Two polymorphic cholesterol monohydrate crystal structures form in macrophage culture models of atherosclerosis

The formation of atherosclerotic plaques in the blood vessel walls is the result of LDL particle uptake, and consequently of cholesterol accumulation in macrophage cells. Excess cholesterol accumulation eventually results in cholesterol crystal deposition, the hallmark of mature atheromas. We followed the formation of cholesterol crystals in J774A.1 macrophage cells with time, during accumulation of LDL particles, using a previously developed correlative cryosoft X-ray tomography (cryo-SXT) and stochastic optical reconstruction microscopy (STORM) technique. We show, in the initial accumulation stages, formation of small quadrilateral crystal plates associated with the cell plasma membrane, which may subsequently assemble into large aggregates. These plates match crystals of the commonly observed cholesterol monohydrate triclinic structure. Large rod-like cholesterol crystals form at a later stage in intracellular locations. Using cryotransmission electron microscopy (cryo-TEM) and cryoelectron diffraction (cryo-ED), we show that the structure of the large elongated rods corresponds to that of monoclinic cholesterol monohydrate, a recently determined polymorph of the triclinic crystal structure. These monoclinic crystals form with an unusual hollow cylinder or helical architecture, which is preserved in the mature rod-like crystals. The rod-like morphology is akin to that observed in crystals isolated from atheromas. We suggest that the crystals in the atherosclerotic plaques preserve in their morphology the memory of the structure in which they were formed. The identification of the polymorph structure, besides explaining the different crystal morphologies, may serve to elucidate mechanisms of cholesterol segregation and precipitation in atherosclerotic plaques.

The Concept of Cholelithiasis as Per Ayurvedic Text

Cholelithiasis (gallstone formation) results from a combination of several factors, including super saturation of bile with cholesterol, accelerated nucleation of cholesterol monohydrate in bile, and bile stasis or delayed gallbladder emptying due to impaired gallbladder motility. In India it is more common in women in north, north-east and east as compared to other zones in the country. The disease Gall Stone has not been described directly in Ayurvedic classics. The word Ashmari in Ayurveda stands for stone which is described only in the context of Bastigat Ashmari (urinary calculi). After analyzing the Ayurvedic texts it was found that the bile secreted from gall bladder can be correlated with Accha Pitta mentioned in Ayurveda due to the similarity in location and function. The pathogenesis of the disease occurs due to the abnormal formation of Kapha during the process of digestion and its vitiation due to Vata. The present article deals with description of formation of gall stone from the Ayurvedic perspective. Along with this the specific remedy for gall stone according to Ayurveda is also described.

Pathogenetic features of the hepatobiliary system damage in patients with metabolic syndrome

A review of articles covering the modern views on the hepatobiliary system damage features in patients with clinical manifestations of metabolic syndrome. 196 original papers published over the last 6 years were found using PubMed, MEDLINE, E-library databases, from which 50 articles were picked out for the review. Considering high prevalence of metabolic syndrome, the studied problem seems important. The influence of obesity and associated insulin resistance at launching the systemic inflammation leading to activation of immunological cascade resulting in terget organs damage in such patients is highlighted. The pathogenesis of liver, gall bladder and bile ducts damage at presence of metabolic disorders is outlined. The role of inflammatory and anti-inflammatory cytokines in liver tissue damage is described. Based on the data of literature review and own data, it was shown that the lipid metabolism alterations are associated with liver functional damage, and liver in patients with metabolic syndrome is not only participating in atherogenic dislipoproteinemia development, but also damaged as the target organ. It was revealed that the key link in the gall bladder pathology in patients with metabolic syndrome is the lipid metabolism alterations that lead to the excess cholesterol bile excretion and cholesterol monohydrate crystals sedimentation. It was also shown that the functionally affected hepatocytes produce imperfect bile micelles with high cholesterol and low phospholipid levels, increasing the bile lithogenicity. High bile cholesterol level stimulating the mucin secretion by gall bladder wall, which is the important component of bile sediment and increases the bile crystalloids aggregation.

Helicobacter pyloriand cholesterol gallstone formation in C57L/J mice: a prospective study

Recently, we demonstrated that cholesterol gallstone-prone C57L/J mice rarely develop gallstones unless they are infected with certain cholelithogenic enterohepatic Helicobacter species. Because the common gastric pathogen H. pylori has been identified in the hepatobiliary tree of cholesterol gallstone patients, we wanted to ascertain if H. pylori is cholelithogenic, by prospectively studying C57L infected mice fed a lithogenic diet. Weanling, Helicobacter spp.-free male C57L mice were either infected with H. pylori SS1 or sham dosed. Mice were then fed a lithogenic diet (1.0% cholesterol, 0.5% cholic acid, and 15% dairy triglycerides) for 8 wk. At 16 wk of age, mice were euthanatized, the biliary phenotype was analyzed microscopically, and tissues were analyzed histopathologically. H. pylori infection did not promote cholesterol monohydrate crystal formation (20% vs. 10%), sandy stone formation (0% for both), or true gallstone formation (20%) compared with uninfected mice fed the lithogenic diet (10%). Additionally, H. pylori failed to stimulate mucin gel accumulation in the gallbladder or alter gallbladder size compared with uninfected animals. H. pylori-infected C57L mice developed moderate to severe gastritis by 12 wk, and the lithogenic diet itself produced lesions in the forestomach, which were exacerbated by the infection. We conclude that H. pylori infection does not play any role in murine cholesterol gallstone formation. Nonetheless, the C57L mouse develops severe lesions of both the glandular and nonglandular stomach in response to H. pylori infection and the lithogenic diet, respectively.