Face-sparing Congenital Generalized Lipodystrophy Type 1 Associated With Nonclassical Congenital Adrenal Hyperplasia

Lysophosphatidic acid triggers inflammation in the liver and white adipose tissue in rat models of 1-acyl-sn-glycerol-3-phosphate acyltransferase 2 deficiency and overnutrition

AGPAT2 (1-acyl-sn-glycerol-3-phosphate-acyltransferase-2) converts lysophosphatidic acid (LPA) into phosphatidic acid (PA), and mutations of the AGPAT2 gene cause the most common form of congenital generalized lipodystrophy which leads to steatohepatitis. The underlying mechanism by which AGPAT2 deficiency leads to lipodystrophy and steatohepatitis has not been elucidated. We addressed this question using an antisense oligonucleotide (ASO) to knockdown expression of Agpat2 in the liver and white adipose tissue (WAT) of adult male Sprague-Dawley rats. Agpat2 ASO treatment induced lipodystrophy and inflammation in WAT and the liver, which was associated with increased LPA content in both tissues, whereas PA content was unchanged. We found that a controlled-release mitochondrial protonophore (CRMP) prevented LPA accumulation and inflammation in WAT whereas an ASO against glycerol-3-phosphate acyltransferase, mitochondrial (Gpam) prevented LPA content and inflammation in the liver in Agpat2 ASO-treated rats. In addition, we show that overnutrition, due to high sucrose feeding, resulted in increased hepatic LPA content and increased activated macrophage content which were both abrogated with Gpam ASO treatment. Taken together, these data identify LPA as a key mediator of liver and WAT inflammation and lipodystrophy due to AGPAT2 deficiency as well as liver inflammation due to overnutrition and identify LPA as a potential therapeutic target to ameliorate these conditions.

Role of Different Members of the AGPAT Gene Family in Milk Fat Synthesis in Bubalus bubalis

During triacylglycerol synthesis, the acylglycerol-3-phosphate acyltransferase (AGPAT) family catalyzes the conversion of lysophosphatidic acid to phosphatidic acid and the acylation of sn-2 fatty acids. However, the catalytic activity of different AGPAT members is different. Therefore, this study aimed to investigate the mechanism through which different AGPATs affect the efficiency of TAG synthesis and fatty acid composition. The conservation of amino acid sequences and protein domains of the AGPAT family was analyzed, and the functions of AGPAT1, AGPAT3, and AGPAT4 genes in buffalo mammary epithelial cells (BMECs) were studied using RNA interference and gene overexpression. Prediction of the protein tertiary structure of the AGPAT family demonstrated that four conservative motifs (motif1, motif2, motif3, and motif6) formed a hydrophobic pocket in AGPAT proteins, except AGPAT6. According to cytological studies, AGPAT1, AGPAT3, and AGPAT4 were found to promote the synthesis and fatty acid compositions of triacylglycerol, especially UFA compositions of triacylglycerol, by regulating ACSL1, FASN, GPAM, DGAT2, and PPARG gene expression. This study provides new insights into the role of different AGPAT gene family members involved in TAG synthesis, and a reference for improving the fatty acid composition of milk.

Is it possible to achieve an acceptable disease control by dietary therapy alone in Berardinelli Seip type 1? Experience from a case report

Background and objective

Severe metabolic complications generally manifest at an early age in Berardinelli - Seip congenital lipodystrophy (BSCL) and their management is especially challenging. Nutritional intervention with low lipid diets is considered by experts to be fundamental in treating the disease when associated with medical therapy, however little is known about the beneficial effects of dietary interventions alone.

Aim

To underline the importance of a well-structured low-fat diet in BSCL patients.

Methods and results

A BSCL male patient strictly followed a hypocaloric hypolipemic diet (60% carbohydrates, 22% fats and 18% proteins) since clinical diagnosis at the age of one year. Interestingly, pharmacological interventions were not required at any point during the follow-up. Aged 16 years the patient was referred to our center. Biochemistry, hormonal evaluation, 75 mg oral glucose tolerance test, cardiac evaluation and abdominal ultrasound were performed, revealing no abnormalities. Genetic analysis and leptin dosage were carried out, confirming the diagnosis of BSCL type 1 (homozygosity for c.493-1G>C pathogenic variant in AGPAT2 gene) and showing undetectable circulating levels of leptin (< 0.2 mcg/L). Diet therapy alone was therefore maintained, scheduling follow-up visits every six months, with acceptable disease control ever since.

Conclusions

This report proves how a low-fat diet is of great help in the management of BSCL and its complications. In addition, a specific hypolipemic diet could be used alone as an effective treatment in selected cases with high compliance and, probably, a milder phenotype.