Comparing microRNA in milk small extracellular vesicles among healthy cattle and cattle at high risk for bovine leukemia virus transmission
Comparing microRNA in milk small extracellular vesicles among healthy cattle and cattle at high risk for bovine leukemia virus transmission
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DOI：
10.3168/jds.2021-20989
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发表时间：
2022-05-11
影响因子：
3.5
通讯作者：
Inoshima, Yasuo
中科院分区：
文献类型：
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作者：
Nakanishi, Ryoka;Takashima, Shigeo;Inoshima, Yasuo
地方性牛白血病（EBL）是由牛白血病病毒（BLV）感染引起的一种B细胞淋巴肉瘤。在日本，法律不允许人类食用被诊断患有EBL的牛，从而给农民造成严重的经济损失。BLV在日本的流行率很高（在奶牛和肉牛中分别为40.9%和28.7%），这使得难以对BLV感染的牛进行检测和屠宰。这就需要通过早期检测、隔离和清除前病毒载量高的BLV感染牛（被认为是BLV传播的高风险）来防止BLV感染在牛中的传播。我们的目的是通过比较牛奶小细胞外囊泡（sEV）中的microRNA（miRNA）谱来识别BLV传播的高风险牛。首先，通过使用含有牛和人的miRNA的混合探针的微阵列，比较了4头未感染牛和4头BLV感染的高前病毒载量的牛中sEV的miRNA谱。与未感染牛相比，在BLV感染牛的乳汁sEV中观察到hsa-miR-557和hsa-miR-19 b-1- 5 p的量显著较低，hsa-miR-424- 5 p的量不显著但较高。接下来，为了评估上述miRNA用于鉴定BLV传播高风险牛的效用，我们使用从5头未感染牛和17头具有高前病毒载量的BLV感染牛新收集的牛奶sEV进行定量实时PCR。hsa-miR-424- 5 p的循环阈值在来自BLV感染牛的乳汁sEV中显著较低。hsa-miR-557和hsa-miR-19 b-1- 5 p的PCR检测不可用或未观察到显著差异。这些结果表明，来自BLV感染牛的乳汁sEV中hsa-miR-424- 5 p的量较高，乳汁sEV中hsa-miR-424- 5 p的增加可能是BLV传播高风险牛的特征趋势之一。此外，评估牛奶sEV中的特征性miRNA量（每天可以通过挤奶回收两次）可能有助于对奶牛群中的牛进行常规监测，而不是采血。
Enzootic bovine leukosis (EBL) is a B-cell lymphosarcoma caused by bovine leukemia virus (BLV) infection. In Japan, cattle diagnosed with EBL are not permitted for human consumption by the law, thereby causing serious economic losses to farmers. The prevalence of BLV is high in Japan (40.9% in dairy cattle and 28.7% in beef cattle, respectively), which makes it difficult to perform the test-and-slaughter of BLV-infected cattle. This necessitates preventing the spread of BLV infection in cattle by early detection, segregation, and the removal of BLV-infected cattle with high proviral load, which are considered high risk for BLV transmission. We aimed to identify cattle that were at high risk for BLV transmission by comparing microRNA (miRNA) profiles in milk small extracellular vesicles (sEV). At first, miRNA profiles in sEV were compared among 4 uninfected cattle and 4 BLV-infected cattle with high proviral load by using a microarray containing mixed probes for miRNA of cattle and humans. Significantly lower amounts of hsa-miR-557 and hsa-miR-19b-1-5p, and insignificantly but higher amounts of hsa-miR-424-5p were observed in milk sEV from BLV-infected cattle than those from uninfected cattle. Next, to evaluate the utility of the aforementioned miRNAs for the identification of cattle that were at high risk for BLV transmission, we performed quantitative real-time PCR using milk sEV newly collected from 5 uninfected cattle and 17 BLV-infected cattle with high proviral load. The cycle threshold value of hsa-miR-424-5p was significantly lower in milk sEV from BLV-infected cattle. The PCR detection was unavailable or a significant difference was not observed for hsa-miR-557 and hsa-miR-19b-1-5p, respectively. These results suggest that the amount of hsa-miR-424-5p was higher in milk sEV from BLV-infected cattle and increasing the hsa-miR-424-5p in milk sEV could be one of the characteristic trends in cattle that are high risk for BLV transmission. Moreover, assessing characteristic miRNA amounts in milk sEV, which can be recovered twice a day by milking, could be useful for the routine monitoring of cattle in dairy herds instead of blood collection.