466 research outputs found
MIR-206 mediates YAP-induced cardiac hypertrophy and survival
No full textRATIONALE:
In Drosophila, the Hippo signaling pathway negatively regulates organ size by suppressing cell proliferation and survival through the inhibition of Yorkie, a transcriptional cofactor. Yes-associated protein (YAP), the mammalian homolog of Yorkie, promotes cardiomyocyte growth and survival in postnatal hearts. However, the underlying mechanism responsible for the beneficial effect of YAP in cardiomyocytes remains unclear.
OBJECTIVES:
We investigated whether miR-206, a microRNA known to promote hypertrophy in skeletal muscle, mediates the effect of YAP on promotion of survival and hypertrophy in cardiomyocytes.
METHODS AND RESULTS:
Microarray analysis indicated that YAP increased miR-206 expression in cardiomyocytes. Increased miR-206 expression induced cardiac hypertrophy and inhibited cell death in cultured cardiomyocytes, similar to that of YAP. Downregulation of endogenous miR-206 in cardiomyocytes attenuated YAP-induced cardiac hypertrophy and survival, suggesting that miR-206 plays a critical role in mediating YAP function. Cardiac-specific overexpression of miR-206 in mice induced hypertrophy and protected the heart from ischemia/reperfusion injury, whereas suppression of miR-206 exacerbated ischemia/reperfusion injury and prevented pressure overload-induced cardiac hypertrophy. miR-206 negatively regulates Forkhead box protein P1 expression in cardiomyocytes and overexpression of Forkhead box protein P1 attenuated miR-206-induced cardiac hypertrophy and survival, suggesting that Forkhead box protein P1 is a functional target of miR-206.
CONCLUSIONS:
YAP increases the abundance of miR-206, which in turn plays an essential role in mediating hypertrophy and survival by silencing Forkhead box protein P1 in cardiomyocytes
Phra Maha Katsapa ro phop Phra Si-an na Kakutthabatkhiri
No full textThe author illustrates the legend of Phra Maha Katsapa -- one of Lord Buddha's important disciples-- and his retreat in the Mount Kakutthabat. Phra Maha Katsapa was believed to wait in a cave on that mountain until the time Phra Si-an would reincarnate and achieve nirvana. The author also refers to recent attempt of a British Buddhist monk in finding the location of the mountain in India
MiR-503 expression in COPD and control lung fibroblasts in the absence or presence of IL-1ß and TNF-α.
No full textControl (White square, n = 19) and COPD (Black triangle, n = 18) lung fibroblasts were cultured with 10% FCS containing DMEM for 2 days, after which the medium was changed to DMEM in the absence and presence of IL-1ß and TNF-α (1 ng/ml). After 1 day, total RNA was extracted from the cultured cells. MiR-503 expression was examined by real time qPCR. Vertical axis: level of miR-503 expression, expressed as fold of 18s-rRNA values in the same sample. Horizontal axis: culture condition. *p p p < 0.001.</p
MiR-503 inhibits VEGF production from control and COPD lung fibroblasts.
No full textPrimary adult control (White bar) and COPD (Black bar) lung fibroblasts (n = 4, respectively) cultured in monolayer were transfected with miR-503 mimic and control transfection reagent, as described in Materials and Methods. 24hr after transfection, the medium was changed to DMEM containing 0.2% FCS, (A, C) without (baseline) or (B, D) with IL-1ß and TNF-α (1 ng/ml). (A, B) After 2 days, the culture medium was harvested and assayed for VEGF by ELISA. Vertical axis: VEGF release (pg per 105 cells per 2 days). (C, D) Cell number after stimulation (105). Horizontal axis: culture condition. *p < 0.05 compared with the values of control miRNA in the same group.</p
MiR-503 inhibits VEGF protein release and mRNA expression of human lung fibroblasts by direct binding to the 3’ untranslated region (UTR) of VEGF mRNA.
No full text(A-D) Primary human fetal lung fibroblasts (HFL-1 cells) cultured in monolayer were transfected with miR-503 mimic (Black bar) or control miRNA (White bar) transfection reagent, as described in Materials and Methods. 24hr after transfection, the medium was changed to DMEM containing 0.2% FCS, with or without IL-1ß and TNF-α (1 ng/ml), TGF-ß1 (1 ng/ml), or PGE2 (1 x 10−7 M). (A, B) 3 days after transfection, the culture medium was harvested and assayed for (A) VEGF or (B) IL-8 (with or without IL-1ß and TNF-α) by ELISA. (A) Vertical axis: VEGF release (pg per 105 cells per 2 days). (B) Vertical axis: IL-8 release (pg per 105 cells per 2 days). Horizontal axis: culture condition. (C) 1 day after transfection, RNA was isolated and endogenous miR-503 expression was analyzed in the presence of control miRNA or miR-503 mimic by real-time qPCR. Vertical axis: level of miR503 expression, expressed as fold of 18s-rRNA values. (D) 2 days after transfection, RNA was isolated and assayed for VEGF mRNA by real-time qPCR. Vertical axis: level of VEGF mRNA expression, expressed as fold of 18s-rRNA values. Horizontal axis: culture conditions. *p p p < 0.05. The data presented are means ± SE from 3 separate experiments.</p
Thioredoxin 1 Negatively Regulates Angiotensin II–Induced Cardiac Hypertrophy Through Upregulation of miR-98/let-7
No full text
Rationale:
Thioredoxin (Trx)1 inhibits pathological cardiac hypertrophy. MicroRNAs (miRNAs) are small noncoding RNAs that downregulate posttranscriptional expression of target molecules.
Objectives:
We investigated the role of miRNAs in mediating the antihypertrophic effect of Trx1 on angiotensin II (Ang II)–induced cardiac hypertrophy.
Methods and Results:
Microarray analyses of mature rodent microRNAs and quantitative RT-PCR/Northern blot analyses showed that Trx1 upregulates members of the let-7 family, including miR-98, in the heart and the cardiomyocytes therein. Adenovirus-mediated expression of miR-98 in cardiomyocytes reduced cell size both at baseline and in response to Ang II. Knockdown of miR-98, and of other members of the let-7 family, augmented Ang II–induced cardiac hypertrophy, and attenuated Trx1-mediated inhibition of Ang II–induced cardiac hypertrophy, suggesting that endogenous miR-98/let-7 mediates the antihypertrophic effect of Trx1. Cyclin D2 is one of the predicted targets of miR-98. Ang II significantly upregulated cyclin D2, which in turn plays an essential role in mediating Ang II–induced cardiac hypertrophy, whereas overexpression of Trx1 inhibited Ang II–induced upregulation of cyclin D2. miR-98 decreased both expression of cyclin D2 and the activity of a cyclin D2 3′UTR luciferase reporter, suggesting that both Trx1 and miR-98 negatively regulate cyclin D2. Overexpression of cyclin D2 attenuated the suppression of Ang II–induced cardiac hypertrophy by miR-98, suggesting that the antihypertrophic actions of miR-98 are mediated in part by downregulation of cyclin D2.
Conclusions:
These results suggest that Trx1 upregulates expression of the let-7 family, including miR-98, which in turn inhibits cardiac hypertrophy, in part through downregulation of cyclin D2.
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G3bp1 regulates miR-1 processing in cardiomyocytes.
No full text<p>(a) Neonatal myocytes were treated with Ad-LacZ or Ad-G3bp1 for 24hrs; total RNA extracted was used for qPCR analysis for rno-primary and rno-pre-miR-1. The results were normalized to 18S, averaged and plotted. Error bars represents SEM, and * is p<0.05, n = 3. (b) Neonatal myocytes cultured in serum free conditions were treated with Ad-LacZ, Ad-G3bp1, Ad-anti-miR-1 (two doses, as indicated) or 10% FBS for 24hrs before extracting total RNA for Northern Blots. Blots were probed for miR-1, anti-miR-1 sequence or U6. 5S is shown as loading control. (c) Myocytes were cultured and treated with adenovirus expressing shRNA against G3bp1 (Ad-siG3bp), Ad-siLUC (control virus) or 10% FBS, as indicated. Northern blots were performed and probed for miR-1 and miR-21 (specificity control), 5S is shown as loading control. (d) Northern blots from 3a and b, and two independent blots were scanned, quantified, averaged and plotted. The error bars represents SEM and * p<0.05 vs. SF control. (e) Western blot analysis of the cytoplasmic and nuclear fractions of protein lysate was performed on myocytes for the indicated genes on myocytes treated with Ad-lacZ (control virus), Ad-G3bp1 or 10% FBS, as indicated for 24hrs. (f) Western blot analysis of cytoplasmic and nuclear fractions of protein lysate was performed on myocytes treated with Ad-siLUC (control virus), Ad-siG3BP1 or 10% FBS, as indicated. (g) Total protein lysate from cultured myocytes treated with Ad-lacZ (control virus), Ad-G3bp1 or Ad-miR-1, as indicated were separated by SDS-PAGE and protein expression of selected genes analyzed, n = 2. (h) Western blots were quantified, averaged and plotted. Error bars represents SEM and * p<0.05 vs. respective control. All experiments were performed in triplicates, unless indicated otherwise and representative blots have been shown.</p
MiR-1 expression is posttranscriptionally regulated during cardiac hypertrophy.
No full text<p>Pool of three sham/adult and TAC operated mouse hearts were used for anti-RNA pol II, anti-H3K9ac and anti-Gtf2b ChIP-Seq. Binary analysis files (BAR) from the ChIP-Seq data was viewed in Affymetrix’s Integrated Genome Browser (IGB), which shows the fragment densities of RNA pol II, H3K9ac and Gtf2b (<i>y-</i>axis) aligned in 32–50 nucleotide bins along the chromosomal coordinates (<i>x</i>-axis) for miR-1-133 clusters. The arrow indicates the transcription start site and the direction of transcription. (a) IGB images of miR-1-1 and miR-133a-2 transcript with RNA polII, H3K3ac and Gtf2b densities across intergenic regions of chromosome 2. (b) IGB images of miR-1-2 and miR-133a-1 cluster with RNA polII, H3K3ac and Gtf2b densities within the Mindbomb 1 (Mib1) gene located in chromosome 18. (c) Total mRNA extracted from mouse hearts from sham or TAC operated hearts for 1day or four days were used for qPCR analysis of primary, pre-miR-1-1, pre-miR-1-2 and mature miR-1 levels. The results were normalized to 18S (primary and pre- transcript) or U6 (mature) and shown as ratio of TAC/sham. Error bars represents standard error of mean (SEM) and * is p< 0.05, n = 3. (d) Neonatal myocytes cultured in growth-inhibited (serum free) conditions were stimulated with 100nM endothelin-1 or 10%FBS for 1hr or 24hrs, as indicated. Total RNA extracted was used for qPCR analysis of primary, pre- and mature miR-1. Error bars represents SEM, and * is p<0.05 and ** is p< 0.005. N = 3.</p
al-Rawiyat de Maha Hasan: métamorphose et réincarnation comme dernière tentative pour préserver la vie
No full textAl-Rawiyat (The Storytellers) is a metafictional novel written by Syrian author Maha Hasan in 2014. The text contains two intertwined levels: the first is the inner monologue of a woman who is writing a novel; the second is represented by the stories of the characters she creates and that become themselves storytellers. In this text Maha Hasan explores the art of storytelling through multiple stories and many female characters. Ḥasan’s storytellers often live in parallel and imaginary worlds, in a permanent state of metamorphosis and perpetual reincarnation. The stories they live and narrate represent their last attempt to preserve life in an inhuman time that changes at a spasmodic rhythm and generates simultaneous events with contradictory effects. This novel translates into fiction the rapid changes of the present period, which—as affirmed by Rosi Braidotti in her Metamorphoses—does not truncate the brutality of power relations, but at deeper view, intensifies them to their point of implosion
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