Iron Deficiency Induces Heart Failure with Ectopic Cardiac Calcification in Mice with Metabolic Syndrome.
Iron Deficiency Induces Heart Failure with Ectopic Cardiac Calcification in Mice with Metabolic Syndrome.
复制标题
缺铁会导致代谢综合征小鼠出现心力衰竭和异位心脏钙化。
DOI：
10.1161/circheartfailure.121.009034
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Ishihara M.
中科院分区：
文献类型：
--
作者：
Naito Y;Sawada H;Yasumura S;Horimatsu T;Okuno K;Tahara S;Nishimura K;Asakura M;Tsujino T;Masuyama T;Ishihara M.
KKAy 小鼠被用作代谢综合征模型，因为这些小鼠会出现肥胖、糖尿病和高脂血症。 4周龄雄性野生型C57BL/6J和KKAy小鼠购自日本CLEA。给小鼠喂食正常饮食或限铁 (IR) 饮食（编号 F2FeDD，东方酵母有限公司，日本）12 周（n = 10/组）。虽然其他组中没有小鼠死亡，但采用 IR 饮食的 KKAy 小鼠中有 40% 的小鼠死亡（KKAy-IR；图 [A]）。尸检显示这些 KKAy-IR 小鼠存在心脏扩大和胸腔积液，表明由于肺充血而导致心源性死亡（图 [A]）。此外，心脏表面还观察到多处白色病变。 KKAy 小鼠比野生型小鼠表现出更高的体重和血糖，而 IR 饮食并不影响这些参数（图 [B]）。无论基因型如何，在接受 IR 饮食的小鼠中均观察到贫血（图 [B]）。各组之间血清尿素氮和肌酐浓度具有可比性（图[B]）。离体测量表明，KKAy-IR 小鼠的心脏和湿肺重量显着高于其他组（图 [C]）。饮食后 11 周的超声心动图显示 KKAy-IR 小鼠左心室扩张，缩短分数减少（图 [C]）。离体和组织学图像显示，KKAy-IR 小鼠表现出心脏增大和心脏间质纤维化增加（图[D]）。同样，KKAy-IR 小鼠中心房钠尿肽 (Anp) 和 I 型胶原蛋白 (Col1) 的心脏 mRNA 丰度比其他组有所增加（图 [D]）。随后，进行茜素红和冯科萨染色来评估心脏钙化。在 KKAy-IR 小鼠中检测到多个钙沉积，但在其他组中未检测到（图 [D]）。为了研究铁限制引起的心脏钙化的分子机制，我们评估了心脏组织中的成骨基因。外核苷酸焦磷酸酶/磷酸二酯酶 1 (Enpp1) 的 mRNA 是骨矿化的关键酶，在 KKAy-IR 小鼠中含量很高。 Runt 相关转录因子 2 (Runx2) 是一种关键的成骨转录因子，在 KKAy-IR 小鼠中也表达上调（图 [D]）。接下来，进行时间过程研究以确定 KKAy-IR 小鼠心脏钙化的开始。在IR饮食后3、7和14天从KKAy小鼠身上采集心脏组织。第 3 天未观察到心脏钙化，而 6 只 KKAy 小鼠中的 1 只在第 7 天表现出轻度钙化。值得注意的是，IR 饮食后第 14 天，6 只 KKAy 小鼠中的 5 只 (83%) 显示出轻度至中度钙化（图 [E]）。马森三色染色表明钙化病变与胶原沉积一致（图[E]）。与 IR 饮食后第 3 天相比，第 14 天心脏 Enpp1 和 Runx2 mRNA 丰度增加（图 [E]）。
KKAy mice were used as a model of metabolic syndrome as these mice develop obesity, diabetes, and hyperlipidemia. Four-week-old male wild-type C57BL/6J and KKAy mice were purchased from Japan CLEA. Mice were fed either a normal diet or iron-restricted (IR) diet (no. F2FeDD, Oriental Yeast Co Ltd, Japan) for 12 weeks (n= 10/group). While no mice died in other groups, 40% of mice died in KKAy mice with IR diet (KKAy-IR; Figure [A]). Necropsy revealed the presence of cardiomegaly and pleural effusion in those KKAy-IR mice, indicating cardiac death due to pulmonary congestion (Figure [A]). In addition, multiple white lesions were observed on the cardiac surface. KKAy mice exhibited higher body weight and blood glucose than wild-type mice, while IR diet did not affect these parameters (Figure [B]). Anemia was observed in mice with IR diet regardless of genotypes (Figure [B]). Serum blood urea nitrogen and creatinine concentrations were comparable among groups (Figure [B]). Ex vivo measurements demonstrated that heart and wet lung weights in KKAy-IR mice were significantly higher than in other groups (Figure [C]). Echocardiography at 11 weeks after diet showed left ventricular dilatation with decreased fractional shortening in KKAy-IR mice (Figure [C]). Ex vivo and histological images revealed thatKKAy-IR mice exhibited enlarged hearts and increased cardiac interstitial fibrosis (Figure [D]). Likewise, cardiac mRNA abundance of atrial natriuretic peptide (Anp) and collagen type I (Col1) was increased in KKAy-IR mice than in other groups (Figure [D]). Subsequently, Alizarin red and von Kossa staining were performed to evaluate cardiac calcification. Multiple calcium depositions were detected in KKAy-IR mice, but not in other groups (Figure [D]). To investigate the molecular mechanism underlying iron restriction-induced cardiac calcification, we assessed osteogenic genes in heart tissues. mRNA of ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1), a key enzyme for bone mineralization, was highly abundant in KKAy-IR mice. Runt-related transcription factor 2 (Runx2), a key osteogenic transcription factor, was also upregulated in KKAy-IR mice (Figure [D]). Next, a time course study was performed to determine the initiation of cardiac calcification in KKAy-IR mice. Heart tissues were harvested from KKAy mice at 3, 7, and 14 days after IR diet. Cardiac calcification was not observed at day 3, while 1 of 6 KKAy mice exhibited mild calcification at day 7. Of note, 5 of 6 KKAy mice (83%) showed mild to moderate calcification at day 14 after IR diet (Figure [E]). Masson trichrome staining demonstrated that calcified lesions coincided with collagen deposition (Figure [E]). Cardiac Enpp1 and Runx2 mRNA abundance was increased at day 14 compared with day 3 after IR diet (Figure [E]).