Background The human genome contains remnants of ancient retroviral infections called human endogenous retroviruses (HERV). Their expression is often observed in several diseases of autoimmune or inflammatory nature. However, the exact biological mechanisms induced by HERVs are still poorly understood. We have previously shown that several HERVs of the HERV-K (HML-2) family are strongly transcribed in the peripheral blood mononuclear cells (PBMC) derived from young and old individuals. To examine the potential functional consequences of HERV-K (HML-2) expression, we have now analyzed the correlation of its expression with age-associated changes in the transcriptome using gene set enrichment analysis (GSEA). We focused our analysis on the HERV-K (HML-2) provirus at 1q22, also known as ERVK-7. Results The genes strongly correlating with the expression of HERV-K (HML-2) provirus at 1q22 expression were found to be almost entirely different in young and old individuals. The number of genes strongly correlating (Pearson correlation coefficient ≥ 0.7) with 1q22 expression was 946 genes in the old and 435 in the young, of which only 41 genes correlated strongly in both. Consequently, the related gene ontology (GO) biological processes were different. In the older individuals, many of the highest correlating processes relate to the function of neutrophils. Conclusions The results of this work suggest that the biological processes associated with the expression of HERV-K (HML-2) provirus at 1q22 are different in the blood of young and old individuals. Specifically, a strong association was found in the older individuals between neutrophil activity and the expression of the HERV-K (HML-2) provirus at 1q22. These findings offer insight into potential effects of altered HERV expression in older individuals.

中文翻译：

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衰老对与 HERV-K (HML-2) 前病毒在 1q22 表达相关的转录组变化的影响。

背景 人类基因组包含称为人类内源性逆转录病毒 (HERV) 的古代逆转录病毒感染的残余物。它们的表达经常在几种自身免疫或炎症性质的疾病中观察到。然而，HERVs诱导的确切生物学机制仍然知之甚少。我们之前已经表明，HERV-K (HML-2) 家族的几种 HERV 在来自年轻和年老个体的外周血单个核细胞 (PBMC) 中强烈转录。为了检查 HERV-K (HML-2) 表达的潜在功能后果，我们现在使用基因集富集分析 (GSEA) 分析了其表达与转录组中年龄相关变化的相关性。我们将分析重点放在 1q22 的 HERV-K (HML-2) 前病毒，也称为 ERVK-7。结果发现与1q22表达的HERV-K（HML-2）前病毒表达强烈相关的基因在年轻人和老年人中几乎完全不同。与 1q22 表达强相关（Pearson 相关系数≥0.7）的基因数量在老年人中为 946 个，在年轻人中为 435 个，其中只有 41 个基因在两者中具有强相关性。因此，相关的基因本体（GO）生物学过程是不同的。在老年人中，许多相关性最高的过程与中性粒细胞的功能有关。结论 这项工作的结果表明，与 HERV-K (HML-2) 前病毒在 1q22 表达相关的生物学过程在年轻人和老年人的血液中是不同的。具体来说，在老年人中发现中性粒细胞活性与 1q22 处 HERV-K (HML-2) 前病毒的表达之间存在很强的关联。这些发现提供了对老年人 HERV 表达改变的潜在影响的深入了解。