Computational Medicine Center, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
University of Utah Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA.
J Thromb Haemost. 2023 Nov;21(11):3252-3267. doi: 10.1016/j.jtha.2023.07.028. Epub 2023 Aug 7.
The small noncoding RNAs (sncRNAs) in megakaryocytes (MKs) and platelets are not well characterized. Neither is the impact of SARS-CoV-2 infection on the sncRNAs of platelets.
To investigate the sorting of MK sncRNAs into platelets, and the differences in the platelet sncRNAomes of healthy donors (HDs) and COVID-19 patients.
We comprehensively profiled sncRNAs from MKs cultured from cord blood-derived CD34 cells, platelets from HDs, and platelets from patients with moderate and severe SARS-CoV-2 infection. We also comprehensively profiled Argonaute (AGO)-bound sncRNAs from the cultured MKs.
We characterized the sncRNAs in MKs and platelets and can account for ∼95% of all sequenced reads. We found that MKs primarily comprise microRNA isoforms (isomiRs), tRNA-derived fragments (tRFs), rRNA-derived fragments (rRFs), and Y RNA-derived fragments (yRFs) in comparable abundances. The platelets of HDs showed a skewed distribution by comparison: 56.7% of all sncRNAs are yRFs, 34.4% are isomiRs, and <2.0% are tRFs and rRFs. Most isomiRs in MKs and platelets are either noncanonical, nontemplated, or both. When comparing MKs and platelets from HDs, we found numerous isomiRs, tRFs, rRFs, and yRFs showing opposite enrichments or depletions, including molecules from the same parental miRNA arm, tRNA, rRNA, or Y RNA. The sncRNAome of platelets from patients with COVID-19 is skewed compared to that of HDs with only 19.8% of all sncRNAs now being yRFs, isomiRs increasing to 63.6%, and tRFs and rRFs more than tripling their presence to 6.1%.
The sncRNAomes of MKs and platelets are very rich and more complex than it has been believed. The evidence suggests complex mechanisms that sort MK sncRNAs into platelets. SARS-CoV-2 infection acutely alters the contents of platelets by changing the relative proportions of their sncRNAs.
巨核细胞（MKs）和血小板中的小非编码 RNA（sncRNA）尚未得到很好的描述。SARS-CoV-2 感染对血小板 sncRNA 的影响也不清楚。
研究 MK sncRNA 向血小板的分选情况，以及健康供体（HD）和 COVID-19 患者血小板 sncRNA 组的差异。
我们全面分析了从脐带血衍生的 CD34 细胞培养的 MK、HD 血小板和中度至重度 SARS-CoV-2 感染患者血小板中的 sncRNA。我们还全面分析了培养的 MK 中 Argonaute（AGO）结合的 sncRNA。
我们对 MK 和血小板中的 sncRNA 进行了特征描述，可解释约 95%的测序reads。我们发现 MK 主要由 microRNA 同工型（isomiRs）、tRNA 衍生片段（tRFs）、rRNA 衍生片段（rRFs）和 Y RNA 衍生片段（yRFs）组成，丰度相当。相比之下，HD 血小板的 sncRNA 分布存在明显的偏倚：所有 sncRNA 的 56.7%是 yRFs，34.4%是 isomiRs，<2.0%是 tRFs 和 rRFs。MK 和血小板中的大多数 isomiRs 是非规范的、非模板的或兼而有之。当比较 HD 的 MK 和血小板时，我们发现许多 isomiRs、tRFs、rRFs 和 yRFs 表现出相反的富集或耗竭，包括来自同一 miRNA 臂、tRNA、rRNA 或 Y RNA 的分子。与 HD 相比，COVID-19 患者的血小板 sncRNA 组存在偏倚，只有 19.8%的所有 sncRNA 是 yRFs，isomiRs 增加到 63.6%，tRFs 和 rRFs 的存在增加了两倍多，达到 6.1%。
MK 和血小板的 sncRNA 组非常丰富，比以前认为的要复杂。有证据表明，通过改变 sncRNA 的相对比例，复杂的机制将 MK sncRNA 分选到血小板中。SARS-CoV-2 感染通过改变血小板 sncRNA 的相对比例，急性改变血小板的内容物。
