Targeted deletion of RasGRP1 impairs skin tumorigenesis.
Ontology highlight
ABSTRACT:
SUBMITTER: Sharma A
PROVIDER: S-EPMC4004207 | biostudies-literature | 2014 May
REPOSITORIES: biostudies-literature
Publications
Targeted deletion of RasGRP1 impairs skin tumorigenesis.
Sharma Amrish A Fonseca Lauren L LL Rajani Cynthia C Yanagida Jodi K JK Endo Yuka Y Cline J Mark JM Stone James C JC Ji Junfang J Ramos Joe W JW Lorenzo Patricia S PS
Carcinogenesis 20140124 5
Ras is frequently activated in cutaneous squamous cell carcinoma, a prevalent form of skin cancer. However, the pathways that contribute to Ras-induced transformation have not been entirely elucidated. We have previously demonstrated that in transgenic mice, overexpression of the Ras activator RasGRP1 promotes the formation of spontaneous skin tumors and enhances malignant progression in the multistage carcinogenesis skin model that relies on the oncogenic activation of H-Ras. Utilizing a RasGRP ...[more]
Similar Datasets
Project description:The epidermis, which consists mainly of keratinocytes, acts as a physical barrier to infections by regulating keratinocyte proliferation and differentiation. Hair follicles undergo continuous cycling to produce new one. Therefore, optimum supply of energy from the mitochondria is essential for maintaining skin homeostasis and hair growth. CRIF1 is a mitochondrial protein that regulates mitoribosome-mediated synthesis and insertion of mitochondrial oxidative phosphorylation polypeptides into the mitochondrial membrane in mammals. Recent studies reveal that conditional knockout (cKO) of Crif1 in specific tissues of mice induced mitochondrial dysfunction. To determine whether the mitochondrial function of keratinocytes affects skin homeostasis and hair morphogenesis, we generated epidermis-specific Crif1 cKO mice. Deletion of Crif1 in epidermis resulted in impaired mitochondrial function and Crif1 cKO mice died within a week. Keratinocyte proliferation and differentiation were markedly inhibited in Crif1 cKO mice. Furthermore, hair follicle morphogenesis of Crif1 cKO mice was disrupted by down-regulation of Wnt/β-catenin signaling. These results demonstrate that mitochondrial function in keratinocytes is essential for maintaining epidermal homeostasis and hair follicle morphogenesis.
| S-EPMC5357846 | biostudies-literature
Project description:KCNE3 (MiRP2) forms heteromeric voltage-gated K+ channels with the skeletal muscle-expressed KCNC4 (Kv3.4) ? subunit. KCNE3 was the first reported skeletal muscle K+ channel disease gene, but the requirement for KCNE3 in skeletal muscle has been questioned. Here, we confirmed KCNE3 transcript and protein expression in mouse skeletal muscle using Kcne3-/- tissue as a negative control. Whole-transcript microarray analysis (770,317 probes, interrogating 28,853 transcripts) findings were consistent with Kcne3 deletion increasing gastrocnemius oxidative metabolic gene expression and the proportion of type IIa fast-twitch oxidative muscle fibers, which was verified using immunofluorescence. The down-regulated transcript set overlapped with muscle unloading gene expression profiles (?1.5-fold change; P < 0.05). Gastrocnemius K+ channel ? subunit remodeling arising from Kcne3 deletion was highly specific, involving just 3 of 69 ? subunit genes probed: known KCNE3 partners KCNC4 and KCNH2 (mERG) were down-regulated, and KCNK4 (TRAAK) was up-regulated (P < 0.05). Functionally, Kcne3-/- mice exhibited abnormal hind-limb clasping upon tail suspension (63% of Kcne3-/- mice ?10-mo-old vs. 0% age-matched Kcne3+/+ littermates). Whereas 5 of 5 Kcne3+/+ mice exhibited the typical biphasic decline in contractile force with repetitive stimuli of hind-limb muscle, both in vivo and in vitro, this was absent in 6 of 6 Kcne3-/- mice tested. Finally, myoblasts isolated from Kcne3-/- mice exhibit faster-inactivating and smaller sustained outward currents than those from Kcne3+/+ mice. Thus, Kcne3 deletion impairs skeletal muscle function in mice.-King, E. C., Patel, V., Anand, M., Zhao, X., Crump, S. M., Hu, Z., Weisleder, N., Abbott, G. W. Targeted deletion of Kcne3 impairs skeletal muscle function in mice.
| S-EPMC5472403 | biostudies-literature
Project description:The spectrin membrane skeleton controls the disposition of selected membrane channels, receptors, and transporters. In the brain betaIII spectrin binds directly to the excitatory amino acid transporter (EAAT4), the glutamate receptor delta, and other proteins. Mutations in betaIII spectrin link strongly to human spinocerebellar ataxia type 5 (SCA5), correlating with alterations in EAAT4. We have explored the mechanistic basis of this phenotype by targeted gene disruption of Spnb3. Mice lacking intact betaIII spectrin develop normally. By 6 months they display a mild nonprogressive ataxia. By 1 year most Spnb3(-/-) animals develop a myoclonic seizure disorder with significant reductions of EAAT4, EAAT1, GluRdelta, IP3R, and NCAM140. Other synaptic proteins are normal. The cerebellum displays increased dark Purkinje cells (PC), a thin molecular layer, fewer synapses, a loss of dendritic spines, and a 2-fold expansion of the PC dendrite diameter. Membrane and expanded Golgi profiles fill the PC dendrite and soma, and both regions accumulate EAAT4. Correlating with the seizure disorder are enhanced hippocampal levels of neuropeptide Y and EAAT3 and increased calpain proteolysis of alphaII spectrin. It appears that betaIII spectrin disruption impairs synaptogenesis by disturbing the intracellular pathways selectively regulating protein trafficking to the synapse. The mislocalization of these proteins secondarily disrupts glutamate transport dynamics, leading to seizures, neuronal damage, and compensatory changes in EAAT3 and neuropeptide Y.
| S-EPMC2851889 | biostudies-other
Project description:miR-132 and miR-212 are structurally related microRNAs that have been found to exert powerful modulatory effects within the central nervous system (CNS). Notably, these microRNAs are tandomly processed from the same noncoding transcript, and share a common seed sequence: thus it has been difficult to assess the distinct contribution of each microRNA to gene expression within the CNS. Here, we employed a combination of conditional knockout and transgenic mouse models to examine the contribution of the miR-132/-212 gene locus to learning and memory, and then to assess the distinct effects that each microRNA has on hippocampal gene expression. Using a conditional deletion approach, we show that miR-132/-212 double-knockout mice exhibit significant cognitive deficits in spatial memory, recognition memory, and in tests of novel object recognition. Next, we utilized transgenic miR-132 and miR-212 overexpression mouse lines and the miR-132/-212 double-knockout line to explore the distinct effects of these two miRNAs on the transcriptional profile of the hippocampus. Illumina sequencing revealed that miR-132/-212 deletion increased the expression of 1138 genes; Venn analysis showed that 96 of these genes were also downregulated in mice overexpressing miR-132. Of the 58 genes that were decreased in animals overexpressing miR-212, only four of them were also increased in the knockout line. Functional gene ontology analysis of downregulated genes revealed significant enrichment of genes related to synaptic transmission, neuronal proliferation, and morphogenesis, processes known for their roles in learning, and memory formation. These data, coupled with previous studies, firmly establish a role for the miR-132/-212 gene locus as a key regulator of cognitive capacity. Further, although miR-132 and miR-212 share a seed sequence, these data indicate that these miRNAs do not exhibit strongly overlapping mRNA targeting profiles, thus indicating that these two genes may function in a complex, nonredundant manner to shape the transcriptional profile of the CNS. The dysregulation of miR-132/-212 expression could contribute to signaling mechanisms that are involved in an array of cognitive disorders.
| S-EPMC4749831 | biostudies-literature
Project description:The Ca(2+)-sensing stromal interaction molecule (STIM) proteins are crucial Ca(2+) signal coordinators. Cre-lox technology was used to generate smooth muscle (sm)-targeted STIM1-, STIM2-, and double STIM1/STIM2-knockout (KO) mouse models, which reveal the essential role of STIM proteins in Ca(2+) homeostasis and their crucial role in controlling function, growth, and development of smooth muscle cells (SMCs). Compared to Cre(+/-) littermates, sm-STIM1-KO mice showed high mortality (50% by 30 d) and reduced bodyweight. While sm-STIM2-KO was without detectable phenotype, the STIM1/STIM double-KO was perinatally lethal, revealing an essential role of STIM1 partially rescued by STIM2. Vascular and intestinal smooth muscle tissues from sm-STIM1-KO mice developed abnormally with distended, thinned morphology. While depolarization-induced aortic contraction was unchanged in sm-STIM1-KO mice, ?1-adrenergic-mediated contraction was 26% reduced, and store-dependent contraction almost eliminated. Neointimal formation induced by carotid artery ligation was suppressed by 54%, and in vitro PDGF-induced proliferation was greatly reduced (79%) in sm-STIM1-KO. Notably, the Ca(2+) store-refilling rate in STIM1-KO SMCs was substantially reduced, and sustained PDGF-induced Ca(2+) entry was abolished. This defective Ca(2+) homeostasis prevents PDGF-induced NFAT activation in both contractile and proliferating SMCs. We conclude that STIM1-regulated Ca(2+) homeostasis is crucial for NFAT-mediated transcriptional control required for induction of SMC proliferation, development, and growth responses to injury.-Mancarella, S., Potireddy, S., Wang, Y., Gao, H., Gandhirajan, K., Autieri, M., Scalia, R., Cheng, Z., Wang, H., Madesh, M., Houser, S. R., Gill, D. L. Targeted STIM deletion impairs calcium homeostasis, NFAT activation, and growth of smooth muscle.
| S-EPMC3574286 | biostudies-literature
Project description:AimsNrf2 is an essential transcription factor for protection against oxidant disorders. However, its role in organ development and neonatal disease has received little attention. Therapeutically administered oxygen has been considered to contribute to bronchopulmonary dysplasia (BPD) in prematurity. The current study was performed to determine Nrf2-mediated molecular events during saccular-to-alveolar lung maturation, and the role of Nrf2 in the pathogenesis of hyperoxic lung injury using newborn Nrf2-deficient (Nrf2(-/-)) and wild-type (Nrf2(+/+)) mice.ResultsPulmonary basal expression of cell cycle, redox balance, and lipid/carbohydrate metabolism genes was lower while lymphocyte immunity genes were more highly expressed in Nrf2(-/-) neonates than in Nrf2(+/+) neonates. Hyperoxia-induced phenotypes, including mortality, arrest of saccular-to-alveolar transition, and lung edema, and inflammation accompanying DNA damage and tissue oxidation were significantly more severe in Nrf2(-/-) neonates than in Nrf2(+/+) neonates. During lung injury pathogenesis, Nrf2 orchestrated expression of lung genes involved in organ injury and morphology, cellular growth/proliferation, vasculature development, immune response, and cell-cell interaction. Bioinformatic identification of Nrf2 binding motifs and augmented hyperoxia-induced inflammation in genetically deficient neonates supported Gpx2 and Marco as Nrf2 effectors.InnovationThis investigation used lung transcriptomics and gene targeted mice to identify novel molecular events during saccular-to-alveolar stage transition and to elucidate Nrf2 downstream mechanisms in protection from hyperoxia-induced injury in neonate mouse lungs.ConclusionNrf2 deficiency augmented lung injury and arrest of alveolarization caused by hyperoxia during the newborn period. Results suggest a therapeutic potential of specific Nrf2 activators for oxidative stress-associated neonatal disorders including BPD.
| S-EPMC3423869 | biostudies-literature
Project description:OBJECTIVE:Adipose tissue cholesterol increases with adipocyte triglyceride content and size during development of obesity. However, how adipocyte cholesterol affects adipocyte function is poorly understood. The aim of this study was to evaluate the role of the cellular cholesterol exporter, Abca1 (ATP-binding cassette transporter A1), on adipose tissue function during diet-induced obesity. APPROACH AND RESULTS:Adiponectin Cre recombinase transgenic mice were crossed with Abca1flox/flox mice to generate ASKO (adipocyte-specific Abca1 knockout) mice. Control and ASKO mice were then fed a high-fat, high-cholesterol (45% calories as fat and 0.2% cholesterol) diet for 16 weeks. Compared with control mice, ASKO mice had a 2-fold increase in adipocyte plasma membrane cholesterol content and significantly lower body weight, epididymal fat pad weight, and adipocyte size. ASKO versus control adipose tissue had decreased PPAR? (peroxisome proliferator-activated receptor ?) and CCAAT/enhancer-binding protein expression, nuclear SREBP1 (sterol regulatory element-binding protein 1) protein, lipogenesis, and triglyceride accretion but similar Akt activation after acute insulin stimulation. Acute siRNA-mediated Abca1 silencing during 3T3L1 adipocyte differentiation reduced adipocyte Abca1 and PPAR? protein expression and triglyceride content. Systemic stimulated triglyceride lipolysis and glucose homeostasis were similar between control and ASKO mice. CONCLUSIONS:Adipocyte Abca1 is a key regulator of adipocyte lipogenesis and lipid accretion, likely because of increased adipose tissue membrane cholesterol, resulting in decreased activation of lipogenic transcription factors PPAR? and SREBP1.
| S-EPMC5864538 | biostudies-literature
Project description:miR-132 and miR-212 are structurally-related microRNAs that have been found to exert powerful modulatory effects within the central nervous system (CNS). Notably, these microRNAs are tandomly processed from the same non-coding transcript, and share a common seed sequence: thus it has been difficult to assess the distinct contribution of each microRNA to gene expression within the CNS. Here, we employed a combination of conditional knockout and transgenic mouse models to examine the contribution of the miR-132/212 gene locus to learning and memory, and then to assess the distinct effects that each microRNA has on hippocampal gene expression. Using a conditional deletion approach, we show that miR-132/212 double knockout mice exhibit significant cognitive deficits in spatial memory, recognition memory, and in tests of novel object recognition. Next, we utilized transgenic miR-132 and miR-212 overexpression mouse lines and the miR-132/212 double knockout line explore the distinct effects of these two miRNAs on the transcriptional profile of the hippocampus. Illumina sequencing revealed that miR-132/212 deletion increased the expression of 1,138 genes; Venn analysis showed that 96 of these genes were also downregulated in mice overexpressing miR-132. Of the 58 genes that were decreased in animals overexpressing miR-212, only four of them were also increased in the knockout line. Functional gene ontology analysis of downregulated genes revealed significant enrichment of genes related to synaptic transmission, neuronal proliferation, and morphogenesis, processes known for their roles in learning, and memory formation. These data, coupled with previous studies, firmly establish a role for the miR-132/212 gene locus as a key regulator of cognitive capacity. Further, although miR-132 and miR-212 share a seed sequence, these data indicate that these miRNAs do not exhibit strongly overlapping mRNA targeting profiles, thus indicating that, these two genes may function in a complex, non-redundant manner to shape the transcriptional profile of the CNS. The dysregulation of miR-132/212 expression could contribute to signaling mechanisms that are involved in an array of cognitive disorders Hippocampal mRNA was isolated from CaMKII-Cre::miR-132/212f/f, tTA::miR132, and tTA::miR212 animals, as well as their respective nontransgenic controls. cDNA from six animals was pooled into three independent biological replicates for each. Libraries were prepared according to the Illumina TruSeqTM Sample Preparation Guide and sequenced using an Illumina Genome Analyzer II. Sequences were aligned to the UCSC mm9 reference genome using Bowtie v0.12.7 and custom R scripts. The sequence data have been submitted to the NCBI Short Read Archive with accession number in progress. Relative abundance was measured in Fragments Per Kilobase of exon per Million fragments mapped using Cufflinks v1.2.
2016-03-01 | E-GEOD-73413 | biostudies-arrayexpress
Project description:Inherited CTPS1, CD27, and CD70 deficiencies in humans have revealed key factors of T-lymphocyte expansion, a critical prerequisite for an efficient immunity to Epstein-Barr virus (EBV) infection. RASGRP1 is a T-lymphocyte-specific nucleotide exchange factor known to activate the pathway of MAP kinases (MAPK). A deleterious homozygous mutation in RASGRP1 leading to the loss RASGRP1 expression was identified in two siblings who both developed a persistent EBV infection leading to Hodgkin lymphoma. RASGRP1-deficient T cells exhibited defective MAPK activation and impaired proliferation that was restored by expression of wild-type RASGRP1. Similar defects were observed in T cells from healthy individuals when RASGRP1 was downregulated. RASGRP1-deficient T cells also exhibited decreased CD27-dependent proliferation toward CD70-expressing EBV-transformed B cells, a crucial pathway required for expansion of antigen-specific T cells during anti-EBV immunity. Furthermore, RASGRP1-deficient T cells failed to upregulate CTPS1, an important enzyme involved in DNA synthesis. These results show that RASGRP1 deficiency leads to susceptibility to EBV infection and demonstrate the key role of RASGRP1 at the crossroad of pathways required for the expansion of activated T lymphocytes.
| S-EPMC5801500 | biostudies-literature
Project description:STAT2 is a central component of the ISGF3 transcriptional complex downstream of type I interferon (IFN-I) signaling. The significance of in vivo IFN-I/STAT1 signals in cDCs is well-established in the generation of antitumor cytotoxic T cell (CTL) responses. However, the role of STAT2 has remained elusive. Here, we report a clinical correlation between cDC markers and STAT2 associated with better survival in human metastatic melanoma. In a murine tumor transplantation model, targeted Stat2 deletion in CD11c+cDCs enhanced tumor growth unaffected by IFNβ therapy. Furthermore, STAT2 was essential for both, the activation of CD8a+cDCs and CD11b+cDCs and antigen cross-presentation in vivo for the generation of robust T cell killing response. In contrast, STAT2 in CD11c+cDCs was dispensable for stimulating an antigen-specific humoral response, which was impaired in global Stat2 deficient mice. Thus, our studies indicate that STAT2 in cDCs is critical in host IFN-I signals by sculpting CTL responses against tumors.
| S-EPMC7781843 | biostudies-literature