scholarly journals Protection against Glucolipotoxicity by High Density Lipoprotein in Human PANC-1 Hybrid 1.1B4 Pancreatic Beta Cells: The Role of microRNA

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 218
Author(s):  
Jamie M.R. Tarlton ◽  
Richard J. Lightbody ◽  
Steven Patterson ◽  
Annette Graham

High-density lipoproteins provide protection against the damaging effects of glucolipotoxicity in beta cells, a factor which sustains insulin secretion and staves off onset of type 2 diabetes mellitus. This study examines epigenetic changes in small non-coding microRNA sequences induced by high density lipoproteins in a human hybrid beta cell model, and tests the impact of delivery of a single sequence in protecting against glucolipotoxicity. Human PANC-1.1B4 cells were used to establish Bmax and Kd for [3H]cholesterol efflux to high density lipoprotein, and minimum concentrations required to protect cell viability and reduce apoptosis to 30mM glucose and 0.25 mM palmitic acid. Microchip array identified the microRNA signature associated with high density lipoprotein treatment, and one sequence, hsa-miR-21-5p, modulated via delivery of a mimic and inhibitor. The results confirm that low concentrations of high-density lipoprotein can protect against glucolipotoxicity, and report the global microRNA profile associated with this lipoprotein; delivery of miR-21-5p mimic altered gene targets, similar to high density lipoprotein, but could not provide sufficient protection against glucolipotoxicity. We conclude that the complex profile of microRNA changes due to HDL treatment may be difficult to replicate using a single microRNA, findings which may inform current drug strategies focused on this approach.

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 857
Author(s):  
Josep Julve ◽  
Joan Carles Escolà-Gil

Epidemiological studies have shown that low levels of plasma high-density lipoprotein cholesterol (HDL-C) are associated with increased atherosclerotic cardiovascular disease (CVD) [...]


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 764
Author(s):  
Arianna Strazzella ◽  
Alice Ossoli ◽  
Laura Calabresi

Dyslipidemia is a typical trait of patients with chronic kidney disease (CKD) and it is typically characterized by reduced high-density lipoprotein (HDL)-cholesterol(c) levels. The low HDL-c concentration is the only lipid alteration associated with the progression of renal disease in mild-to-moderate CKD patients. Plasma HDL levels are not only reduced but also characterized by alterations in composition and structure, which are responsible for the loss of atheroprotective functions, like the ability to promote cholesterol efflux from peripheral cells and antioxidant and anti-inflammatory proprieties. The interconnection between HDL and renal function is confirmed by the fact that genetic HDL defects can lead to kidney disease; in fact, mutations in apoA-I, apoE, apoL, and lecithin–cholesterol acyltransferase (LCAT) are associated with the development of renal damage. Genetic LCAT deficiency is the most emblematic case and represents a unique tool to evaluate the impact of alterations in the HDL system on the progression of renal disease. Lipid abnormalities detected in LCAT-deficient carriers mirror the ones observed in CKD patients, which indeed present an acquired LCAT deficiency. In this context, circulating LCAT levels predict CKD progression in individuals at early stages of renal dysfunction and in the general population. This review summarizes the main alterations of HDL in CKD, focusing on the latest update of acquired and genetic LCAT defects associated with the progression of renal disease.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Scott M Gordon ◽  
Catherine A Reardon ◽  
Godfrey S Getz ◽  
W S Davidson

High density lipoproteins (HDL) are a highly heterogeneous population of particles composed of various lipids and proteins. They have been demonstrated to possess a diverse variety of functional properties which are thought to contribute to protection against cardiovascular disease (CVD). Proteomics studies have identified up to 75 different proteins which can associate with HDL. The basis for the compositional diversity of HDL is not known but a better understanding will yield important information about its broad functional diversity. To investigate the impact of common HDL apolipoproteins on the distribution of other apolipoproteins, we have begun to systematically fractionate plasma from various HDL apolipoprotein KO mice. Plasma from apoA-I, apoA-IV and apoA-II global KO mice was applied to gel filtration chromatography to distinguish HDL size populations. HDL particles sequestered by a phospholipid binding resin were proteomically analyzed by electrospray ionization mass spectrometry. By comparing elution volume shifts (i.e. particle size variations) for each HDL protein between WT controls and the KO models, we assessed the impact of the deleted protein on HDL size distributions. Ablation of apoA-I, while decreasing total HDL phospholipid by 70%, had a surprisingly small impact on the distribution of the majority of other HDL associated proteins - affecting only 9 of them. Genetic apoA-IV ablation had a similar modest effect shifting a distinct subset of 9 proteins. However, loss of apoA-II, in addition to causing a similar 70% reduction in overall HDL phospholipids, affected the size distribution of some 45 HDL proteins (including several complement proteins and paraoxonase-1). These data suggest that apoA-I, while associated with the majority of HDL phospholipid, may actually interact with relatively few of the lower abundance proteins known to be associated with HDL. ApoA-II on the other hand, may interact with many of these, perhaps acting as a docking site or adaptor molecule.


1980 ◽  
Vol 26 (9) ◽  
pp. 1275-1277 ◽  
Author(s):  
Y Yamaguchi

Abstract I describe a method for measuring high-density lipoprotein phospholipids. Magnesium chloride and dextran sulfate are used to precipitate all low-density and very-low-density lipoproteins. The supernate contains only high-density lipoproteins, the phospholipid concentration of which is determined by an enzymic method. The precision of the method (CV) is 2.35% (10 repeated assays), and the mean value for HDL-phospholipids was 1006 (SD 248) mg/L for 30 apparently healthy subjects. I used electrophoresis and enzymic color development to confirm the presence of HDL-phospholipids. Results are compared with those obtained by an ultracentrifugation method.


2017 ◽  
Vol 242 (12) ◽  
pp. 1244-1253 ◽  
Author(s):  
Eric Soupene ◽  
Sandra K Larkin ◽  
Frans A Kuypers

In sickle cell disease (SCD), alterations of cholesterol metabolism is in part related to abnormal levels and activity of plasma proteins such as lecithin cholesterol acyltransferase (LCAT), and apolipoprotein A-I (ApoA-I). In addition, the size distribution of ApoA-I high density lipoproteins (HDL) differs from normal blood. The ratio of the amount of HDL2 particle relative to the smaller higher density pre-β HDL (HDL3) particle was shifted toward HDL2. This lipoprotein imbalance is exacerbated during acute vaso-occlusive episodes (VOE) as the relative levels of HDL3 decrease. HDL3 deficiency in SCD plasma was found to relate to a slower ApoA-I exchange rate, which suggests an impaired ABCA1-mediated cholesterol efflux in SCD. HDL2 isolated from SCD plasma displayed an antioxidant capacity normally associated with HDL3, providing evidence for a change in function of HDL2 in SCD as compared to HDL2 in normal plasma. Although SCD plasma is depleted in HDL3, this altered capacity of HDL2 could account for the lack of difference in pro-inflammatory HDL levels in SCD as compared to normal. Exposure of human umbilical vein endothelial cells to HDL2 isolated from SCD plasma resulted in higher mRNA levels of the acute phase protein long pentraxin 3 (PTX3) as compared to incubation with HDL2 from control plasma. Addition of the heme-scavenger hemopexin protein prevented increased expression of PTX3 in sickle HDL2-treated cells. These findings suggest that ApoA-I lipoprotein composition and functions are altered in SCD plasma, and that whole blood transfusion may be considered as a blood replacement therapy in SCD. Impact statement Our study adds to the growing evidence that the dysfunctional red blood cell (RBC) in sickle cell disease (SCD) affects the plasma environment, which contributes significantly in the vasculopathy that defines the disease. Remodeling of anti-inflammatory high density lipoprotein (HDL) to pro-inflammatory entities can occur during the acute phase response. SCD plasma is depleted of the pre-β particle (HDL3), which is essential for stimulation of reverse cholesterol from macrophages, and the function of the larger HDL2 particle is altered. These dysfunctions are exacerbated during vaso-occlusive episodes. Interaction of lipoproteins with endothelium increases formation of inflammatory mediators, a process counteracted by the heme-scavenger hemopexin. This links hemolysis to lipoprotein-mediated inflammation in SCD, and hemopexin treatment could be considered. The use of RBC concentrates in transfusion therapy of SCD patients underestimates the importance of the dysfunctional plasma compartment, and transfusion of whole blood or plasma may be warranted.


Angiology ◽  
2009 ◽  
Vol 60 (5) ◽  
pp. 644-649 ◽  
Author(s):  
Thomas F. Whayne

High-density lipoproteins are regarded as “good guys” but not always. Situations involving high-density lipoproteins are discussed and medication results are considered. Clinicians usually consider high-density lipoprotein cholesterol. Nicotinic acid is the best available medication to elevate high-density lipoprotein cholesterol and this appears beneficial for cardiovascular risk. The major problem with nicotinic acid is that many patients do not tolerate the associated flushing. Laropiprant decreases this flushing and has an approval in Europe but not in the United States. The most potent medications for increasing high-density lipoprotein cholesterol are cholesteryl ester transfer protein inhibitors. The initial drug in this class, torcetrapib, was eliminated by excess cardiovascular problems. Two newer cholesteryl ester transfer protein inhibitors, R1658 and anacetrapib, initially appear promising. High-density lipoprotein cholesterol may play an important role in improving cardiovascular risk in the 60% of patients who do not receive cardiovascular mortality/morbidity benefit from low-density lipoproteins reduction by statins.


1995 ◽  
Vol 88 (3) ◽  
pp. 311-318 ◽  
Author(s):  
Richard H. Neary ◽  
Mark D. Kilby ◽  
Padma Kumpatula ◽  
Francis L. Game ◽  
Deepak Bhatnagar ◽  
...  

1. Lipid, apolipoprotein concentration and composition were determined in maternal venous and umbilical arterial and venous blood at delivery by elective Caesarean section in 13 full-term pregnancies and in 25 healthy non-pregnant females. The indications of Caesarean section were a previous Caesarean section or breech presentation. None of the women was in labour and there were no other complications of pregnancy or fetal distress. 2. The objectives of the study were to establish whether the placenta has a role in feto-maternal cholesterol metabolism through either synthesis or transplacental cholesterol flux. The potential for free cholesterol diffusion between mother and fetus and rates of cholesterol esterification and transfer between lipoproteins were determined and related to the differences in composition between fetal and maternal lipoproteins. 3. Pregnant women had raised levels of all lipid and lipoprotein fractions compared with control subjects. The greatest increases were in free cholesterol and triacylglycerol (P < 0.0001). Lipoprotein (a) levels were significantly greater in the pregnant women [112(12.2) mg/l] than in the control women [50 (10.0) mg/l]. 4. The only significant correlation between maternal and fetal lipoprotein concentrations was in lipoprotein (a) levels (r = 0.791, P = 0.002). In both umbilical venous and arterial blood, concentrations of very-low- and low-density lipoproteins, particularly apolipoprotein B, cholesteryl ester and triacylglycerol, were lower than in maternal blood (P < 0.0001), but high-density lipoprotein levels were similar. 5. There was no umbilical arteriovenous differences in lipoprotein concentration or composition. This suggests that cholesterol synthesis or free cholesterol diffusion does not occur in the placenta. The relative concentrations of free cholesterol to phospholipid in maternal and fetal lipoproteins do not indicate the existence of a concentration gradient favouring free cholesterol diffusion across the placenta. 6. The esterification of free cholesterol was significantly reduced in maternal [17.7 (2.4) μmol h−1 l−1, P < 0.001] and fetal [6.7 (3.5) μmol h−1 l−1, P < 0.0001] compared with control [40.9 (13.2) μmol h−1 l−1] blood. 7. In fetal compared with maternal high-density lipoproteins the ratios cholesteryl ester/apoliproprotein A-I [0.84 (0.35) versus 0.40 (0.05), P < 0.01] and phospholipid/apolipoprotein A-I [1.66 (0.14) versus 0.58 (0.10), P < 0.0001] indicated lipid enrichment of these particles in the fetus. 8. Lipid enrichment of high-density lipoprotein is due in part to a marked reduction in transfer of cholesteryl ester in the fetus [1.0 (0.6) μmol h−1 l−1] compared with maternal [6.15 (1.3) μmol h−1 l−1, P = 0.004] and control [17.3 (7.2) μmol h−1 l−1, P < 0.0001] blood. 9. In conclusion, there was no evidence for involvement of the placenta in cholesterol metabolism during pregnancy. In fetal life high-density lipoproteins are lipid rich, partly because of a reduction in transfer of esterified cholesterol to other particles. Maternal and fetal lipoprotein levels are not correlated, although the results suggested that lipoprotein (a) levels may be related.


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