A functional genomic framework to elucidate novel causal non-alcoholic fatty liver disease genes.

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver pathology in western countries, with serious public health consequences. Efforts to identify causal genes for NAFLD have been hampered by the relative paucity of human data from gold-standard magnetic resonance quantification of hepatic fat. To overcome insufficient sample size, genome-wide association studies using NAFLD surrogate phenotypes have been used, but only a small number of loci have been identified to date. In this study, we combined GWAS of NAFLD composite surrogate phenotypes with genetic colocalization studies followed by functional in vitro screens to identify bona fide causal genes for NAFLD. Approach & Results: We used the UK Biobank to explore the associations of our novel NAFLD score, and genetic colocalization to prioritize putative causal genes for in vitro validation. We created a functional genomic framework to study NAFLD genes in vitro using CRISPRi. Our data identify VKORC1, TNKS, LYPLAL1 and GPAM as regulators of lipid accumulation in hepatocytes and suggest the involvement of VKORC1 in the lipid storage related to the development of NAFLD. Conclusions: Complementary genetic and genomic approaches are useful for the identification of NAFLD genes. Our data supports VKORC1 as a bona fide NAFLD gene. We have established a functional genomic framework to study at scale putative novel NAFLD genes from human genetic association studies.

Association between +45T>G adiponectin polymorphism gene and type 2 diabetes mellitus and metabolic syndrome in a Venezuelan population.

Background: Adiponectin (ADIPOQ) is a hormone primarily synthesized by adipocytes and encoded by the ADIPOQ gene, which exerts anti-inflammatory, antiatheratogenic and insulin sensitizing functions. It has been shown that its plasma concentrations are decreased in individuals with metabolic syndrome (MS) and type 2 diabetes mellitus (DM2), which could be due to variations in the gene coding for this protein. The aim of this study was to detect the +45 T>G polymorphism of the ADIPOQ gene in subjects with DM2 and MS in Maracaibo municipality, Zulia state, Venezuela. Methods: A total of 90 subjects who attended the Center for Metabolic Endocrine Research "Dr. Félix Gómez" were enrolled for this study, 46 of which had MS-DM2 and 44 of which were healthy control individuals. Genomic DNA was extracted from blood samples and PCR-restriction fragment length polymorphism analysis was carried out for the promoter region of the ADIPOQ gene. Likewise, the +45 T> G polymorphism was identified and correlated with MS and DM2 in the studied population. Results: The most frequent allele in both groups was the T allele, and the predominant genotype was homozygous T/T (79%). Genotypes with heterozygous T/G and G/G homozygous polymorphism were more frequent in the control group than in the MS-DM2 group. Regarding the individuals with T/G and G/G genotypes, statistically significant lower mean values ​​were found for fasting glucose, total cholesterol, triacylglycerides, abdominal circumference, and for the medians of systolic and diastolic blood pressure. Odds ratio were calculated for the presence or absence of MS and DM2. Conclusions: The results suggested that the presence of the G allele exerts a protective effect on the carrier individuals, thus avoiding the appearance of the aforementioned metabolic alterations.

Polimorfismo 3’UTR +62G>A del gen RETN codificante de resistina y asociación con componentes del síndrome metabólico / 3’UTR +62G>A polymorphism of the RETN gene coding resistin and its association with metabolic syndrome components

Fundamento y objetivo: Diversos polimorfismos del gen de la resistina (RETN) se han asociado con alteraciones metabólicas. En este estudio se evaluó la asociación entre el polimorfismo 3’UTR +62G>A del genRETN y elementos del síndrome metabólico. Sujetos y método: La población de estudio (n = 218) fue distribuida en 3 grupos: control, sin alteraciones metabólicas (n = 77); AMnS, con alteraciones metabólicas aisladas (n = 94); y SM, con síndrome metabólico (n = 47). El polimorfismo 3’UTR +62G>A se analizó por PCR-RFLP. Resultados: La obesidad central fue la alteración más frecuentemente descrita tanto en el grupo AMnS (56,4%) como en el SM (91,5%), seguida de bajos niveles de colesterol unido a lipoproteínas de alta densidad (colesterol HDL) (42,6%) en el grupo AMnS e hipertensión arterial (85%) en el grupo SM. La frecuencia del genotipo +62G/A para la población fue del 20,2%. El genotipo G/A fue más frecuente en los grupos SM (38,3%) y AMnS (17%) que en el grupo control (13%). La distribución alélica fue significativamente diferente entre grupos control (+62G = 0,94, +62A = 0,06) y SM (+62G = 0,81, +62A = 0,19) (p = 0,0001). Se encontró asociación significativa entre el genotipo G/A y valores elevados de circunferencia abdominal (p = 0,047), glucemia basal (p = 0,02) y presión arterial sistólica (p = 0,003). Conclusión: Los resultados sugieren una asociación del genotipo RETN +62G/A con valores elevados de presión arterial sistólica, hiperglucemia y obesidad central. La asociación con estas alteraciones parece ser independiente de posibles efectos de agrupación en el contexto de síndrome metabólico (AU)

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[3'UTR +62G>A polymorphism of the RETN gene coding resistin and its association with metabolic syndrome components]. / Polimorfismo 3'UTR +62G>A del gen RETN codificante de resistina y asociación con componentes del síndrome metabólico.

BACKGROUND AND OBJECTIVE: The polymorphism of the resistin gene (RETN/RSTN) has been associated with metabolic alterations. In this study the association between the 3'UTR +62G>A polymorphism and metabolic syndrome components was evaluated. SUBJECTS AND METHODS: The population (n=218) was distributed in 3 groups: the control group with no metabolic alterations (n=77), nSMA group with isolated metabolic alterations (n=94) and MS group with metabolic syndrome (n=47). The 3'UTR +62G>A polymorphism was analyzed by PCR-RFLP. RESULTS: Central obesity was the most frequent alteration in both nSMA (56.4%) and MS (91.5%) groups followed by low c-HDL levels in the nSMA group (42.6%) and arterial hypertension in the MS group (85%). The frequency of the +62G/A genotype was 20.2% in the population. The G/A genotype was more frequently found in the MS (38.3%) and nSMA (17%) groups than in the control group (13%). The allelic distribution between the control group (+62G=0.94, +62A=0.06) and MS group (+62G=0.81, +62A=0.19) was significantly different (P=.0001). Significant associations between the G/A genotype and high values of abdominal circumference (P=.047), basal glycemia (P=.02) and systolic arterial pressure (P=.003) were found. CONCLUSION: The findings suggest the association between the G/A genotype and high values of systolic arterial pressure, basal glycemia and abdominal circumference. This association was independent of the metabolic syndrome context.

Evidence of zoonotic Chlamydophila psittaci transmission in a population at risk in Zulia state, Venezuela.

OBJECTIVE: This study was aimed at investigating the frequency of infection by Cp. psittaci and determining its genotype in individuals at potential risk of exposure to the bacteria. METHODOLOGY: The study involved 170 individuals: a risk group (n= 96) and a low-risk control group (n=74). Cp. psittaci was detected and genotyped by single-tube nested PCR and ompA gene sequencing. RESULTS: Eight (8.3 %) positive cases were detected in the risk group and 1 (1.4 %) in the control group (p<0.04). Cp. psittaci was found in 16.7 % of pigeons' fecal samples. Cp. psittaci infection with was more frequent in symptomatic (17.7 %) than asymptomatic (6.3 %) individuals in the risk group. Analysing the genomes isolated from human and bird specimens revealed the presence of genotype B. CONCLUSION: The presence of Cp. psittaci genotype B in the population being evaluated could have been attributed to zoonotic transmission from pigeons to humans, an underestimated potential public health problem in Venezuela requiring the health authorities' involvement.

Curable sexually transmitted infections among female sex workers in a population of Zulia State, Venezuela / Infecciones de transmisión sexual curables en trabajadoras sexuales en una población del estado Zulia, Venezuela

Sexually transmitted infections (STIs) represent a public health problem worldwide. The aim of this study was to investigate the prevalence of curable STIs caused by Neisseria gonorrhoeae, Chlamydia trachomatis and Ureaplasma urealyticum in female sex workers in a population from Zulia State, Venezuela. Seventy eight (78) women attended a health monitoring sanitary controls were evaluated, and PCR amplification assays were used to detect the three microorganisms in endocervical samples. In 33.3% of the samples, at least one microorganism was detected: U. urealyticum was found more frequently (25.6%), followed by N. gonorrhoeae (18%), and C. trachomatis (12.8%). A significant association between N. gonorrhoeae and C. trachomatis was found (p <0.0001). STIs cases represented 42.9% and 28% for symptomatic and asymptomatic groups, respectively. In the symptomatic group, N. gonorrhoeae was 2.4 times (28.6%) more frequent than in the asymptomatic one (12%) (p=0.015), particularly associated with mucopurulent discharge (p=0.025). No association was found between C. trachomatis (p=0.078), and U. urealyticum (p=0.432) with clinical manifestations. Prevalence of curable STIs in the study population was relatively low compared with other high-risk populations worldwide. The results support the possible association between C. trachomatis and N. gonorrhoeae, therefore, treatment would be indicated against both pathogens when one of them is detected in vulnerable populations.

Las infecciones de transmisión sexual (ITS) representan un problema de salud pública a nivel mundial. El objetivo de este estudio fue investigar la prevalencia de ITS curables causadas por Neisseria gonorrhoeae, Chlamydia trachomatis y Ureaplasma urealyticum en trabajadoras sexuales de una población del estado Zulia, Venezuela. Se evaluaron 78 mujeres que asistieron a jornadas de control sanitario y se utilizaron ensayos de amplificación por PCR para detectar los tres microorganismos en muestras endocervicales. En 33,3% de las muestras, se detectó al menos un microorganismo: U. urealyticum fue encontrado con mayor frecuencia (25,6%), seguido de N. gonorrhoeae (18%) y C. trachomatis (12,8%). Se encontró asociación significativa entre N. gonorrhoeae y C. trachomatis (p<0,0001). Los casos de ITS representaron porcentajes de 42% y 28% para los grupos sintomático y asintomático, respectivamente. N. gonorrhoeae fue 2,4 veces más frecuente en el grupo sintomático (28,6%) que en el asintomático (12%) (p=0,015), particularmente asociado con secreción mucopurulenta (p=0,025). No se encontró asociación entre C. trachomatis (p=0,078) y U. urealyticum (p=0,432) con manifestaciones clínicas. La prevalencia de ITS de la población en estudio fue relativamente baja comparada con otras poblaciones de alto riesgo a nivel mundial. Los resultados apoyan la posible asociación entre C. trachomatis y N. gonorrhoeae, por lo tanto se debería considerar el tratamiento contra ambos patógenos, cuando uno de ellos sea detectado en poblaciones vulnerables.

Novel mutations identification in exon 4 of LDLR gene in patients with moderate hypercholesterolemia in a Venezuelan population.

Familial hypercholesterolemia (FH) is an autosomal dominant disease characterized by increase in low-density lipoprotein (LDL) cholesterol levels and premature coronary artery disease. In Venezuela, the molecular basis of FH has not been characterized, thus, the aim of this study was to investigate mutations in the exon 4 of the LDLR (LDL-receptor) gene in 225 Venezuelan mixed race individuals (65 hypercholesterolemic and 160 normolipidemic). The exon 4 of the LDLR gene was screened by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. Additionally, ApoB-100 gene mutations were investigated. Different LDLR gene mutations were identified in 5 hypercholesterolemic patients (7.7%), 3 missense mutations (4.6%), and 2 frameshift mutations (3%). All mutations were heterozygous. The missense mutations included the amino acid substitution p.E180K, p.R194S, and p.C152G. The frameshift mutations are caused by insertions resulting in the creation of stop codons: p.D157fsX158 and p.S173fsX174, which could code for truncated LDLR of 157 and 173 amino acids, respectively. The apoB gene mutations were not detected in any of our patients and to our knowledge 4 mutations identified in this study have not been reported previously, this study being the first comprehensive mutation analysis of the LDLR causing FH in our region. The early identification of individuals at risk allows changes in lifestyle, including dietary intervention, followed by drug treatment.

Evidence of zoonotic Chlamydophila psittaci transmission in a population at risk in Zulia state, Venezuela / Evidencia de transmisión zoonótica de Chlamydophila psittacci en una población de riesgo del Estado Zulia, Venezuela

Objective This study was aimed at investigating the frequency of infection by Cp. psittaci and determining its genotype in individuals at potential risk of exposure to the bacteria. Methodology The study involved 170 individuals: a risk group (n= 96) and a low-risk control group (n=74). Cp. psittaci was detected and genotyped by single-tube nested PCR and ompA gene sequencing. Results Eight (8.3 %) positive cases were detected in the risk group and 1 (1.4 %) in the control group (p<0.04). Cp. psittaci was found in 16.7 % of pigeons' fecal samples. Cp. psittaci infection with was more frequent in symptomatic (17.7 %) than asymptomatic (6.3 %) individuals in the risk group. Analysing the genomes isolated from human and bird specimens revealed the presence of genotype B. Conclusion The presence of Cp. psittaci genotype B in the population being evaluated could have been attributed to zoonotic transmission from pigeons to humans, an underestimated potential public health problem in Venezuela requiring the health authorities' involvement.

Objetivo El objetivo de este estudio fue investigar la frecuencia de infecciones por Cp. psittaci y determinar su genotipo en individuos con potencial riesgo de exposición a la bacteria. Metodología Se incluyeron 170 individuos, un grupo de riesgo (n=96) y un grupo control (n=74). La detección y genotipificación de Cp. psittaci se llevó a cabo por PCR anidada y secuenciación del gen ompA. Resultados Se detectaron ocho (8,3 %) casos positivos en el grupo de riesgo y 1 (1,35 %) en el grupo control (p<0,04). Cp. psittaci fue detectada en 16,7 % muestras fecales de palomas. En el grupo de riesgo, la frecuencia de infección por Cp. psittaci fue 17,7 % en individuos sintomáticos y 6,3% en asintomáticos. El análisis de los genomas aislados de muestras humanas y aves, revelaron la presencia del genotipo B. Conclusión La presencia de Cp. psittaci genotipo B en la población evaluada podría ser atribuida a transmisión zoonótica de palomas a humanos, un potencial problema de salud pública en nuestra región que requiere la intervención de autoridades sanitarias.