant variables established using Chi-square test was further tested by using multiple logistic regression.

Results

Of the 4121 participants, the prevalence of consuming any form of tobacco was 51.9% [95% confidence interval (CI) (49.6%- 54.3%)]; chewing/sniffing tobacco was 34.8% (95% CI: 32.4%- 37.3%) and tobacco smoking was 33.6% (95% CI 31.3%-36.0%).

Men with no education [Odds Ratio (OR) 3.477; 95% CI (2.380-5.080)], from an older age group (36–49) [OR 2.399; 95% CI (1.858-3.096)] who were from a manual occupation [OR 1.538; 95% CI (1.188-1.985)], who were married[OR 1.938; 95% CI ( 1.552-2.420)], and who were from the Terai region [OR 1.351; 95% CI (1.083-1.684)] were more likely to consume tobacco. Men who watched television at least once a week [OR 0.642; 95% CI (0.504-0.819)] were less likely to consume tobacco.

Conclusions

The current study showed that over half of Nepalese men consume tobacco. There is an urgent need to fully implement Nepal’s Tobacco Control and Regulation Act which will ban smoking in public places; enforced plain packaging and display of health warnings over 75% of the packaging, and has banned selling of tobacco products to those under 18 years of age. There is a need to increase the social unacceptability of tobacco in Nepal by raising awareness through different electronic and cultural media. Anti-tobacco campaigns should focus on those who are less educated, have manual occupations, are in poorer economic groups, and are from the Terai region of Nepal.

Smoking and Pancreatic Disease

Smoking is a major risk factor for chronic pancreatitis and pancreatic cancer. However, the mechanisms through which it causes the diseases remain unknown. In the present manuscript we reviewed the latest knowledge gained on the effect of cigarette smoke and smoking compounds on cell signaling pathways mediating both diseases. We also reviewed the effect of smoking on the pancreatic cell microenvironment including inflammatory cells and stellate cells.