SIRT1 activity orchestrates ECM expression during hESC-chondrogenic differentiation.
SIRT1 activity orchestrates ECM expression during hESC-chondrogenic differentiation.
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DOI：
10.1096/fj.202200169r
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
Kimber SJ
中科院分区：
文献类型：
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作者：
Smith CA;Humphreys PA;Bates N;Naven MA;Cain SA;Dvir-Ginzberg M;Kimber SJ
表观遗传修饰是分化的关键驱动力，脱乙酰酶Sirtuin 1（SIRT 1）是细胞功能，衰老和关节软骨稳态的既定调节因子。在这里，我们调查SIRT 1在软骨细胞发育过程中的作用，通过使用人胚胎干细胞（hESCs）。在分化期间，用SIRT 1激活剂SRT 1720或抑制剂EX 527处理HESC-软骨祖细胞。在3D颗粒培养早期激活SIRT 1导致II型胶原（COL 2A 1）和聚集蛋白聚糖（ACAN）以及软骨形成转录因子SOX 5和ARID 5 B的ECM基因表达显著增加，SOX 5 ChIP分析表明ACAN的软骨细胞特异性-10（A1）增强子富集。出乎意料的是，当SIRT 1被激活时，ACAN增强，糖胺聚糖（GAG）减少，这是由于负责GAG链起始/延伸的1型N-乙酰半乳糖胺转移酶（GALNT 1）的基因表达下调。观察到ARID 5 B和COL 2A 1之间的正相关性，并且co-IP测定表明ARID 5 B与SIRT 1的关联，进一步表明COL 2A 1表达通过ARID 5 B-SIRT 1相互作用促进。总之，SIRT 1激活对主要ECM蛋白的表达产生积极影响，同时改变ECM组成并抑制人软骨发育期间的GAG含量。这些结果表明，SIRT 1活性对发育中的hESC-软骨细胞中的GAG和蛋白质具有不同的影响，并且如果通过添加阳性GAG介质来平衡，则仅对软骨发育和基质蛋白合成有益。
Epigenetic modification is a key driver of differentiation, and the deacetylase Sirtuin1 (SIRT1) is an established regulator of cell function, ageing, and articular cartilage homeostasis. Here we investigate the role of SIRT1 during development of chondrocytes by using human embryonic stem cells (hESCs). HESC‐chondroprogenitors were treated with SIRT1 activator; SRT1720, or inhibitor; EX527, during differentiation. Activation of SIRT1 early in 3D‐pellet culture led to significant increases in the expression of ECM genes for type‐II collagen (COL2A1) and aggrecan (ACAN), and chondrogenic transcription factors SOX5 and ARID5B, with SOX5 ChIP analysis demonstrating enrichment on the chondrocyte specific –10 (A1) enhancer of ACAN. Unexpectedly, when SIRT1 was activated, while ACAN was enhanced, glycosaminoglycans (GAGs) were reduced, paralleled by down regulation of gene expression for N‐acetylgalactosaminyltransferase type 1 (GALNT1) responsible for GAG chain initiation/elongation. A positive correlation between ARID5B and COL2A1 was observed, and co‐IP assays indicated association of ARID5B with SIRT1, further suggesting that COL2A1 expression is promoted by an ARID5B‐SIRT1 interaction. In conclusion, SIRT1 activation positively impacts on the expression of the main ECM proteins, while altering ECM composition and suppressing GAG content during human cartilage development. These results suggest that SIRT1 activity has a differential effect on GAGs and proteins in developing hESC‐chondrocytes and could only be beneficial to cartilage development and matrix protein synthesis if balanced by addition of positive GAG mediators.