Interleukin-4 deficiency promotes gallstone formation

Gallbladder Interleukins in Children with Calculous Cholecystitis

Calculous cholecystitis connects to inflammation and various complications. It is a common disease in the paediatric population, yet it is still uncertain how inflammation factors are involved in its morphopathogenesis. Twenty calculous cholecystitis surgery tissue samples were obtained from 20 children. As a control, seven unaffected gallbladders were used. Tissues were immunohistochemically stained for IL-1α, IL-4, IL-6, IL-7, IL-8, IL-10, and IL-17A, and the slides were inspected by light microscopy. To evaluate statistical differences and correlations between interleukins, Mann-Whitney U and Spearman's tests were used. Statistically significant difference between patient and control gallbladder epithelium was for IL-1α and IL-17A, but connective tissue-IL-1α, IL-4, IL-6, IL-7, IL-8, and IL-17A positive structures. A strong positive correlation in patients was detected between epithelial IL-1α and IL-1α in connective tissue, epithelial IL-6 and IL-7, IL-6 and IL-17A, IL-7 and IL-10, IL-7 and IL-17A, as well as between IL-6 and IL-7, IL-7 and IL-10 in connective tissue. The increase of IL-1α, IL-4, IL-6, IL-7, IL-8 and IL-17A positive structures suggests their role in the morphopathogenesis of calculous cholecystitis. The correlations between interleukins in epithelium and in connective tissues prove that the epithelial barrier function and inflammatory response in deeper layers are sustained through intercellular signalling pathways.

Inhibition of RORα/γ suppresses atherosclerosis via inhibition of both cholesterol absorption and inflammation

OBJECTIVE

Cardiovascular diseases (CVDs) are the leading cause of mortality in Western countries. Atherosclerosis is a multi-step inflammatory disease characterized at early stages by accumulation of cholesterol in the arterial wall followed by recruitment of immune cells. We sought to determine if pharmacological suppression of RORα/γ activity is beneficial in treatment of atherosclerosis.

METHODS

To identify the role of RORα and RORγ in atherosclerosis, we used the LDL-R(-/-) mouse model of atherosclerosis placed on a high cholesterol diet treated with SR1001, a RORα/γ inverse agonist, for four weeks.

RESULTS

Our results demonstrate that treatment with the ROR inverse agonist substantially decreases plaque formation in vivo. The mechanism of the anti-atherogenic activity of the inhibition of RORα/γ activity appeared to be due to targeting two distinct pathways. SR1001 treatment reduced plasma low density lipoprotein (LDL) level without affecting high density lipoprotein (HDL) via increasing intestinal cholesterol excretion. Treatment with SR1001 also induced an anti-atherogenic immune profile that was characterized by a reduction in Th17 cells and an increase in Treg and Th2 cells. Our data suggest that RORα and RORγ play a critical role in atherosclerosis development by regulating at least two major pathways important in the pathology of this disease: cholesterol flux and inflammation.

CONCLUSION

Our data suggest that pharmacological targeting of RORα/γ may be an effective method for treatment of atherosclerosis offering a distinct mechanism of action relative to statins.

Cytokine single nucleotide polymorphisms in patients' with gallstone: dose TGF-β gene variants affect gallstone formation?

Gallstone is a common biliary disorder with several risk factors. Immune responses and inflammatory cytokines are important in this disease; as a result, some cytokines can be detected in bile fluid. In this research, cytokine gene polymorphisms were studied, and their effects on gallstone formation were evaluated. On 158 gallstone patients and 254 normal subjects, by PCR- RFLP method, IL-4-C590T polymorphism and by ARMS-PCR method, IFN-γ T+874A, TNF-α-A308G, IL-6 G-174C and TGF-β T+869C variants were studied. Pathologic evaluations were done on surgical specimens. There were no significant differences in distribution of evaluated polymorphisms between patient group and normal control group (P > 0.05), except TGF-β +869T allele (P = 0.04, OR = 1.23, 95 % CI = 1-1.79) which was higher in patients with gallstone. Although the pro-inflammatory cytokines such as TNF-α and IL-6 may promote gallstone formation, in this study no significant correlation between TNF-α and IL-6 polymorphisms and gallstone formation was seen. It is taught that TGF-β may affect gallbladder cells to promote gallstone formation and higher producer TGF-β +869T allele can be a risk factor of gallstone disease, so further studies would be more elucidative

Chronic Opisthorchis felineus infection attenuates atherosclerosis--an autopsy study

Previously, we proposed a hypothesis that chronic helminthic infection may have beneficial effects on the development of atherosclerosis. The aim of this study was to investigate an association between Opisthorchis felineus chronic helminthic infections with aortic atherosclerosis and serum total cholesterol. A series of medico-legal autopsy specimens collected in Khanty-Mansiisk (the region in Russia endemic for O. felineus) were studied to assess O. felineus worm burden in cadaver livers. The areas of atherosclerotic lesions in the cadaver aortas were measured by visual planimetry. A family history of cardiovascular disease, smoking, hypertension or diabetes was elicited, and serum total cholesterol levels examined. Three hundred and nineteen cadavers (280 (87.8%) males and 39 (12.2%) females) aged 20-72 years were divided into five age groups: (i) 20-29, (ii) 30-39, (iii) 40-49, (iv) 50-59 and (v) >60 years old. The O. felineus mean worm burden was 257±312 worms/liver. Infected subjects were categorised into three subgroups depending on the worm burden: mild (<100 worms), moderate (100-500 worms) and severe (>500 worms). Infected subjects had lower serum total cholesterol (mild worm burden, 186.4±25.6 mg/dl; moderate worm burden, 183.4±23.1mg/dl, P=0.002; severe worm burden, 170.6±25.1mg/dl, P<0.001) than non-infected subjects (201.1±21.2 mg/dl). The average percentage of aortic surface covered by fatty streaks, fibrotic plaques and complicated lesions was negatively related to worm burden in the infected subjects. Chronic helminthic infections was a negative predictor of aortic atherosclerosis; with an odds ratio of 1.72 (1.02-2.91), P=0.041 for all subjects; and 3.19 (1.35-7.58), P=0.008 for subjects aged >40 years old. Opisthorchis felineus chronic helminthic infectionswas found to be associated with lower serum total cholesterol levels and a significant attenuation of atherosclerosis.

Small interfering RNA against transcription factor STAT6 leads to increased cholesterol synthesis in lung cancer cell lines

STAT6 transcription factor has become a potential molecule for therapeutic intervention because it regulates broad range of cellular processes in a large variety of cell types. Although some target genes and interacting partners of STAT6 have been identified, its exact mechanism of action needs to be elucidated. In this study, we sought to further characterize the molecular interactions, networks, and functions of STAT6 by profiling the mRNA expression of STAT6 silenced human lung cells (NCI-H460) using microarrays. Our analysis revealed 273 differentially expressed genes after STAT6 silencing. Analysis of the gene expression data with Ingenuity Pathway Analysis (IPA) software revealed Gene expression, Cell death, Lipid metabolism as the functions associated with highest rated network. Cholesterol biosynthesis was among the most enriched pathways in IPA as well as in PANTHER analysis. These results have been validated by real-time PCR and cholesterol assay using scrambled siRNA as a negative control. Similar findings were also observed with human type II pulmonary alveolar epithelial cells, A549. In the present study we have, for the first time, shown the inverse relationship of STAT6 with the cholesterol biosynthesis in lung cancer cells. The present findings are potentially significant to advance the understanding and design of therapeutics for the pathological conditions where both STAT6 and cholesterol biosynthesis are implicated viz. asthma, atherosclerosis etc.

Investigation of cytotoxic T-lymphocyte-associated protein 4 gene polymorphisms in symptomatic gallstone disease

Gallstone disease (GSD), which is increasingly prevalent in Taiwan, develops through a complex process involving genetic, environmental, and immune factors. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4) limits T-cell proliferation. The present study looked for associations between symptomatic GSD and polymorphisms of the CTLA4 gene. For this case-control cross-sectional study among Taiwanese, 275 patients with symptomatic GSD and 852 controls were enrolled. Genotyping of CTLA4-318 C/T, +49 A/G, and CT60 A/G single nucleotide polymorphisms (SNPs) was performed by polymerase chain reaction-restriction fragment length polymorphism. The genotype, allele, carrier, and haplotype frequencies were calculated by direct counting or with Haploview 4.1 software. Genotype, allele, carrier, and haplotype frequencies of the CTLA4 SNPs studied were equally distributed in symptomatic GSD patients and controls. No significant associations between symptomatic GSD and these 3 SNPs were observed. Our data suggest that CTLA4-318 C/T, +49 A/G, and CT60 A/G SNPs do not confer increased susceptibility to symptomatic GSD.

Interleukin-4 does not influence development of hypercholesterolemia or angiotensin II-induced atherosclerotic lesions in mice

Interleukin-4 (IL-4) has been detected in both human and mouse atherosclerotic lesions, although its effects on the development of the disease are undefined. We determined the role of IL-4 in the most commonly used murine models of atherosclerosis by defining the effects of exogenous delivery and genetic deficiency of this cytokine on both hypercholesterolemia and AngII-induced atherosclerosis in apolipoprotein E (apoE)(-/-) mice and different dietary stimuli in low-density lipoprotein (LDL) receptor(-/-) mice. Exogenous administration of IL-4 (1.1 ng g(-1) day(-1) i.p. for 30 days) into female apoE(-/-) mice had no effect on lesion size or composition in mice fed normal or saturated fat diets. Also, IL-4 deficiency had no significant effect on the size or composition of atherosclerotic lesions in two vascular areas of male and female apoE(-/-) mice fed either a normal or saturated fat diet. IL-4 deficiency was also studied in age-matched male mice infused with AngII (1000 ng kg(-1) min(-1)) for 28 days. Whereas AngII infusion augmented atherosclerotic lesion formation, IL-4 deficiency did not influence atherosclerotic lesion size or composition. Finally, different dietary stimuli also had no effect on atherosclerotic lesion size in female LDL receptor(-/-) mice. These data demonstrate that IL-4 does not significantly influence the development of atherosclerotic lesions in apoE(-/-) mice of either gender or in female LDL receptor(-/-) mice, irrespective of the mode of induction of atherosclerosis.

Chronic exposure to schistosome eggs reduces serum cholesterol but has no effect on atherosclerotic lesion development

Previous studies have shown that people infected with schistosomiasis have lower levels of serum cholesterol than uninfected controls. To better understand the impact of this parasitic infection on serum cholesterol levels and on atherosclerotic lesion development induced by hypercholesterolemia, apolipoprotein E (ApoE)-deficient mice were chronically exposed to the eggs of Schistosoma mansoni over a period of 16 weeks. Total serum cholesterol and low-density lipoprotein (LDL) were reduced in egg-exposed ApoE-deficient mice fed a diet high in cholesterol compared to unexposed controls. However, exposure to eggs had no effect on atherosclerotic lesion size or progression in ApoE-deficient mice. Macrophages isolated from egg-exposed mice had an enhanced ability to take up LDL but not acetylated LDL (acLDL). This study suggests that schistosome eggs alone may alter serum lipid profiles through enhancing LDL uptake by macrophages, but these changes do not ultimately affect atherosclerotic lesion development.