Disfunción del transportador del surfactante pulmonar ABCA3: reporte de un caso peruano / Surfactant ABCA3 transporter dysfunction: a case report from Peru

Resumen Introducción: Los trastornos genéticos que afectan la homeostasis del surfactante pulmonar son una causa importante del síndrome de dificultad respiratoria en el recién nacido a término y de enfermedad pulmonar intersticial difusa en niños. El transportador ABCA3 (ATP binding cassette A3) interviene en la producción normal del surfactante que recubre el interior de las paredes alveolares y funciona como agente tensioactivo. Caso clínico: Recién nacido a término que presentó dificultad respiratoria a los 3 días de vida y requirió ventilación mecánica. Los estudios para determinar otras causas de enfermedad pulmonar fueron negativos. Se realizó una biopsia de pulmón para realizar estudios de microscopía óptica y microscopía electrónica. Esta última mostró pequeños cuerpos lamelares anómalos, además de condensaciones electrodensas periféricas, características de las mutaciones del transportador ABCA3. Se inició tratamiento con pulsos de metilprednisolona, hidroxicloroquina, azitromicina y corticoides inhalados a dosis altas, y la respuesta clínica y radiológica fue favorable durante el seguimiento. Conclusiones: La correlación de las características clínicas y de las imágenes (tomografía y microscopía electrónica) puede ser útil para el diagnóstico de la disfunción del surfactante pulmonar, especialmente en los países de bajos y medianos recursos que no disponen de estudios genéticos para determinar las diferentes mutaciones del transportador ABCA3. Este es uno de los primeros casos reportados en Perú con respuesta adecuada al tratamiento y evolución favorable durante el seguimiento.

Abstract Background: Genetic disorders affecting pulmonary surfactant homeostasis are a major cause of respiratory distress syndrome in full-term newborn and childhood interstitial lung disease. The ABCA3 transporter (ATP binding cassette A3) intervenes in the normal production of surfactant that covers the interior of alveolar walls and plays a fundamental role as a surfactant. Case report: Male term newborn who presented respiratory distress 3 days after birth and required mechanical ventilation. Studies to determine other causes of lung disease were negative. Lung biopsy was performed for the study with light microscopy and electron microscopy. Electron microscopy showed small abnormal lamellar bodies in addition to peripheral electrodense condensations characteristic of ABCA3 transporter mutation. Treatment was started with pulses of methylprednisolone, hydroxychloroquine, azithromycin, and high-dose inhaled corticosteroids, finding a favorable clinical and radiological response to follow-up. Conclusions: Correlation of clinical characteristics and images (tomography and electron microscopy) can be useful for the diagnosis of lung surfactant dysfunction, especially in low and medium-income countries where genetic studies to determine the different ABCA3 transporter mutations are not available. This is one of the first cases reported in Peru with an adequate response to treatment and favorable evolution to follow-up.

El intersticio pulmonar y sus enfermedades en la infancia. Deficiencia de ABCA3. Seguimiento durante doce años. Perspectivas ¿Un nuevo paradigma genético? / The pulmonary interstitium and its diseases in childhood. ABCA3 deficiency. Follow-up for 12 years. Perspectives. A new genetic paradigm?

Introducción. Sobre la base de un caso clínico, se presenta la descripción del cuadro intersticial por deficiencia de ABCA3, de una paciente de catorce años de edad, en seguimiento durante doce años. Método. Evaluación clínica con extensos estudios para descartar otras patologías semejantes. El diagnóstico definitivo fue determinado por el estudio genético para deficiencias de ABCA3 y otros defectos genéticos realizados por el Dr. Larry Nogee, Hospital Johns Hopkins, EE. UU. Objetivos. Describir detalladamente la evolución de la paciente durante doce años, con énfasis en los estudios anteriormente mencionados. Sugerir la presencia de un cambio de paradigma pronóstico en lo que se conocía sobre la evolución de esta enfermedad intersticial pulmonar grave, tratar de mejorar la calidad de vida y posiblemente el pronóstico. Presentar los hallazgos de genética, anatomía patológica y radiología en consultas y evaluaciones por centros de referencia. Resultados. Realizado su diagnóstico de deficiencia genética de ABCA3, presentamos su seguimiento actualizado hasta el año 2020. Esta debe ser sospechada en niños pequeños desde el nacimiento y durante los primeros años ante la persistencia de cuadros pulmonares crónicos con desaturación de oxígeno e imágenes tomográficas que sugieren cuadro intersticial. Se decidió tratar el cuadro en los años 2019-2020, durante seis meses, según bibliografía y consultas con centros de referencia en los Estados Unidos, con la finalidad de determinar la posible mejoría de su patología y decidir la continuación o suspensión de la medicación. Se usaron pulsos con metilprednisolona- hidroxicloroquina y azitromicina. Se logró mantener estable su función pulmonar y mejorar notablemente su calidad de vida. (AU)

Introduction. A clinical case diagnosed with ABCA3 deficiency is described. Patient is now fourteen years old. She´s being followed up since she was two years old. Methodology. clinical follow ­ up with extensive studies to rule out other similar pathologies. Final diagnosis was done through genetic studies done at Johns Hopkins Hospital by Nogee LM. Objective. To present a detailed evolution description of twelve years' follow-up with the support of the aforementioned studies, to suggest a change in diagnostic ­ prognostic paradigm on what was known of mortality in this severe pulmonary interstitial pathology to improve life quality and possibly prognosis. Present the findings of genetics, pathological anatomy and radiology in consultations and evaluations by reference centers. Results. Having made her diagnosis of genetic ABCA3 deficiency, we present her up dated follow-up until 2020. This should be suspected in young children from birth and during the first years due to the persistence of chronic pulmonary symptoms with oxygen desaturation and tomographic images that suggest interstitial symptoms. It was decided to treat the condition in the years 2019-2020, for six months, according to the bibliography and consultations with reference centers in the United States, in order to determine the possible improvement of her pathology and decide to continue or suspend the medication. Pulses with methylprednisolone hydroxychloroquine and azithromycin were used. Her lung function was stable and her quality of life significantly improved. (AU)

Gene expression profile of ABC transporters and cytotoxic effect of ibuprofen and acetaminophen in an epithelial ovarian cancer cell line in vitro / Perfil da expressão gênica dos transportadores ABC e efeito citotóxico do ibuprofeno e acetaminofen em uma linhagem celular de câncer epitelial de ovário in vitro

PURPOSES: To determine the basic expression of ABC transporters in an epithelial ovarian cancer cell line, and to investigate whether low concentrations of acetaminophen and ibuprofen inhibited the growth of this cell line in vitro. METHODS: TOV-21 G cells were exposed to different concentrations of acetaminophen (1.5 to 15 μg/mL) and ibuprofen (2.0 to 20 μg/mL) for 24 to 48 hours. The cellular growth was assessed using a cell viability assay. Cellular morphology was determined by fluorescence microscopy. The gene expression profile of ABC transporters was determined by assessing a panel including 42 genes of the ABC transporter superfamily. RESULTS: We observed a significant decrease in TOV-21 G cell growth after exposure to 15 μg/mL of acetaminophen for 24 (p=0.02) and 48 hours (p=0.01), or to 20 μg/mL of ibuprofen for 48 hours (p=0.04). Assessing the morphology of TOV-21 G cells did not reveal evidence of extensive apoptosis. TOV-21 G cells had a reduced expression of the genes ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 and ABCE1 within the ABC transporter superfamily. CONCLUSIONS: This study provides in vitro evidence of inhibitory effects of growth in therapeutic concentrations of acetaminophen and ibuprofen on TOV-21 G cells. Additionally, TOV-21 G cells presented a reduced expression of the ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 and ABCE1 transporters. .

OBJETIVOS: Determinar a expressão básica dos transportadores ABC em uma linhagem celular do câncer epitelial de ovário, e investigar se o acetaminofen e o ibuprofeno em baixas concentrações são capazes de inibir o crescimento desta linhagem celular in vitro. MÉTODOS: A linhagem celular TOV-21 G foi exposta a diferentes concentrações de acetaminofen (1,5 a 15 µg/mL) e ibuprofeno (2,0 a 20 µg/mL), de 24 a 48 horas. O crescimento celular foi avaliado utilizando-se um ensaio de viabilidade celular. A morfologia celular foi determinada por meio da microscopia de fluorescência. O perfil de expressão gênica foi estabelecido por um painel de 42 genes da superfamília de transportadores ABC. RESULTADOS: Observou-se um decréscimo significativo no crescimento das células TOV-21 G expostas a 15 µg/mL de acetaminofen durante 24 (p=0,02) e 48 horas (p=0,01), ou a 20 µg/mL de ibuprofeno por 48 horas (p=0,04). Ao avaliar a morfologia das células cultivadas, não foi observada evidência de apoptose extensiva. A linhagem de células estudada subexpressa os genes de ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 e ABCE1 na superfamília de transportadores ABC. CONCLUSÕES: Este estudo fornece evidências in vitro referentes aos efeitos inibidores do crescimento de concentrações terapêuticas do acetaminofen e ibuprofeno na linhagem celular testada. Além disso, as células TOV-21 G apresentaram uma expressão reduzida de genes dos transportadores ABCA1, ABCC3, ABCC4, ABCD3, ABCD4 e ABCE1. .

A novel ABCG-like transporter of Trypanosoma cruzi is involved in natural resistance to benznidazole

Benznidazole (BZ) is one of the two drugs used for Chagas disease treatment. Nevertheless therapeutic failures of BZ have been reported, which were mostly attributed to variable drug susceptibility among Trypanosoma cruzi strains. ATP-binding cassette (ABC) transporters are involved in a variety of translocation processes and some members have been implicated in drug resistance. Here we report the characterisation of the first T. cruzi ABCG transporter gene, named TcABCG1, which is over-expressed in parasite strains naturally resistant to BZ. Comparison of TcABCG1 gene sequence of two TcI BZ-resistant strains with CL Brener BZ-susceptible strain showed several single nucleotide polymorphisms, which determined 11 amino acid changes. CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene. Only in the parasites transfected with TcI genes there was 2-2.6-fold increased abundance of TcABCG1 transporter protein. The analysis in wild type strains also suggests that the level of TcABCG1 transporter is related to BZ natural resistance. The characteristics of untranslated regions of TcABCG1 genes of BZ-susceptible and resistant strains were investigated by computational tools.

Genetic analysis of ABCG2 and SLC2A9 gene polymorphisms in gouty arthritis in a Korean population

BACKGROUND/AIMS: Gout is a common inf lammatory arthritis triggered by the crystallization of uric acid in the joints. Serum uric acid levels are highly heritable, suggesting a strong genetic component. Independent studies to confirm the genetic associations with gout in various ethnic populations are warranted. We investigated the association of polymorphisms in the ABCG2 and SLC2A9 genes with gout in Korean patients and healthy individuals. METHODS: We consecutively enrolled 109 patients with gout and 102 healthy controls. The diagnosis of gout was based on the preliminary criteria of the America College of Rheumatology. Genomic DNA was extracted from whole blood samples. We identified single nucleotide polymorphism (SNP) changes in the ABCG2 and SLC2A9 genes using a direct sequencing technique. rs2231142 in ABCG2 and rs6449213 and rs16890979 in SLC2A9 and nearby regions were amplified by polymerase chain reaction. RESULTS: Patients with gout had significantly higher A/A genotype (29.3% vs. 4.9%, respectively) and A allele (52.8% vs. 26.5%, respectively) frequencies of rs2231142 in ABCG2 than did controls (chi2 = 29.42, p G and c.1002+78G>A) in the SLC2A9 gene. The univariate logistic regression analysis revealed that the c.881A>G and c.1002+78G>A SNPs were significantly higher in patients than in controls. CONCLUSIONS: We demonstrated a significant association between rs2231142 in the ABCG2 gene and gout and identified novel SNPs, c.881A>G and c.1002+78G>A, in the SLC2A9 gene that may be associated with gout in a Korean population.

Association study of the ABCC8 gene variants with type 2 diabetes in south Indians.

BACKGROUND: The ABCC8 gene which encodes the sulfonylurea receptor plays a major role in insulin secretion and is a potential candidate for type 2 diabetes. The ‑3c → t (rs1799854) and Thr759Thr (C → T, rs1801261) single nucleotide polymorphisms (SNPs) of the ABCC8 gene have been associated with type 2 diabetes in many populations. The present study was designed to investigate the association of these two SNPs in an Asian Indian population from south India. MATERIALS AND METHODS: A total of 1,300 subjects, 663 normal glucose tolerant (NGT) and 637 type 2 diabetic subjects were randomly selected from the Chennai Urban Rural Epidemiology Study (CURES). The ‑3c → t and Thr759Thr were genotyped in these subjects using polymerase chain reaction‑restriction fragment length polymorphism (PCR‑RFLP) and a few variants were confirmed by direct sequencing. RESULTS: The frequency of the ‘t’ allele of the ‑3c → t SNP was found to be 0.27 in NGT and 0.29 in type 2 diabetic subjects (P = 0.44). There was no significant difference in the genotypic frequency between the NGT and type 2 diabetic group (P = 0.18). Neither the genotypic frequency nor the allele frequency of the Thr759Thr polymorphism was found to differ significantly between the NGT and type 2 diabetic groups. CONCLUSION: The ‑3c → t and the Thr759Thr polymorphisms of the ABCC8 gene were not associated with type 2 diabetes in this study. However, an effect of these genetic variants on specific unidentified sub groups of type 2 diabetes cannot be excluded.

Isolated Cerebellar Variant of Adrenoleukodystrophy with a de novo Adenosine Triphosphate-Binding Cassette D1 (ABCD1) Gene Mutation

X-linked adrenoleukodystrophy (X-ALD) shows a wide range of phenotypic expression, but clinical presentation as an isolated lesion of the cerebellar white matter and dentate nuclei has not been reported. We report an unusual presentation of X-ALD only with an isolated lesion of the cerebellar white matter and dentate nuclei. The proband, a 37-year-old man presented with bladder incontinence, slurred speech, dysmetria in all limbs, difficulties in balancing, and gait ataxia. Brain magnetic resonance imaging showed an isolated signal change of white matter around the dentate nucleus in cerebellum. With high level of very long chain fatty acid, gene study showed a de novo mutation in exon 1 at nucleotide position c.277_296dup20 (p.Ala100Cysfs*10) of the adenosine triphosphate-binding cassette D1 gene. It is advised to consider X-ALD as a differential diagnosis in patients with isolated cerebellar degeneration symptoms.

Clinical and Genetic Aspects in Twelve Korean Patients with Adrenomyeloneuropathy

PURPOSE: This study was designed to investigate the characteristics of Korean adrenomyeloneuropathy (AMN) patients. MATERIALS AND METHODS: We retrospectively selected 12 Korean AMN patients diagnosed by clinical analysis and increased plasma content of very long chain fatty acids. RESULTS: All 12 patients were men. Patient ages at symptom onset ranged from 18 to 55 years. Family history was positive in two patients. The phenotype distributions consisted of AMN without cerebral involvement in seven patients, AMN with cerebral involvement in two patients, and the spinocerebellar phenotype in three patients. Nerve conduction studies revealed abnormalities in four patients and visual evoked tests revealed abnormalities in three patients. Somatosensory evoked potential tests revealed central conduction defects in all of the tested patients. Spinal MRI showed diffuse cord atrophy or subtle signal changes in all 12 patients. Brain MRI findings were abnormal in six of the nine tested patients. These brain abnormalities reflected the clinical phenotypes. Mutational analysis identified nine different ABCD1 mutations in 10 of 11 tested patients. Among them, nine have been previously reported and shown to be associated with various phenotypes; one was a novel mutation. CONCLUSION: In conclusion, the present study is the first to report on the clinical and mutational spectrum of Korean AMN patients, and confirms various clinical presentations and the usefulness of brain MRI scan.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.

Effects of R219K polymorphism of ATP-binding cassette transporter 1 gene on serum lipids ratios induced by a high-carbohydrate and low-fat diet in healthy youth

BACKGROUND: Diets are the important players in regulating plasma lipid profiles. And the R219K polymorphism at the gene of ATP-binding cassette transporter 1(ABCA1) was reported to be associated with the profiles. However, no efforts have been made to investigate the changes of lipid profiles after a high-carbohydrate and low-fat diet in different subjects with different genotypes of this polymorphism. This study was to evaluate the effects of ABCA1 R219K polymorphism on serum lipid and apolipoprotein (apo) ratios induced by a high-carbohydrate/low-fat (high-CHO) diet. After a washout diet of 54.1% carbohydrate for 7 days, 56 healthy young subjects (22.89 ± 1.80 years old) were given a high-CHO diet of 70.1% carbohydrate for 6 days. Height, weight, waist circumference, hip circumference, glucose (Glu), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apoA-1 and apoB-100 were measured on the 1st, 8th and 14th days of this study. Body mass index (BMI), waist-to-hip ratios (WHR), log(TG/HDL-C), TC/HDL-C, LDL-C/HDL-C and apoA-1/apoB-100 were calculated. ABCA1 R219K was analyzed by a PCR-RFLP method. RESULTS: The results indicate that the male subjects of all the genotypes had higher WHR than their female counterparts on the 1st, 8th and 14th days of this study. The male K carriers had higher log(TG/HDL-C) and TC/HDL-C than the female carriers on the 1st and 14th days, and higher LDL-C/HDL-C on the 14th day. When compared with that on the 8th day, TC/HDL-C was decreased regardless of the genotypes and genders on the 14th day. Log(TG/HDL-C) was increased in the males with the RR genotype and the female K carriers. Lowered BMI, Glu and LDL-C/HDL-C were found in the male K carriers, but only lowered BMI in the female K carriers and only lowered LDL-C/HDL-C in the females with the RR genotype. CONCLUSIONS: These results suggest that ABCA1 R219K polymorphism is associated differently in males and females with elevated log(TG/HDL-C) and decreased LDL-C/HDL-C induced by the high-CHO diet.

Effect of garlic extract on some serum biochemical parameters and expression of npc1l1, abca1, abcg5 and abcg8 genes in the intestine of hypercholesterolemic mice.

Some compounds in the garlic inhibit cholesterol synthesis, resulting in lowering of serum cholesterol and triglycerides and increase in HDL level. However, the mechanism of this specific effect is not fully understood. In the small intestine, ATP-binding cassette transporters G5, G8 and A1 (ABCG5, ABCG8 and ABCA1), as well as Niemann-Pick C1 like 1 (NPC1L1) protein have important roles in cholesterol metabolism. In this study, we evaluated the beneficial effect of aqueous extract of garlic on lipid profile and also expression of npc1l1, abca1, abcg5 and abcg8 genes in the intestine of N-Marry mice fed a high cholesterol diet as a possible mechanism of garlic effect. Twenty-four mice were randomly divided into three groups: Group 1: hypercholesterolmic (received chow + 2% cholesterol + 0.5% cholic acid); Group 2: garlic (received chow + 4% (w/w) garlic extract + 2% cholesterol + 0.5% cholic acid); and Group 3: received chow only. After one month, mice were anesthetized and blood was collected from their heart. The jejunum was removed, washed with PBS and entrocytes were scraped and used for the experiments. Serum lipids were measured enzymatically and expression of mRNA levels for the above-mentioned proteins was determined by semi-quantitative RT-PCR. Garlic extract significantly reduced serum lipids (p<0.05), compared with the hypercholesterolemic group. Expression of the intestinal npc1l1 was significantly decreased (p<0.01) in the garlic group, compared with the chow group, while abcg5 (p<0.01), abcg8 (p<0.01) and abca1 (p<0.05) expressions were significantly increased. In conclusion, this study reveals a possible mechanism for the beneficial effects of the garlic in lowering serum lipids by decreasing the intestinal lipid absorption and increasing excretion of cholesterol back into the intestinal lumen.

A novel ABCB11 mutation in an Iranian girl with progressive familial intrahepatic cholestasis.

Progressive familial intrahepatic cholestasis is an autosomal recessive liver disorder caused by (biallelic) mutations in the ATP8B1 of ABCB11 gene. A nine‑year‑old girl with cholestasis was referred for genetic counseling. She had a family history of cholestasis in two previous expired siblings. Genetic analysis of the ABCB11 gene led to the identification of a novel homozygous mutation in exon 25. The mutation 3593‑ A > G lead to a missense mutation at the amino acid level (His1198Arg). This mutation caused PFIC2 due to abnormal function in the bile salt export pump protein (BSEP).

La respuesta terapéutica a ezetimiba en ratones C57BL/6 es mediada por cambios en la expresión de NPC1L1, ABCG5 y ABCG8 en el enterocito / Therapeutic response to ezetimibe in C57BL/6 mice is mediated by changes in NPC1L1, ABCG5 and ABCG8 expression in the enterocyte

Las proteínas NPC1L1, ABCG5 y ABCG8 participan en la absorción intestinal de colesterol. Ezetimiba inhibe este proceso bloqueando a NPC1L1, sin embargo, su efecto sobre ABCG5 y ABCG8 aún no está claro. Así, el objetivo del presente trabajo fue evaluar en ratones C57BL/6 con hipercolesterolemia inducida por dieta y tratados con ezetimiba, la expresión de NPC1L1, ABCG5 y ABCG8 mediante PCR en tiempo real y Western blot, en 3 grupos de animales: 1, dieta hipercolesterolémica D12336; 2, dieta D12336 más 5 mg/kg/día de ezetimiba; 3, dieta control. El nivel sérico de colesterol total fue significativamente diferente entre los grupos estudiados (control: 1,85 +/- 0,49 mmol/L; dieta D12336: 3,11 +/- 0,73 mmol/L; ezetimiba: 2,11 +/- 0,50 mmol/L, P = 0,001). La expresión génica de NPC1L1 aumentó 5,4 veces en el grupo que recibió la dieta D12336 (P = 0,003). Por otro lado, la expresión génica de ABCG5 y ABCG8 no fue diferente en el grupo con hipercolesterolemia (P = 0,239 y P = 0,201, respectivamente). Después del tratamiento con ezetimiba, la expresión génica de ABCG5 se incrementó 15,6 veces (P = 0.038). No hubo diferencias significativas en la expresión génica de NPC1L1 (P = 0,134) y ABCG8 (P = 0,067). En relación a la expresión proteica, la dieta D12336 incrementó los niveles de expresión de NPC1L1 (P = 0,022) y ABCG5 (P = 0,008); el tratamiento con ezetimiba incrementó los niveles de NPC1L1 (P = 0,048) y redujo los niveles de ABCG5 (P = 0,036) y ABCG8 (P = 0,016). En conclusión, nuestros resultados sugieren que tanto la dieta hipercolesterolémica como el tratamiento con ezetimiba, en un modelo experimental, afectan los niveles de expresión de NPC1L1, ABCG5 y ABCG8, sugiriendo que ABCG5 y ABCG8 están involucrados en la respuesta hipolipemiante a este fármaco. No obstante, el mecanismo mediante el cual se explica esta interacción requiere de un futuro estudio.

Proteins NPC1L1, ABCG5 and ABCG8 are involved in the intestinal absorption of cholesterol. Ezetimibe inhibits this process by blocking NPC1L1, however, its effect on ABCG5 and ABCG8 is not yet clear. Thus, the objective of this study was to evaluate in C57BL / 6 mice with diet-induced hypercholesterolemia treated with ezetimibe, the expression of NPC1L1, ABCG5 and ABCG8 by real time PCR and Western blot, in 3 groups of animals: 1, diet hypercholesterolemic D12336, 2, D12336 diet plus 5 mg/kg/ day of ezetimibe, 3, diet control. The serum level of total cholesterol was significantly different between groups (control: 1.85 +/- 0.49 mmol / L; diet D12336: 3.11 +/- 0.73 mmol / L; ezetimibe: 2.11 +/- 0.50 mmol / L, P = 0.001). NPC1L1 gene expression increased 5.4-fold in the group receiving the diet D12336 (P = 0.003). Furthermore, the gene expression of ABCG5 and ABCG8 was not different in the group with hypercholesterolemia (P = 0.239 and P = 0.201, respectively). After treatment with ezetimibe, ABCG5 gene expression was increased 15.6 times (P = 0.038). No significant differences in gene expression of NPC1L1 (P = 0.134) and ABCG8 (P = 0.067). Regarding protein expression, the D12336 diet increased the levels of expression of NPC1L1 (P = 0.022) and ABCG5 (P = 0.008), treatment with ezetimibe increased the levels of NPC1L1 (P = 0.048) and reduced levels of ABCG5 (P = 0.036) and ABCG8 (P = 0.016). In conclusion, our results suggest that both hypercholesterolemic diet as treatment with ezetimibe, in an experimental model, affect the expression levels of NPC1L1, ABCG5 and ABCG8, suggesting that ABCG5 and ABCG8 are involved in lipid-lowering response to this drug. However, the mechanism by which this interaction is explained requires further study.

Effect of five single nucleotide polymorphisms of ABCG5 and ABCG8 genes on eLipid-lowering response / Efecto de cinco polimorfismos de los genes ABCG5 y ABCG8 sobre la respuesta hipolipemiante a ezetimiba

In this study we evaluated the possible association between five single nucleotide polymorphisms in ABCG5 (rs6720173) and ABCG8 (rs11887534, rs4148211, rs4148217 and rs6544718) genes and ezetimibe response in Chilean hypercholesterolemic subjects. A total of 60 non-related hypercholesterolemic subjects, aged 18 to 65 years old were included in this study. These subjects were treated with ezetimibe (10mg/day) during one month. The ABCG5 and ABCG8 genotypes were assessed by PCR-RFLP. The genotype distribution of the ABCG5/ABCG8 polymorphisms was in Hardy-Weinberg equilibrium. Our results showed that the investigated polymorphisms were not associated with the response to ezetimibe. Nevertheless, the T allele of rs6544718 polymorphism was related to higher baseline levels of LDL-cholesterol (p<0.001). In addition, the G allele for the rs4148211 polymorphism was associated with greater baseline concentrations of triglycerides (P=0.019). This allele was also associated with lower concentrations of HDL-cholesterol (P=0.027), after ezetimibe treatment. Our results suggest that the studied polymorphisms do not affect the therapeutic response to ezetimibe in the evaluated subjects.

En este estudio se evaluó la posible asociación entre cinco polimorfismos de nucleótido único en los genes ABCG5 (rs6720173) y ABCG8 (rs11887534, rs4148211, rs4148217 y rs6544718) y la respuesta a ezetimiba en pacientes hipercolesterolémicos chilenos. Un total de 60 individuos hipercolesterolemicos, no relacionados, con edades entre 18 y 65 años fueron incluidos. Estos sujetos fueron tratados con ezetimiba (10mg/día) durante un mes. Los genotipos de ABCG5 y ABCG8 fueron evaluados por PCR-RFLP. La distribución de genotipos de los polimorfismos de ABCG5/ABCG8 se encontraba en equilibrio de Hardy-Weinberg. Nuestros resultados mostraron que los polimorfismos estudiados no se asociaron con la respuesta a la ezetimiba. Sin embargo, el alelo T del polimorfismo rs6544718 fue relacionado con niveles basales elevados de LDL-colesterol (p <0,001). Además, el alelo G para el polimorfismo rs4148211 se asoció con una mayor concentración basal de triglicéridos (p = 0,019). Este alelo también se asoció con concentraciones más bajas de HDL-colesterol (p = 0,027), después del tratamiento con ezetimiba. Nuestros resultados sugieren que los polimorfismos estudiados no afectan a la respuesta terapéutica a la ezetimiba en los sujetos evaluados.

Adenovirus adenine nucleotide translocator-2 shRNA effectively induces apoptosis and enhances chemosensitivity by the down-regulation of ABCG2 in breast cancer stem-like cells

Cancer stem cells (CSCs) are resistant to chemo- and radio-therapy, and can survive to regenerate new tumors. This is an important reason why various anti-cancer therapies often fail to completely control tumors, although they kill and eliminate the bulk of cancer cells. In this study, we determined whether or not adenine nucleotide translocator-2 (ANT2) suppression could also be effective in inducing cell death of breast cancer stem-like cells. A sub-population (SP; CD44+/CD24-) of breast cancer cells has been reported to have stem/progenitor cell properties. We utilized the adeno-ANT2 shRNA virus to inhibit ANT2 expression and then observed the treatment effect in a SP of breast cancer cell line. In this study, MCF7, MDA-MB-231 cells, and breast epithelial cells (MCF10A) mesenchymally-transdifferentiated through E-cadherin knockdown were used. ANT2 expression was high in both stem-like cells and non-stem-like cells of MCF7 and MDA-MB-231 cells, and was induced and up-regulated by mesenchymal transdifferentiation in MCF10A cells (MCF10AEMT). Knockdown of ANT2 by adeno-shRNA virus efficiently induced apoptotic cell death in the stem-like cells of MCF7 and MDA-MB-231 cells, and MCF10AEMT. Stem-like cells of MCF7 and MDA-MB-231, and MCF10AEMT cells exhibited increased drug (doxorubicin) resistance, and expressed a multi-drug resistant related molecule, ABCG2, at a high level. Adeno-ANT2 shRNA virus markedly sensitized the stem-like cells of MCF7 and MDA-MB-231, and the MCF10AEMT cells to doxorubicin, which was accompanied by down-regulation of ABCG2. Our results suggest that ANT2 suppression by adeno-shRNA virus is an effective strategy to induce cell death and increase the chemosensitivity of stem-like cells in breast cancer.

association between sporadic Alzheimer's disease and the human ABCA1 and APOE gene polymorphisms in Iranian population

Apolipoprotein E [APOE], which its epsilon4 allele has been reported as a risk factor in late onset Alzheimer's disease [AD], is the main cholesterol carrier in the brain. ATP-binding cassette transporter A1 [ABCA1] gene on chromosome 9, which has been known by genome-wide AD linkage study, has an important role in cellular cholesterol efflux. This study determines the association between sporadic AD and the human ABCA1 and APOE gene polymorphisms in Iranian population. 154 AD cases and 162 control subjects from Iranian population were genotyped for APOE genotypes and ABCA1 polymorphism [R219K]. The frequency of epsilon2epsilon3 genotype was higher in control subjects comparing AD patients but was not significant [13% versus 5.8%] and epsilon3epsilon4 genotype frequency was significantly higher in AD cases comparing with control subjects. APOE-epsilon2 allele frequency in cases was lower than control subjects but this difference was not significant [4.5% versus 8%]. Individuals carrying epsilon4 allele, developed AD 6.5 times more than non-carriers [OR=6.52, 95%CI=2.63-16.17]. There was no significant association between ABCA1 polymorphism and AD. Unlike other studies, R219K polymorphism was not dependent on gender and APOE-epsilon4 allele and there was no association between APOE and ABCA1 in AD patients compared to controls

Phenotypic variability in a family with x-linked adrenoleukodystrophy caused by the p.Trp132Ter mutation / Variabilidade fenotípica em uma família com adrenoleucodistrofia ligada ao X causada pela mutação p.Trp132Ter

X-linked adrenoleukodystrophy (X-ALD) is an inherited disease with clinical heterogeneity varying from presymptomatic individuals to rapidly progressive cerebral ALD forms. This disease is characterized by increased concentration of very long chain fatty acids (VLCFAs) in plasma and in adrenal, testicular and nervous tissues. Affected individuals can be classified in different clinical settings, according to phenotypic expression and age at onset of initial symptoms. Molecular defects in X-ALD individuals usually result from ABCD1 gene mutations. In the present report we describe clinical data and the ABCD1 gene study in two boys affected with the childhood cerebral form that presented with different symptomatic manifestations at diagnosis. In addition, their maternal grandfather had been diagnosed with Addison's disease indicating phenotypic variation for X-ALD within this family. The mutation p.Trp132Ter was identified in both male patients; additionally, three females, out of eleven family members, were found to be heterozygous after screening for this mutation. In the present report, the molecular analysis was especially important since one of the heterozygous females was in first stages of pregnancy. Therefore, depending on the fetus outcome, if male and p.Trp132Ter carrier, storage of the umbilical cord blood should be recommended as hematopoietic stem cell transplantation could be considered as an option for treatment in the future.

A adrenoleucodistrofia é uma doença genética com padrão de herança ligado ao X (X-ALD) que apresenta heterogeneidade clínica e varia desde a forma infantil cerebral severa até casos de indivíduos pré-sintomáticos. Essa doença é caracterizada pelo acúmulo de ácidos graxos de cadeia muito longa (VLCFA) no plasma, nas adrenais, nos testículos e no sistema nervoso. Indivíduos afetados podem apresentar diferentes formas clínicas, as quais são classificadas de acordo com a expressão fenotípica e a idade de aparecimento dos sintomas iniciais. Alterações moleculares em indivíduos com X-ALD são geralmente mutações no gene ABCD1. No presente trabalho, descrevemos os dados clínicos e a investigação molecular do gene ABCD1 em uma família com duas crianças do sexo masculino afetadas com a forma infantil cerebral, que apresentaram diferenças nas primeiras manifestações sintomáticas para o diagnóstico. Além disso, houve referência ao avô materno diagnosticado com doença de Addison's, indicando a variabilidade fenotípica da X-ALD nessa família. A análise molecular indicou a mutação p.Trp132Ter nos dois pacientes masculinos, e três indivíduos do sexo feminino, entre os onze estudados, mostraram-se heterozigotos para mutação. O conhecimento molecular descrito no presente relato adquiriu maior importância uma vez que uma das portadoras da mutação apresentou-se nos primeiros estágios de gestação. Assim, poderá ser oferecida a possibilidade de armazenamento de sangue de cordão umbilical para que se possa considerar, no futuro, o transplante de células-tronco hematopoiéticas como forma de tratamento, caso a criança seja do sexo masculino e afetada.

Novel insertion mutation of ABCB1 gene in an ivermectin-sensitive Border Collie

P-glycoprotein (P-gp) is encoded by the ABCB1 gene and acts as an efflux pump for xenobiotics. In the Border Collie, a nonsense mutation caused by a 4-base pair deletion in the ABCB1 gene is associated with a premature stop to P-gp synthesis. In this study, we examined the full-length coding sequence of the ABCB1 gene in an ivermectin-sensitive Border Collie that lacked the aforementioned deletion mutation. The sequence was compared to the corresponding sequences of a wild-type Beagle and seven ivermectin-tolerant family members of the Border Collie. When compared to the wild-type Beagle sequence, that of the ivermectin-sensitive Border Collie was found to have one insertion mutation and eight single nucleotide polymorphisms (SNPs) in the coding sequence of the ABCB1 gene. While the eight SNPs were also found in the family members' sequences, the insertion mutation was found only in the ivermectin-sensitive dog. These results suggest the possibility that the SNPs are species-specific features of the ABCB1 gene in Border Collies, and that the insertion mutation may be related to ivermectin intolerance.

Transient neonatal diabetes due to activating mutation in the ABCC8 gene encoding SUR1.

We report a 2 month male child presenting with diabetic ketoacidosis (DKA) and seizures treated with intravenous fluids and intravenous insulin infusion till the ketoacidosis was reversed, thereafter responding well to sulphonylureas and at age of 13 months going into complete remission. At age of 11 mo developmental delay in the form of negative neck holding and inability to sit without support was seen. The child is 3 yr of age now ,euglycemic without any insulin or oral hypoglycemic agents but has severe developmental delay. Genetic analysis was negative for mutations of KCNJ11, 6q24, Glucokinase and IPF-1 genes. A mutation R1183W was found in the ABCC8 gene encoding SUR1, which was the cause of neonatal diabetes in this case.