MicroRNAs （miRNAs）, approximately 21 to 23 nucleotides （nt） in length, belong to a set of smal non-coding RNA molecules that were not thought to be functional until the recent decades. miRNAs play important roles ...MicroRNAs （miRNAs）, approximately 21 to 23 nucleotides （nt） in length, belong to a set of smal non-coding RNA molecules that were not thought to be functional until the recent decades. miRNAs play important roles in many diseases such as various kinds of cancers and immune disorders. Many studies have focused on the relationship between miRNAs and diseases. miRNAs are significant mediators in human growth and development and in the genesis and development of diseases. Almost 30% of the activity of protein-coding genes is forecasted to be regulated by miRNAs in mammals, and some miRNAs are regarded as potential therapeutic targets for various diseases. In this review, we outline some functions of miRNAs, especialy those related to diseases.展开更多
Transposable elements(TEs) are mobile genomic sequences of DNA capable of autonomous and nonautonomous duplication. TEs have been highly successful,and nearly half of the human genome now consists of various families ...Transposable elements(TEs) are mobile genomic sequences of DNA capable of autonomous and nonautonomous duplication. TEs have been highly successful,and nearly half of the human genome now consists of various families of TEs. Originally thought to be non-functional,these elements have been co-opted by animal genomes to perform a variety of physiological functions ranging from TE-derived proteins acting directly in normal biological functions, to innovations in transcription factor logic and influence on epigenetic control of gene expression. During embryonic development, when the genome is epigenetically reprogrammed and DNA-demethylated, TEs are released from repression and show embryonic stage-specific expression, and in human and mouse embryos, intact TEderived endogenous viral particles can even be detected. Asimilar process occurs during the reprogramming of somatic cells to pluripotent cells: When the somatic DNA is demethylated, TEs are released from repression. In embryonic stem cells(ESCs), where DNA is hypomethylated, an elaborate system of epigenetic control is employed to suppress TEs, a system that often overlaps with normal epigenetic control of ESC gene expression. Finally, many long non-coding RNAs(lnc RNAs) involved in normal ESC function and those assisting or impairing reprogramming contain multiple TEs in their RNA. These TEs may act as regulatory units to recruit RNA-binding proteins and epigenetic modifiers. This review covers how TEs are interlinked with the epigenetic machinery and lnc RNAs, and how these links influence each other to modulate aspects of ESCs,embryogenesis, and somatic cell reprogramming.展开更多
基金Supported by a grant from the Natural Science Foundation of Hebei Province(No.C2009001151)
文摘MicroRNAs （miRNAs）, approximately 21 to 23 nucleotides （nt） in length, belong to a set of smal non-coding RNA molecules that were not thought to be functional until the recent decades. miRNAs play important roles in many diseases such as various kinds of cancers and immune disorders. Many studies have focused on the relationship between miRNAs and diseases. miRNAs are significant mediators in human growth and development and in the genesis and development of diseases. Almost 30% of the activity of protein-coding genes is forecasted to be regulated by miRNAs in mammals, and some miRNAs are regarded as potential therapeutic targets for various diseases. In this review, we outline some functions of miRNAs, especialy those related to diseases.
基金supported by the National Natural Science Foundation of China(31471242,31550110206)China Postdoctoral Association(2014M552250)the Science and Technology Planning Project of Guangdong Province,China(2014B030301058)
文摘Transposable elements(TEs) are mobile genomic sequences of DNA capable of autonomous and nonautonomous duplication. TEs have been highly successful,and nearly half of the human genome now consists of various families of TEs. Originally thought to be non-functional,these elements have been co-opted by animal genomes to perform a variety of physiological functions ranging from TE-derived proteins acting directly in normal biological functions, to innovations in transcription factor logic and influence on epigenetic control of gene expression. During embryonic development, when the genome is epigenetically reprogrammed and DNA-demethylated, TEs are released from repression and show embryonic stage-specific expression, and in human and mouse embryos, intact TEderived endogenous viral particles can even be detected. Asimilar process occurs during the reprogramming of somatic cells to pluripotent cells: When the somatic DNA is demethylated, TEs are released from repression. In embryonic stem cells(ESCs), where DNA is hypomethylated, an elaborate system of epigenetic control is employed to suppress TEs, a system that often overlaps with normal epigenetic control of ESC gene expression. Finally, many long non-coding RNAs(lnc RNAs) involved in normal ESC function and those assisting or impairing reprogramming contain multiple TEs in their RNA. These TEs may act as regulatory units to recruit RNA-binding proteins and epigenetic modifiers. This review covers how TEs are interlinked with the epigenetic machinery and lnc RNAs, and how these links influence each other to modulate aspects of ESCs,embryogenesis, and somatic cell reprogramming.
