Low-fat hypocaloric diet reduces neprilysin in overweight and obese human subjects

Increased neprilysin expression is linked to atrial fibrotic remodeling in cardiovascular surgery patients

Background

Neprilysin (NEP) is a membrane-bound neutral endopeptidase with various physiological functions. We investigated the roles of NEP in atrial fibrotic remodeling and atrial fibrillation (AF) in patients undergoing cardiovascular surgery.

Methods

Atrial tissue samples were obtained from left atrium (LA) appendages, and mRNA expression level was analyzed by real-time reverse transcription polymerase chain reaction in 61 cases (25 paroxysmal fibrillation (PAF), 36 AF). Adipose tissue (AT) mRNA expression levels were also analyzed. Western blotting and immunohistochemical staining were used for determining tissue protein expression. Serum NEP levels were measured by enzyme-linked immunosorbent assay (ELISA). Two-dimensional speckle tracking echocardiography was performed to measure mean left atrial reservoir strain (mLASr) to evaluate atrial remodeling in pre-operative patients and control participants.

Results

Immunohistochemical staining and western blotting revealed NEP expression in both AT and LA. Serum NEP levels did not correlate with NEP mRNA or protein expression in AT and LA. NEP mRNA expression levels correlated with fibrosis-related gene expression. NEP mRNA, protein, and fibrosis-related gene expression levels increased in PAF patients with low mLASr compared with high mLASr. PAF patients with high NEP mRNA expression showed increased fibrosis-related gene expression compared with those with low NEP expression. Multiple regression analysis revealed that NEP mRNA expression level was an independent variable for predicting fibrosis-related gene expression, whereas NOX4 and NLRP3 were independent variables for predicting NEP expression levels.

Conclusions

Increased atrial expression of NEP is linked to atrial fibrotic remodeling, and the development of AF in patients undergoing cardiovascular surgery.

Subgroup disproportionality analysis of dementia-related adverse events with sacubitril/valsartan across geographical regions

This study aimed to evaluate the association between sacubitril/valsartan and dementia-related adverse events (AEs) in geographical subpopulations using subgroup disproportionality analysis. Cases from the FDA adverse event reporting system involving patients aged 60 or older with sacubitril/valsartan or angiotensin receptor blockers (ARBs) were analyzed. The adjusted reporting odds ratios (RORs) for dementia-related AEs were calculated for each continent. A total of 61,518 AEs associated with sacubitril/valsartan or ARBs were identified. Among these, 1441 were dementia-related AEs. In Asia, Europe, and Africa, the reporting risk of dementia-related AEs associated with sacubitril/valsartan was lower compared to ARBs (adjusted ROR, 0.57 [95% CI 0.31-1.01]; adjusted ROR, 0.89 [95% CI 0.69-1.14]; adjusted ROR, 0.40 [95% CI 0.27-0.61], respectively). In Latin America and Oceania, the reporting risk of dementia-related AEs associated with sacubitril/valsartan was similar to that associated with ARBs (adjusted ROR, 1.04 [95% CI 0.75-1.44]; adjusted ROR, 1.02 [95% CI 0.31-3.37], respectively). On the contrary, in North America, the reporting risk associated with sacubitril/valsartan was higher compared to ARBs (adjusted ROR, 1.29 [95% CI 1.10-1.53]). Although the ROR value did not meet the criteria for signal detection, the significantly greater than 1 ROR observed in North America suggests that caution may be warranted regarding potential dementia-related adverse events associated with sacubitril/valsartan.

A systematic review and meta-analysis of randomized controlled trials: effects of mediterranean diet and low-fat diet on liver enzymes and liver fat content of NAFLD

Background: Non-alcoholic fatty liver disease (NAFLD) has emerged as a leading cause of several chronic diseases, imposing a significant global economic burden. The Mediterranean diet (MD) and low-fat diet (LFD) are the two primary recommended dietary patterns that exhibit distinct positive effects on treating NAFLD. Objective: To investigate which of the two diets, MD and LFD, is more effective in the treatment of NAFLD. Methods: Randomized controlled trials (RCTs) up to April 2024 were searched for in PubMed, Web of Science, Medline, Scopus and Embase. Interventions included MD or LFD, with primary outcome measures being intrahepatic lipid, liver stiffness, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, gamma-glutamyl transferase, and homeostasis model assessment of insulin resistance. Secondary outcomes included weight, waist circumference, and body mass index. Use of random effects meta-analysis to assess outcomes of interest. Results: meta-analysis revealed no significant differences between MD and LFD in improving liver enzymes, liver fat, and related indices in NAFLD patients. Our findings provide compelling evidence for patients and healthcare professionals, allowing patients to choose a dietary pattern that aligns with their preferences and disease conditions. In summary, both MD and LFD can equivalently ameliorate NAFLD in the short term. Conclusions: Our results show that MD and LFD have similar therapeutic effects on liver enzymes and liver fat content in patients with NAFLD in the short term. Furthermore, our meta-analysis results have also opened up a new avenue of thought as to whether similar effects are achieved by alternating MD and LFD on alternate days.

Neprilysin activity is increased in metabolic dysfunction-associated steatotic liver disease and normalizes after bariatric surgery or GLP-1 therapy

Inhibitors of neprilysin improve glycemia in patients with heart failure and type 2 diabetes (T2D). The effect of weight loss by diet, surgery, or pharmacotherapy on neprilysin activity (NEPa) is unknown. We investigated circulating NEPa and neprilysin protein concentrations in obesity, T2D, metabolic dysfunction-associated steatotic liver disease (MASLD), and following bariatric surgery, or GLP-1-receptor-agonist therapy. NEPa, but not neprilysin protein, was enhanced in obesity, T2D, and MASLD. Notably, MASLD associated with NEPa independently of BMI and HbA1c. NEPa decreased after bariatric surgery with a concurrent increase in OGTT-stimulated GLP-1. Diet-induced weight loss did not affect NEPa, but individuals randomized to 52-week weight maintenance with liraglutide (1.2 mg/day) decreased NEPa, consistent with another study following 6-week liraglutide (3 mg/day). A 90-min GLP-1 infusion did not alter NEPa. Thus, MASLD may drive exaggerated NEPa, and lowered NEPa following bariatric surgery or liraglutide therapy may contribute to the reported improved cardiometabolic effects.

Association between the NEP rs701109 polymorphism and the clinical efficacy and safety of sacubitril/valsartan in Chinese patients with heart failure

OBJECTIVE

Sacubitril/valsartan is a commonly used medicine for treating heart failure (HF) patients, but the treatment effects significantly vary. Neprilysin (NEP) and carboxylesterase 1 (CES1) play an important role in the efficacy of sacubitril/valsartan. The purpose of this study was to explore the relationship between NEP and CES1 gene polymorphisms and the efficacy and safety of sacubitril/valsartan treatment in HF patients.

METHODS

Genotyping of 10 single nucleotide polymorphisms (SNPs) of the NEP and CES1 genes in 116 HF patients was performed by the Sequenom MassARRAY method, and logistic regression and haplotype analysis were used to evaluate the associations between SNPs and the clinical efficacy and safety of sacubitril/valsartan in HF patients.

RESULTS

A total of 116 Chinese patients with HF completed the whole trial, and T variations in rs701109 in NEP gene were an independent risk factor (P = 0.013, OR = 3.292, 95% CI:1.287-8.422) for the clinical efficacy of sacubitril/valsartan. Furthermore, haplotype analysis of 6 NEP SNPs (including rs701109) was performed and showed that the CGTACC and TGTACC haplotypes were significantly associated with clinical efficacy (OR = 0.095, 95%CI: 0.012-0.723, P = 0.003; OR = 5.586, 95% CI: 1.621-19.248, P = 0.005). Moreover, no association was found between SNPs of other selected genes in terms of efficacy in HF patients, and no association was observed between SNPs and symptomatic hypotension.

CONCLUSION

Our results suggest an association between rs701109 and sacubitril/valsartan response in HF patients. Symptomatic hypotension is not associated with the presence of NEP polymorphisms.

Radio frequency as an innovative method to produce low-fat French fries

BACKGROUND

A large amount of evidence shows that excessive fat intake can increase the risk of obesity, type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular disease. The main purpose of this study was to use radio frequency (RF) technology to prepare low-fat French fries.

RESULTS

RF treatment for 10 min significantly decreased the force required to cut potatoes and inhibited the enzymatic browning of fresh-cut potatoes. Moreover, RF treatment increased the hardness, gumminess, and chewiness of French fries from 388.55 g, 85.67, and 33.27 to 776.93 g, 159.36, and 70.11, respectively. Furthermore, RF treatment for 10 min reduced the oil content of French fries by 28.0% compared to that of the control group. This result was related to the pre-gelatinized potato starch content after RF treatment. Pre-gelatinized starch forms a 'protective film', that prevents oil from entering the fries during frying.

CONCLUSION

Moderate RF treatment (10 min) reduced the oil content of French fries without making their texture significantly different from that of commercial French fries. These findings may provide a new perspective for the application of RF technology in the development of low-fat fried foods. © 2022 Society of Chemical Industry.

Low-fat hypocaloric diet reduces neprilysin in overweight and obese human subjects

AIMS

Neprilysin (NEP), a zinc metallopeptidase, degrades a variety of bioactive peptides including natriuretic peptides terminating their biological action on arterial blood pressure and natriuresis. Pharmacological inhibition of NEP reduces mortality in patients with heart failure with reduced ejection fraction. Physiological interventions reducing NEP levels are unknown in humans. Because obesity leads to increased NEP levels and increases the risk for heart failure, we hypothesized that weight loss reduces NEP concentrations in plasma and tissue.

METHODS AND RESULTS

We randomized overweight to obese human subjects to a low-fat or low-carbohydrate hypocaloric 6 month weight loss intervention. Soluble NEP was determined in plasma, and NEP mRNA was analysed from subcutaneous adipose tissue before and after diet. Low-fat diet-induced weight loss reduced soluble NEP levels from 0.83 ± 0.18 to 0.72 ± 0.18 μg/L (P = 0.038), while subcutaneous adipose tissue NEP mRNA expression was reduced by both dietary interventions [21% (P = 0.0057) by low-fat diet and 16% (P = 0.048) by low-carbohydrate diet]. We also analysed the polymorphisms of the gene coding for NEP, rs9827586 and rs701109, known to be associated with plasma NEP levels. For both single-nucleotide polymorphisms, minor allele carriers (A/A) had higher baseline plasma NEP levels (rs9827586: β = 0.53 ± 0.23, P < 0.0001; rs701109: β = 0.43 ± 0.22, P = 0.0016), and minor allele carriers of rs9827586 responded to weight loss with a larger NEP reduction (rs9827586: P = 0.0048).

CONCLUSIONS

Our study identifies weight loss via a hypocaloric low-fat diet as the first physiological intervention in humans to reduce NEP in plasma and adipose tissue. Specific single-nucleotide polymorphisms further contribute to the decrease. Our findings may help to explain the beneficial effect of weight loss on cardiac function in patients with heart failure.