This is a mechanism module, not a specific disease. Disorder entries reference individual nodes via conforms_to (e.g., "cholelithiasis_biliary_supersaturation#Gallbladder Hypomotility and Bile Stasis"). The module defines the conserved cholesterol-gallstone pathway; conforming nodes should include the corresponding cell types, biological processes, and causal edges. Disorder-specific substitutions: monogenic defects substitute the affected hepatic transporter (ABCG5/G8 cholesterol hypersecretion, ABCB4 phospholipid deficiency) at the supersaturation node; metabolic disorders (obesity, type 2 diabetes, hypertriglyceridemia) emphasize insulin-resistance-driven hypersecretion and CCK-1R-related gallbladder hypomotility.
Biliary Cholesterol Supersaturation
trigger
Hepatic hypersecretion of cholesterol, in excess of the bile salts and phospholipids needed to keep it solubilized in mixed micelles and vesicles, yields gallbladder bile that is supersaturated with cholesterol. This metastable, cholesterol-rich physical-chemical state of bile is the initiating lesion of cholesterol gallstone disease and is driven by lithogenic transporter variants (ABCG5/G8, ABCB4) and metabolic factors such as insulin resistance.
Downstream
-
Pronucleating Cholesterol Crystal Nucleation
Show evidence (2 references)
"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."
Review evidence identifies hepatic cholesterol hypersecretion and supersaturated bile as the initiating pathogenetic factors of cholesterol gallstone disease. Evidence source is OTHER because this is a review synthesizing human and animal-model data.
"A reduction or deficiency of biliary phospholipids results in a distinctly abnormal metastable physical-chemical state of bile predisposing to supersaturation with cholesterol."
Establishes that loss of the phospholipid component of bile (as in ABCB4 deficiency) drives the metastable, cholesterol-supersaturated state. Evidence source is OTHER because this is a review of clinical, animal, and in vitro studies.
Pronucleating Cholesterol Crystal Nucleation
amplifier
Within supersaturated bile, accelerated nucleation drives the phase transition from soluble cholesterol in vesicles and micelles to solid cholesterol monohydrate crystals. Pronucleating factors secreted into the gallbladder lumen, chiefly gallbladder mucin glycoprotein, bind biliary lipids and shorten the cholesterol crystal appearance time, tipping the metastable bile toward crystal precipitation.
Downstream
-
Gallbladder Hypomotility and Bile Stasis
Show evidence (2 references)
"Mucin has a central role in the pathogenesis of cholesterol gallstones, in part because of its ability to bind biliary lipids and accelerate cholesterol crystal appearance time."
Demonstrates that gallbladder mucin acts as a pronucleating agent, binding biliary lipids and accelerating cholesterol crystal nucleation in model bile. Evidence source is IN_VITRO because the pronucleating activity was measured with a recombinant mucin polypeptide in cholesterol crystal appearance assays.
"Cholesterol crystal formation requires the presence of one or more of the following: (a) cholesterol supersaturation, (b) accelerated nucleation, or (c) gallbladder hypomotility/bile stasis."
Review establishes accelerated nucleation as one of the three conserved requirements for cholesterol crystal formation. Evidence source is OTHER because this is a review synthesizing the lithogenesis literature.
Gallbladder Hypomotility and Bile Stasis
central effector
Impaired gallbladder smooth muscle contraction with incomplete postprandial emptying and enlarged residual volumes produces bile stasis. The prolonged gallbladder residence time allows cholesterol crystals to be retained, aggregate, and grow rather than being expelled. Gallbladder hypomotility frequently antedates stone formation and is linked to cholesterol-laden smooth muscle, lipotoxicity, and impaired CCK-1 receptor signaling.
Downstream
-
Gallstone Aggregation and Growth
Show evidence (2 references)
"About one-third of cholesterol gallstone patients display enlarged fasting and postprandial residual gallbladder volumes with delayed emptying"
Documents impaired gallbladder emptying with increased residual volumes in cholesterol gallstone patients, the clinical signature of gallbladder hypomotility and bile stasis. Evidence source is OTHER because this is a review summarizing multiple clinical studies.
"Dysfunctional gallbladder motility provides sufficient time for cholesterol nucleation and gallstone growth"
Directly links gallbladder dysmotility and bile stasis to the residence time required for crystal nucleation and stone growth. Evidence source is OTHER because this is a review.
Gallstone Aggregation and Growth
effector
Retained cholesterol monohydrate crystals aggregate and, embedded in a mucin gel matrix in the stagnant gallbladder, grow and coalesce into macroscopic cholesterol gallstones. Continued supersaturation and stasis sustain crystal growth, converting microscopic crystals into clinically relevant calculi.
Show evidence (2 references)
"Changes in biliary phospholipid concentrations influence cholesterol crystallization by yielding both liquid crystalline and "anhydrous" crystalline metastable intermediates, evolving into classical parallelogram-shaped cholesterol monohydrate crystals in supersaturated bile."
Describes the progression of crystallization through metastable intermediates to mature cholesterol monohydrate crystals, the building blocks of cholesterol gallstones. Evidence source is OTHER because this is a review of clinical, animal, and in vitro studies.
"supersaturated bile which give life to precipitating cholesterol crystals that accumulate and grow in a sluggish gallbladder."
States that precipitated cholesterol crystals accumulate and grow in the hypomotile gallbladder, the step that produces macroscopic stones. Evidence source is OTHER because this is a review.
Cholelithiasis
consequence
Macroscopic gallstones in the gallbladder constitute cholelithiasis. When stones become impacted in the gallbladder neck or cystic duct they cause biliary colic and mechanical obstruction, which raises intraluminal pressure and precipitates acute cholecystitis; migration into the biliary tree can cause obstructive complications. This is the clinical phenotype that the conserved supersaturation-nucleation-stasis pathway produces.
Show evidence (2 references)
"In acute calculous cholecystitis, gallstones are the cause of obstruction and are often impacted in the gallbladder neck or cystic duct, leading to gallbladder inflammation."
Establishes that gallstones cause mechanical obstruction at the gallbladder neck or cystic duct and resulting cholecystitis, the defining clinical consequence of cholelithiasis. Evidence source is OTHER because this is a review of clinical imaging and pathology.
"In acute cholecystitis, increased dilatation and high intraluminal pressures lead to gallbladder inflammation and may progress to gangrenous changes, focal wall necrosis, and subsequent perforation."
Describes how obstruction-driven intraluminal pressure produces gallbladder inflammation and its complications, the downstream morbidity of cholelithiasis. Evidence source is OTHER because this is a review.