RESUMO
BACKGROUND: Human dental pulp stem cells are important oral mesenchymal stem cells with strongproliferation and multidirectional differentiation functions. In-depth studies on the Human Genome Project make people gradually reali ze that functional non-coding RNAs play an extraordinary role in regulating gene expression. OBJECTIVE: To discuss the function and application of non-coding RNAs in human dental pulp stem cells. METHODS: Using “ncRNAs, human dental pulp stem cells, regenerative medicine” as keywords in English and Chinese, the first author searched PubMed, Medline, CNKI, and WanFang for relevant articles published from 2005 to 2019. Literatures unrelated to the purpose of the study and repetitive literatures were excluded, and 71 articles that meet the criteria were included for review. RESULTS AND CONCLUSION: It is now generally believed that non-coding RNAs can be used as a signal of specific cell state, providing prognostic value and even providing treatment options for patients. With the continuous development of regenerative medicine applications, human dental pulp stem cells are arousing increasing attentions. Exploration on the relationship between non-coding RNAs and human dental pulp stem cells provides a new approach for the clinical application of human dental pulp stem cells.
RESUMO
PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs of 24－32 nucleotides (nt) in length, which were first found in 2006. The piRNAs in germ cells interact with reproduction-specific PIWI proteins and play an important role in the development of the reproductive system. In the reproductive system of the male mouse, piRNAs arise from long single stranded precursor transcripts expressed in discrete genomic regions. The productions of piRNAs are termed primary piRNA biogenesis and secondary piRNA biogenesis. Mature piRNAs can silence the genome instability threat posed by mobile genetic elements called transposons. Furthermore, piRNAs regulate the expression of mRNAs transcriptionally and post-transcriptionally in spermiogenesis. This review summarizes the biogenesis and key functions of piRNAs in the reproductive system of male mice.
RESUMO
Piwi-interacting RNAs (piRNAs) are a distinct class of small non-coding RNAs specifically expressed in the germline of many species. Studies show that the piRNA pathway influences spermatogenesis by translation regulation, germline stem cell maintenance, RNA degradation and gene defense in addition to inhibition of transposable elements. This review presents an overview of the piRNA pathway focusing on piRNA, PIWI protein and other related proteins and outlines the latest advances in the studies of the piRNA pathway in spermatogenesis.
RESUMO
Recently, a significant understanding of the molecular mechanisms regulating spermatogenesis has been achieved utilizing small RNA molecules (small RNAs), including small interfering RNAs (siRNAs), microRNAs (miRNAs), and Piwi-interacting RNAs (piRNAs) which emerged as important regulators of gene expression at the post-transcriptional or translation level. piRNAs are only present in pachytene spermatocytes and round spermatids, whereas miRNAs are expressed abundantly in male germ cells throughout spermatogenesis. This review is aimed at providing a glimpse of piRNAs and their interacting family proteins such as PIWIL1, PIWIL2, and PIWIL4 in spermatogenesis.