Monteagudo S, Cornelis F M F, Wang X, de Roover A, Peeters T, Quintiens J, Sermon A, de Almeida R C, Meulenbelt I, Lories R J
Laboratory of Tissue Homeostasis and Disease, Skeletal Biology and Engineering Research Center, Department of Development and Regeneration, KU Leuven, Leuven, Belgium.
Department of Trauma Surgery, University Hospitals Leuven, Leuven, Belgium; Department of Development and Regeneration, KU Leuven, Leuven, Belgium.
Osteoarthritis Cartilage. 2022 May;30(5):724-734. doi: 10.1016/j.joca.2022.02.615. Epub 2022 Feb 25.
To investigate how ANP32A, previously linked to the antioxidant response, regulates Wnt signaling as unraveled by transcriptome analysis of Anp32a-deficient mouse articular cartilage, and its implications for osteoarthritis (OA) and diseases beyond the joint.
Anp32a knockdown chondrogenic ATDC5 cells were cultured in micromasses. Wnt target genes, differentiation markers and matrix deposition were quantified. Wnt target genes were determined in articular cartilage from Anp32a-deficient mice and primary human articular chondrocytes upon ANP32A silencing, using qPCR, luciferase assays and immunohistochemistry. Co-immunoprecipitation, immunofluorescence and chromatin-immunoprecipitation quantitative PCR probed the molecular mechanism via which ANP32A regulates Wnt signaling. Anp32a-deficient mice were subjected to the destabilization of the medial meniscus (DMM) OA model and treated with a Wnt inhibitor and an antioxidant. Severity of OA was assessed by cartilage damage and osteophyte formation. Human Protein Atlas data analysis identified additional organs where ANP32A may regulate Wnt signaling. Wnt target genes were determined in heart and hippocampus from Anp32a-deficient mice, and cardiac hypertrophy and fibrosis quantified.
Anp32a loss triggered Wnt signaling hyper-activation in articular cartilage. Mechanistically, ANP32A inhibited target gene expression via histone acetylation masking. Wnt antagonist treatment reduced OA severity in Anp32a-deficient mice by preventing osteophyte formation but not cartilage degradation, contrasting with antioxidant treatment. Dual therapy ameliorated more OA features than individual treatments. Anp32a-deficient mice also showed Wnt hyper-activation in the heart, potentially explaining the cardiac hypertrophy phenotype found.
ANP32A is a novel translationally relevant repressor of Wnt signaling impacting osteoarthritis and cardiac disease.
通过对Anp32a基因缺陷型小鼠关节软骨进行转录组分析，研究先前与抗氧化反应相关的ANP32A如何调节Wnt信号通路，及其对骨关节炎（OA）和关节以外疾病的影响。
将敲低Anp32a基因的软骨生成ATDC5细胞培养成微团。对Wnt靶基因、分化标志物和基质沉积进行定量分析。使用qPCR、荧光素酶测定和免疫组织化学方法，在Anp32a基因缺陷型小鼠的关节软骨和原代人关节软骨细胞中，于ANP32A沉默后测定Wnt靶基因。通过免疫共沉淀、免疫荧光和染色质免疫沉淀定量PCR探究ANP32A调节Wnt信号通路的分子机制。将Anp32a基因缺陷型小鼠用于内侧半月板不稳定（DMM）OA模型，并给予Wnt抑制剂和抗氧化剂治疗。通过软骨损伤和骨赘形成评估OA的严重程度。利用人类蛋白质图谱数据分析确定ANP32A可能调节Wnt信号通路的其他器官。在Anp32a基因缺陷型小鼠的心脏和海马中测定Wnt靶基因，并对心脏肥大和纤维化进行定量分析。
Anp32a基因缺失引发关节软骨中Wnt信号通路的过度激活。机制上，ANP32A通过掩盖组蛋白乙酰化来抑制靶基因表达。与抗氧化剂治疗相反，Wnt拮抗剂治疗通过防止骨赘形成而非软骨降解降低了Anp32a基因缺陷型小鼠的OA严重程度。联合治疗比单一治疗改善了更多的OA特征。Anp32a基因缺陷型小鼠的心脏中也表现出Wnt过度激活，这可能解释了所发现的心脏肥大表型。
ANP32A是一种新型的与翻译相关的Wnt信号通路抑制因子，对骨关节炎和心脏病有影响。
