孕期蛋白质限制对雄性小鼠后代心脏发育的最早影响

The earliest impact of restricted protein intake during pregnancy on heart development in male mouse offspring.

作者信息Marina S Folguieri, Bruno Calsa, Patricia Aline Boer, José Antonio Rocha Gontijo
PMID41244074
发布时间2025-10-30
DOI10.3389/fcell.2025.1678126

实验完整度

中

实验包含动物模型、RT-qPCR、免疫组化、自噬通量转基因模型及统计分析,但主要聚焦于分子和形态学变化,未涉及明确的功能验证或机制验证。

主要模型

C57BL/6J小鼠品系 CAG-RFP-EGFP-LC3转基因小鼠

重点核对

孕鼠饮食处理(17%酪蛋白 vs 6%酪蛋白) 胎儿收集时间点(14 GD 和 18 GD) 基因表达检测(RT-qPCR) 蛋白表达检测(免疫组化)

摘要

Introduction: Maternal protein restriction in animal models poses significant risks that lead to detrimental outcomes such as decreased birth weights, reduced nephron counts, neurological disorders, and increased arterial hypertension. Previous studies have shown that gestational protein deficiency is linked to reductions in cardiac mass, an increased presence of cardiac fibroblasts, and the development of fibrosis in both the left and right ventricles of adult rodents. This leads to the hypothesis that nutritional deprivation negatively impacts cellular proliferation mechanisms, ultimately resulting in a decrease in cell populations.Aims: The present study aims to elucidate the complex relationships among growth factor signaling, molecular expression profiles, and developmental pathways that underpin cardiac morphogenesis during the embryonic and fetal stages of development. We focus on the potentially harmful effects of maternal protein restriction on the cardiogenesis of the offspring.Methods: Methodologically, we analyzed the responses of female mice subjected to protein deficiency and evaluated the effects on their offspring, with a particular emphasis on early cardiac remodeling and key cellular pathways. Specifically, we analyzed cleaved caspase-3 as a marker for apoptosis, along with autophagy. Techniques employed include RT-qPCR, immunohistochemistry, and a transgenic model for direct quantification of autophagic flux.Results: Our findings indicate that gestational protein restriction alters the expression profiles of genes associated with cardiac remodeling and increases the levels of apoptotic markers. In contrast, autophagic flux did not show significant alterations.Conclusion: We conclude that early protein restriction triggers a cascade of remodeling responses, including transient heart volume expansion accompanied by cardiomyocyte hypertrophy, which may progress towards fibrosis and metabolic stress. Autophagic flux was not significantly altered. We conclude that early protein restriction triggers a cascade of remodeling responses, including a transient heart volume expansion accompanied by cardiomyocyte hypertrophy, which has the potential to progress towards fibrosis and metabolic stress.

实验结论

提炼研究问题、关键发现与证据,快速把握文章的核心贡献。

研究问题
孕期蛋白质限制是否影响子代心脏发育?
核心机制
孕期蛋白质限制导致心脏体积增加、心肌细胞肥大、凋亡标志物水平升高,以及HIF-1α、VEGF、DNMT3、OXCT1等蛋白表达降低,未发现自噬通量显著改变。
主要证据
通过小鼠模型(C57BL/6J和转基因CAG-RFP-EGFP-LC3),在14和18天孕龄取材,采用RT-qPCR检测基因表达,免疫组化检测蛋白水平,以及利用转基因模型直接量化自噬通量。
研究意义
研究为早期心脏重塑和代谢应激提供了基础,并提出这些改变可能进展为纤维化和代谢应激,但需进一步转录组学和蛋白质组学研究。

研究路径

按研究推进顺序梳理实验设计、验证步骤与关键观察。

1

动物模型建立与分组

建立孕期蛋白质限制的动物模型,比较低蛋白和正常蛋白饮食对子代的影响。

将16周龄雌性CAG-RFP-EGFP-LC3小鼠与雄性C57BL/6J小鼠交配,雌鼠分别喂食正常蛋白饮食(17%酪蛋白)或低蛋白饮食(6%酪蛋白),在14和18天孕龄取材。

2

胎儿心脏形态学分析

评估蛋白质限制对胎儿心脏体积、室壁厚度和心肌细胞面积的影响。

固定胎儿心脏,计算心脏体积,测量心室壁厚度和心肌细胞面积,使用免疫组化检测蛋白表达。

3

基因表达分析

检测心脏发育相关基因(如mTOR, TGFβ1, HIF1α等)的mRNA表达变化。

从14 GD和18 GD胎儿心脏提取RNA,进行RT-qPCR检测。

4

自噬通量检测

评估蛋白质限制是否改变心肌组织中的自噬通量。

使用转基因小鼠(CAG-RFP-EGFP-LC3)表达荧光标记的LC3,通过共聚焦显微镜成像,定量自噬囊泡。

5

免疫组化分析

检测心脏组织中凋亡、增殖、代谢和信号通路相关蛋白的表达。

对心脏组织切片进行免疫过氧化物酶和免疫荧光染色,检测cleaved caspase-3、PCNA、mTOR、AMPKα、HIF1α、VEGF、BCL2、CALML3、DNMT3、OXCT1和TGFβ1。

研究方法

按研究目的归类文中使用的方法,便于定位所需技术。

产品清单

实验环节名称品牌货号
RNeasy Plus Micro 试剂盒Qiagen74034
NanoDrop 2000c 分光光度计Thermo Fisher--
ReadyMix JumpStart Taq SYBR 预混液Sigma AldrichS4438
StepOne Plus 实时荧光定量PCR仪----
GoTaq G2 Green 预混液PromegaM7823
溶酶体相关膜蛋白1抗体Novus BiologicalsNB120-19294
增殖细胞核抗原抗体Santa CruzSC25280
活化的caspase-3抗体Cell Signaling9662S
mTOR抗体SigmaSAB4300583
AMPKα抗体Santa CruzSC7446
抗小鼠Alexa 488二抗BiomolA21202
抗兔Dylight 594二抗AbcamAB9840
抗兔IgG Alexa 647二抗Jackson Immuno Research711-605-152
HIF1α抗体NovusNB11057031
VEGF抗体NovusNB100-664
BCL2抗体Santa CruzSC492
CALML3抗体NovusBioNBP2-15667
DNMT3a抗体BiossBS0497R
OXCT1抗体BiossBS5089R
抗兔IgG HRP标记二抗Cell Signaling7074S
抗鼠IgG HRP标记二抗Invitrogen31430
DAPI 染色液SigmaD9564-10MG
Paraplast 石蜡Sigma-Aldrich--
Entellan 封片剂----
Axio Scope A1 显微镜Carl Zeiss--
Axio Cam MRc 数字相机Carl Zeiss--
EC Plan-Neofluar 40x/1.3 油浸物镜Carl Zeiss--
异氟烷----
正己烷----

关键环节

汇总复现实验时建议重点确认的条件及原文阅读提示。

环节核对要点
动物模型
小鼠品系:C57BL/6J和CAG-RFP-EGFP-LC3;年龄:8-10周;交配时间:16周龄雌鼠,2小时;饮食:17%酪蛋白(NP)和6%酪蛋白(LP);取材时间:14 GD和18 GD
阅读提示:Methods: Animals and ethical procedures 和 Experimental model
基因表达分析
RNA提取方法:RNeasy Plus Micro kit;cDNA合成:RT2 First Strand kit和High Capacity cDNA Reverse Transcription kit;引物序列和浓度见表1;PCR条件;内参基因Gapdh
阅读提示:Methods: RT-qPCR 和 Table 1
蛋白表达分析
抗体种类、稀释比例和供应商见表2;抗原修复:柠檬酸缓冲液pH 6.0 30分钟;封闭液:5%非免疫血清;一抗孵育:4°C过夜;二抗孵育:2小时
阅读提示:Methods: Immunohistochemistry 和 Table 2
自噬通量分析
转基因小鼠模型;固定和冷冻方法;图像采集参数;自动囊泡选择标准;囊泡颜色分类方法
阅读提示:Methods: Autophagic flux 和 Figure 1