Family sitosterolemia: report of two cases in Colombia. / Sitosterolemia familiar: reporte de dos casos en Colombia.

Sitosterolemia is an autosomal recessive and very rare disease. Its main characteristic is that there is a greater absorption and a decrease in the excretion of sterols, which leads to them being deposited in tissues. It is given by mutations in the ABCG5 or ABCG8 genes found on chromosome 2p21. In this clinical note, we describe the first two patients with familial sitosterolemia described in Colombia, brothers, one of them with xanthomas in extremities as the only symptom, and the other, completely asymptomatic. Genetic studies were performed as a diagnostic test in both patients, where a pathogenic homozygous variant could be identified in the ABCG8 gene in the first case (symptomatic), and a heterozygous variant in the ABCG8 gene in the second case (asymptomatic); the first patient has responded to treatment with ezetimibe. In conclusion, xanthomas should be studied in depth in pediatric age as they may be the only visible sign of such complex and hereditary diseases as familial sitosterolemia, which can be controlled and prevent cardiovascular complications of the disease.

Update on Sitosterolemia and Atherosclerosis.

PURPOSE OF REVIEW: The purpose of this review was to summarize important and updated information on sitosterolemia. Sitosterolemia is an inherited lipid disorder consisting of high levels of plasma plant sterols. This sterol storage condition is caused by biallelic loss-of-function genetic variants in either ABCG5 or ABCG8, leading to increased intestinal absorption and decreased hepatic excretion of plant sterols. Clinically, patients with sitosterolemia usually exhibit xanthomatosis, high levels of plasma cholesterol, and premature atherosclerotic disease, but presentation can be highly heterogeneous. Therefore, recognition of this condition requires a high level of suspicion, with confirmation upon genetic diagnosis or through measurement of plasma phytosterols. Treatment of sitosterolemia with both a plant sterol-restricted diet and the intestinal cholesterol absorption inhibitor ezetimibe can reduce efficiently the levels of plasma plant sterols, consisting in the first-line therapy for this disease. RECENT FINDINGS: Since hypercholesterolemia is often present in individuals with sitosterolemia, it is important to search for genetic variants in ABCG5 and ABCG8 in patients with clinical criteria for familial hypercholesterolemia (FH), but no variants in FH implicated genes. Indeed, recent studies have suggested that genetic variants in ABCG5/ABCG8 can mimic FH, and even when in heterozygosis, they may potentially exacerbate the phenotype of patients with severe dyslipidemia. Sitosterolemia is a genetic lipid disorder characterized by increased circulating levels of plant sterols and clinically manifested by xanthomatosis, hematologic disorders, and early atherosclerosis. Awareness about this condition, a rare, but commonly underdiagnosed and yet treatable cause of premature atherosclerotic disease, is imperative.

Identification of potential molecular pathogenesis mechanisms modulated by microRNAs in patients with Intestinal Neuronal Dysplasia type B.

This study proposed to determine global microRNA (miRNA) expression and miRNA-regulated pathways in Intestinal Neuronal Dysplasia type B (IND-B). Fifty patients (0-15 years old) with IND-B were included in the study. Peripheral blood samples were collected from all 50 patients and from 10 healthy asymptomatic children (controls). Rectal biopsies were collected from 29/50 patients; biopsy tissues were needle microdissected to isolate the different intestinal layers, for molecular analysis. Global miRNA expression was determined using TaqMan arrays. Correlation analysis between miRNA expression in plasma and biopsy samples as well as among tissues derived from the distinct intestinal layers was performed. Computational approaches were used for miRNA target prediction/identification of miRNA-regulated genes and enriched pathways biologically relevant to IND-B pathogenesis. miRNAs were statistically significantly deregulated (FC ≥ 2 and p ≤ 0.05) in submucosal and muscular layers: over-expressed (miR-146a and miR-146b) and under-expressed (miR-99a, miR-100, miR-130a, miR-133b, miR-145, miR-365, miR-374-5p, miR-451). Notably, let-7a-5p was highly over-expressed in patient plasma compared to healthy controls (FC = 17.4). In addition, miR-451 was significantly under-expressed in both plasma and all biopsy tissues from the same patients. Enriched pathways (p < 0.01) were axon guidance, nerve growth factor signalling, NCAM signalling for neurite out-growth, neuronal system and apoptosis. miRNA expression is deregulated in the submucosa and muscular layers of the rectum and detected in plasma from patients with IND-B. Biologically enriched pathways regulated by the identified miRNAs may play a role in IND-B disease pathogenesis, due to the activity related to the neurons of the enteric nervous system.

Kcnn4 is a modifier gene of intestinal cystic fibrosis preventing lethality in the Cftr-F508del mouse.

Nearly 70% of cystic fibrosis (CF) patients bear the phenylalanine-508 deletion but disease severity differs greatly, and is not explained by the existence of different mutations in compound heterozygous. Studies demonstrated that genes other than CFTR relate to intestinal disease in humans and CF-mouse. Kcnn4, the gene encoding the calcium-activated potassium channel KCa3.1, important for intestinal secretion, is present in a locus linked with occurrence of intestinal CF-disease in mice and humans. We reasoned that it might be a CF-modifier gene and bred a CF-mouse with Kcnn4 silencing, finding that lethality was almost abolished. Silencing of Kcnn4 did not improve intestinal secretory functions, but rather corrected increased circulating TNF-α level and reduced intestinal mast cell increase. Given the importance of mast cells in intestinal disease additional double mutant CF-animals were tested, one lacking mast cells (C-kitW-sh/W-sh) and Stat6-/- to block IgE production. While mast cell depletion had no effect, silencing Stat6 significantly reduced lethality. Our results show that Kcnn4 is an intestinal CF modifier gene partially acting through a STAT6-dependent mechanism.

Cryptogenic Cirrhosis and Sitosterolemia: A Treatable Disease If Identified but Fatal If Missed.

Sitosterolemia is an autosomal recessive metabolic disease caused by mutations in ABCG5 or ABCG8 genes which encode for the (ATP)-binding cassette (ABC) transporters that are responsible for the trafficking of xenosterols. Liver involvement is not a recognized manifestation of this disease, and cirrhosis has been reported only once in the medical literature. We describe a fatal case of a 21-year old South Asian male who presented with decompensated cirrhosis, and biochemical abnormalities consistent with sitosterolemia. Genetic testing showed a homozygous pathogenic mutation in ABCG5, confirming the diagnosis. Sitosterolemia is a rare, but likely under-recognized condition, and a high degree of suspicion is imperative to make the diagnosis. We propose that sitosterolemia should be included in the differential diagnosis for patients with cryptogenic cirrhosis, especially as there are effective oral therapies to treat this condition. Newly diagnosed sitosterolemia patients should undergo a thorough hepatology evaluation and follow-up to evaluate for the presence, development, and progression of any hepatic involvement.

mRNA levels of low-density lipoprotein receptors are overexpressed in the foci of deep bowel endometriosis.

STUDY QUESTION: Is mRNA expression of LDL receptors altered in deep bowel endometriotic foci? SUMMARY ANSWER: mRNA expression of LDL receptors is up-regulated in deep bowel endometriotic foci of patients with endometriosis. WHAT IS KNOWN ALREADY: Several studies have demonstrated the overexpression of low-density lipoprotein receptors in various tumour cell lines and endometriosis has similar aspects to cancer, mainly concerning the pathogenesis of both diseases. This is the first study we know of to investigate lipoprotein receptors expression in deep endometriosis with bowel involvement. STUDY DESIGN, SIZE, DURATION: During 2014-2015, an exploratory case-control study was conducted with 39 patients, including 20 women with a histological diagnosis of deep endometriosis compromising the bowel and 19 women without endometriosis who underwent laparoscopic tubal ligation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Peripheral blood samples were collected on the day of surgery for lipid profile analysis, and samples of endometrial tissue and of bowel endometriotic lesions were also collected. The tissue samples were sent for histopathological analysis and for LDL-R and LRP-1 gene expression screening using quantitative real-time PCR. MAIN RESULTS AND THE ROLE OF CHANCE: Patients with deep endometriosis had lower LDL-cholesterol than patients without the disease (119 ± 23 versus 156 ± 35; P = 0.001). Gene expression analysis of LDL receptors revealed that LDL-R was more highly expressed in endometriotic lesions when compared to the endometrium of the same patient but not more than in the endometrium of women without endometriosis (0.027 ± 0.022 versus 0.012 ± 0.009 versus 0.019 ± 0.01, respectively; P < 0.001). LRP-1 was more highly expressed in endometriotic lesions, both when compared with the endometrium of the same patient and when compared with the endometrium of patients without the disease (0.307 ± 0.207 versus 0.089 ± 0.076 and versus 0.126 ± 0.072, respectively; P < 0.001). The study also showed that LDL-R gene expression in the endometrium of women with endometriosis was higher during the secretory phase of the menstrual cycle (P = 0.001). LRP-1 gene expression was increased during the secretory phase in the endometrium of women without the disease (P = 0.008). LIMITATIONS, REASONS FOR CAUTION: In the endometriotic lesions, the presence of fibrosis is substantial, restricting access to the stromal and glandular components of the lesion. Despite that, we found that LDL receptor mRNA was overexpressed. Future studies may perform laser microdissection to isolate the area of interest in the target tissue, excluding fibrosis contamination. WIDER IMPLICATIONS OF THE FINDINGS: This study supports the feasibility of LDL-R targeted therapy in the treatment of deep endometriosis. STUDY FUNDING/COMPETING INTERESTS: This study was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP #2011/17245-0). The authors have no conflicts of interest to declare.

Two novel mutations in the ABCG5 gene, c.144 -1G>A and c.1523 delC, in a Mexican family with sitosterolemia.

Sitosterolemia is a disease characterized by an intestinal hyperabsorption of plant sterols and cholesterol. Affected individuals have mutations in both alleles of either ABCG5 or ABCG8 genes, leading to a total loss of one of the proteins and subsequent functional deficiency. We here report a Mexican family with clinical and biochemical features of sitosterolemia carrying 2 new mutations of the ABCG5 gene. Concentrations of sitosterol, campesterol, and cholesterol were found to be higher for the index case (a 10-year-old girl) than for her also affected sibling (64.1 vs 19 mg/dL, 32 vs 12.1 mg/dL, and cholesterol 295 vs 235 mg/dL, respectively). Both individuals showed 2 new ABCG5 gene mutations identified by sequencing, which is concordant with their biochemical diagnosis of sitosterolemia. The first mutation was a c.144 -1G>A transition that disrupts the intron 1 splicing acceptor site. The second mutation is the deletion c.1523 delC, which occurred in exon 11, causing an amino acid change at codon 510 (p.His510Thr) and a stop codon at codon 511 (p.Leu511X). The father is heterozygote for the mutation c.144 -1G>A, whereas the mother is heterozygote for the mutation c.1523 delC. In conclusion, we here report the first case of a Mexican family with sitosterolemia carrying two new ABCG5 gene mutations.

The Adaptor Protein Myd88 Is a Key Signaling Molecule in the Pathogenesis of Irinotecan-Induced Intestinal Mucositis.

Intestinal mucositis is a common side effect of irinotecan-based anticancer regimens. Mucositis causes cell damage, bacterial/endotoxin translocation and production of cytokines including IL-1 and IL-18. These molecules and toll-like receptors (TLRs) activate a common signaling pathway that involves the Myeloid Differentiation adaptor protein, MyD88, whose role in intestinal mucositis is unknown. Then, we evaluated the involvement of TLRs and MyD88 in the pathogenesis of irinotecan-induced intestinal mucositis. MyD88-, TLR2- or TLR9-knockout mice and C57BL/6 (WT) mice were given either saline or irinotecan (75 mg/kg, i.p. for 4 days). On day 7, animal survival, diarrhea and bacteremia were assessed, and following euthanasia, samples of the ileum were obtained for morphometric analysis, myeloperoxidase (MPO) assay and measurement of pro-inflammatory markers. Irinotecan reduced the animal survival (50%) and induced a pronounced diarrhea, increased bacteremia, neutrophil accumulation in the intestinal tissue, intestinal damage and more than twofold increased expression of MyD88 (200%), TLR9 (400%), TRAF6 (236%), IL-1ß (405%), IL-18 (365%), COX-2 (2,777%) and NF-κB (245%) in the WT animals when compared with saline-injected group (P<0.05). Genetic deletion of MyD88, TLR2 or TLR9 effectively controlled the signs of intestinal injury when compared with irinotecan-administered WT controls (P<0.05). In contrast to the MyD88-/- and TLR2-/- mice, the irinotecan-injected TLR9-/- mice showed a reduced survival, a marked diarrhea and an enhanced expression of IL-18 versus irinotecan-injected WT controls. Additionally, the expression of MyD88 was reduced in the TLR2-/- or TLR9-/- mice. This study shows a critical role of the MyD88-mediated TLR2 and TLR9 signaling in the pathogenesis of irinotecan-induced intestinal mucositis.

Single nucleotide polymorphisms in candidate genes associated with gastrointestinal nematode infection in goats.

Cytokines are small cell-signaling proteins that play an important role in the immune system, participating in intracellular communication. Four candidate genes of the cytokine family (IL2, IL4, IL13, and IFNG) were selected to identify Single Nucleotide Polymorphisms (SNPs) that might be associated with resistance to gastrointestinal endoparasites in goats. A population of 229 goats, F2 offspring from an F1 intercross was produced by crossing pure Saanen goats, considered as susceptible to gastrointestinal endoparasites, with pure Anglo-Nubian goats, considered resistant. Blood was collected for DNA extraction and fecal samples were also collected for parasite egg count. Polymorphisms were prospected by sequencing animals with extreme phenotype for fecal egg count (FEC) distribution. The association between SNPs and phenotype was determined by using the Fisher exact test with correction for multiple tests. Three of the 10 SNPs were identified as significant (P ≤ 0.03). They were found in intron 1 of IL2 (ENSBTA00000020883), intron 3 of IL13 (ENSBTA00000015953) and exon 3 of IFNG (ENSBTA00000012529), suggesting an association between them and gastrointestinal endoparasite resistance. Further studies will help describe the effects of these markers accurately before implementing them in marker assisted selection. This study is the pioneer in describing such associations in goats.

Enteropatia com formação de tufos epiteliais e mutação do gene EpCAM: relato de caso / Tufting enteropathy with EpCAM mutation: case report

Tufting enteropathy (TE), also known as intestinal epithelial dysplasia (IED), is a rare congenital enteropathy related to an earlyonset of severe intractable diarrhea due to specific abnormalities of the intestinal epithelium and mutations of the EpCAM gene. TE is characterized by clinical and histological heterogeneity, such as with low or without mononuclear cell infiltration of the lamina propria, and abnormalities of basement membrane. TE can be associated with malformations, other epithelial diseases, or to abnormal enterocytes development and/or differentiation. The authors report a case of a Brazilian child with TE associated with c.556-14A>G mutation in the EpCAM gene (NM_002354.2)...

Enteropatia com formação de tufos epiteliais (ETE), também conhecida como displasia epitelial intestinal (DEI), é uma rara enteropatia congênita relacionada com um início precoce de diarreia intratável grave devido a anormalidades específicas do epitélio intestinal e mutações do gene EpCAM. ETE caracteriza-se por uma heterogeneidade clínica e histológica, como ausência ou leve infiltrado de células mononucleares na lâmina própria e anormalidades de membrana basal. Pode ser associada a malformações, outras doenças epiteliais ou anormalidades no desenvolvimento/na diferenciação dos enterócitos. Os autores relatam um caso de ETE, em uma criança brasileira, associada à mutação c.556-14A> g do gene EPCAM (NM_002354.2)...

Long polar fimbriae participates in the induction of neutrophils transepithelial migration across intestinal cells infected with enterohemorrhagic E. coli O157:H7.

Enterohemorrhagic Escherichia coli (EHEC) strains are causative agents of diarrhea and hemorrhagic colitis, both diseases associated with intestinal inflammation and cell damage. Several studies have correlated EHEC virulence factors to high levels of intestinal pro-inflammatory cytokines and we have previously described that the Long polar fimbriae (Lpf) is involved in the secretion of interleukin-8 (IL-8) and up-regulation of genes belonging to the NF-κB pathway using non-polarized epithelial intestinal T84 cells. In the current study, we evaluated the two EHEC O157 Lpf fimbriae (Lpf1 and Lpf2) for their ability to induce intestinal secretion of IL-8 and the activation of IL8, CCL20, and ICAM1 genes on polarized T84 cells. We also determined the participation of Lpf1 and Lpf2 in transepithelial migration of polymorphonuclear neutrophils (PMNs). Polarized T84 cells infected with EHEC revealed that both, Lpf1 and Lpf2, were required for the secretion of IL-8 and the induction of IL8, CCL20, and ICAM1 genes. Both fimbriae also played a role in the migration of PMNs trough the intestinal cells monolayer. Overall, the present work further demonstrated that the fimbriae Lpf1 and Lpf2 are important bacterial virulence factors that might be involved in the inflammatory responses associated with EHEC infections.

Transcriptional changes in the expression of chemokines related to natural killer and T-regulatory cells in patients with deep infiltrative endometriosis.

OBJECTIVE: To evaluate the expression of chemokines that regulate natural killer (NK) and T-regulatory (T-reg) cell activity in eutopic and ectopic endometrial tissue samples from endometriosis patients. DESIGN: Case-control study (Canadian Task Force classification II-2). SETTING: Tertiary referral hospital. PATIENT(S): Sixty-four consecutive patients with and without endometriosis. INTERVENTION(S): After videolaparoscopy, patients were divided into three groups: bowel endometriosis (n = 22), retrocervical endometriosis (n = 10), and endometriosis-free women (n = 32). MAIN OUTCOME MEASURE(S): Gene expression of the chemokines that regulate NK (CXCL9, CXCL10, CXCL11, CXCL12, XCL1, and CX3CL1) and T-reg cell activity (CCL17 and CCL21) evaluated by real-time polymerase chain reaction. RESULT(S): Of the chemokines associated with NK cells, CX3CL1 and CXCL12 expression was statistically significantly greater in the foci of endometriosis compared with the eutopic endometrium in patients and controls. From the chemokines associated with T-reg cells, CCL17 expression was statistically significantly greater in the eutopic endometrium of the patients with rectosigmoid endometriosis compared with the foci of endometriosis or eutopic endometrium of the patients with retrocervical endometriosis or the disease-free women. CONCLUSION(S): Both T-reg and NK cells mediate inflammatory response and may play a fundamental role in endometriosis by causing an impaired clearing of endometrial cells. Establishing how CCL17, CXCL12, and CX3CL1 modulate this response is essential to understanding inflammatory responses in endometriosis.

B4GALT1-congenital disorders of glycosylation presents as a non-neurologic glycosylation disorder with hepatointestinal involvement.

The clinical phenotype of congenital disorders of glycosylation is heterogeneous, mostly including a severe neurological involvement and multisystem disease. We identified a novel patient with a galactosyltransferase deficiency with mild hepatopathy and coagulation anomalies, but normal psychomotor development. The tissue-specific expression of the defective B4GALT1 gene correlated with the clinical phenotype.

Experimental intestinal endometriosis is characterized by increased levels of soluble TNFRSF1B and downregulation of Tnfrsf1a and Tnfrsf1b gene expression.

Endometriosis is commonly associated with symptoms similar to those of gastrointestinal diseases, such as inflammatory bowel disease (IBD), leading to erroneous diagnosis and inappropriate management. The role of tumor necrosis factor alpha (TNF) in IBD is well established, but its role in endometriosis--also characterized by the activation of inflammatory mechanisms--is still under study. Furthermore, little is known about the involvement of TNF receptors. Intestinal endometriosis was surgically induced in female Sprague-Dawley rats (n = 10). Control rats (n = 10) received sutures with no implants. Samples of tissue and fluids were collected 60 days after surgery. Endometriotic implants were classified in grades, and the gastrointestinal tract was examined for damage. A significant increase was observed in protein levels of TNF and soluble TNFRSF1B in the peritoneal fluid of experimental rats compared to controls. Expression of Tnf mRNA was significantly increased both in peritoneal leukocytes and in intestinal segments associated with implants in experimental animals. Bioactivity of TNF in tissues was confirmed by overexpression of Icam1, Sele, Vegfa, Flt1 and Kdr. Gene expression of Tnfrsf1a and Tnfrsf1b was downregulated in colon and small intestine of experimental animals, possibly as a mechanism of protection against TNF cytotoxicity. Significant overexpression of genes encoding TNF receptor-associated factors that have been linked to activation of antiapoptotic pathways also was observed. Overexpression of TNF and target genes, underexpression of TNF-receptor genes, and increased shedding of TNFRSF1B in this animal model provide further evidence for involvement of the TNF system in the pathogenesis of endometriosis.

Aneuploidies, deletion, and overexpression of TP53 gene in intestinal metaplasia of patients without gastric cancer.

Gastric carcinogenesis is attributable to interacting environmental and genetic factors, through a sequence of events including intestinal metaplasia. Using a fluorescence in situ hybridization technique, we investigated the occurrence of aneuploidies of chromosomes 3, 7, 8, 9, and 17, TP53 gene deletion, and expression of p53 in 21 intestinal metaplasia (IM) samples from cancer-free patients and in 20 gastric adenocarcinoma samples. Aneuploidies were found in 71% (15/21) of the IM samples. Trisomy of chromosomes 7 and 9 occurred mainly in complete-type IM; in the incomplete type, trisomy of chromosomes 7 and 8 were more commonly found. The TP53 gene deletion was observed in 60% (3/5) of the IM cases, and immunohistochemistry revealed p53 overexpression in 12% (2/17) of the analyzed IM cases. All gastric adenocarcinoma cases presented higher frequencies of trisomy or tetrasomy of chromosomes 3, 7, 8, 9, and 17. The TP53 deletion was found in all three of the gastric adenocarcinoma analyzed for it, and immunohistochemistry detected overexpression of protein p53 in 80% (12/15) of the analyzed cases. Our study revealed for the first time the presence of aneuploidies of chromosomes 7, 8, 9, and 17 and of TP53 gene deletion and overexpression in IM samples from cancer-free patients. These results suggest that IM and gastric adenocarcinoma may share the same genetic alterations.

Familial autoimmune enteropathy with circulating anti-bullous pemphigoid antibodies and chronic autoimmune hepatitis.

In a family of four children (two boys and two girls), the two brothers had severe, protracted watery diarrhea beginning at 2 and 3 weeks of life, respectively. Duodenal mucosa in both patients showed total villous atrophy and severe inflammatory infiltration of the entire bowel. The first patient also had lymphoid cell infiltration of the pancreas and died at 6 weeks of age. The second boy is alive at 2 years of age and is immunocompetent, but still receives total parenteral nutrition. Indirect immunofluorescence studies revealed circulating antibodies to enterocytes, smooth muscle, thyroid, and islet cells. Bullous pemphigoid antibodies (230 and 180 kd), specific for hemidesmosomal proteins and usually associated with a subepidermal blistering skin disease, were detected by direct and indirect immunofluorescence studies and by Western immunoblot. A diagnosis of autoimmune hepatitis was made, based on evidence of chronic active hepatitis and circulating anti-smooth muscle antibody. Immunosuppressive treatments induced partial clinical remission of the diarrhea but no resolution of the small bowel injury. At 16 months of age, remission of the diarrhea occurred, but persistent autoimmune hepatitis led us to maintain treatment with prednisone and azathioprine, and later with cyclosporine. In this child, as in other patients with autoimmune disease, the link between autoantibodies and organ damage remains uncertain but immunosuppressive treatment is indicated.

Prospective study of Lewis antigen alterations in the gastric precancerous process.

A prospective study with two gastric biopsies taken several years apart was carried out in 117 subjects with intestinal metaplasia who are of the Lewis(a-b+) phenotype. They are residents of a rural Andean region in Colombia displaying very high rates of gastric cancer. The anomalous expression of Lewis(a) antigens in the metaplastic epithelium carried a significantly increased risk of colonic metaplasia and dysplasia. Such risk was much higher when the simultaneous expression of sulfomucins and Lewis(a) antigen was observed.