scholarly journals Long-Term Soy Protein Isolate Consumption Reduces Liver Steatosis Through Changes in Global Transcriptomics in Obese Zucker Rats

2020 ◽  
Vol 7 ◽  
Author(s):  
Melisa Kozaczek ◽  
Walter Bottje ◽  
Byungwhi Kong ◽  
Sami Dridi ◽  
Diyana Albataineh ◽  
...  

To determine how soy protein isolate (SPI) ameliorated liver steatosis in male obese Zucker rats, we conducted global transcriptomic expression (RNAseq) analysis on liver samples of male rats fed either the SPI or a control casein (CAS)-based diet (n = 8 per group) for 16 weeks. Liver transcriptomics were analyzed using an Ilumina HiSeq system with 2 × 100 base pair paired-end reads method. Bioinformatics was conducted using Ingenuity Pathway Analysis (IPA) software (Qiagen, CA) with P < 0.05 and 1.3-fold differential expression cutoff values. Regression analysis between RNAseq data and targeted mRNA expression analysis of 12 top differentially expressed genes (from the IPA program) using quantitative PCR (qPCR) revealed a significant regression analysis (r2 = 0.69, P = 0.0008). In addition, all qPCR values had qualitatively similar direction of up- or down-regulation compared to the RNAseq transcriptomic data. Diseases and function analyses that were based on differentially expressed target molecules in the dataset predicted that lipid metabolism would be enhanced whereas inflammation was predicted to be inhibited in SPI-fed compared to CAS-fed rats at 16 weeks. Combining upstream regulator and regulator effects functions in IPA facilitates the prediction of upstream regulators (e.g., transcription regulators) that could play important roles in attenuating or promoting liver steatosis due to SPI or CAS diets. Upstream regulators that were predicted to be activated (from expression of down-stream targets) linked to increased conversion of lipid and transport of lipid in SPI-fed rats included hepatocyte nuclear factor 4 alpha (HNF4A) and aryl hydrocarbon receptor (AHR). Upstream regulators that were predicted to be activated in CAS-fed rats linked to activation of phagocytosis and neutrophil chemotaxis included colony stimulating factor 2 and tumor necrosis factor. The results provide clear indication that long-term SPI-fed rats exhibited diminished inflammatory response and increased lipid transport in liver compared to CAS-fed rats that likely would contribute to reduced liver steatosis in this obese Zucker rat model.

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 1225-1225
Author(s):  
Melisa Kozaczek ◽  
Walter Bottje ◽  
Reza Hakkak

Abstract Objectives To determine the effects feeding for 8 (short-term) and 16 weeks (long-term) soy protein isolate on hepatic CYP gene expression. Methods 7-weeks old rats were randomly assigned to either a casein (CAS) or a soy protein isolate (SPI) diet. They were provided the diets ad libitum for 8 and 16 weeks. Rats were euthanized and livers were stored at − 80°C. RNA was extracted from liver samples, and sequenced to obtain transcriptomic data (RNAseq). Ingenuity Pathway Analysis software (IPA, Qiagen, CA) was used in the analysis of global gene expression data. This analysis includes predictions of activation or inhibition of molecules or upstream regulators and functions based on a generated z-score and p-value of overlap (P = 0.05). Z-scores were consider significant when > 2 (activation) and < −2 (inhibition). Results Comparing short- vs long-term feeding revealed an increase in the number of down-regulated CYP genes from only 3 at 8 weeks of SPI diet to 10 at 16 weeks of same diet (P < 0.05). In contrast, upregulated CYP gene numbers showed a small increase in long-term SPI diet compared to short-term, from 14 genes at 8 weeks to 17 genes at 16 weeks (P < 0.05). In addition, we present a predicted activation of the transcription factor Aryl hydrocarbon receptor (AHR, activation z-score = 2.146, P = 4.20E-11), linked to the subsequent activation or up-regulation of various CYPs genes, indirectly leading to the activation and inhibition of two main metabolic functions under SPI feeding: conversion of lipid (lipid metabolism) –predicted to be activated (z-score = 2.089, P = 2.77E-08), and recruitment of phagocytes (inflammatory response) –predicted to be inhibited (z-score = −2.311, P = 2.10E-05). Conclusions Through global gene expression analysis we showed that gene expression of drug-metabolizing cytochrome P450 genes was modified in genetically obese Zucker rats after being fed a soy-based diet for short- and long-term, and that this change could have an important role in attenuation of liver steatosis. Further research is needed to corroborate these results. Funding Sources This study was supported in part by the College of Medicine's University Medical Group (RH) and the Arkansas Biosciences Institute (WB, RH).


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Reza Hakkak ◽  
Soheila Korourian ◽  
Oleksandra Pavliv ◽  
Stepan Melnyk

Abstract Objectives The obesity epidemic is continuing to grow in the United States and world for past two decades. There is a link between obesity and chronic diseases development such as diabetes, cardiovascular disease, certain types of cancer and liver diseases. Previously, we reported that obesity caused a significant increase liver steatosis and feeding soy protein isolate (SPI) reduced liver steatosis. The mechanism of SPI protection against liver steatosis is less known. We hypothesize that soy protein diet will reduce development of liver steatosis caused by obesity in part by changing methylation status. The objective of the present study was to investigate the effects of SPI feeding on liver metabolic methylation status using obese zucker rat model. Methods After one week of acclimation, five weeks old female lean and obese Zucker rats (n = 8/group) were randomly fed AIN-93-G diet with either casein (CAS as control) or SPI as source of protein for 22 weeks. Rats were weighted twice per week. Liver sample metabolites concentrations were measured using HPLC with Electrochemical Detection and LC-MS. Results Our results shows that; 1) obesity increased body weight significantly (P < 0.001) for both CAS and SPI diets; 2) Obese SPI-fed rats significantly (P < 0.001) reduced liver steatosis compared to obese CAS-fed rats. Also, our results show that liver metabolic profile in lean SPI-fed rats significantly (P < 0.025) increased SAM/SAH ratio (methylation ratio) compare to CAS-fed rats. Obese SPI-fed rats significantly (P < 0.001) decrease level of Homocysteine in liver and increase significantly (P < 0.001) Methionine/Homocysteine ratio. Conclusions In summary we showed that SPI diet can reduce liver steatosis by changing methylation status and improved metabolism of Homocysteine, toxic intracellular compound, through remethylation to Methionine. Funding Sources Arkansas Children's Research Institute's University Medical Group Fund grant program and Arkansas.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1650-1650
Author(s):  
Melisa Kozaczek ◽  
Walter Bottje ◽  
Elizabeth Greene ◽  
Kentu Lassiter ◽  
Byungwhi Caleb Kong ◽  
...  

Abstract Objectives To understand how soy protein isolate (SPI) reduced liver steatosis in male obese Zucker rats, we conducted global gene expression (RNAseq) analysis on liver samples of male rats fed either the SPI or a control casein (CAS)-based diet (n = 8 per group) for 8 or 16 weeks. Methods Data was analyzed using Ingenuity Pathway Analysis (IPA) software (Qiagen, CA) using a P &lt; 0.05 and 1.3 fold differential expression cutoff values. Results Out of 12 top differentially expressed genes (both up- and down-regulated) that were listed at either 8 or 16 wks of feeding (24 total), only the expression of one gene exhibited a reversal (from down-regulated to up-regulated) between 8 and 16 wks indicating consistency in the liver steatosis model. An assessment of diseases and functions based on differentially expressed target molecules in the dataset revealed that lipid metabolism was predicted to be enhanced at 16 wks whereas inflammatory response was predicted to be inhibited in SPI-fed compared to CAS-fed rats at both 8 and 16 weeks. Using the upstream regulator analysis and regulator effects functions of the IPA program enables the prediction of a number of upstream regulators (e.g., transcription regulators) that could be playing important roles in attenuating or promoting liver steatosis due to SPI or CAS diets. Examples of upstream regulators that were predicted to be activated (based on expression of down-stream target molecules) that were linked to increased conversion of lipid and transport of lipid in SPI-fed rats included hepatocyte nuclear factor 4 alpha and aryl hydrocarbon receptor. Examples of upstream regulators that were predicated to be activated in CAS-fed rats that were linked to predicted activation of phagocytosis and neutrophil chemotaxis included colony stimulating factor 2 and tumor necrosis factor. Conclusions We believe these findings may shed light on mechanisms that SPI is able to reduce liver steatosis in this obese Zucker rat model. Funding Sources Arkansas Bioscience Institute and U of A Chancellor Innovative Fund.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 1226-1226
Author(s):  
Melisa Kozaczek ◽  
Walter Bottje ◽  
Reza Hakkak

Abstract Objectives To identify possible mechanisms involved in the development and progression of NAFLD through protein expression (shotgun proteomics) analysis on liver samples of obese Zucker rats fed with either casein (CAS) or soy protein isolate (SPI) during 8 and 16 weeks. Methods 7 weeks old rats (n = 8–9 per group) were randomly assigned to an either CAS-based or a SPI-based diet. Rats were sacrificed after 8 weeks or 16 weeks of SPI feeding. Livers were immediately obtained and stored at −80 C. Ingenuity Pathway Analysis (IPA) software was used to facilitate interpretation of proteomics data. Predictions of activation or inhibition of molecules in the data was made based on activation z-score and P value of overlap (P &lt; 0.05). Activation z-scores &gt; 2.0 indicate that a molecule is activated, whereas activation z-scores of &lt; −2.0 indicate that a target molecule is inhibited. Results Upstream regulator analysis by IPA revealed 6 molecules predicted to be activated (z-scores between 2 and 2.8) and 9 inhibited (z-scores between −2 and −2.6) in SPI vs CAS-fed rats in proteomics data at 8 weeks of SPI feeding. In contrast, at 16 weeks of SPI feeding there were 12 molecules activated (z-scores between 2 and 2.5) and 18 inhibited (z-scores between −2 and −2.8) in SPI vs CAS-fed. All p values were &lt;0.05. Regulator effects analysis also revealed that some of these molecules would be participating, directly or indirectly, in the inhibition of the immune response of cells (such as IL27 and CSF2) and synthesis of lipids (CEBPA, Ins1 and IRF8) in SPI-fed rats. Conclusions These molecules and their downstream target proteins may provide clues by which soy protein produces the observed attenuation of liver steatosis that can be tested in future experiments in this obese rat model. Funding Sources This study was supported in part by the College of Medicine's University Medical Group (RH) and the Arkansas Biosciences Institute (WB, RH).


2012 ◽  
Vol 60 (21) ◽  
pp. 5367-5372 ◽  
Author(s):  
Masashi Asanoma ◽  
Nobuhiko Tachibana ◽  
Motohiko Hirotsuka ◽  
Mitsutaka Kohno ◽  
Yasuo Watanabe

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