Project description:Chronic inflammation is known to contribute to the development of hypertension, but while the role of lymphocytes is well-established, the myeloid lineage, particularly as a possible mediator of renin-mediated hypertension, has not been studied. Vitamin D deficiency has pro-inflammatory consequences in monocytes, and it is linked to renin-mediated hypertension in mice. This prompted us to test the hypothesis that conditional knockout of the vitamin D receptor (VDR) in macrophages (KODMAC) would promote renin-dependent hypertension. We found that lack of macrophage vdr signaling was sufficient to induce high blood pressure (BP) in mice. Recipients of bone marrow from KODMAC mice experienced increased BP via activation of the renal renin-angiotensin system. Conversely BM transplants from mice with intact vdr signaling reduced BP in KODMAC mice by decreasing plasma renin and increasing urinary Na excretion. Deletion of myeloid vdr promotes vascular macrophage infiltration, increasing ROS-mediated scavenging of NO and reducing renal perfusion, resulting in increased plasma renin. Interestingly, deletion of macrophage vdr promotes their infiltration into the JG cell apparatus, regulating JG cell renin production by an unexpected communication between macrophages and JG cells through miR-106b-5p. Induction of macrophage endoplasmic reticulum stress phospho-PERK and CHOP pathways increased miR-106b-5p secretion, the uptake of which into JG cells induced renin production and release by repression of E2f1 and Pde3b transcription factors, constituting a novel mechanism by which inflammation causes hypertension.
Project description:Adult beta cells in the pancreas are the sole source of insulin in our body. Beta cell loss or increased demand for insulin, impose metabolic challenges because adult beta cells are generally quiescent and infrequently re-enter the cell division cycle. miR-17-92/106b is a family of proto-oncogene microRNAs, that regulate proliferation in normal tissues and in cancer. Here, we employ mouse genetics to demonstrate a critical role for miR-17-92/106b in glucose homeostasis and in controlling insulin secretion. Mass spectrometry analysis was performed on miR-17-92LoxP/LoxP;106-25-/- MEF lysate, without or with CRE-Adenovirus. miR-17-92LoxP/LoxP;106-25+/+ MEFs with GFP-Adenovirus served as controls. We demonstrate that miR-17-92/106b regulate the adult beta cell mitotic checkpoint and that miR-17-92/106b deficiency results in reduction in beta cell mass in-vivo. Furthermore, protein kinase A (PKA) is a new relevant molecular pathway downstream of miR-17-92/106b in control of adult beta cell division and glucose homeostasis. Therefore, contributes to the understanding of proto-oncogene miRNAs in the normal, untransformed endocrine pancreas, and illustrates new genetic means for regulation of beta cell mitosis and function by non-coding RNAs.
Project description:microRNAs in the miR-106b family are overexpressed in multiple tumor types and are correlated with the expression of genes that regulate the cell cycle. Consistent with these observations, miR-106b family gain of function promotes cell cycle progression, whereas loss of function reverses this phenotype. Microarray profiling uncovers multiple targets of the family, including the cyclin-dependent kinase inhibitor p21/CDKN1A. We show that p21 is a direct target of miR-106b and that its silencing plays a key role in miR-106b-induced cell cycle phenotypes. We also show that miR-106b overrides a doxorubicin-induced DNA damage checkpoint. Thus, miR-106b family members contribute to tumor cell proliferation in part by regulating cell cycle progression and by modulating checkpoint functions. HCT116 Dicerex5 cells were transfected with microRNAs in six-well plates, and RNA was isolated 10 h after transfection. Transcripts containing the miR-106b family hexamers in their 3' UTRs were identified. By microarray analysis, 103 transcripts that contained miR-106b family complementary hexamers in their 3' UTRs were down-regulated by miR-106b, miR-106a, miR-20b, and miR-17-5p within 10 h of transfection.
Project description:We and others previously reported that the miR-106b-25 microRNA cluster is a candidate oncogene in human prostate cancer. Here, we made the novel observation that miR-106b-25 expression is further up-regulated in distant metastasis. Moreover, increased tumor miR-106b expression was associated with early disease recurrence. To identify yet unknown oncogenic functions of the prognostic miR-106b, we overexpressed it in LNCaP human prostate cancer cells to examine miR-106b-induced global expression changes among protein-coding genes. The approach revealed that caspase-7 is a candidate direct target of miR-106b, which was confirmed by Western blot analysis and a 3M-bM-^@M-^YUTR reporter assay. Other analyses showed that caspase-7 is down-regulated in primary human prostate tumors and metastatic lesions across multiple datasets and is by itself associated with disease recurrence. Using bioinformatics, we also discovered that miR-106b-25 may specifically influence focal adhesion-related pathways. This observation was experimentally confirmed using miR-106b-25-transduced 22Rv1 human prostate cancer cells. After infection with a miR-106b-25 lentiviral expression construct, 22Rv1 cells showed increased adhesion to basement membrane- and bone matrix-related filaments and enhanced soft agar growth. In summary, miR-106b-25 was found to be associated with prostate cancer progression and metastasis and may do so by altering apoptosis- and focal adhesion-related pathways. To elucidate the effects miR-106b, we up-regulated miR-106b in LNCaP cells and examined gene expression alterations on a global scale with Affymetrix arrays. LNCaP cells were transfected with pre-miR oligos and 24 hr post-transfection total RNA was collected for microarray anaylsis.
Project description:Myocardial regeneration is restricted to early postnatal life, when mammalian cardiomyocytes still retain the ability to proliferate. The molecular cues that induce cell cycle arrest of neonatal cardiomyocytes towards terminally differentiated adult heart muscle cells remain obscure. We report that the miR-106b~25cluster is higher expressed in the early postnatal myocardium and decreases in expression towards adulthood, especially under conditions of overload, and orchestrates the transition of cardiomyocyte hyperplasia towards cell cycle arrest and hypertrophy by virtue of its targetome. To identify the relevant targets of individual miRNAs in the miR-106b~15 cluster and elucidate the molecular mechanisms underlying the proliferative effects of this microRNA cluster, we assessed the global transcriptomic changes by deep-sequencing total neonatal mouse cardiomyocyte RNA after exogeneous transfection with hsa-miR-106b-5p, hsa-miR-93-5p, hsa-miR-25-3p and compared the transcriptomic profiles to cardiomyocytes transfected with cel-miR-67, a control miRNA.
Project description:We and others previously reported that the miR-106b-25 microRNA cluster is a candidate oncogene in human prostate cancer. Here, we made the novel observation that miR-106b-25 expression is further up-regulated in distant metastasis. Moreover, increased tumor miR-106b expression was associated with early disease recurrence. To identify yet unknown oncogenic functions of the prognostic miR-106b, we overexpressed it in LNCaP human prostate cancer cells to examine miR-106b-induced global expression changes among protein-coding genes. The approach revealed that caspase-7 is a candidate direct target of miR-106b, which was confirmed by Western blot analysis and a 3’UTR reporter assay. Other analyses showed that caspase-7 is down-regulated in primary human prostate tumors and metastatic lesions across multiple datasets and is by itself associated with disease recurrence. Using bioinformatics, we also discovered that miR-106b-25 may specifically influence focal adhesion-related pathways. This observation was experimentally confirmed using miR-106b-25-transduced 22Rv1 human prostate cancer cells. After infection with a miR-106b-25 lentiviral expression construct, 22Rv1 cells showed increased adhesion to basement membrane- and bone matrix-related filaments and enhanced soft agar growth. In summary, miR-106b-25 was found to be associated with prostate cancer progression and metastasis and may do so by altering apoptosis- and focal adhesion-related pathways. To elucidate the effects miR-106b, we up-regulated miR-106b in LNCaP cells and examined gene expression alterations on a global scale with Affymetrix arrays.
Project description:microRNAs in the miR-106b family are overexpressed in multiple tumor types and are correlated with the expression of genes that regulate the cell cycle. Consistent with these observations, miR-106b family gain of function promotes cell cycle progression, whereas loss of function reverses this phenotype. Microarray profiling uncovers multiple targets of the family, including the cyclin-dependent kinase inhibitor p21/CDKN1A. We show that p21 is a direct target of miR-106b and that its silencing plays a key role in miR-106b-induced cell cycle phenotypes. We also show that miR-106b overrides a doxorubicin-induced DNA damage checkpoint. Thus, miR-106b family members contribute to tumor cell proliferation in part by regulating cell cycle progression and by modulating checkpoint functions.
Project description:The RAVER1 protein was proposed to serve as a co-factor in guiding the PTBP-dependent control of alternative splicing (AS). Whether RAVER1 solely acts in concert with PTBPs and how it affects cancer cell fate remained elusive. Here we provide the first comprehensive investigation of RAVER1-controlled AS in cancer cell models and reveal a pro-oncogenic role of RAVER1 in tumor growth. This unravels that RAVER1 guides AS in synergy with PTBPs but more prominently serves PTBP1-independent roles in splicing. In cancer cells, one major function of RAVER1 is the control of proliferation and apoptosis, which involves the modulation of AS events within the miR/RISC pathway. Associated with this regulatory role, RAVER1 antagonizes lethal, TGFB-driven epithelial-mesenchymal-transition (EMT) by limiting TGFB signaling. RAVER1-modulated splicing events affect the insertion of protein interaction modules in factors guiding miR/RISC-dependent gene silencing. Most prominently, in all three human TNRC6 proteins, RAVER1 controls AS of GW-enriched motifs, which are essential for AGO2-binding. Disturbance of RAVER1-guided AS events in TNRC6 proteins and other facilitators of miR/RISC activity compromise miR/RISC activity which is essential to restrict TGFB signaling and lethal EMT.
Project description:miR-93/106b and their host gene minichromosome maintenance complex component 7 (MCM7) reside at chr7q22, a region frequently rearranged in leiomyomas. We explored the expression of miR-93/106b in leiomyoma and paired myometrium (N=62) from untreated and patients exposed to hormonal therapies (GnRHa, Depo-Provera and oral contraceptives) from African Americans and Caucasians, and their regulatory functions in isolated paired (N=15) leiomyoma and myometrial smooth muscle cells (LSMC and MSMC) and leiomyosarcoma cell line (SKLM-S1). At tissue level leiomyomas expressed significantly lower levels of miR-93 and elevated MCM7 as compared to myometrium with limited racial influence or hormonal exposure on their expression. Assessing the regulatory function of miR-93/106b through doxycycline-inducible lentiviral transduction in microarray analysis, tissue factor (F3) and IL-8 were identified as their possible targets. At tissue level leiomyomas expressed a significantly lower level of F3 and an elevated IL-8 which exhibited an inverse relationship with miR-93, but with limited racial or hormonal influences. Gain-of-function of miR-93/106b in LSMC, MSMC and SKLM-S1 dose-dependently repressed F3 and IL-8 through direct interactions with their respective 3M-bM-^@M-^YUTRs and indirectly through F3 repression inhibited IL8, CTGF and PAI-1 expression, confirmed by using siRNA silencing or factor Vlla (FVIIa) activation of F3, as well as reducing the rate of proliferation, while increasing caspase 3/7 activity. We concluded that differential expression of miR-93/106b and their direct and/or indirect regulatory functions on F3, IL-8, CTGF and PAI-1 expression, with key roles in inflammation and tissue turnover may be of significance in the outcome of leiomyoma growth and associated symptoms. Total RNA isolated from TF324 cells transfected with DOX-inducible lentiviral construct carrying miR-106b~25 cluster with and without Dox treatments for 6 days was subjected to gene expression profiling using Sentirx Beadchip Array HumanHT-12_v4.