484 Echocardiographic patterns in patients with apolipoprotein AI amyloidosis

Aims Hereditary amyloidosis are rare diseases characterized by extracellular deposition of insoluble fibril proteins in target organs disrupting their structure and function. The APOA1 gene encodes the precursor of apolipoprotein AI (ApoAI), whose mature form is the major component of high-density lipoproteins. There are some clusters of ApoAI amyloidosis (AApoAI) worldwide, including in the Lombardy and Veneto regions. Patients with AApoAI often present with chronic kidney disease, liver and spleen enlargement, with occasional involvement of the heart, peripheral nervous system, and other organs. Patterns of cardiac disease in AApoAI have never been systematically investigated. Methods and results We examined all patients with an established diagnosis of AApoAI referred to a dedicated outpatient clinic in Brescia from 2010 to 2020. The cardiac screening included a transthoracic echocardiogram with 2D speckle-tracking analysis. One-hundred and eighty-nine patients were evaluated [n = 102 (54%) men, median age 55 years (interquartile range 42–67)]. Renal disease was present in 39% and liver disease in 31%. Almost all patients were in sinus rhythm (96%). Median left ventricular ejection fraction (LVEF) was 60% (55–66), and just 2% of patients had LVEF <50%. Diastolic function was preserved, with E/e′ ratio of 7 (6–10). Overall, patients did not display a prominent LV hypertrophy, with median interventricular septal thickness of 11 mm (9–12), a posterior wall thickness of 9 mm (8–11), and a LV mass index of 92 g/m2 (74–111). Global longitudinal strain [−19% (−21 to − 17)], and the mass to strain ratio (MSR) [10.0 (6.8–12.1)] were within normal limits. Ten percent of patients displayed apical sparing, and 19% had a ‘granular sparkling’ appearance of the interventricular septum, which are both echocardiographic red flags of cardiac amyloidosis. Right ventricular (RV) function was preserved [median tricuspid annular plane systolic excursion of 23 mm (20–26)], with a borderline RV free wall thickness [6 mm (5–8)]. A pericardial effusion was present in 11%. Moderate to severe mitral, aortic or tricuspid regurgitation or aortic stenosis were found in 11%, 4%, 6% and no patients, respectively. We found moderately strong correlations between age and several echocardiographic findings, namely: IVS (P < 0.001, r = 0.484), LVMI (P < 0.001, r = 0.459), E/e′ (P < 0.001, r = 0.501), and RV free wall thickness (P < 0.001, r = 0.459). Absolute GLS tended to decrease with age (P < 0.001, r = 0.380), and MSR to increase (P < 0.001, r = 0.357). Conclusions In the largest series of patients with AApoAI so far, minor signs of cardiac disease emerged from transthoracic echocardiography. Nonetheless, some red flags of cardiac amyloidosis were found in some patients. Furthermore, the correlations between age and echocardiographic findings suggested a progressive increase in wall thickness, a decline in systolic and diastolic function, and a greater uncoupling between LV mass and contractility over time.

CRISPR/dCas9 Transcriptional Activation of Endogenous Apolipoprotein AI and Paraoxonase 1 in Enterocytes Alleviates Endothelial Cell Dysfunction

Atherosclerosis is the main cause of cardiovascular diseases with high prevalence worldwide. A promising therapeutic strategy to reverse atherosclerotic process is to improve the athero-protective potential of high-density lipoproteins (HDL). Since the small intestine is a source of HDL, we aimed to activate transcription of the endogenous HDL major proteins, apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1), in enterocytes, and to evaluate their potential to correct the pro-inflammatory status of endothelial cells (EC). Caco-2 enterocytes were transfected with CRISPR activation plasmids targeting ApoAI or PON1, and their gene and protein expression were measured in cells and conditioned medium (CM). ATP binding cassette A1 and G8 transporters (ABCA1, ABCG8), scavenger receptor BI (SR-BI), and transcription regulators peroxisome proliferator-activated receptor γ (PPARγ), liver X receptors (LXRs), and sirtuin-1 (SIRT1) were assessed. Anti-inflammatory effects of CM from transfected enterocytes were estimated through its ability to inhibit tumor necrosis factor α (TNFα) activation of EC. Transcriptional activation of ApoAI or PON1 in enterocytes induces: (i) increase of their gene and protein expression, and secretion in CM; (ii) stimulation of ABCA1/G8 and SR-BI; (iii) upregulation of PPARγ, LXRs, and SIRT1. CM from transfected enterocytes attenuated the TNFα-induced inflammatory and oxidative stress in EC, by decreasing TNF receptor 1, monocyte chemoattractant protein-1, and p22phox. In conclusion, transcriptional activation of endogenous ApoAI or PON1 in enterocytes by CRISPR/dCas9 system is a realistic approach to stimulate biogenesis and function of major HDL proteins which can regulate cholesterol efflux transporters and reduce the inflammatory stress in activated EC.

Differential Expression of the Apolipoprotein AI Gene in Spotnape Ponyfish (Nuchequula nuchalis) Inhabiting Different Salinity Ranges at the Top of the Estuary and in the Deep-Bay Area of Gwangyang Bay, South Korea

Spotnape ponyfish (Nuchequula nuchalis) is a dominant species that is broadly distributed from estuarine to deep-bay areas, reflecting a euryhaline habitat. Apolipoprotein AI (ApoAI) is a main component of plasma lipoproteins and has crucial roles in lipid metabolism and the defense immune system. In this study, we characterized the N. nuchalis ApoAI gene and analyzed the expression of the ApoAI transcript in N. nuchalis collected at various sites in the estuary and the deep-bay area which have different salinities. Owing to the fish’s mobility, we conducted stable isotope analyses to confirm the habitat characteristics of N. nuchalis. Carbon and nitrogen isotope ratios (δ13C and δ15N) from N. nuchalis indicated different feeding sources and trophic levels in the estuarine and deep-bay habitats. The characterized N. nuchalis ApoAI displayed residual repeats that formed a pair of alpha helices, indicating that the protein belongs to the apolipoprotein family. In the phylogenetic analysis, there was no sister group of N. nuchalis ApoAI among the large clades of fish species. The transcriptional expression level of ApoAI was higher in N. nuchalis inhabiting the deep-bay area with a high salinity (over 31 psu) than in N. nuchalis inhabiting the top of the estuary with a low salinity (6~15 psu). In addition, the expression patterns of N. nuchalis ApoAI were positively correlated with environmental factors (transparency, pH, TC, and TIC) in the high salinity area. These results suggest that ApoAI gene expression can reflect habitat characteristics of N. nuchalis which traverse broad salinity ranges and is associated with functional roles of osmoregulation and lipid metabolism for fish growth and development.

Relationship Between Hyperuricemia and Apolipoprotein AI in Chinese Healthy People: a Cohort Study

Background: Hyperuricemia is an independent risk factor for various cardiovascular diseases. However the association of plasma uric acid and Apolipoprotein AI among Chinese healthy people is still unclear.Aims: To evaluate the relationship between blood uric acid and Apolipoprotein AI level in Chinese healthy people. Method; A total of 3501 normal healthy subjects who were undergone physical examination were divided into hyperuricemia (HUA) group and normouricemia (NUA) group.Result: Apo AI (1.33±0.21 vs. 1.47±0.26) and HDL-c (1.12±0.27 vs. 1.36±0.33)decreased significantly in HUA group than NUA group. LDL-C(2.81±0.77 vs. 2.69±0.73),Apo B(0.96±0.20 vs. 0.89±0.20), FBG(5.48±0.48 vs. 5.36±0.48) and HOMA-IR(2.75（1.92-3.91）vs. 2.18（1.50-3.12）) was significantly higher in HAU group than NUA group. Increased plasma UA was correlated with decreased HDL-c(r=-0.289, P<0.01 ) and Apo AI(r=-0.236, p<0.01) .Conclusion: Hyperuricemia was associated with decreased plasma Apolipoprotein AI and HDL-c. Inhibiting Apolipoprotein AI may be one of the mechanisms of UA involved in the progression of cardiovascular disease.

Effect of eight weeks of regular aerobic exercise on apolipoprotein AI gene expression and lipid profile indices in obese women

Background: Heart disease is a multifactorial disease with genetic background and environmental factors involved. And new studies believe that markers such as apolipoprotein AI are a better criterion for diagnosis. Therefore, the purpose of this study was to investigate the effect of eight weeks of regular aerobic exercise on apolipoprotein AI gene expression and lipid profile indices in obese women. Methods: In this experimental study, 30 healthy obese women aged 35-30 years were randomly selected and divided into control (n =15) and experimental (n =15) groups. The experimental group underwent 8 weeks of regular aerobic exercise at 60-75% of the heart rate reserve three sessions per week for 60 minutes each session. Apolipoprotein AI mRNA expression was measured by Semi-quantitative-RT-PCR method and lipid profiles were measured in both pre-test and post-test. Results: The apolipoprotein AI gene expression was significantly increased in the experimental group compared to the control group (P<0.05). Also, TG (P = 0.003), TG LDL in the experimental group showed a significant decrease compared to the control group and HDL level in the experimental group was significantly higher than the control group (P = 0.001) Conclusion: The regular aerobic exercise has an important role in reducing cardiovascular diseases through increasing apolipoprotein AI gene expression and improving lipid

Apolipoprotein AI-Derived Vitreous Amyloidosis: An Elusive Diagnosis

A 56-year-old female presented with vitreous opacity with gradual visual disturbance in her right eye of 1-year duration. A Non-Hodgkin’s lymphoma had been treated 15 years before. Presenting best-corrected visual acuity (BCVA) was 20/200 in her right eye and 20/25 in her left eye. Intraocular pressure was 18 mm Hg bilaterally. Slit-lamp examination revealed no abnormal findings in the anterior segment of both eyes, including the absence of cells and flare. Fundoscopic examination indicated hazy media with the typical glass-wool-like appearance in her right eye. B-scan ultrasound demonstrated that the vitreous was full of middle-echo spots, vitreous opacities, and posterior vitreous detachment occurred. The patient underwent vitreous biopsy and a standard 25-gauge pars plana vitrectomy (diagnostic and therapeutic). Intraoperatively, the eye was noted to have severe diffuse debris and very strong vitreoretinal adhesions. Cytospin smears prepared from the vitreous aspirate indicated amorphous acellular material that stained positively with Congo Red and showed apple green birefringence on polarized microscopy, consistent with the diagnosis of amyloidosis. A genetic evaluation of tongue tissue demonstrated apolipoprotein AI-derived amyloidosis. The BCVA was 20/25 OU at 3 months postoperatively.