Blood transcriptome analysis revealing aging gene expression profiles in red panda

Abstract

The red panda is an endangered forest species distributed on the edge of the Qinghai Tibet Plateau. The species has been conserved in ex-situ in many countries and its survival is threatened by many diseases. Its immune system is vulnerable to age-associated alterations, which accumulate and result in a progressive deterioration that leads to an increased incidence of diseases. We identified 2,219 differentially expressed genes (DEGs) between geriatric (11-16 years) and adult individuals (4-8 years), and 1690 DEGs between adults and juveniles (1 year). The gene expression and functional annotation results showed that the innate immunity of red pandas increases significantly in geriatric individuals, whereas its change remains unclear when comparing adults and juveniles. We found that the adaptive immunity of red pandas first increased and then decreased with age. We identified CXCR3, BLNK, and CCR4 as the hub genes in the age-related protein-protein interaction network, which showed their central role in age-related immune changes. Many DNA repair genes were down-regulated in geriatric red pandas, suggesting that the DNA repair ability of the blood tissue in geriatric red pandas is significantly reduced. The significantly up-regulated TLR5 in geriatric individuals also suggests the possibility of enhancing the vaccination immune response by incorporating flagellin, which could be used to address decreased vaccine responses caused by age-related declines in immune system function. This work provides an insight into gene expression changes associated with aging and paves the way for effective disease prevention and treatment strategies for red pandas in the future.

Keywords: Aging; Disease prevention; Immune alternations; Red panda; Transcriptome.

Figure 1. Differentially expressed genes.

(A) Volcano plot between geriatric and adults showing the distribution of gene expression plotted against log2 fold change for each gene. Purple and blue dots indicate differentially expressed genes (FDR ≤ 0.05), black dots indicate non-differentially expressed genes. (B) Volcano plot between adults and juveniles. (C) Principal component analysis (PCA) of gene expression between 12 samples. (D) The comparative distribution of 563 common DEGs.

Figure 2. Chord diagram of categories of immune DEGs between geriatric and adults.

Figure 3. Chord diagram of categories of immune DEGs between adults and juveniles.

Figure 4. Cluster analysis of Mfuzz transcriptome expression pattern.

Trend analysis clusters genes with similar expression patterns according to their temporal profiles (juvenile, adult, geriatric). GO enrichment analysis for each cluster is shown in Table S7.