Smooth muscle function and dysfunction in gallbladder disease

Comprehensive analysis of differential long non-coding RNA and messenger RNA expression in cholelithiasis using high-throughput sequencing and bioinformatics

Background

The etiology of gallstone disease (GSD) has not been fully elucidated. Consequently, the primary objective of this study was to scrutinize and provisionally authenticate the distinctive expression profiles of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in GSD.

Methods

RiboNucleic Acid (RNA) sequencing was used on four paired human gallbladder samples for the purpose of this study. Differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were identified and subjected to analysis of their biological functions. The Pearson's correlation coefficients between DElncRNAs and DEmRNAs were computed to construct a co-expression network delineating their associations. Furthermore, both cis- and trans-regulatory networks of selected lncRNAs were established and visualized. Additionally, a competing endogenous RNA (ceRNA) regulatory network was constructed. To validate the RNA-sequencing data, we performed a Quantitative Real-time Polymerase Chain Reaction (RT-qPCR) on 10 paired human gallbladder samples, assessing the expressions of the top 4 DEmRNAs and DElncRNAs in gallstone and control samples.

Results

A total of 934 DEmRNAs and 304DElncRNAs were successfully identified. Functional enrichment analysis indicated a predominant involvement in metabolic-related biological functions. Correlation analysis revealed a strong association between the expressions of 597 DEmRNAs and 194 DElncRNAs. Subsequently, both a cis-lncRNA-mRNA and a trans-lncRNA-Transcription Factor (TF)-mRNA regulatory network were meticulously constructed. Additionally, a ceRNA network, comprising of 24 DElncRNAs, 201 DEmRNAs, and 120 predicted miRNAs, was established. Furthermore, using RT-qPCR, we observed significant upregulation of AC004692.4, HECW1-IT1, SFRP4, and COMP, while LINC01564, SLC26A3, RP1-27K12.2, and GSTA2 exhibited marked downregulation in gallstone samples. Importantly, these findings were consistent with the sequencing.

Conclusion

We conducted a screening process to identify DElncRNAs and DEmRNAs in GSD. This approach contributes to a deeper understanding of the genetic factors involved in the etiology of gallstones.

Personality differences in patients with and without gallstones

OBJECTIVE

Presence of gallstones is associated with a range of risk factors that have previously shown associations with personality traits. Our aim was to assess the differences in personality traits between the patients with and without gallstones.

METHODS

This study used a case-control design with 308 participants from the general population, 68.2% female, mean age 49.2 (SD 9.24) years, of whom 154 (50%) participants had asymptomatic gallstones. Personality was assessed with the Temperament and Character Inventory - Revised - 140 (TCI-R-140) and depression with the Center for Epidemiological Study of Depression Scale (CESD). Cut-off ≥16 on the CES-D was used as an exclusion criterion. Subjects were also checked for metabolic risk factors and sociodemographic characteristics.

RESULTS

The group with gallstones had significantly more pronounced metabolic risk factors and higher prevalence of smoking and alcohol usage in comparison with the group without gallstones. This group also exhibited higher temperament dimension Harm avoidance (HA) and lower character dimension Self-directedness (SD). Metabolic variables differed based on character dimension Cooperativeness (CO), smoking based on temperament dimensions Novelty seeking (NS) and HA, and alcohol usage on dimension NS within the gallstones group. In the logistic regression, controlled for smoking, alcohol usage and metabolic variables, temperament dimension HA was shown to be a significant predictor of the presence of gallstones.

CONCLUSION

Our findings indicate that personality may be associated with the presence of gallstones. Future longitudinal studies addressing the complex interplay of personality traits, psychological mechanisms and the associated behavioral, metabolic and neurobiological factors, are needed.

Proteomic analysis identifies dysregulated proteins and associated molecular pathways in a cohort of gallbladder cancer patients of African ancestry

BACKGROUND

Gallbladder cancer (GBC) is a lethal cancer with a poor prognosis. The lack of specific and sensitive biomarkers results in delayed diagnosis with most patients presenting at late stages of the disease. Furthermore, there is little known about the molecular mechanisms associated with GBC, especially in patients of African ancestry. This study aimed to determine dysregulated proteins in South African GBC patients to identify potential mechanisms of the disease progression and plausible biomarkers.

METHODS

Tissues (27 GBC, 13 Gallstone disease, and 5 normal tissues) and blood plasma (54 GBC and 73 Benign biliary pathology) were obtained from consenting patients. Protein extraction was performed on all tissues and liquid chromatography-mass spectrometry was used for proteomic profiling. A project-specific spectral library was built using the Pulsar search algorithm. Principal component and Spearman's rank correlation analyses were performed using PAST (V4.07b). Pathway and Network analyses were conducted using REACTOME (v3.7) and stringAPP (v1.7.0), respectively.

RESULTS

In the tissue sample group, there were 62 and 194 dysregulated proteins in GBC compared to normal and gallstone groups, respectively. In the plasma group, there were 33 altered proteins in GBC compared to the benign biliary pathology group. We found 9 proteins (APOA1, APOA2, RET4, TTR, HEMO, HBB, HBA, PIGR, and APOE) to be commonly dysregulated in both tissue and plasma. Furthermore, a subset analysis demonstrated that 2 proteins, S100A8 and S100A9, were downregulated in GBC patients with GD history compared to those without. Pathway analysis showed that the dysregulated proteins in GBC patients were enriched in pathways involved in smooth muscle contraction, metabolism, ECM organization, and integrin cell surface interactions.

CONCLUSION

The identified dysregulated proteins help in understanding GBC molecular mechanisms in our patient group. Furthermore, the alteration of specific proteins in both tissue and plasma samples suggests their potential utility as biomarkers of GBC in this sample cohort.

Changes in Gallbladder Contractile Function and its Influencing Factors After Minimally Invasive Gallbladder-Preserving Surgery for Cholecystitis With Incarcerated Gallstones

Background

Cholecystitis with incarcerated gallstones (CIG) is a type of acute abdomen in the field of hepatobiliary surgery. Whether gallbladder-preserving surgery (GPS) can be performed to treat it, however, depends on the improvement of gallbladder contractile function. The present study aimed to investigate the changes in gallbladder contractile function and its influencing factors after minimally invasive GPS for CIG.

Methods

A total of 95 patients with CIG treated in the Aerospace Center Hospital between May 2017 and May 2019 were enrolled as the study subjects. All patients received minimally invasive GPS. The patients' operation-related conditions (including stone removal success rate, duration of surgery, intraoperative blood loss, etc.), changes in gallbladder contractile function, and influencing factors of GPS were analyzed.

Results

Among the 95 patients included in the study, the success rate of stone removal was 100%, the duration of surgery was 76.0 ± 26.5 min, and the intraoperative blood loss was 10.17 ± 4.43 ml. The rate of good gallbladder contractile function at one and two years after surgery was significantly higher than before surgery (P < 0.05). Age, duration of surgery, stone recurrence, and diabetes were the independent risk factors for postoperative gallbladder contractile function (P < 0.05).

Conclusion

Minimally invasive GPS for patients with CIG has a good curative effect. The changes in gallbladder contractile function after the surgery are influenced by many factors.

Glucagon-Like Peptide 2 Inhibits Postprandial Gallbladder Emptying in Man: A Randomized, Double-Blinded, Crossover Study

INTRODUCTION:

A recent study in mice points to the gut-derived hormone glucagon-like peptide 2 (GLP-2) as an important regulator of gallbladder motility inducing gallbladder relaxation and refilling. In this study, we evaluated the effect of exogenous GLP-2 on postprandial gallbladder motility in healthy men.

METHODS:

In a randomized, double-blinded, placebo-controlled, crossover study, we evaluated the effect of 4-hour intravenous infusions of high-dose GLP-2 (10 pmol × kg⁻¹ × min⁻¹), low-dose GLP-2 (1 pmol × kg⁻¹ × min⁻¹), and placebo (saline) on postprandial gallbladder motility. A 300-kcal liquid-mixed meal (added 1.5 g of acetaminophen for indirect measurement of gastric emptying) was served 30 minutes after start of intravenous infusions. Gallbladder volume was assessed by ultrasonography.

RESULTS:

Fifteen healthy men, age 24.3 (22.4–26.1) years (mean [95% confidence interval]) and body mass index 22.5 (21.7–23.4) kg × m⁻², were included. Basal plasma GLP-2 concentration was 14 (11–17) pmol/L. During low-dose and high-dose GLP-2 infusions, steady-state postprandial plasma GLP-2 concentrations amounted to 201 (188–214) and 2,658 (2,443–2,873) pmol/L, respectively, compared with maximum postprandial plasma GLP-2 concentration of 34 (25–44) pmol/L during placebo. Gallbladder emptying (assessed as baseline-subtracted area under the curve for gallbladder volume) was reduced by low-dose GLP-2 (−0.8 [0.7–1.9] L × min, P < 0.0001) and nearly abolished by high-dose GLP-2 (1.3 [−1.7 to 0.01] L × min, P = 0.029) compared to placebo (−2.0 [−2.8 to −1.1] L × min). Compared to placebo, gastric emptying was reduced by high-dose GLP-2 (P = 0.0060 and 0.019), whereas low-dose GLP-2 did not affect gastric emptying (P = 0.13 and 0.85).

DISCUSSION:

Exogenous GLP-2 exerts a dose-dependent inhibitory effect on postprandial gallbladder emptying in healthy men.

[Comparative effectiveness of ursodeoxycholic acid preparations in the treatment of biliary sludge]

In the clinical classification of cholelithiasis, biliary sludge (BS) is distinguished as the pre-stone stage. Ursodeoxycholic acid (UDCA) is a drug with an evidence base for effective and safe effects on BS. The therapeutic equivalence of various UDCA drugs remains an important issue for clinical practice.

AIM

To conduct a comparative analysis of the effectiveness of the use of UDCA: Ursofalk with other UDCA drugs for the treatment of BS in a fixed dose of 10 mg/kg of body weight.

MATERIAL AND METHODS

The observation group consisted of 225 patients with various types of BS. In randomized groups, the comparison of the effectiveness of UDCA drugs in the dissolution of BS was determined by the data of ultrasound of the gallbladder. Dynamic ultrasound cholecystography using a standardized technique was performed to study the effect of the compared drugs on the contractile function of the liver. When analyzing the impact of ursotherapy on the clinical manifestations of BS, the dynamics of biliary pain syndrome and dyspeptic disorders were evaluated.

RESULTS

A comparative analysis of the effectiveness of UDCA drugs for BS lysis with a high degree of confidence established the advantage of Ursofalk: after 3 months in 80%, and after 6 months of therapy in 95.65% of patients, a regression of BS was detected. In the group of patients who took other UDCA, the corresponding indicators were 46.36% and 67.27%. The greatest effectiveness of ursotherapy was demonstrated in the BS variant by the type of suspension of hyperechogenic particles, the lowest in the variant by the type of putty-like bile in the form of mobile or fixed clots. In the last variant of BS, the relationship between the success of lysis with the extension of the UDCA intake period to 6 months and the preferred choice of Ursofalk was traced. Normalization of the contractile function of the gallbladder was noted in patients who took Ursofalk.

CONCLUSION

From the standpoint of therapeutic effectiveness, the drug of choice for the treatment of BS, regardless of its type, is Ursofalk, which has proven the best dynamics of BS litolysis, recovery of the contractile function of the gastrointestinal tract, and relief of clinical symptoms.

Physical Activity Modulating Lipid Metabolism in Gallbladder Diseases

Physical activity encompasses a series of overall benefits on cardiovascular health and metabolic disorders. Research has recently focused on the hepatobiliary tract, as an additional target of the health-related outcomes of different types of physical exercise. Here, we focus on the global features of physical activity with respect to exercise modality and intensity, and on studies linking physical activity to lipid metabolism, gallbladder diseases (gallstones, symptoms, complications and health-related quality of life), gallbladder motor-function, enterohepatic circulation of bile acids, and systemic metabolic inflammation. Additional studies need to unravel the pathophysiological mechanisms involved in both beneficial and harmful effects of physical activity in populations with different metabolic conditions.

The Vagus Nerve and the Celiaco-mesenteric Ganglia Participate in the Feeding Responses Evoked by Non-sulfated Cholecystokinin-8 in Male Sprague Dawley Rats

We have shown that non-sulfated cholecystokinin-8 (NS CCK-8) reduces food intake in adult male Sprague Dawley rats by activating cholecystokinin-B receptor (CCK-BR). Here, we tested the hypothesis that the vagus nerve and the celiaco-mesenteric ganglia may play a role in this reduction. The hypothesis stems from the following facts. The vagus and the celiaco-mesenteric ganglia contain NS CCK-8, they express and have binding sites for CCK-BR, NS CCK-8 activates CCK-BR on afferent vagal and sympathetic fibers and the two structures link the gastrointestinal tract to central feeding nuclei in the brain, which also contain the peptide and CCK-BR. To test this hypothesis, three groups of free-feeding rats, vagotomy (VGX), celiaco-mesenteric ganglionectomy (CMGX) and sham-operated, received NS CCK-8 (0, 0.5 and 1 nmol/kg) intraperitoneally prior to the onset of the dark cycle and various feeding behaviors were recorded. We found that in sham-operated rats both doses of NS CCK-8 reduced meal size (MS), prolonged the intermeal interval (IMI, time between first and second meal), increased satiety ratio (SR = IMI/MS), reduced 24-h food intake and reduced the number of meals relative to saline control. In the VGX and the CMGX groups, all of the previous responses were attenuated. Consistent with our hypothesis, the findings of the current work suggest a role for the vagus nerve and the celiaco-mesenteric ganglia in the feeding responses evoked by NS CCK-8.

Role of gallbladder-preserving surgery in the treatment of gallstone diseases in young and middle-aged patients in China: results of a 10-year prospective study

BACKGROUND

The aim of the study was to prospectively investigate the long-term effects of gallbladder-preserving cholecystolithotomy in a selected population of Chinese patients.

METHODS

Between January 2007 and December 2016, all gallstone patients who met the criteria for gallbladder-preserving cholecystolithotomy in our hospital were included in the study and followed prospectively. The primary endpoint was the time of recurrence of cholecystolithiasis, and the secondary endpoint was the end of the study. The data were collected in half-year intervals.

RESULTS

We surveyed 81 male patients and 135 female patients. Most patients (176/216) had only 1 gallstone in the gallbladder. All patients underwent gallbladder-preserving cholecystolithotomy successfully. After the operation, 200 of the 216 patients were symptom free. There was no difference in the percentage of gallbladder emptying (the gallbladder emptying index) between the time prior to the operation and 6 months after gallbladder-preserving cholecystolithotomy (0.47 ± 0.18 vs 0.49 ± 0.18, P = .837). Twenty patients (9.3%) developed recurrent gallstones during the follow-up period. There was no difference in stone recurrence between patients who were treated with ursodeoxycholic acid for 6 months postoperatively and those treated with ursodeoxycholic acid for 12 months (P = .589). Most instances of recurrence occurred within 2 years of gallbladder-preserving cholecystolithotomy. Overall, the recurrence rates at 6, 12, and 24 months were 2.3%, 3.7%, and 7.6%, respectively.

CONCLUSION

Gallbladder-preserving cholecystolithotomy is a safe and effective operative procedure for selected Chinese patients. The function of the gallbladder can be maintained after gallbladder-preserving cholecystolithotomy. The recurrence of cholelithiasis is infrequent in this Chinese population with a mean follow-up of 59 (range 8 to 120) months, and most patients with recurrent gallbladder stones experience no symptoms or only minor symptoms.

New Avenues in the Regulation of Gallbladder Motility-Implications for the Use of Glucagon-Like Peptide-Derived Drugs

CONTEXT

Several cases of cholelithiasis and cholecystitis have been reported in patients treated with glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) and GLP-2 receptor agonists (GLP-2RAs), respectively. Thus, the effects of GLP-1 and GLP-2 on gallbladder motility have been investigated. We have provided an overview of the mechanisms regulating gallbladder motility and highlight novel findings on the effects of bile acids and glucagon-like peptides on gallbladder motility.

EVIDENCE ACQUISITION

The articles included in the present review were identified using electronic literature searches. The search results were narrowed to data reporting the effects of bile acids and GLPs on gallbladder motility.

EVIDENCE SYNTHESIS

Bile acids negate the effect of postprandial cholecystokinin-mediated gallbladder contraction. Two bile acid receptors seem to be involved in this feedback mechanism, the transmembrane Takeda G protein-coupled receptor 5 (TGR5) and the nuclear farnesoid X receptor. Furthermore, activation of TGR5 in enteroendocrine L cells leads to release of GLP-1 and, possibly, GLP-2. Recent findings have pointed to the existence of a bile acid-TGR5-L cell-GLP-2 axis that serves to terminate meal-induced gallbladder contraction and thereby initiate gallbladder refilling. GLP-2 might play a dominant role in this axis by directly relaxing the gallbladder. Moreover, recent findings have suggested GLP-1RA treatment prolongs the refilling phase of the gallbladder.

CONCLUSIONS

GLP-2 receptor activation in rodents acutely increases the volume of the gallbladder, which might explain the risk of gallbladder diseases associated with GLP-2RA treatment observed in humans. GLP-1RA-induced prolongation of human gallbladder refilling may explain the gallbladder events observed in GLP-1RA clinical trials.

Constitutive law of healthy gallbladder walls in passive state with damage effect

Biomechanical properties of human gallbladder (GB) wall in passive state can be valuable to diagnosis of GB diseases. In the article, an approach for identifying damage effect in GB walls during uniaxial tensile test was proposed and a strain energy function with the damage effect was devised as a constitutive law phenomenologically. Scalar damage variables were introduced respectively into the matrix and two families of fibres to assess the damage degree in GB walls. The parameters in the constitutive law with the damage effect were determined with a custom MATLAB code based on two sets of existing uniaxial tensile test data on human and porcine GB walls in passive state. It turned out that the uniaxial tensile test data for GB walls could not be fitted properly by using the existing strain energy function without the damage effect, but could be done by means of the proposed strain energy function with the damage effect involved. The stresses and Young moduli developed in two families of fibres were more than thousands higher than the stresses and Young's moduli in the matrix. According to the damage variables estimated, the damage effect occurred in two families of fibres only. Once the damage occurs, the value of the strain energy function will decrease. The proposed constitutive laws are meaningful for finite element analysis on human GB walls.

Exercising the hepatobiliary-gut axis. The impact of physical activity performance

BACKGROUND

Physical inactivity puts the populations at risk of several health problems, while regular physical activity brings beneficial effects on cardiovascular disease, mortality and other health outcomes, including obesity, glycaemic control and insulin resistance. The hepatobiliary tract is greatly involved in several metabolic aspects which include digestion and absorption of nutrients in concert with intestinal motility, bile acid secretion and flow across the enterohepatic circulation and intestinal microbiota. Several metabolic abnormalities, including nonalcoholic fatty liver as well as cholesterol cholelithiasis, represent two conditions explained by changes of the aforementioned pathways.

MATERIALS AND METHODS

This review defines different training modalities and discusses the effects of physical activity in two metabolic disorders, that is nonalcoholic fatty liver disease (NAFLD) and cholelithiasis. Emphasis is given to pathogenic mechanisms involving intestinal bile acids, microbiota and inflammatory status.

RESULTS

A full definition of physical activity includes the knowledge of aerobic and endurance exercise, metabolic equivalent tasks, duration, frequency and intensity, beneficial and harmful effects. Physical activity influences the hepatobiliary-gut axis at different levels and brings benefits to fat distribution, liver fat and gallbladder disease while interacting with bile acids as signalling molecules, intestinal microbiota and inflammatory changes in the body.

CONCLUSIONS

Several beneficial effects of physical activity are anticipated on metabolic disorders linking liver steatosis, gallstone disease, gut motility, enterohepatic circulation of signalling bile acids in relation to intestinal microbiota and inflammatory changes.

An update on the pathogenesis of cholesterol gallstone disease

PURPOSE OF REVIEW

Gallstone disease is a major epidemiologic and economic burden worldwide, and the most frequent form is cholesterol gallstone disease.

RECENT FINDINGS

Major pathogenetic factors for cholesterol gallstones include a genetic background, hepatic hypersecretion of cholesterol, and supersaturated bile which give life to precipitating cholesterol crystals that accumulate and grow in a sluggish gallbladder. Additional factors include mucin and inflammatory changes in the gallbladder, slow intestinal motility, increased intestinal absorption of cholesterol, and altered gut microbiota. Mechanisms of disease are linked with insulin resistance, obesity, the metabolic syndrome, and type 2 diabetes. The role of nuclear receptors, signaling pathways, gut microbiota, and epigenome are being actively investigated.

SUMMARY

Ongoing research on cholesterol gallstone disease is intensively investigating several pathogenic mechanisms, associated metabolic disorders, new therapeutic approaches, and novel strategies for primary prevention, including lifestyles.

Recent advances in understanding and managing cholesterol gallstones

The high prevalence of cholesterol gallstones, the availability of new information about pathogenesis, and the relevant health costs due to the management of cholelithiasis in both children and adults contribute to a growing interest in this disease. From an epidemiologic point of view, the risk of gallstones has been associated with higher risk of incident ischemic heart disease, total mortality, and disease-specific mortality (including cancer) independently from the presence of traditional risk factors such as body weight, lifestyle, diabetes, and dyslipidemia. This evidence points to the existence of complex pathogenic pathways linking the occurrence of gallstones to altered systemic homeostasis involving multiple organs and dynamics. In fact, the formation of gallstones is secondary to local factors strictly dependent on the gallbladder (that is, impaired smooth muscle function, wall inflammation, and intraluminal mucin accumulation) and bile (that is, supersaturation in cholesterol and precipitation of solid crystals) but also to "extra-gallbladder" features such as gene polymorphism, epigenetic factors, expression and activity of nuclear receptors, hormonal factors (in particular, insulin resistance), multi-level alterations in cholesterol metabolism, altered intestinal motility, and variations in gut microbiota. Of note, the majority of these factors are potentially manageable. Thus, cholelithiasis appears as the expression of systemic unbalances that, besides the classic therapeutic approaches to patients with clinical evidence of symptomatic disease or complications (surgery and, in a small subgroup of subjects, oral litholysis with bile acids), could be managed with tools oriented to primary prevention (changes in diet and lifestyle and pharmacologic prevention in subgroups at high risk), and there could be relevant implications in reducing both prevalence and health costs.

Embryonic cholecystitis and defective gallbladder contraction in the Sox17-haploinsufficient mouse model of biliary atresia

The gallbladder excretes cytotoxic bile acids into the duodenum through the cystic duct and common bile duct system. Sox17 haploinsufficiency causes biliary atresia-like phenotypes and hepatitis in late organogenesis mouse embryos, but the molecular and cellular mechanisms underlying this remain unclear. In this study, transcriptomic analyses revealed the early onset of cholecystitis in Sox17^+/- embryos, together with the appearance of ectopic cystic duct-like epithelia in their gallbladders. The embryonic hepatitis showed positive correlations with the severity of cholecystitis in individual Sox17^+/- embryos. Embryonic hepatitis could be induced by conditional deletion of Sox17 in the primordial gallbladder epithelia but not in fetal liver hepatoblasts. The Sox17^+/- gallbladder also showed a drastic reduction in sonic hedgehog expression, leading to aberrant smooth muscle formation and defective contraction of the fetal gallbladder. The defective gallbladder contraction positively correlated with the severity of embryonic hepatitis in Sox17^+/- embryos, suggesting a potential contribution of embryonic cholecystitis and fetal gallbladder contraction in the early pathogenesis of congenital biliary atresia.

Vitamin D and gallstone disease-A population-based study

Gallstone disease is highly prevalent in the general population and is a major gastrointestinal cause of hospital admissions. The objectives were to determine whether circulating levels of 25-hydroxyvitamin D were associated to ultrasound proven gallstones or cholecystectomy in a general population sample. Determinants of vitamin D status were also explored. A random sample of 4130 people from the population of Copenhagen with ages 41-71 years were invited (N = 4130) and 2650 participants were included. Ultrasound examinations were performed to assess gallstone status and blood samples were drawn to assess 25-hydroxyvitamin D and biomarkers of renal and hepatic function. Gallstone disease was found in 422 participants. Associations were estimated by logistic regression models. Levels of 25-hydroxyvitamin D was not significantly associated with gallstone disease. Time of birth during low vitamin D exposure was associated with gallstone disease (gallstone prevalence 18.0 versus 14.4 %, odds ratio 1.33, 95 % confidence interval [1.07; 1.65]). Highest quartile of cystatin C was significantly associated with gallstone disease (gallstone prevalence 22.1 versus 12.0 %, odds ratio 1.53, 95 % confidence interval [1.08; 2.18]). Serum levels of creatinine and alanine amino transferase were not associated with gallstone disease. Sensitivity analyses excluding participants with cholecystectomy did not alter results significantly. No association between 25-hydroxyvitamin D and gallstone disease was identified. Findings suggest gallstones to be associated to low vitamin D exposure in utero and to renal failure suggesting that vitamin D might have an impact on gallstone disease. Future studies should explore associations for vitamin D and gallstone disease prospectively.

Correlations between metabolic syndrome, serologic factors, and gallstones

[Purpose] This study investigated the serologic factors associated with metabolic syndrome and gallstones. [Subjects and Methods] The study evaluated subjects who visited a health promotion center in Seoul from March 2, 2013 to February 28, 2014, and had undergone abdominal ultrasonography. Height, weight, and blood pressure were measured. Blood sampling was performed for high-density lipoprotein cholesterol, triglyceride, fasting blood glucose, total bilirubin, direct bilirubin, indirect bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, uric acid, total cholesterol, low-density lipoprotein cholesterol, thyroid stimulating hormone, and red and white blood cell counts. We conducted logistic regression analysis to assess the risk factors associated with metabolic syndrome. [Results] The risk factors for metabolic syndrome in men, in order of decreasing weight, were red blood cell count, body mass index, maximum size of gallstones, white blood cell count, waist circumference, and uric acid level. The factors in women, in order of decreasing weight, were red blood cell count, presence/absence of gallstones, uric acid level, body mass index, fasting blood glucose, and waist circumference. [Conclusion] Most serum biochemical factors and gallstone occurrence could be used to indicate the presence or absence of metabolic syndrome, independent of gender.

Functions of the Gallbladder

The gallbladder stores and concentrates bile between meals. Gallbladder motor function is regulated by bile acids via the membrane bile acid receptor, TGR5, and by neurohormonal signals linked to digestion, for example, cholecystokinin and FGF15/19 intestinal hormones, which trigger gallbladder emptying and refilling, respectively. The cycle of gallbladder filling and emptying controls the flow of bile into the intestine and thereby the enterohepatic circulation of bile acids. The gallbladder also largely contributes to the regulation of bile composition by unique absorptive and secretory capacities. The gallbladder epithelium secretes bicarbonate and mucins, which both provide cytoprotection against bile acids. The reversal of fluid transport from absorption to secretion occurs together with bicarbonate secretion after feeding, predominantly in response to an adenosine 3',5'-cyclic monophosphate (cAMP)-dependent pathway triggered by neurohormonal factors, such as vasoactive intestinal peptide. Mucin secretion in the gallbladder is stimulated predominantly by calcium-dependent pathways that are activated by ATP present in bile, and bile acids. The gallbladder epithelium has the capacity to absorb cholesterol and provides a cholecystohepatic shunt pathway for bile acids. Changes in gallbladder motor function not only can contribute to gallstone disease, but also subserve protective functions in multiple pathological settings through the sequestration of bile acids and changes in the bile acid composition. Cholecystectomy increases the enterohepatic recirculation rates of bile acids leading to metabolic effects and an increased risk of nonalcoholic fatty liver disease, cirrhosis, and small-intestine carcinoid, independently of cholelithiasis. Among subjects with gallstones, cholecystectomy remains a priority in those at risk of gallbladder cancer, while others could benefit from gallbladder-preserving strategies. © 2016 American Physiological Society. Compr Physiol 6:1549-1577, 2016.

Role of ROCK expression in gallbladder smooth muscle contraction

Cholelithiasis is a common medical condition whose incidence rate is increasing yearly, while its pathogenesis has yet to be elucidated. The present study assessed the expression of Rho-kinase (ROCK) in gallbladder smooth muscles and its effect on the contractile function of gallbladder smooth muscles during gallstone formation. Thirty male guinea pigs were randomly divided into three groups: The control group, the gallstone model group and the fasudil interference group. The fasting volume (FV) and bile capacity of the gallbladder (FB) as well as the total cholesterol (TC) and triglyceride (TG) contents of the gallbladder bile were determined. In addition, the gallbladder was dissected to identify whether any gallstones had formed. Part of the gallbladder tissue specimens were used for immunohistochemical analysis of ROCK expression in gallbladder smooth muscles. The results showed that four guinea pigs in the model group and eight in the fasudil group displayed gallstone formation, while there was no gallstone formation in the control group. The FV and FB were significantly increased in the model and fasudil groups. Similarly, the TC and TG contents of gallbladder bile were increased in these groups. The positive expression rate of ROCK in gallbladder smooth muscles in the model and fasudil groups was significantly reduced compared with that in the control group (P<0.05). The results of the present study indicated that the reduction of ROCK expression in guinea pig gallbladder smooth muscles weakened gallbladder contraction and thereby promoted gallstone formation.

The APOB gene polymorphism in the pathogenesis of gallstone disease in pre- and postmenopausal women

Aim of the study

The decrease in estrogen levels in the postmenopausal period changes the lipid profile by the expression of hepatic genes related to metabolism of cholesterol and bile acid synthesis that could be important in the pathogenesis of cholelithiasis. The aim of the study was to determine the APOB gene 7673C>T and 12669G>A polymorphisms in the pathogenesis of gallstones and analysis of the composition of gallstones in pre- and postmenopausal women.

Material and methods

The study group consisted of 94 women qualified to the laparoscopic cholecystectomy while the control group consisted of 81 women in whom gallstones and other changes in the bile ducts were excluded. Gallstones composition analysis was performed using commercially available assays. The prevalence of the APOB gene polymorphisms was determined using the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).

Results

When assessing the composition of gallstones in pre- and postmenopausal women, we observed differences in the studied parameters. Analysis of genetic variants of APOB gene 7673C>T and 12669G>A polymorphisms showed no significant statistical differences between studied groups and controls.

Conclusions

Analysis of 7673C>T and 12669G>A polymorphisms showed no relationship between specific genetic variants and the risk of gallstones in pre- and postmenopausal women, pointing to the fact that the investigated polymorphisms are not relevant as prognostic factors in gallstone disease in the Caucasian population. Because of the possible contribution of a variety of factors in gallstones pathogenesis the studies are required to take account of additional environmental factors, what may indicate different occurrence between investigated polymorphisms, gallstone disease development and gallstones composition in Caucasians.

Clinical impact of body mass index on bactibilia and bacteremia

Background

The aim of this study was to evaluate the association between obesity and infected bile or bacteremia in patients with acute calculous cholecystitis.

Methods

Authors analyzed the medical records of 139 patients who had undergone cholecystectomy for the treatment of acute calculous cholecystitis from January 2007 to June 2013 in a single teaching hospital. Association of body mass index (BMI) with bactibilia and bacteremia was assessed using univariate and multivariate analysis. Clinical findings and biliary infection related data were recorded for the following variables: gender, age, alcohol and smoking history, the results of blood and bile cultures, cholesterolosis, diabetes, hypertension, and duration of the hospital stay.

Results

The microbial culture rate of bactibilia and bacteremia were 50.4% and 21.6%, respectively. In the univariate analysis, bacteremia was associated with bactibilia (OR: 4.33, p = 0.002). In the multivariate analysis for the risk factors of bactibilia, BMI and bacteremia were related with bactibilia (OR: 0.59, 95% CI: 0.42-0.84, p = 0.003) (OR: 3.32, 95% CI: 1.22-9, p = 0.02). In the multivariate analysis for the risk factors of bacteremia, BMI, bactibilia and age were related with bacteremia (OR: 0.76, 95% CI: 0.59-0.99, p = 0.04) (OR: 3.46, 95% CI: 1.27-9.45, p = 0.02) (OR: 1.05, 95% CI: 1.01-1.09, p = 0.02).

Conclusion

In this retrospective study, BMI was inversely correlated with bacteremia or bactibilia, which means obese or overweight patients are less likely to be associated with bacteremia or bactibilia in patients with acute calculous cholecystitis.

An estimation of the number of cells in the human body

BACKGROUND

All living organisms are made of individual and identifiable cells, whose number, together with their size and type, ultimately defines the structure and functions of an organism. While the total cell number of lower organisms is often known, it has not yet been defined in higher organisms. In particular, the reported total cell number of a human being ranges between 10(12) and 10(16) and it is widely mentioned without a proper reference.

AIM

To study and discuss the theoretical issue of the total number of cells that compose the standard human adult organism.

SUBJECTS AND METHODS

A systematic calculation of the total cell number of the whole human body and of the single organs was carried out using bibliographical and/or mathematical approaches.

RESULTS

A current estimation of human total cell number calculated for a variety of organs and cell types is presented. These partial data correspond to a total number of 3.72 × 10(13).

CONCLUSIONS

Knowing the total cell number of the human body as well as of individual organs is important from a cultural, biological, medical and comparative modelling point of view. The presented cell count could be a starting point for a common effort to complete the total calculation.

Disruption of gallbladder smooth muscle function is an early feature in the development of cholesterol gallstone disease

BACKGROUND; Decreased gallbladder smooth muscle (GBSM) contractility is a hallmark of cholesterol gallstone disease, but the interrelationship between lithogenicity, biliary stasis, and inflammation are poorly understood. We studied a mouse model of gallstone disease to evaluate the development of GBSM dysfunction relative to changes in bile composition and the onset of sterile cholecystitis.

METHODS

BALB/cJ mice were fed a lithogenic diet for up to 8 weeks, and tension generated by gallbladder muscle strips was measured. Smooth muscle Ca(2+) transients were imaged in intact gallbladder.

KEY RESULTS

Lipid composition of bile was altered lithogenically as early as 1 week, with increased hydrophobicity and cholesterol saturation indexes; however, inflammation was not detectable until the fourth week. Agonist-induced contractility was reduced from weeks 2 through 8. GBSM normally exhibits rhythmic synchronized Ca(2+) flashes, and their frequency is increased by carbachol (3 μm). After 1 week, lithogenic diet-fed mice exhibited disrupted Ca(2+) flash activity, manifesting as clustered flashes, asynchronous flashes, or prolonged quiescent periods. These changes could lead to a depletion of intracellular Ca(2+) stores, which are required for agonist-induced contraction, and diminished basal tone of the organ. Responsiveness of Ca(2+) transients to carbachol was reduced in mice on the lithogenic diet, particularly after 4-8 weeks, concomitant with appearance of mucosal inflammatory changes.

CONCLUSIONS & INFERENCES

These observations demonstrate that GBSM dysfunction is an early event in the progression of cholesterol gallstone disease and that it precedes mucosal inflammation.

Metabolomic study of serum from rabbits with acute acalculous cholecystitis

OBJECTIVES

(1)H-NMR is a powerful approach of metabolomics. This study aimed to apply it to detect the serum metabolites in rabbits with acute acalculous cholecystitis (AAC), and to analyze their potential roles in AAC.

METHODS

Fourteen rabbits were randomly divided into two groups, the AAC group and the CON group. In the AAC rabbit model, Escherichia coli solution was injected into the gallbladder, while same volume of saline, instead of E. coli solution, was injected into the gallbladder of the CON rabbit. General morphological, light microscopic and transmission electron microscopic observations were used to evaluate the model. Metabolic profiles of serum from rabbits with AAC were investigated through (1)H-NMR spectroscopy coupled with multivariate statistical analysis, such as principal components analysis and orthogonal partial least-squares discriminant analysis.

RESULTS

The pathohistology of gallbladders showed a significant difference between the two groups, proving the successful induction of inflammation in the gallbladders of the AAC group. The serum concentration of lipids (LDL and VLDL) increased during AAC, while the concentrations of phospholipids, lactic acid, 3-hydroxybutyric acid, lysine, citric acid, asparagine, histidine, glucose and some other small molecular metabolites decreased.

CONCLUSION

The profiling of serum metabolites in rabbits with acute acalculous cholecystitis changed significantly. These changes referred to the metabolic disturbance of carbohydrate, amino acids and lipids, inhibition of immunological functions and inflammation reaction.

[Obesity and gallbladder diseases]

Obesity is an important health problem in the world and related to many critical diseases, such as diabetes, cardiovascular disease, and metabolic syndrome. Obesity leads to fat infiltration of multiple organs and infiltrated adipose tissue produces many cytokines resulting in the dysfunction of organs such as the gallbladder. In the biliary diseases, obesity and overweight have been known as a major risk factor for gallstones. According to current studies, obesity, insulin resistance, hyperinsulinemia, and metabolic syndrome are related to various gallbladder diseases including gallbladder stones, cholecystitis, gallbladder polyps, and gallbladder cancers. We reviewed further literature on the obesity and gallbladder diseases, in aspects of epidemiology, mechanism, pathology and prevention.

Targets for current pharmacologic therapy in cholesterol gallstone disease

Gallstone disease is a frequent condition throughout the world and, cholesterol stones are the most frequent form in Western countries. The standard treatment of symptomatic gallstone subjects is laparoscopic cholecystectomy. The selection of patients amenable for nonsurgical, medical therapy is of key importance; a careful analysis should consider the natural history of the disease and the overall costs of therapy. Only patients with mild symptoms and small, uncalcified cholesterol gallstones in a functioning gallbladder with a patent cystic duct are considered for oral litholysis by hydrophilic ursodeoxycholic acid, in the hope of achieving cholesterol desaturation of bile and progressive stone dissolution. Recent studies have raised the possibility that cholesterol-lowering agents that inhibit hepatic cholesterol synthesis (statins) or intestinal cholesterol absorption (ezetimibe), or drugs acting on specific nuclear receptors involved in cholesterol and bile acid homeostasis, may offer, alone or in combination, additional medical therapeutic tools for treating cholesterol gallstones. Recent perspectives on medical treatment of cholesterol gallstone disease are discussed in this article.

Steatocholecystitis and fatty gallbladder disease

Obesity has become an epidemic worldwide. It is accompanied by a multitude of medical complications including metabolic syndrome. Obesity may lead to fatty infiltration of multiple internal organs including liver, heart, kidney, and pancreas, causing organ dysfunctions. Fatty infiltration leads to chronic inflammation and tissue damage. Fatty infiltration in the liver results in nonalcoholic fatty liver disease, which is increasingly common nowadays. Recent studies in animals and humans indicate that obesity also is associated with fatty infiltration of gallbladder, resulting in cholecystosteatosis. The increased gallbladder lipids include free fatty acids, phospholipids, and triglycerides. Enhanced inflammation with an increased amount of fat in the gallbladder results in an abnormal wall structure and decreased contractility. In support of this notion, a recent experiment on the effect of Ezetimibe, which is a novel drug that inhibits intestinal fat absorption, on fatty gallbladder disease reveals that Ezetimibe can ameliorate cholecystosteatosis and restore in vivo gallbladder contractility. The proportion of cholecystectomies performed for chronic acalculous cholecystitis has increased significantly over the past two decades. An increase in gallbladder fat, which leads to poor gallbladder emptying and biliary symptoms, may partly explain this phenomenon. Although dietary carbohydrates have been demonstrated to be associated with fatty gallbladder disease, other potential modifiable environmental factors are not clear. The pathogenesis and prognosis of fatty gallbladder disease, including steatocholecystitis, and the relations of fatty gallbladder disease to nonalcoholic fatty liver disease, including steatohepatitis, and other components of metabolic syndrome are largely unknown. More research is needed to answer these questions.

Effects of NO/L-arginine pathway on gallbladder contractility in bile duct ligated guinea pigs

BACKGROUND

Common bile duct ligation (CBDL) produces gallbladder distension and acute inflammation similar to that seen in human acute acalculous cholecystitis. CBDL in the guinea pig affects smooth muscle contractility. The aim of this study was to determine whether the nitric oxide-L-arginine pathway plays a role in the inflammatory process and abnormal gallbladder contractility that occur after CBDL.

MATERIALS AND METHODS

Contractility of gallbladder muscle from CBDL and sham-operated guinea pigs was studied in vitro. Animals were treated with saline, aminoguanidine (AG), or an aminoguanidine + L-arginine combination (AG + L-Arg) in vivo. Potassium chloride, carbachol, and electric field stimulation (EFS) were used for contracting the gallbladder muscle strips or activating intrinsic nerves. Hematoxylin and eosin-stained slides of muscle strips were scored for inflammation.

RESULTS

Contraction responses to carbachol and EFS were decreased significantly in CBDL guinea pigs compared with those in the sham-operated group. AG partly reversed the smooth muscle contractile response to carbachol and EFS, but did not reduce the inflammation score. Treatment with AG + L-arg did not reverse either the contraction response or the inflammation score.

CONCLUSIONS

These findings suggest that AG and AG + L-Arg treatments have no beneficial effect on inflammation in guinea pigs after CBDL, although AG significantly reversed the effect on muscle contractility (P < 0.05). This improvement was independent of inflammation and may be due to a decreased level of NO and its diminished relaxant effect.

Patients with iron deficiency anemia have an increased prevalence of gallstones

We determined the frequency of gallstones (GS) in iron deficiency anemia (IDA) patients and evaluated factors that could affect GS formation-like lipid levels and gallbladder (GB) motilities of the patients. One hundred and eleven IDA patients (88 females, 23 males; median age, 42) and 81 healthy controls (68 females, 13 males; median age, 42) were included into our study. The clinical findings of all IDA patients were recorded down; biochemical values and body mass index (BMI) were determined; and abdominal ultrasonography was performed. In addition, GB emptying was monitored by ultrasound at 30-min intervals for 2 h after a mixed meal in randomly chosen, age-matched 25 IDA patients and 26 controls. Fasting volume (FV), residual volume (RV), and ejection fraction (EF) for all GBs were determined. The frequency of GS plus cholecystectomy was significantly higher in IDA patients (15 cases, 13.5%) than in the control group (five cases, 6.2%, p = 0.048). IDA patients with GS plus cholecystectomy were older than those without GS plus cholecystectomy (p < 0.001). FV and EF did not differ between IDA and control groups (p > 0.05). On the other hand, RV was significantly higher in IDA group than in controls (p = 0.035). The frequency of GS in IDA patients was significantly higher than in controls. The increased prevalence of GS in IDA might be explained with impaired GB motility.

A putative role of ribonuclear inclusions and MBNL1 in the impairment of gallbladder smooth muscle contractility with cholelithiasis in myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystemic disorder caused by expansion of unstable trinucleotide (CTG) repeats at 3' untranslated region of the DMPK gene on chromosome 19q13.3. Mutant transcripts are retained in muscle nuclei as ribonuclear inclusions and interact with RNA-binding proteins, such as muscleblind-like protein 1 (MBNL1), leading to a reduction in their activity. The reduced MBNL1 activity has been associated to skeletal and cardiac muscle dysfunction. However, other organs and systems may be involved. It has been reported that 25-50% of DM1 patients have abdominal symptoms due to cholelithiasis or gallstones. Since impaired gallbladder motility plays an important role in gallstones formation, we have analyzed by FISH combined with MBNL1-immunofluorescence, the gallbladder obtained from a woman affected by DM1 who required a cholecystectomy at the age of 30. Gallbladders obtained from two no-DM1 subjects have been used as controls. Ribonuclear inclusions and MBNL1 foci accumulate and colocalize in nuclei of DM1 gallbladder smooth muscle cells. On the contrary, no ribonuclear inclusions are detectable in cell nuclei of control gallbladders and MBNL1 is uniformly distributed in smooth muscle cell nuclei. These results suggest that nuclear accumulation of MBNL1 and ribonuclear inclusions may have a direct adverse effect on gallbladder smooth muscle contractility and thus contribute to gallstones formation in DM1 patients.

Effects of cholecystokinin on gallbladder muscle stripes of guinea pigs with cholesterol gallstone in vitro

AIM: To establish an animal model of cholesterol stone and to explore the effects of cholecystokinin (CCK) on gallbladder muscle stripes of guinea pigs with cholesterol stone in vitro as well as to investigate the role of biliary kinetics in cholesterol stone formation.

METHODS: The animal model of cholesterol stone was established by feeding guinea pig with stone-leading forage. The guinea pigs were assigned to four groups: group A (the normal guinea pigs), group B (stone-leading forage for 4 wk), group C (stone-leading forage for 8 wk), and group D (the normal guinea pigs with injury of interstitial cell of cajal (ICC). Effects of 10^-9, 10^-8 and 10^-7 mol/L cholecystokinin (CCK) on gallbladder muscle stripes of guinea pigs in vitro among the four groups were recorded and analyzed.

RESULTS: No cholesterol stone was observed in group A, and a total of 13 cases of cholesterol stone were observed in group B and C. The amplitude of contraction showed a dose-independent relationship with CCK-8 in groups A, B and C. Compared with group A, there was statistically significant diffference in group B and group C (P < 0.05). The contraction of smooth muscle was nearly abolished when interstitial cells of Cajal were destroyed using methylene blue incubation and intensive illumination. Although CCK was administered, there was no significant difference in the amplitude of the contraction of smooth muscle strip in group D (10^-9 mol/L: 0.461 ± 0.071 vs 1.461 ± 0.252; 10^-8 mol/L: 0.608 ± 0.118 vs 2.484 ± 0.283; 10^-7 mol/L: 0.641 ± 0.129 vs 3.312 ± 0.311, all P < 0.01).

CONCLUSION: Muscular tension is significantly inhibited following injury of interstitial cells of Cajal. The damage of interstitial cells of Cajal may be an important factor related to cholelithiasis.

Physical chemistry of intestinal absorption of biliary cholesterol in mice

Although many putative sterol transporters influencing cholesterol absorption and physical-chemical factors affecting dietary cholesterol absorption have been extensively investigated, it is still unclear how biliary cholesterol contributes to the regulation of intestinal cholesterol absorption. We studied whether the gallbladder can modulate the microaggregates of cholesterol carriers, which may in turn influence the intestinal absorption of biliary cholesterol. Supersaturated, crystallized, or micellar model biles were delivered via a duodenal catheter to conscious, freely moving C57L mice daily for 2 days. Intestinal uptake and absorption of biliary cholesterol and its fecal excretion, as well as expression levels of intestinal sterol transporters, were analyzed. Cholesterol uptake and absorption by the enterocyte were dramatically reduced in mice treated with crystallized biles compared with supersaturated biles. This correlated with the higher cumulative radioactivity of cholesterol recovered in the feces at 24 hours. Such findings were absent with the added reference compound sitostanol. After removing cholesterol crystals from crystallized biles, micellar biles showed essentially identical effects on intestinal absorption but with lower fecal cholesterol excretion compared with the original samples containing crystals. Expression levels of the jejunal Abcg5 (ATP-binding cassette transporter G5) and Abcg8, but not Npc1l1 (Niemann-Pick C1 like 1), were significantly increased by supersaturated biles compared with crystallized biles.

CONCLUSION

Different physical forms of biliary cholesterol dramatically determine intestinal uptake and absorption of cholesterol. Solid plate-like cholesterol monohydrate crystals in bile are probably not absorbed and are totally excreted in feces from the body. The gallbladder may have a role in regulating cholesterol homeostasis by modulating the physical forms of biliary cholesterol.

Effect of ezetimibe on the prevention and dissolution of cholesterol gallstones

BACKGROUND & AIMS

Cholesterol cholelithiasis is one of the most prevalent and most costly digestive diseases in developed countries and its incidence has increased markedly in Asian countries owing to the adoption of Western-type dietary habits. Because animal experiments showed that high efficiency of intestinal cholesterol absorption contributes to gallstone formation, we explored whether the potent cholesterol absorption inhibitor ezetimibe could prevent gallstones and promote gallstone dissolution in mice and reduce biliary cholesterol content in human beings.

METHODS

Male gallstone-susceptible C57L mice were fed a lithogenic diet and concomitantly administered with ezetimibe at 0, 0.8, 4, or 8 mg/kg/day for 8 or 12 weeks. Gallbladder biles and gallstones were examined by microscopy. Gallbladder emptying in response to cholecystokinin octapeptide was measured gravimetrically. Biliary lipid outputs were analyzed by physical-chemical methods. Cholesterol absorption efficiency was determined by fecal dual-isotope ratio and mass balance methods. Lipid changes in gallbladder biles of gallstone patients vs overweight subjects without gallstones were examined before (day 0) and at 30 days after ezetimibe treatment (20 mg/day).

RESULTS

Ezetimibe prevented gallstones by effectively reducing intestinal cholesterol absorption and biliary cholesterol secretion, and protected gallbladder motility function by desaturating bile in mice. Treatment with ezetimibe promoted the dissolution of gallstones by forming an abundance of unsaturated micelles. Furthermore, ezetimibe significantly reduced biliary cholesterol saturation and retarded cholesterol crystallization in biles of patients with gallstones.

CONCLUSIONS

Ezetimibe is a novel approach to reduce biliary cholesterol content and a promising strategy for preventing or treating cholesterol gallstones by inhibiting intestinal cholesterol absorption.

Coordinate regulation of gallbladder motor function in the gut-liver axis

Gallstones are one of the most common digestive diseases with an estimated prevalence of 10%-15% in adults living in the western world, where cholesterol-enriched gallstones represent 75%-80% of all gallstones. In cholesterol gallstone disease, the gallbladder becomes the target organ of a complex metabolic disease. Indeed, a fine coordinated hepatobiliary and gastrointestinal function, including gallbladder motility in the fasting and postprandial state, is of crucial importance to prevent crystallization and precipitation of excess cholesterol in gallbladder bile. Also, gallbladder itself plays a physiopathological role in biliary lipid absorption. Here, we present a comprehensive view on the regulation of gallbladder motor function by focusing on recent discoveries in animal and human studies, and we discuss the role of the gallbladder in the pathogenesis of gallstone formation.

Cholecystokinin receptor positivity in children with chronic acalculous gallbladder dysfunction: a pilot study to investigate the etiology of chronic acalculous gallbladder dysfunction

BACKGROUND

The etiology of chronic acalculous gallbladder dysfunction (CAGD) is unknown. However, cholecystectomy is being performed as treatment, based on gallbladder (GB) ejection fraction studies. The aim of this study was to examine the pathology and immunohistology of GBs from children with CAGD.

METHODS

Children with a diagnosis of CAGD were identified. Control patients had their GB removed for nonbiliary indications. Immunoperoxidase staining was performed using rabbit antihuman cholecystokinin receptor (CCK-R) antibody. The pathologist was blinded to the study and controls.

RESULTS

Fifteen children were evaluated: 6 children with CAGD and 9 controls. All children with CAGD had abnormal cholecystokinin-stimulated nuclear imaging. Ejection fractions ranged from 8% to 30%. All patients reported resolution of symptoms on follow-up at 6 months. Histopathology of the GB was normal for both the controls and children with CAGD. Both control and CAGD GBs demonstrated positive staining for CCK-R in the vascular endothelium and smooth muscle. Mucosal epithelial staining was only observed in 5 of 6 of GBs of children with CAGD. In the sixth GB, the epithelium was too necrotic to assess.

CONCLUSIONS

In this pilot study, expression of CCK-Rs in the epithelial cells is noted in children with CAGD compared with controls. The significance of this finding requires further investigation.

Gallbladder disease in Shetland Sheepdogs: 38 cases (1995-2005)

OBJECTIVE

To determine risk, clinical features, and treatment responses for gallbladder disorders in Shetland Sheepdogs.

DESIGN

Retrospective case-control study.

ANIMALS

38 Shetland Sheepdogs with gallbladder disease.

PROCEDURES

Medical records were reviewed for signalment, history, physical findings, laboratory results, imaging features, coexistent illnesses, histologic findings, treatments, and survival rates.

RESULTS

Mature dogs with gastrointestinal signs were predisposed (odds ratio, 7.2) to gallbladder disorders. Gallbladder mucocele was confirmed in 25 dogs. Concurrent problems included pancreatitis, hyperlipidemia, corticosteroid excess, hypothyroidism, protein-losing nephropathy, diabetes mellitus, cholelithiasis, and gallbladder dysmotility. Mortality rate was 68% with and 32% without bile peritonitis. Nonsurvivors had high WBC and neutrophil count and low potassium concentration. Although preprandial hypercholesterolemia, hypertriglyceridemia, and high serum liver enzyme activities were common, gallbladder disease was serendipitously discovered in 11 of 38 dogs. Histologic examination (n=20 dogs) revealed gallbladder cystic mucosal hyperplasia in 20 dogs, cholecystitis in 16, periportal hepatitis in 9, and vacuolar hepatopathy in 7. Surgery included cholecystectomy (n=17) and cholecystoenterostomy (4). In 1 hyperlipidemic dog without clinical signs, gallbladder mucocele resolved 6 months after beginning use of a fat-restricted diet and ursodeoxycholic acid.

CONCLUSIONS AND CLINICAL RELEVANCE

Shetland Sheepdogs are predisposed to gallbladder disorders, with mucoceles and concurrent dyslipidemia or dysmotility in many affected dogs. Most dogs were without clinical signs during mucocele development. Low survival rate after cholecystectomy in clinically affected dogs suggested that preemptive surgical interventions may be a more appropriate treatment strategy.

Gallbladder wall inflammatory cells in pediatric patients with biliary dyskinesia and cholelithiasis: a pilot study

BACKGROUND/PURPOSE

Inflammation has been implicated in functional gastrointestinal disorders, including functional dyspepsia and irritable bowel syndrome. This study was undertaken to evaluate gallbladder wall inflammatory cells in children with abdominal pain related to gallstones and biliary dyskinesia to determine the candidate cell types that may be contributing to the pathophysiology of these entities.

METHODS

Gallbladder specimens from 20 patients with cholelithiasis, 20 biliary patients with dyskinesia, and 12 autopsy controls were evaluated in a blinded fashion. Eosinophil, tryptase-positive, and CD3+ cell densities were determined for the lamina propria and muscularis mucosa layers and compared between groups.

RESULTS

Patients with biliary dyskinesia and cholelithiasis had a 9- to 12-fold increase in mean and peak mast cell densities, respectively, in both layers as compared with controls. Peak (13.7 vs 8.4) and mean (9.2 vs 5.2) CD3+ cell densities were increased in the muscularis mucosae of cholelithiasis specimens as compared with biliary dyskinesia specimens.

CONCLUSION

Gallbladder wall inflammatory cell densities, particularly mast cells, differ between children with cholelithiasis, children with biliary dyskinesia, and controls. Future studies are warranted to define the roles for specific inflammatory cell types.

Effect of Fructus Psoraleae on motility of gallbladder isolated smooth muscle strips from guinea pigs

AIM: To observe the effect of Fructus Psoraleae on motility of isolated gallbladder muscle strips of guinea pigs and its mechanism.

METHODS: Guinea pigs were hit to lose consciousness and the whole gallbladder was removed quickly. Two or three smooth muscle strips (8 mm × 3 mm) were cut along a longitudinal direction. The mucosa was gently removed. Every longitudinal muscle strip was suspended in a tissue chamber which was continuously perfused with 5 mL Krebs solution (37°C), pH 7.4, and aerated with 950 mL/L O₂ and 50 mL /L CO₂. The isometric response was recorded with an ink-writing recorder. After 2 h equilibration under 1 g-load, 50 μL Fructus Psoraleae (10, 20, 70, 200, 700, 1000 g/L) was added cumulatively into the tissue chamber in turn every 2 min to observe their effects on gallbladder muscle strips (cumulating final concentration of Fructus Psoraleae was 0.1, 0.3, 1.0, 3.0, 10.0, 20.0 g/L). The antagonists, including 4-DAMP, benzhydramine, hexamethonium, phentolamine, verapamil and idomethine were given 2 min before Fructus Psoraleae respectively to investigate the mechanisms involved.

RESULTS: Fructus Psoraleae dose-dependently increased the resting tension (r = 0.992, P < 0.001), decreased the mean contractile amplitude (r = 0.970, P < 0.001) and meanwhile increased the contractile frequency of the gallbladder muscle strip in vitro (r = 0.965, P < 0.001). The exciting action of Fructus Psoraleae on the resting tension could be partially blocked by 4-DAMP (the resting tension decreased from 1.37 ± 0.41 to 0.70 ± 0.35, P < 0.001), benzhydramine (from 1.37 ± 0.41 to 0.45 ± 0.38, P < 0.001), hexamethonium (from 1.37 ± 0.41 to 0.94 ± 0.23, P < 0.05), phentolamine ( from 1.37 ± 0.41 to 0.89 ± 0.22, P < 0.01) and verapamil (from 1.37 ± 0.41 to 0.94 ± 0.26, P < 0.05). But the above antagonists had no significant effect on the action of Fructus Psoraleae–induced mean contractile amplitude (P > 0.05). Moreover, the increase of the contractile frequency due to Fructus Psoraleae was inhibited by 4-DAMP (decreased from 8.3 ± 1.2 to 6.8 ± 0.5, P < 0.01) and hexamethonium (from 8.3 ± 1.2 to 7.0 ± 0.9, P < 0.05). Idomethine had no significant effect on the Fructus Psoraleae-induced responses (P > 0.05).

CONCLUSION: Fructus Psoraleae enhances the motility of isolated gallbladder muscle strips from guinea pigs, in a dose-dependent manner. The effect of Fructus Psoraleae is partly related to M₃, N receptor, α receptor, H₁ receptor, Ca²⁺ channel, but not related to prostaglandin.

Cholesterol gallstone disease

With a prevalence of 10-15% in adults in Europe and the USA, gallstones are the most common digestive disease needing admission to hospital in the West. The interplay between interprandial and postprandial physiological responses to endogenous and dietary lipids underscores the importance of coordinated hepatobiliary and gastrointestinal functions to prevent crystallisation and precipitation of excess biliary cholesterol. Indeed, identifying the metabolic and transcriptional pathways that drive the regulation of biliary lipid secretion has been a major achievement in the field. We highlight scientific advances in protein and gene regulation of cholesterol absorption, synthesis, and catabolism, and biliary lipid secretion with respect to the pathogenesis of cholesterol gallstone disease. We discuss the physical-chemical mechanisms of gallstone formation in bile and the active role of the gallbladder and the intestine. We also discuss gaps in our knowledge of the pathogenesis of gallstone formation and the potential for gene targeting in therapy.

Increased cholinergic contractions of jejunal smooth muscle caused by a high cholesterol diet are prevented by the 5-HT4 agonist--tegaserod

Background

Excess cholesterol in bile and in blood is a major risk factor for the respective development of gallbladder disease and atherosclerosis. This lipid in excess negatively impacts the functioning of other smooth muscles, including the intestine. Serotonin is an important mediator of the contractile responses of the small intestine. Drugs targeting the serotonin receptor are used as prokinetic agents to manage intestinal motor disorders, in particular irritable bowel syndrome. Thus, tegaserod, acting on 5-HT₄ receptor, ideally should obviate detrimental effects of excessive cholesterol on gastrointestinal smooth muscle. In this study we examined the effect of tegaserod on cholesterol-induced changes in the contractile responses of intestinal smooth muscle.

Methods

The effects of a high cholesterol (1%) diet on the in vitro contractile responses of jejunal longitudinal smooth muscle from Richardson ground squirrels to the cholinergic agonist carbachol were examined in the presence or absence of tetrodrodotoxin (TTX). Two groups of animals, fed either low (0.03%) or high cholesterol rat chow diet, were further divided into two subgroups and treated for 28 days with either vehicle or tegaserod.

Results

The high cholesterol diet increased, by nearly 2-fold, contractions of the jejunal longitudinal smooth muscle elicited by carbachol. These cholinergic contractions were mediated by muscarinic receptors since they were blocked by scopolamine, a muscarinic receptor antagonist, but not by the nicotinic receptor antagonist, hexamethonium. Tegaserod treatment, which did not affect cholinergic contractions of tissues from low cholesterol fed animals, abrogated the increase caused by the high cholesterol diet. With low cholesterol diet TTX enhanced carbachol-evoked contractions, whereas this action potential blocker did not affect the augmented cholinergic contractions seen with tissues from animals on the high cholesterol diet. Tegaserod-treatment removed the effects of a high cholesterol diet on neuronal muscarinic receptors, as the potentiating effect of TTX on carbachol-elicited contractions was maintained in these animals.

Conclusion

A high cholesterol diet causes significant changes to cholinergic neurotransmission in the enteric nerves of the jejunum. The mechanisms by which these effects of cholesterol are reversed by tegaserod are unknown, but relate to removal of an inhibitory effect of cholesterol on enteric nerves.

Rho kinase expression and its central role in ovine gallbladder contractions elicited by a variety of excitatory stimuli

Rho kinase has contractile activity, which induces Ca2+ sensitization in various cells. Several receptors are linked to the Rho/Rho-kinase pathway. Therefore, in this study we aimed to demonstrate the central importance of this novel pathway for diverse excitatory stimuli in the smooth muscle of the sheep gallbladder. Accordingly, the effects of a Rho kinase inhibitor, (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride monohydrate (Y-27632, 10(-8)-3 x 10(-5) M), were investigated on cholecystokinin-8 (CCK-8, 10(-8) M), endothelin-1 (10(-8) M), carbachol (10(-6)-10(-5) M), 5-hydroxytryptamine (5-HT, 10(-6)-10(-5) M), histamine (10(-6)-10(-5) M), phenylephrine (10(-5)-10(-4) M), neurokinin A (10(-7)-10(-6) M), electrical field stimulation (40 V, 0.5 ms, 2, 4, 8, 16, 32 Hz, 15 s, 3 min intervals) and potassium chloride (KCl, 25-50 mM)-induced contractions as well as spontaneous contractile activity. Electrical field stimulation evoked tetrodotoxin (3 x 10(-6) M)-sensitive reproducible contractions, which were inhibited by atropine (2 x 10(-6) M) and potentiated by eserine (5 x 10(-7) M). EFS-induced contraction was significantly inhibited by Y-27632 (10(-5) M). In addition, spontaneous contractile activity was suppressed in the presence of the compound (10(-6)-10(-5) M). This Rho kinase inhibitor also dramatically decreased the contractions elicited by 5-HT, neurokinin A and carbachol. KCl-induced contraction, which was not atropine-sensitive, was also conspicuously attenuated by Y-27632. Moreover, Y-27632 (10(-8)-3 x 10(-5) M) relaxed gallbladder strips that were contracted by histamine, endothelin-1, CCK-8 and phenylephrine in a concentration-dependent manner. pEC50 values for Y-27632 were 6.25+/-0.10, 5.79+/-0.12, 5.83+/-0.09 and 5.70+/-0.13 for the contraction elicited by histamine, CCK-8, endothelin-1 and phenylephrine, respectively. Furthermore, we also demonstrated Rho kinase protein expression (ROCK-1 and ROCK-2) by Western blot analysis. In conclusion, ROCK is expressed in the smooth muscle of the ovine gallbladder, and it has a central role in the contractile activity induced by diverse excitatory stimuli.