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MDRL lncRNA regulates the processing of miR-484 primary transcript by targeting miR-361.

Wang K, Sun T, Li N, Wang Y, Wang JX, Zhou LY, Long B, Liu CY, Liu F, Li PF - PLoS Genet. (2014)

Bottom Line: The results showed that miR-361 that predominantly located in nucleus can directly bind to primary transcript of miR-484 (pri-miR-484) and prevent its processing by Drosha into pre-miR-484. miR-361 is able to regulate mitochondrial fission and apoptosis by regulating miR-484 levels.Our present study reveals a novel regulating model of mitochondrial fission program which is composed of MDRL, miR-361 and miR-484.Our work not only expands the function of the lncRNA pathway in gene regulation but also establishes a new mechanism for controlling miRNA expression.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation, but whether lncRNAs operate in the processing of miRNA primary transcript is unclear. Also, whether lncRNAs are involved in the regulation of the mitochondrial network remains to be elucidated. Here, we report that a long noncoding RNA, named mitochondrial dynamic related lncRNA (MDRL), affects the processing of miR-484 primary transcript in nucleus and regulates the mitochondrial network by targeting miR-361 and miR-484. The results showed that miR-361 that predominantly located in nucleus can directly bind to primary transcript of miR-484 (pri-miR-484) and prevent its processing by Drosha into pre-miR-484. miR-361 is able to regulate mitochondrial fission and apoptosis by regulating miR-484 levels. In exploring the underlying molecular mechanism by which miR-361 is regulated, we identified MDRL and demonstrated that it could directly bind to miR-361 and downregulate its expression levels, which promotes the processing of pri-miR-484. MDRL inhibits mitochondrial fission and apoptosis by downregulating miR-361, which in turn relieves inhibition of miR-484 processing by miR-361. Our present study reveals a novel regulating model of mitochondrial fission program which is composed of MDRL, miR-361 and miR-484. Our work not only expands the function of the lncRNA pathway in gene regulation but also establishes a new mechanism for controlling miRNA expression.

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miR-361 provokes mitochondrial fission program.A. Knockdown of miR-361 prevents mitochondrial fission induced by A/R. Cardiomyocytes were transfected with miR-361 antagomir (anta-361) or the antagomir negative control (anta-NC), then exposed to A/R. The cells were stained with MitoTracker Green (left panel), Bar = 20 µm. The cells with fragmented mitochondria were counted (right panel). *p<0.05 versus A/R alone. B. Knockdown of miR-361 prevents apoptosis induced by A/R. Cardiomyocytes were treated as described for (A). Apoptosis was analyzed by TUNEL assay. *p<0.05 versus A/R alone. C. Knockdown of miR-361 attenuates mitochondrial fission upon I/R. Adult male C57BL/6 mice (8 weeks old) were delivered in three consecutive days, intravenous injections of miR-361 antagomir (anta-361) or antagomir control (anta-NC) at doses of 35 mg/kg body weight. 3 days after injection the mice were exposed to 45 min of ischemia and 3 hours of reperfusion. Counting of the fragmented mitochondria was shown in upper panel. Counting of the apoptotic cell was shown in low panel and right panel. TUNEL-positive myocyte nuclei (apoptotic cells) are green. Nuclei stained by DAPI show blue. Cardiomyocytes were labeled with α-actinin. n = 6, *p<0.05 versus I/R alone. D and E. miR-361 transgenic mice exhibited increased mitochondrial fission, apoptosis and myocardial infarction sizes in response to ischemia/reperfusion (I/R). Wild type C57BL/6 mice and miR-361 transgenic mice (8 weeks old) were exposed to 45 min of ischemia and 3 hours of reperfusion. Mitochondrial fission, apoptosis (D) and myocardial infarction sizes (E) were analyzed. n = 8, *p<0.05 versus WT+I/R. F. The knockdown of miR-484 attenuates the inhibitory effect of miR-361 knockdown on mitochondria fission and apoptosis. Cardiomyocytes were transfeted with the miR-361 antagomir, miR-484 antagomir or antagomir negative control, and then treated with A/R. Mitochondria fission and apoptosis were analyzed. *p<0.05.
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pgen-1004467-g003: miR-361 provokes mitochondrial fission program.A. Knockdown of miR-361 prevents mitochondrial fission induced by A/R. Cardiomyocytes were transfected with miR-361 antagomir (anta-361) or the antagomir negative control (anta-NC), then exposed to A/R. The cells were stained with MitoTracker Green (left panel), Bar = 20 µm. The cells with fragmented mitochondria were counted (right panel). *p<0.05 versus A/R alone. B. Knockdown of miR-361 prevents apoptosis induced by A/R. Cardiomyocytes were treated as described for (A). Apoptosis was analyzed by TUNEL assay. *p<0.05 versus A/R alone. C. Knockdown of miR-361 attenuates mitochondrial fission upon I/R. Adult male C57BL/6 mice (8 weeks old) were delivered in three consecutive days, intravenous injections of miR-361 antagomir (anta-361) or antagomir control (anta-NC) at doses of 35 mg/kg body weight. 3 days after injection the mice were exposed to 45 min of ischemia and 3 hours of reperfusion. Counting of the fragmented mitochondria was shown in upper panel. Counting of the apoptotic cell was shown in low panel and right panel. TUNEL-positive myocyte nuclei (apoptotic cells) are green. Nuclei stained by DAPI show blue. Cardiomyocytes were labeled with α-actinin. n = 6, *p<0.05 versus I/R alone. D and E. miR-361 transgenic mice exhibited increased mitochondrial fission, apoptosis and myocardial infarction sizes in response to ischemia/reperfusion (I/R). Wild type C57BL/6 mice and miR-361 transgenic mice (8 weeks old) were exposed to 45 min of ischemia and 3 hours of reperfusion. Mitochondrial fission, apoptosis (D) and myocardial infarction sizes (E) were analyzed. n = 8, *p<0.05 versus WT+I/R. F. The knockdown of miR-484 attenuates the inhibitory effect of miR-361 knockdown on mitochondria fission and apoptosis. Cardiomyocytes were transfeted with the miR-361 antagomir, miR-484 antagomir or antagomir negative control, and then treated with A/R. Mitochondria fission and apoptosis were analyzed. *p<0.05.

Mentions: Our previous findings found that miR-484 could inhibit mitochondrial fission and apoptosis in cardiomyocytes [24]. The present result appears that miR-361 can interact with pri-miR-484 and regulate mature miR-484 levels. We thus explored the functional role of miR-361 in mitochondrial fission and apoptosis. To this end, the antagomir of miR-361 was employed to knock down endogenous miR-361. Mitochondrial fission induced by A/R was attenuated by the knockdown of miR-361 (Figure 3A). Concomitantly, apoptosis was reduced in the presence of miR-361 antagomir (Figure 3B). These data indicate that miR-361 can promote mitochondrial fission and apoptosis upon A/R treatment.


MDRL lncRNA regulates the processing of miR-484 primary transcript by targeting miR-361.

Wang K, Sun T, Li N, Wang Y, Wang JX, Zhou LY, Long B, Liu CY, Liu F, Li PF - PLoS Genet. (2014)

miR-361 provokes mitochondrial fission program.A. Knockdown of miR-361 prevents mitochondrial fission induced by A/R. Cardiomyocytes were transfected with miR-361 antagomir (anta-361) or the antagomir negative control (anta-NC), then exposed to A/R. The cells were stained with MitoTracker Green (left panel), Bar = 20 µm. The cells with fragmented mitochondria were counted (right panel). *p<0.05 versus A/R alone. B. Knockdown of miR-361 prevents apoptosis induced by A/R. Cardiomyocytes were treated as described for (A). Apoptosis was analyzed by TUNEL assay. *p<0.05 versus A/R alone. C. Knockdown of miR-361 attenuates mitochondrial fission upon I/R. Adult male C57BL/6 mice (8 weeks old) were delivered in three consecutive days, intravenous injections of miR-361 antagomir (anta-361) or antagomir control (anta-NC) at doses of 35 mg/kg body weight. 3 days after injection the mice were exposed to 45 min of ischemia and 3 hours of reperfusion. Counting of the fragmented mitochondria was shown in upper panel. Counting of the apoptotic cell was shown in low panel and right panel. TUNEL-positive myocyte nuclei (apoptotic cells) are green. Nuclei stained by DAPI show blue. Cardiomyocytes were labeled with α-actinin. n = 6, *p<0.05 versus I/R alone. D and E. miR-361 transgenic mice exhibited increased mitochondrial fission, apoptosis and myocardial infarction sizes in response to ischemia/reperfusion (I/R). Wild type C57BL/6 mice and miR-361 transgenic mice (8 weeks old) were exposed to 45 min of ischemia and 3 hours of reperfusion. Mitochondrial fission, apoptosis (D) and myocardial infarction sizes (E) were analyzed. n = 8, *p<0.05 versus WT+I/R. F. The knockdown of miR-484 attenuates the inhibitory effect of miR-361 knockdown on mitochondria fission and apoptosis. Cardiomyocytes were transfeted with the miR-361 antagomir, miR-484 antagomir or antagomir negative control, and then treated with A/R. Mitochondria fission and apoptosis were analyzed. *p<0.05.
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Related In: Results  -  Collection

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pgen-1004467-g003: miR-361 provokes mitochondrial fission program.A. Knockdown of miR-361 prevents mitochondrial fission induced by A/R. Cardiomyocytes were transfected with miR-361 antagomir (anta-361) or the antagomir negative control (anta-NC), then exposed to A/R. The cells were stained with MitoTracker Green (left panel), Bar = 20 µm. The cells with fragmented mitochondria were counted (right panel). *p<0.05 versus A/R alone. B. Knockdown of miR-361 prevents apoptosis induced by A/R. Cardiomyocytes were treated as described for (A). Apoptosis was analyzed by TUNEL assay. *p<0.05 versus A/R alone. C. Knockdown of miR-361 attenuates mitochondrial fission upon I/R. Adult male C57BL/6 mice (8 weeks old) were delivered in three consecutive days, intravenous injections of miR-361 antagomir (anta-361) or antagomir control (anta-NC) at doses of 35 mg/kg body weight. 3 days after injection the mice were exposed to 45 min of ischemia and 3 hours of reperfusion. Counting of the fragmented mitochondria was shown in upper panel. Counting of the apoptotic cell was shown in low panel and right panel. TUNEL-positive myocyte nuclei (apoptotic cells) are green. Nuclei stained by DAPI show blue. Cardiomyocytes were labeled with α-actinin. n = 6, *p<0.05 versus I/R alone. D and E. miR-361 transgenic mice exhibited increased mitochondrial fission, apoptosis and myocardial infarction sizes in response to ischemia/reperfusion (I/R). Wild type C57BL/6 mice and miR-361 transgenic mice (8 weeks old) were exposed to 45 min of ischemia and 3 hours of reperfusion. Mitochondrial fission, apoptosis (D) and myocardial infarction sizes (E) were analyzed. n = 8, *p<0.05 versus WT+I/R. F. The knockdown of miR-484 attenuates the inhibitory effect of miR-361 knockdown on mitochondria fission and apoptosis. Cardiomyocytes were transfeted with the miR-361 antagomir, miR-484 antagomir or antagomir negative control, and then treated with A/R. Mitochondria fission and apoptosis were analyzed. *p<0.05.
Mentions: Our previous findings found that miR-484 could inhibit mitochondrial fission and apoptosis in cardiomyocytes [24]. The present result appears that miR-361 can interact with pri-miR-484 and regulate mature miR-484 levels. We thus explored the functional role of miR-361 in mitochondrial fission and apoptosis. To this end, the antagomir of miR-361 was employed to knock down endogenous miR-361. Mitochondrial fission induced by A/R was attenuated by the knockdown of miR-361 (Figure 3A). Concomitantly, apoptosis was reduced in the presence of miR-361 antagomir (Figure 3B). These data indicate that miR-361 can promote mitochondrial fission and apoptosis upon A/R treatment.

Bottom Line: The results showed that miR-361 that predominantly located in nucleus can directly bind to primary transcript of miR-484 (pri-miR-484) and prevent its processing by Drosha into pre-miR-484. miR-361 is able to regulate mitochondrial fission and apoptosis by regulating miR-484 levels.Our present study reveals a novel regulating model of mitochondrial fission program which is composed of MDRL, miR-361 and miR-484.Our work not only expands the function of the lncRNA pathway in gene regulation but also establishes a new mechanism for controlling miRNA expression.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation, but whether lncRNAs operate in the processing of miRNA primary transcript is unclear. Also, whether lncRNAs are involved in the regulation of the mitochondrial network remains to be elucidated. Here, we report that a long noncoding RNA, named mitochondrial dynamic related lncRNA (MDRL), affects the processing of miR-484 primary transcript in nucleus and regulates the mitochondrial network by targeting miR-361 and miR-484. The results showed that miR-361 that predominantly located in nucleus can directly bind to primary transcript of miR-484 (pri-miR-484) and prevent its processing by Drosha into pre-miR-484. miR-361 is able to regulate mitochondrial fission and apoptosis by regulating miR-484 levels. In exploring the underlying molecular mechanism by which miR-361 is regulated, we identified MDRL and demonstrated that it could directly bind to miR-361 and downregulate its expression levels, which promotes the processing of pri-miR-484. MDRL inhibits mitochondrial fission and apoptosis by downregulating miR-361, which in turn relieves inhibition of miR-484 processing by miR-361. Our present study reveals a novel regulating model of mitochondrial fission program which is composed of MDRL, miR-361 and miR-484. Our work not only expands the function of the lncRNA pathway in gene regulation but also establishes a new mechanism for controlling miRNA expression.

Show MeSH
Related in: MedlinePlus