scholarly journals Variable Expressivity and Allelic Heterogeneity in Type 2 Familial Partial Lipodystrophy: The p.(Thr528Met) LMNA Variant

2021 ◽  
Vol 10 (7) ◽  
pp. 1497
Author(s):  
David Araújo-Vilar ◽  
Antía Fernández-Pombo ◽  
Berta Victoria-Martínez ◽  
Adrián Mosquera-Orgueira ◽  
Silvia Cobelo-Gómez ◽  
...  
Keyword(s):  
Intracellular Localization ◽  
Rare Condition ◽  
Lmna Gene ◽  
Partial Lipodystrophy ◽  
Anthropometric Features ◽  
Familial Partial Lipodystrophy ◽  
Exon 9 ◽  
Subcutaneous Adipose ◽  
Oil Red O Staining

Type 2 familial partial lipodystrophy, or Dunnigan disease, is a metabolic disorder characterized by abnormal subcutaneous adipose tissue distribution. This rare condition results from variants principally affecting exons 8 and 11 of the LMNA gene. In this study, five FPLD2-diagnosed patients carrying the c.1583C>T, p.(Thr528Met) variant in exon 9 of the LMNA gene and with obvious clinical heterogeneity were evaluated. Specific polymorphisms in LMNA and in PPARG were also detected. Exhaustive clinical course, physical examination, biochemical features and family history were recorded, along with the assessment of anthropometric features and body composition by dual-energy X-ray absorptiometry. Preadipocytes obtained from a T528M patient were treated with the classic adipose differentiation medium with pioglitazone. Various adipogenes were evaluated by real-time PCR, and immunofluorescence was used to study intracellular localization of emerin, lamin A and its precursors. As demonstrated with Oil red O staining, the preadipocytes of the T528M patient failed to differentiate, the expression of various adipogenic genes was reduced in the lipodystrophic patient and immunofluorescence studies showed an accumulation of farnesylated prelamin A in T528M cells. We conclude that the T528M variant in LMNA could lead to FPLD2, as the adipogenic machinery is compromised.

scholarly journals Familial Partial Lipodystrophy: A Case Study and Review of Recent Literature

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A308-A309
Author(s):  
Ali Tipu ◽  
Farhad Hasan ◽  
Michael Grimes
Keyword(s):  
Adipose Tissue ◽  
Autosomal Dominant ◽  
Recent Literature ◽  
Subcutaneous Fat ◽  
Metabolic Abnormalities ◽  
Partial Lipodystrophy ◽  
Type 2 Dm ◽  
Familial Partial Lipodystrophy ◽  
Subcutaneous Adipose

Abstract Introduction: Familial partial lipodystrophy (FPLD) is a rare genetic disorder characterized by loss of subcutaneous adipose tissue, mainly from the extremities and gluteal region. FPLD is associated with a variety of metabolic abnormalities including severe hypertriglyceridemia (HTG), insulin resistance (IR), and hepatic steatosis. We present a case of FPLD and summarize recent literature on the metabolic features and their management in patients with this rare disease. Case: A 44 year old female with medical history of Type 2 DM, hypertension, hypothyroidism and recurrent pancreatitis from severe HTG was referred to our clinic. She was diagnosed with Type 2 DM in her 30s. Over the ensuing years she had significant IR requiring increasing doses of concentrated insulin (up to 250 units/day). She reported progressive loss of subcutaneous fat from extremities in the preceding 2–3 years. She had recurrent pancreatitis, including a recent hospitalization with TG>8000 mg/dL. On examination, she had typical features of FPLD including loss of subcutaneous adipose tissue from upper and lower extremities including gluteal region, visible skeletal muscles and veins in the extremities, and neck and truncal obesity (Fig. 1). Family history was significant for similar physical and metabolic manifestations in her father and brother. For HTG, she is treated with fibrates and high intensity statin. We avoided the use of fish oil in the patient, because she did not feel well when she was previously on this. Results of the genetic testing are pending. Discussion: FPLD is rare, predominantly autosomal dominant, disorder characterized phenotypically by variable loss of subcutaneous fat and metabolically by severe HTG and insulin resistance. The severity of metabolic derangements is proportional to the degree of the lipodystrophy. The proposed mechanism is limited capacity of adipose tissue to store fat leading to ectopic fat deposition, lipotoxicity and vascular inflammation. Diagnosis is often clinical, especially the loss of subcutaneous fat in the extremities and signs of IR, and is confirmed by genetic testing. Dunnigan syndrome is the most common type of FPLD, which occurs from an autosomal dominant missense mutation in lamin A/C (LMNA). Gene mutations encoding for PPAR-gamma, Akt2, CIDEC, perilipin and the ZMPSTE 24 enzyme are much less common. Treatment of FPLD is challenging, and mostly focuses on managing the metabolic abnormalities. Recent evidence suggests that fish oil may in fact worsen HTG when the main defect driving increased TG is impaired chylomicron clearance, which our patient had on lipid NMR profile. Metreleptin, a human leptin analog, has recently been approved for the management of FPLD with evidence of improved metabolic abnormalities. Recent data also suggests that GLP1 agonists and SGLT2 inhibitors improved glycemic control and reduced daily insulin requirements.

scholarly journals Variable Expressivity in Type 2 Familial Partial Lipodystrophy Related to R482 and N466 Variants in the LMNA Gene

2021 ◽  
Vol 10 (6) ◽  
pp. 1259
Author(s):  
David Araújo-Vilar ◽  
Sofía Sánchez-Iglesias ◽  
Ana I. Castro ◽  
Silvia Cobelo-Gómez ◽  
Álvaro Hermida-Ameijeiras ◽  
...  
Keyword(s):  
Body Composition ◽  
Skinfold Thickness ◽  
Pathogenic Variant ◽  
The Other ◽  
Metabolic Abnormalities ◽  
Lmna Gene ◽  
Partial Lipodystrophy ◽  
Variable Expressivity ◽  
Familial Partial Lipodystrophy

Patients with Dunnigan disease (FPLD2) with a pathogenic variant affecting exon 8 of the LMNA gene are considered to have the classic disease, whereas those with variants in other exons manifest the “atypical” disease. The aim of this study was to investigate the degree of variable expressivity when comparing patients carrying the R482 and N466 variants in exon 8. Thus, 47 subjects with FPLD2 were studied: one group of 15 patients carrying the N466 variant and the other group of 32 patients with the R482 variant. Clinical, metabolic, and body composition data were compared between both groups. The thigh skinfold thickness was significantly decreased in the R482 group in comparison with the N466 group (4.2 ± 1.8 and 5.6 ± 2.0 mm, respectively, p = 0.002), with no other differences in body composition. Patients with the N466 variant showed higher triglyceride levels (177.5 [56–1937] vs. 130.0 [55–505] mg/dL, p = 0.029) and acute pancreatitis was only present in these subjects (20%). Other classic metabolic abnormalities related with the disease were present regardless of the pathogenic variant. Thus, although FPLD2 patients with the R482 and N466 variants share most of the classic characteristics, some phenotypic and metabolic differences suggest possible heterogeneity even within exon 8 of the LMNA gene.

scholarly journals Pathogenic Microenvironment from Diabetic–Obese Visceral and Subcutaneous Adipocytes Activating Differentiation of Human Healthy Preadipocytes Increases Intracellular Fat, Effect of the Apocarotenoid Crocetin

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1032
Author(s):  
Lesgui Alviz ◽  
David Tebar-García ◽  
Raquel Lopez-Rosa ◽  
Eva M. Galan-Moya ◽  
Natalia Moratalla-López ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Bioactive Components ◽  
Hypertrophic Growth ◽  
Visceral Adipose ◽  
Subcutaneous Adipose ◽  
Oil Red O Staining ◽  
Oil Red O ◽  
Excessive Accumulation

In diabetes mellitus type 2 (DM2), developed obesity is referred to as diabesity. Implementation of a healthy diet, such as the Mediterranean, prevents diabesity. Saffron is frequently used in this diet because of its bioactive components, such as crocetin (CCT), exhibit healthful properties. It is well known that obesity, defined as an excessive accumulation of fat, leads to cardiometabolic pathology through adiposopathy or hypertrophic growth of adipose tissue (AT).This is related to an impaired adipogenic process or death of adipocytes by obesogenic signals. We aimed to evaluate the effect of the pathogenic microenvironment and CCT, activating differentiation of healthy preadipocytes (PA). For this, we used human cryopreserved PA from visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) depots obtained from healthy and obese-DM2 donors. We studied the effect of a metabolically detrimental (diabesogenic) environment, generated by obese-DM2 adipocytes from VAT (VdDM) or SAT (SdDM), on the viability and accumulation of intracellular fat of adipocytes differentiated from healthy PA, in the presence or absence of CCT (1 or 10 μM). Intracellular fat was quantified by Oil Red O staining. Cytotoxicity was measured using the MTT assay. Our results showed that diabesogenic conditions induce cytotoxicity and provide a proadipogenic environment only for visceral PA. CCT at 10 μM acted as an antiadipogenic and cytoprotective compound.

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