Mutación DGAT1 en dos hermanas con falla de medro: reporte de caso / DGAT1 mutation in two sisters with failure to thrive: a case report

Las diarreas y enteropatías congénitas (CODE por su sigla en inglés) son un grupo de trastornos monogénicos que se han descrito en los últimos años. Dentro de las CODE, la mutación del gen de la diacilglicerol o-aciltransferasa 1 (DGAT1) es un trastorno enzimático poco común asociado con diarrea crónica grave de aparición temprana. El objetivo es presentar a dos hermanas que consultaron por diarrea crónica, retraso en el crecimiento, vómitos e hipoalbuminemia en la primera infancia. En ambas pacientes se encontró un compuesto heterocigota de la mutación del DGAT1. Esta mutación se describió previamente en la población asiática; sin embargo, estas son las dos primeras pacientes en tener esta mutación en la población latinoamericana. Estos dos casos pueden ampliar nuestro conocimiento sobre las diarreas congénitas en general y las características clínicas de los pacientes con mutaciones en DGAT1 en particular.

Congenital diarrhea and enteropathies (CODEs) are a group of monogenic disorders that have been described in recent years. Within the CODEs, the mutation in the diacylglycerol O-acyltransferase 1 (DGAT1) gene is a rare enzyme disorder associated with severe, early-onset chronic diarrhea. Our objective is to describe the case of 2 sisters who consulted for chronic diarrhea, growth retardation, vomiting, and hypoalbuminemia in early childhood. A compound heterozygous DGAT1 mutation was found in both patients. This mutation was previously described in the Asian population; however, these are the first 2 patients to show this mutation in the Latin American population. These 2 cases may expand our knowledge about congenital diarrhea in general and the clinical characteristics of patients with DGAT1 mutations in particular.

PF-04620110, a Potent Antidiabetic Agent, Suppresses Fatty Acid-Induced NLRP3 Inflammasome Activation in Macrophages

BACKGROUND: Chronic inflammation has been linked to insulin resistance and type 2 diabetes mellitus (T2DM). High-fat diet (HFD)-derived fatty acid is associated with the activation of chronic inflammation in T2DM. PF-04620110, which is currently in phase 1 clinical trials as a selective acyl-CoA:diacylglycerol acyltransferase-1 (DGAT1) inhibitor, is a potent anti-diabetic agent that may be important for the regulation of chronic inflammation in T2DM. However, the mechanisms by which PF-04620110 regulates fatty acid-induced chronic inflammation remain unclear. METHODS: PF-04620110 was used in vitro and in vivo. DGAT1-targeting gRNAs were used for deletion of mouse DGAT1 via CRISPR ribonucleoprotein (RNP) system. The activation of NLRP3 inflammasome was measured by immunoblot or cytokine analysis in vitro and in vivo. RESULTS: Here we show that PF-04620110 suppressed fatty acid-induced nucleotide-binding domain, leucine-rich-repeat-containing receptor (NLR), pyrin-domain-containing 3 (NLRP3) inflammasome activation in macrophages. In contrast, PF-04620110 did not change the activation of the NLR family, CARD-domain-containing 4 (NLRC4), or the absent in melanoma 2 (AIM2) inflammasomes. Moreover, PF-04620110 inhibited K⁺ efflux and the NLRP3 inflammasome complex formation, which are required for NLRP3 inflammasome activation. PF-04620110 reduced the production of interleukin 1β (IL-1β) and IL-18 and blood glucose levels in the plasma of mice fed HFD. Furthermore, genetic inhibition of DGAT1 suppressed fatty acid-induced NLRP3 inflammasome activation. CONCLUSION: Our results suggest that PF-04620110 suppresses fatty acid-induced NLRP3 inflammasome activation.

Triglyceride-Rich Lipoproteins and Novel Targets for Anti-atherosclerotic Therapy

Although elevated serum low-density lipoprotein-cholesterol (LDL-C) is without any doubts accepted as an important risk factor for cardiovascular disease (CVD), the role of elevated triglycerides (TGs)-rich lipoproteins as an independent risk factor has until recently been quite controversial. Recent data strongly suggest that elevated TG-rich lipoproteins are an independent risk factor for CVD and that therapeutic targeting of them could possibly provide further benefit in reducing CVD morbidity, events and mortality, apart from LDL-C lowering. Today elevated TGs are treated with lifestyle interventions, and with fibrates which could be combined with omega-3 fatty acids. There are also some new drugs. Volanesorsen, is an antisense oligonucleotid that inhibits the production of the Apo C-III which is crucial in regulating TGs metabolism because it inhibits lipoprotein lipase (LPL) and hepatic lipase activity but also hepatic uptake of TGs-rich particles. Evinacumab is a monoclonal antibody against angiopoietin-like protein 3 (ANGPTL3) and it seems that it can substantially lower elevated TGs levels because ANGPTL3 also regulates TGs metabolism. Pemafibrate is a selective peroxisome proliferator-activated receptor alpha modulator which also decreases TGs, and improves other lipid parameters. It seems that it also has some other possible antiatherogenic effects. Alipogene tiparvovec is a nonreplicating adeno-associated viral vector that delivers copies of the LPL gene to muscle tissue which accelerates the clearance of TG-rich lipoproteins thus decreasing extremely high TGs levels. Pradigastat is a novel diacylglycerol acyltransferase 1 inhibitor which substantially reduces extremely high TGs levels and appears to be promising in treatment of the rare familial chylomicronemia syndrome.

Analysis of the population structure of Uruguayan Creole cattle as inferred from milk major gene polymorphisms

The ancestors of Uruguayan Creole cattle were introduced by the Spanish conquerors in the XVII century, following which the population grew extensively and became semi-feral before the introduction of selected breeds. Today the Uruguayan Creole cattle genetic reserve consists of 575 animals. We used the tetra primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR) to analyze the kappa-casein, beta-casein, alphaS1-casein and alpha-lactoalbumin gene polymorphisms and restriction fragment length polymorphism PCR (RFLP-PCR) for the beta-lactoglobulin and the acylCoA:diacyl glycerol acyltransferase 1 (DGAT1) genes. The kappa-casein and beta-lactoglobulin genes presented very similar A and B allele frequencies, while the alphas1-casein and alpha-lactoalbumin gene B alleles showed much higher frequencies than the corresponding A alleles. The beta-casein B allele was not found in the population sampled. There was a very high frequency of the DGAT1 gene A allele which is associated with low milk fat content and high milk yield. All loci were in Hardy-Weinberg equilibrium and the level of heterozygosity agreed with the high genetic diversity observed in a previous analysis of this population. Preservation of the allelic richness observed in the Uruguayan Creole cattle should be considered for future dairy management and livestock genetic improvement. The results also emphasize the value of the tetra primers ARMS-PCR technique as a rapid, easy and economical way of genotyping cattle breeds for milk gene single nucleotide polymorphisms.

DGAT1 K232A polymorphism in Brazilian cattle breeds

Recent reports identified DGAT1 (EC 2.3.1.20) harboring a lysine to alanine substitution (K232A) as a candidate gene with a strong effect on milk production traits. Our objective was to estimate the frequency of the DGAT1 K232A polymorphism in the main Zebu and Taurine breeds in Brazil as well as in Zebu x Taurine crossbreds as a potential QTL for marker-assisted selection. Samples of 331 animals from the main Brazilian breeds, Nellore, Guzerat, Red Sindhi, Gyr, Holstein, and Gyr x Holstein F1 were genotyped for DGAT1 K232A polymorphism (A and K alleles) using the PCR-RFLP technique. The highest frequency of the A allele was found in the Holstein sample (73%) followed by Gyr x Holstein F1 (39%). Gyr and Red Sindhi showed low frequencies of A alleles (4 and 2.5%, respectively). The A allele was not found in the Nellore and Guzerat samples. Our results could be used to guide association studies between this locus and milk traits in these breeds.