Deficiency of Capicua disrupts bile acid homeostasis

Capicua (CIC) has been implicated in pathogenesis of spinocerebellar ataxia type 1 and cancer in mammals; however, the in vivo physiological functions of CIC remain largely unknown. Here we show that Cic hypomorphic (Cic-L-/-) mice have impaired bile acid (BA) homeostasis associated with induction of proinflammatory cytokines. We discovered that several drug metabolism and BA transporter genes were down-regulated in Cic-L-/- liver, and that BA was increased in the liver and serum whereas bile was decreased within the gallbladder of Cic-L-/- mice. We also found that levels of proinflammatory cytokine genes were up-regulated in Cic-L-/- liver. Consistent with this finding, levels of hepatic transcriptional regulators, such as hepatic nuclear factor 1 alpha (HNF1 alpha), CCAAT/enhancer-binding protein beta (C/EBP beta), forkhead box protein A2 (FOXA2), and retinoid X receptor alpha (RXR alpha), were markedly decreased in Cic-L-/- mice. Moreover, induction of tumor necrosis factor alpha (Tnf alpha) expression and decrease in the levels of FOXA2, C/EBP beta, and RXRa were found in Cic-L-/- liver before BA was accumulated, suggesting that inflammation might be the cause for the cholestasis in Cic-L-/- mice. Our findings indicate that CIC is a critical regulator of BA homeostasis, and that its dysfunction might be associated with chronic liver disease and metabolic disorders.open11810Ysciescopu

Replenishment of microRNA-188-5p restores the synaptic and cognitive deficits in 5XFAD Mouse Model of Alzheimer’s Disease

MicroRNAs have emerged as key factors in development, neurogenesis and synaptic functions in the central nervous system. In the present study, we investigated a pathophysiological significance of microRNA-188-5p (miR-188-5p) in Alzheimer’s disease (AD). We found that oligomeric Aβ(1-42) treatment diminished miR-188-5p expression in primary hippocampal neuron cultures and that miR-188-5p rescued the Aβ(1-42)-mediated synapse elimination and synaptic dysfunctions. Moreover, the impairments in cognitive function and synaptic transmission observed in 7-month-old five familial AD (5XFAD) transgenic mice, were ameliorated via viral-mediated expression of miR-188-5p. miR-188-5p expression was down-regulated in the brain tissues from AD patients and 5XFAD mice. The addition of miR-188-5p rescued the reduction in dendritic spine density in the primary hippocampal neurons treated with oligomeric Aβ(1-42) and cultured from 5XFAD mice. The reduction in the frequency of mEPSCs was also restored by addition of miR-188-5p. The impairments in basal fEPSPs and cognition observed in 7-month-old 5XFAD mice were ameliorated via the viral-mediated expression of miR-188-5p in the hippocampus. Furthermore, we found that miR-188 expression is CREB-dependent. Taken together, our results suggest that dysregulation of miR-188-5p expression contributes to the pathogenesis of AD by inducing synaptic dysfunction and cognitive deficits associated with Aβ-mediated pathophysiology in the disease

Hypoxia-inducible factor-1 alpha regulates microglial functions affecting neuronal survival in the acute phase of ischemic stroke in mice

Cells universally adapt to ischemic conditions by turning on a transcription factor hypoxia-inducible factor (HIF), in which its role is known to differ widely across many different types of cells. Given that microglia have been reported as an essential mediator of neuroinflammation in many brain diseases, we examined the role of HIF in microglia in the progression of an acute phase of ischemic stroke by challenging our novel strains of myeloid-specific Hif-1 alpha or Hif-2 alpha knockout (KO) mice created by Cre-loxP system via middle cerebral artery occlusion (MCAO). We observed that Hif-1 alpha but not Hif-2 alpha KO mice exhibited an improved recovery compared to wild-type (WT) mice determined by behavioral tests. Immunostaining analyses revealed that there were increased numbers of both mature and immature neurons while microglia and apoptotic cells were significantly decreased in the dentate gyrus of Hif-1 alpha KO mice following MCAO. By isolating microglia with fluorescence-activated cell sorter, we found that HIF-1 alpha-deficient microglia were impaired in phagocytosis, reactive oxygen species (ROS) production, and tumor necrosis factor-alpha (TNF-alpha) secretion. We further observed a significant decrease in the expression of Cd36 and milk fat globule-epidermal growth factor 8 (Mfg-e8) genes, both of which contain hypoxia-responsive element (HRE). Knocking down either of these genes in BV2 microglial cells was sufficient to abrogate HIF-mediated increase in phagocytosis, production of intracellular ROS, or TNF-alpha secretion. Our results therefore suggest that HIF-1 alpha in microglia is a novel therapeutic target to protect neuronal survival following an acute phase of ischemic stroke.113Ysciescopu

Capicua suppresses hepatocellular carcinoma progression by controlling the ETV4–MMP1 axis

Hepatocellular carcinoma (HCC) is developed by multiple steps accompanying progressive alterations of gene expression, which leads to increased cell proliferation and malignancy. Although environmental factors and intracellular signaling pathways that are critical for HCC progression have been identified, gene expression changes and the related genetic factors contributing to HCC pathogenesis are still insufficiently understood. In this study, we identify a transcriptional repressor Capicua/CIC as a suppressor of HCC progression and a potential therapeutic target. Expression of CIC is posttranscriptionally reduced in HCC cells. CIC levels are correlated with survival rates in patients with HCC. CIC overexpression suppresses HCC cell proliferation and invasion, whereas loss of CIC exerts opposite effects in vivo as well as in vitro. The levels of PEA3 group genes, the best-known CIC target genes, are correlated with lethality in patients with HCC. Among the PEA3 group genes, ETV4 is the most significantly upregulated gene in CIC-deficient HCC cells, consequently promoting HCC progression. Furthermore, ETV4 induces expression of MMP1, the MMP gene highly relevant to HCC progression, in HCC cells, and knockdown of MMP1 completely blocks the CIC deficiency-induced HCC cell proliferation and invasion. CONCLUSION: Our study demonstrates that the CIC-ETV4-MMP1 axis is a novel regulatory module controlling HCC progression. This article is protected by copyright. All rights reserved.113sciescopu

Deficiency of Capicua disrupts bile acid homeostasis

Capicua (CIC) has been implicated in pathogenesis of spinocerebellar ataxia type 1 and cancer in mammals; however, the in vivo physiological functions of CIC remain largely unknown. Here we show that Cic hypomorphic (Cic-L-/-) mice have impaired bile acid (BA) homeostasis associated with induction of proinflammatory cytokines. We discovered that several drug metabolism and BA transporter genes were down-regulated in Cic-L-/- liver, and that BA was increased in the liver and serum whereas bile was decreased within the gallbladder of Cic-L-/- mice. We also found that levels of proinflammatory cytokine genes were up-regulated in Cic-L-/- liver. Consistent with this finding, levels of hepatic transcriptional regulators, such as hepatic nuclear factor 1 alpha (HNF1 alpha), CCAAT/enhancer-binding protein beta (C/EBP beta), forkhead box protein A2 (FOXA2), and retinoid X receptor alpha (RXR alpha), were markedly decreased in Cic-L-/- mice. Moreover, induction of tumor necrosis factor alpha (Tnf alpha) expression and decrease in the levels of FOXA2, C/EBP beta, and RXRa were found in Cic-L-/- liver before BA was accumulated, suggesting that inflammation might be the cause for the cholestasis in Cic-L-/- mice. Our findings indicate that CIC is a critical regulator of BA homeostasis, and that its dysfunction might be associated with chronic liver disease and metabolic disorders.1

Human embryonic stem cells express a unique set of microRNAs.

Abstract Human embryonic stem (hES) cells are pluripotent cell lines established from the explanted inner cell mass of human blastocysts. Despite their importance for human embryology and regenerative medicine, studies on hES cells, unlike those on mouse ES (mES) cells, have been hampered by difficulties in culture and by scant knowledge concerning the regulatory mechanism. Recent evidence from plants and animals indicates small RNAs of approximately 22 nucleotides (nt), collectively named microRNAs, play important roles in developmental regulation. Here we describe 36 miRNAs (from 32 stem-loops) identified by cDNA cloning in hES cells. Importantly, most of the newly cloned miRNAs are specifically expressed in hES cells and downregulated during development into embryoid bodies (EBs), while miRNAs previously reported from other human cell types are poorly expressed in hES cells. We further show that some of the ES-specific miRNA genes are highly related to each other, organized as clusters, and transcribed as polycistronic primary transcripts. These miRNA gene families have murine homologues that have similar genomic organizations and expression patterns, suggesting that they may operate key regulatory networks conserved in mammalian pluripotent stem cells. The newly identified hES-specific miRNAs may also serve as molecular markers for the early embryonic stage and for undifferentiated hES cells

Molecular transport along the exterior of single-walled carbon nanotube

Single walled carbon nanotube (SWNT) is an excellent material for studying the transport phenomenon at nanoscale due to their atomically smooth surface, small diameter (1-2 nm), and extremely high aspect ratio. The tubular nature of the material allows efficient molecular transport both externally and internally. Due to challenges in setting up a reliable experimental platform experimental studies on the transport has started only recently. Here we show experimentally the evidence of the ionic transport along the exterior of SWNTs. When an electrical bias is applied to droplets of salty water placed on each side of carbon nanotubes, nanocrystals are formed along the nanotubes. This result is a direct evidence of the exterior transport of ions. Surface analyses show the distribution of cations and anions during the transport. We also investigate how the transport of ions depends on the diameter and metallicity of nanotubes. Recent studies in this area have largely focused on the interior of nanotubes, but our study suggests there still remain many questions to answer and opportunities to explore in the exterior of nanotubes

Transport of ions along the exterior of single-walled carbon nanotubes

Single walled carbon nanotube (SWNT) is an excellent material for studying the transport phenomenon at nanoscale due to their atomically smooth surface, small diameter (1-2 nm), and extremely high aspect ratio. The tubular nature of the material allows efficient molecular transport both externally and internally. Due to challenges in setting up a reliable experimental platform experimental studies on the transport has started only recently. Here we show experimentally the evidence of the ionic transport along the exterior of SWNTs. When an electrical bias is applied to droplets of salty water placed on each side of carbon nanotubes, nanocrystals are formed along the nanotubes. This result is a direct evidence of the exterior transport of ions and helps one visualize individual nanotubes under an optical microscope. Surface analyses show the distribution of cations and anions during the transport. We also investigate using Raman spectroscopy how the transport of ions depends on the diameter and metallicity of nanotubes. Recent studies in this area have largely focused on the interior of nanotubes, but our study suggests there still remain many questions to answer and opportunities to explore in the exterior of nanotubes

Single-walled carbon nanotube as a biomimetic molecular conduit

Single-walled carbon nanotubes (SWNTs) are promising nanoscale conduits that resemble the structure of protein ion channels in biological systems. Molecular transport along the surface of carbon nanotube is known to be highly efficient because of its atomically smooth surface. The material potentially allows for in situ measurement of the transport using inherent near-infrared photoluminescence and Raman scattering. However, only limited amount of information has been available thus far due to experimental challenges. Here we show experimentally the evidence of the ionic transport along the exterior of SWNTs. When an electrical bias is applied to droplets of salty water placed on each side of carbon nanotubes, nanocrystals are formed along the nanotubes. This result is a direct evidence of the exterior transport of ions. Surface analyses show the distribution of cations and anions during the transport. We also investigate using Raman spectroscopy how the transport of ions depends on the diameter and metallicity of nanotubes. Recent studies in this area have largely focused on the interior of nanotubes, but our study suggests there still remain many questions to answer and opportunities to explore in the exterior of nanotubes