The exposure of the developing foetal heart to hyperglycaemia in mothers with diabetes mellitus is a major risk factor for foetal cardiac complications that lead to heart failure. We studied the effects of hyperglycaemia on the layout of cardiac myofilament proteins in stem cell-derived cardiomyocytes and their possible underlying mechanisms. Mouse embryonic stem cells (mESCs) were differentiated into cardiac-like cells and cultured in media containing baseline- or high glucose concentrations. Cellular biomarkers were detected using Western blot analysis, immunocytochemistry, 5–ethynyl–2′-deoxyuridine (EdU) cell proliferation assay, and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay. High glucose decreased the proportion of cardiac troponin T and α-actinin 2 positive mESCs as well as disrupted the α-actinin 2 striated pattern and the distribution of the cardiac myosin heavy chain α- and β isoforms. However, there was no alteration of the cellular EdU uptake nor the expression of the receptor of advanced glycation end-product (RAGE). High glucose also increased the presence of the oxidative stress marker nitrotyrosine as well as the number of TUNEL-stained nuclei in cardiac-like cells. Treatment with the antioxidant N-acetyl cysteine decreased the number of TUNEL-stained cells in high glucose and improved the α-actinin 2 striated pattern. Hyperglycaemia negatively impacted the expression and cellular organisation of cardiac myofilament proteins in mESC-derived cardiomyocytes through oxidative stress. The results add further insights into the pathophysiological mechanisms of cardiac contractile dysfunction in diabetic cardiac developmental disease.

在患有糖尿病的母亲中，发育中的胎儿心脏暴露于高血糖是导致心力衰竭的胎儿心脏并发症的主要危险因素。我们研究了高血糖对干细胞衍生的心肌细胞中心肌肌丝蛋白布局的影响及其可能的潜在机制。小鼠胚胎干细胞 (mESC) 分化为心脏样细胞，并在含有基线或高葡萄糖浓度的培养基中培养。使用蛋白质印迹分析、免疫细胞化学、5-乙炔基-2'-脱氧尿苷 (EdU) 细胞增殖测定和末端脱氧核苷酸转移酶 dUTP 缺口末端标记 (TUNEL) 测定检测细胞生物标志物。高糖降低了心肌肌钙蛋白 T 和 α-肌动蛋白 2 阳性 mESC 的比例，并破坏了 α-肌动蛋白 2 条纹模式和心肌肌球蛋白重链 α- 和 β 同种型的分布。然而，细胞 EdU 摄取没有改变，晚期糖基化终产物 (RAGE) 受体的表达也没有改变。高葡萄糖还增加了氧化应激标志物硝基酪氨酸的存在以及心脏样细胞中 TUNEL 染色的细胞核的数量。用抗氧化剂 N-乙酰半胱氨酸处理减少了高葡萄糖中 TUNEL 染色的细胞数量并改善了 α-辅肌动蛋白 2 条纹模式。高血糖通过氧化应激对 mESC 衍生的心肌细胞中心肌肌丝蛋白的表达和细胞组织产生负面影响。