背景:常染色体隐性多囊肾病(ARPKD)是一种罕见的儿科疾病,主要由PKHD1的序列变异引起。ARPKD表现出与PKHD1序列变异类型相关的相当大的临床变异性,但不是它的位置。多囊肾病(PKD)的动物模型表明了复杂的遗传景观,遗传修饰剂是疾病变异性的潜在原因。
方法:以无偏见的方式研究ARPKD的分子机制,并确定疾病严重程度的潜在指标,在人ARPKD肾脏和年龄匹配的健康对照上采用全外显子组测序(WES)和RNA-测序(RNA-Seq)。
结果:WES在由10个ARPKD肾脏组成的患者队列中证实了ARPKD的临床诊断。序列变异类型,也没有PKHD1序列变体的位置,与疾病严重程度有关。在ARPKD队列中检测到与其他纤毛病相关的基因的序列变异,但只有PKD1与疾病严重程度有关。对代表重度和中度ARPKD的四个ARPKD肾脏的子集进行转录组学分析,确定了大量与WNT信号相关的基因,细胞代谢和发育。通过RT-qPCR在重度和中度ARPKD肾脏中验证了WNT信号相关基因的表达增加。我们队列中的两个人具有相同的PKHD1序列变异,但肾脏疾病进展率不同,在WNT信号基因的表达中显示出转录组差异。
结论:ARPKD肾脏转录组学强调WNT信号的变化在ARPKD表现和严重程度中具有潜在的意义。提供减缓ARPKD进展的指标。
BACKGROUND: Autosomal Recessive Polycystic Kidney Disease (ARPKD) is a rare paediatric disease primarily caused by sequence variants in PKHD1. ARPKD presents with considerable clinical variability relating to the type of PKHD1 sequence variant, but not its position. Animal models of Polycystic Kidney Disease (PKD) suggest a complex genetic landscape, with genetic modifiers as a potential cause of disease variability.
METHODS: To investigate in an unbiased manner the molecular mechanisms of ARPKD and identify potential indicators of disease severity, Whole Exome Sequencing (
WES) and RNA-Sequencing (RNA-Seq) were employed on human ARPKD kidneys and age-matched healthy controls.
RESULTS: WES confirmed the clinical diagnosis of ARPKD in our patient cohort consisting of ten ARPKD kidneys. Sequence variant type, nor position of PKHD1 sequence variants, was linked to disease severity. Sequence variants in genes associated with other ciliopathies were detected in the ARPKD cohort, but only PKD1 could be linked to disease severity. Transcriptomic analysis on a subset of four ARPKD kidneys representing severe and moderate ARPKD, identified a significant number of genes relating to WNT signalling, cellular metabolism and development. Increased expression of WNT signalling-related genes was validated by RT-qPCR in severe and moderate ARPKD kidneys. Two individuals in our cohort with the same PKHD1 sequence variants but different rates of kidney disease progression, with displayed transcriptomic differences in the expression of WNT signalling genes.
CONCLUSIONS: ARPKD kidney transcriptomics highlights changes in WNT signalling as potentially significant in ARPKD manifestation and severity, providing indicators for slowing down the progression of ARPKD.