Project description:Anorexia nervosa (AN) is a devastating eating disorder characterized by self-starvation that mainly affects women. Its etiology is unknown, which impedes successful treatment options leading to a limited chance of full recovery. Here, we show that gestation is a vulnerable window that can influence the predisposition to AN. By screening placental microRNA expression of naive and prenatally stressed (PNS) fetuses and assessing vulnerability to activity-based anorexia (ABA) in early adulthood, we identify miR-340 as a sexually dimorphic regulator involved in prenatal programming of ABA. PNS caused gene-body hypermethylation of placental miR-340, which is associated with reduced miR-340 expression and increased protein levels of several target transcripts; Gr, Cry2 and H3F3b. MiR-340 is linked to the expression of several nutrient transporters both in mice and human placentas. Using placenta-specific lentiviral transgenes and embryo transfer, we demonstrate the key role miR-340 plays in the mechanism involved in early life programming of ABA.
Project description:We tested the hypothesis that a panel of placental mammal-specific miRNAs and their targets play important to establish receptivity to implantation and their dysregulated expression may be a feature in women with early pregnancy loss. Relative expression levels of miR-340-5p, −542-3p, and −671-5p all increased following treatment of Ishikawa cells with progesterone (10 μg/ml) for 24 hrs (p < 0.05). RNA sequencing of these P4-treated cells identified co-ordinate changes to 6,367 transcripts of which 1713 were predicted targets of miR-340-5p, 670 of miR-542-3p, and 618 of miR-671-5p. Quantitative proteomic analysis of Ishikawa cells transfected with mimic or inhibitor (48 hrs: n=3 biological replicates) for each of the P4-regulated miRNAs was carried out to identify targets of these miRNAs. Excluding off target effects, mir-340-5p mimic altered 1,369 proteins while inhibition changed expression of 376 proteins (p < 0.05) of which, 72 were common to both treatments. A total of 280 proteins were identified between predicted (mirDB) and confirmed (in vitro) targets. In total, 171 proteins predicted to be targets by mirDB were altered in vitro by treatment with miR-340-5p mimic or inhibitor and were also altered by treatment of endometrial epithelial cells with P4. In vitro targets of miR-542-3p identified 1,378 proteins altered by mimic while inhibition altered 975 a core of 200 proteins were changed by both. 100 protein targets were predicted and only 46 proteins were P4 regulated. miR-671-mimic altered 1,252 proteins with inhibition changing 492 proteins of which 97 were common to both, 95 were miDB predicted targets and 46 were also P4-regulated. All miRNAs were detected in endometrial biopsies taken from patients during the luteal phase of their cycle, irrespective of prior or future pregnancy outcomes Expression of mir-340-5p showed an overall increase in patients who had previously suffered a miscarriage and had a subsequent miscarriage, as compared to those who had infertility or previous miscarriage and subsequently went on to have a life birth outcome. The regulation of these miRNAs and their protein targets regulate the function of transport and secretion, and adhesion of the endometrial epithelia required for successful implantation in humans. Dysfunction of these miRNAs (and therefore the targets they regulate) may contribute to endometrial-derived recurrent pregnancy loss in women.
Project description:The goal of this study was to identify accessible chromatin peaks in lamina-associated domains of senescent cells. To establish senescence we used ionizing radiation (IR), overexpression of miR-340-5p, and knockdown of Lamin B Receptor (LBR).One of the cellular processes influenced by microRNAs is senescence, a state of indefinite growth arrest triggered by sublethal cell damage. Here, through bioinformatic analysis and experimental validation, we identified miR-340-5p as a novel miRNA that foments cellular senescence. miR340-5p was highly abundant in diverse senescence models, and miR-340-5p overexpression in proliferating cells rendered them senescent. Among the target mRNAs, miR-340-5p prominently reduced the levels of LBR mRNA, encoding Lamin B Receptor (LBR). Loss of LBR by ectopic overexpression of miR-340-5p derepressed heterochromatin in lamina-associated domains (LADs), promoting the expression of DNA repetitive elements characteristic of senescence. Importantly, overexpressing miR-340-5p enhanced cellular sensitivity to senolytic compounds, while antagonization of miR-340-5p reduced senescent-cell markers and engendered resistance to senolytic-induced cell death. We propose that miR-340-5p can be exploited for clearing senescent cells to restore tissue homeostasis and mitigate damage by senescent cells in aging human pathologies.
Project description:One of the cellular processes influenced by microRNAs is senescence, a state of indefinite growth arrest triggered by sublethal cell damage. Here, through bioinformatic analysis and experimental validation, we identified miR-340-5p as a novel miRNA that foments cellular senescence. miR340-5p was highly abundant in diverse senescence models, and miR-340-5p overexpression in proliferating cells rendered them senescent. Among the target mRNAs, miR-340-5p prominently reduced the levels of LBR mRNA, encoding Lamin B Receptor (LBR). Loss of LBR by ectopic overexpression of miR-340-5p derepressed heterochromatin in lamina-associated domains (LADs), promoting the expression of DNA repetitive elements characteristic of senescence. Importantly, overexpressing miR-340-5p enhanced cellular sensitivity to senolytic compounds, while antagonization of miR-340-5p reduced senescent-cell markers and engendered resistance to senolytic-induced cell death. We propose that miR-340-5p can be exploited for clearing senescent cells to restore tissue homeostasis and mitigate damage by senescent cells in aging human pathologies.
Project description:One of the cellular processes influenced by microRNAs is senescence, a state of indefinite growth arrest triggered by sublethal cell damage. Here, through bioinformatic analysis and experimental validation, we identified miR-340-5p as a novel miRNA that foments cellular senescence. miR340-5p was highly abundant in diverse senescence models, and miR-340-5p overexpression in proliferating cells rendered them senescent. Among the target mRNAs, miR-340-5p prominently reduced the levels of LBR mRNA, encoding Lamin B Receptor (LBR). Loss of LBR by ectopic overexpression of miR-340-5p derepressed heterochromatin in lamina-associated domains (LADs), promoting the expression of DNA repetitive elements characteristic of senescence. Importantly, overexpressing miR-340-5p enhanced cellular sensitivity to senolytic compounds, while antagonization of miR-340-5p reduced senescent-cell markers and engendered resistance to senolytic-induced cell death. We propose that miR-340-5p can be exploited for clearing senescent cells to restore tissue homeostasis and mitigate damage by senescent cells in aging human pathologies.
Project description:To identify functional targets of miR-340, we compared the gene expression profiles of miR-340 overexpressing human GICs with the profiles of their parental cells.
Project description:To identify functional targets of miR-340, we compared the gene expression profiles of miR-340 overexpressing human GICs with the profiles of their parental cells. The precursor form of miR-340 or control miRNA was overexpressed in glioma cells using miRNA lentiviral particles. The cells were incubated with recombinant virus at 37°C for 12 hr and cultured in the presence of puromycin for 3 days.
Project description:Anorexia and other side effects of chemotherapy significantly limit the clinical applications of these chemotherapeutic agents, with underlying mechanisms still unclear. A growing body of research reveals that elevated levels of circulating GDF15 after chemotherapy are essential in initiating anorexia and other side effects by activating GFRAL+ neurons in the brainstem. However, the full array of context-dependent transcriptional regulators controlling Gdf15 expression remains to be defined. This study reports that chemotherapy drugs acutely stimulate liver GDF15 production via selective activation of the hepatic stress sensor IRE1α, thereby controlling circulating GDF15 levels. Genetic ablation of hepatic IRE1α reduces circulating GDF15 and alleviates anorexia and body weight loss following chemotherapy drug treatments in tumor-bearing mice. Mechanistically, chemotherapy drugs activate hepatic IRE1α RNase activity to produce the active form of the transcription factor XBP1 to promotes the expression of Gdf15 gene in hepatocytes. Moreover, treatment with pharmacological IRE1α RNase inhibitor effectively suppresses liver Gdf15 expression and circulating GDF15 levels, resulting in improvements in chemotherapy-induced anorexia and body weight loss. Our results reveal a stress-responsive mechanism that mediates communication between the liver and brain. This mechanism can be targeted pharmacologically to alleviate anorexic side effects that accompany chemotherapy-induced body weight loss.
Project description:We reported that peri-tumoral CpG-ODN treatment, probably activating TLR9-expressing cells present in the tumor microenvironment, sensitized cancer cells to DNA-damaging chemotherapy (Cancer Res 2011 Oct 15;71(20):6382-90). Here, we investigated whether this treatment induces a modulation of miRNAs and their involvement in chemotherapy sensitivity. Twenty miRNAs were found differentially expressed in tumors from CpG-ODN-treated mice versus controls. Evaluation of the role of miR-424, miR-340 and miR-302b on cisplatin sensitivity revealed that ectopic expression of miR-302b (up-modulated in our array) in IGROV1 cells significantly improved cisplatin activity. The identification of miRNAs able to modify sensitivity to chemotherapy treatment will provide an experimental base for its future possible use as a target or tool of specific therapies.