A comparative study of gene expression level in peripheral blood mononuclear cells between children and adults patients with Kashin-Beck disease

Abstract

Objective To investigate and compare the differentially expressed genes of children and adults patients with Kashin-Beck disease (KBD) in peripheral blood mononuclear cells (PBMCs) so as to provide new clues to identify the genes related to cartilage lesion of KBD. Methods Eighteen KBD children and 18 healthy children were selected and divided into 6 matched groups according to age and gender. Twenty-one KBD adults and 21 healthy adults were selected and divided into 7 matched groups according to age and gender. Every group had 3 patients and 3 healthy persons. Peripheral blood samples were collected and total RNA was extracted respectively. The expression levels of 367 target genes in 4 child groups (24 subjects) and 5 adult groups (30 subjects) were evaluated using customized oligonucleotide microarray. Those genes with ≥2.0 or ≤0.5 expression ratio were regarded as differentially expressed genes. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was conducted to validate the microarray data using the remaining 2 child groups (12 subjects) and 2 adult groups (12 subjects). Results There detected 101 differentially expressed genes in KBD children, accounting for 27.5% of all 367 target genes. It was less than that in KBD adults (159, 43.3%, χ2 = 20.036, P < 0.01). Fifty-seven differentially expressed genes were shared by KBD children and KBD adults but 21 of them were asynchronously expressed in KBD children compared to KBD adults. The result of qRT-PCR experiment was consistent with that of the microarray study. Conclusions There are significant differences in gene expression pattern between KBD children and KBD adults relating to the severity of articular cartilage and motor function damages. Bone-development related genes may play an important role in epiphyseal plate lesion of KBD children and we should pay more attention to its role in the early stage of KBD. Key words: Kashin-Beck disease; Gene expression; Child; Adult