Expression profile of CREB knockdown in myeloid leukemia cells.

BackgroundThe cAMP Response Element Binding Protein, CREB, is a transcription factor that regulates cell proliferation, differentiation, and survival in several model systems, including neuronal and hematopoietic cells. We demonstrated that CREB is overexpressed in acute myeloid and leukemia cells compared to normal hematopoietic stem cells. CREB knockdown inhibits leukemic cell proliferation in vitro and in vivo, but does not affect long-term hematopoietic reconstitution.MethodsTo understand downstream pathways regulating CREB, we performed expression profiling with RNA from the K562 myeloid leukemia cell line transduced with CREB shRNA.ResultsBy combining our expression data from CREB knockdown cells with prior ChIP data on CREB binding we were able to identify a list of putative CREB regulated genes. We performed extensive analyses on the top genes in this list as high confidence CREB targets. We found that this list is enriched for genes involved in cancer, and unexpectedly, highly enriched for histone genes. Furthermore, histone genes regulated by CREB were more likely to be specifically expressed in hematopoietic lineages. Decreased expression of specific histone genes was validated in K562, TF-1, and primary AML cells transduced with CREB shRNA.ConclusionWe have identified a high confidence list of CREB targets in K562 cells. These genes allow us to begin to understand the mechanisms by which CREB contributes to acute leukemia. We speculate that regulation of histone genes may play an important role by possibly altering the regulation of DNA replication during the cell cycle

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ABSTRACT. Objective. To determine whether men with gout may have an increased prevalence of erectile dysfunction (ED) as compared with men without gout. Methods. In this cross-sectional study, men aged 18-89 presenting to the rheumatology clinic between August 26, 2010, and May 13, 2013, were Erectile dysfunction (ED) is common in the general population, affecting about 50% of 40-to 70-year-old men 1 . The National Institutes of Health Consensus Development statement defined ED as the "inability of the male to attain and maintain erection of the penis sufficient to permit satisfactory sexual intercourse" 2 . The likelihood of ED increases with age, but is not an inevitable consequence of aging 2 . The importance of cardiovascular (CV) disease (CVD) as an underlying cause of ED is well established 3,4 . This is not surprising because CVD and ED share mutual risk factors such as diabetes mellitus (DM), hypertension (HTN), advanced age, hypercholesterolemia, obesity, metabolic syndrome, certain medications such as antidepressants, and tobacco abuse New evidence shows that hyperuricemia and inflammation may be independent risk factors for ED in addition to the established ones. In a recent study by Solak, et al 7 , of 312 men who underwent an exercise stress test because of chest pain, each 1 mg/dl increase in serum urate (SU) was associated with a 31% increased risk of ED. Compared with patients in the first quartile of SU level, those in the fourth quartile had a 2.6 times increased risk of ED. However, in an adjusted analysis for traditional CV risk factors, the relationship with SU was no longer significant. Another recent study, by Salem, et al 8 , evaluated SU level and the distribution of potential ED risk factors in 251 men with newly diagnosed ED versus 252 age-matched controls without ED. A significant difference was found between mean SU levels in men with ED (6.12 mg/dl) versus men without ED (4.97 mg/dl). The men in the highest tertile of SU level had a 6-fold increased risk of ED compared with men in the lowest tertile. Each 1 mg/dl increase in SU level was associated with a 2-fold increased risk of ED. Inflammation, too, plays an important role in ED 9,10 . Low levels of interleukin 6 (IL-6) and fibrinogen exclude the presence of ED in patients with coronary artery disease (CAD) or with unfavorable risk factor

Sex Differences in Neighborhood Perceptions and Physical Activity among Older Adults Living in Car-dependent Neighborhoods

INTRODUCTION: Older adults may have more physical limitations and no longer routinely travel outside their neighborhoods to work. Their daily living, health, and well-being may depend on neighborhood resources close to their homes. Therefore, access to resources critical for healthy aging may influence health in various aspects. In this study we investigated differences in neighborhood perceptions (NP) and their influences on physical activity (PA). METHODS: Between 2012 and 2015, 111 men and 103 women aged 65 years and older living in car-dependent neighborhoods were queried on NP, use of neighborhood resources, and frequency and location of PA. Participants wore an accelerometer for 7 consecutive days. RESULTS: Compared to women, men had a higher daily step count (mean (SD) 4385 (2122) men vs. 3671(1723) women, p=0.008). Men reported higher frequencies of any PA and moderate-to-vigorous PA, and a lower frequency of PA inside the home. Mean daily step counts and frequency of PA outside the home decreased progressively with age for both genders. Women had a sharper decline in frequencies of self-reported PA. Men had a significant decrease in utilitarian walking, which women did not (p=0.07). Among participants who reported any PA (n=190), more women indicated exercising indoors more often than outdoors (59% vs. 44%, p=0.04). Men perceived their neighborhoods more favorably than women. However, women perceived better accessibility to neighborhood resources. Higher NPs were associated with more frequent total PA and exercise outside the home. Association of NP with recreational walking was limited to men whereas association of NP with utilitarian walking was limited to women. CONCLUSION: Older men and women differed in levels, types and location preferences of PA, NPs and their influences on PA. Consideration of these sex differences is necessary to improve the effectiveness of active living promotion programs among older adults, especially those targeting NPs

CREB is a critical regulator of normal hematopoiesis and leukemogenesis

The cAMP-responsive element binding protein (CREB) is a 43-kDa nuclear transcription factor that regulates cell growth, memory, and glucose homeostasis. We showed previously that CREB is amplified in myeloid leukemia blasts and expressed at higher levels in leukemia stem cells from patients with myeloid leukemia. CREB transgenic mice develop myeloproliferative disease after 1 year, but not leukemia, suggesting that CREB contributes to but is not sufficient for leukemogenesis. Here, we show that CREB is most highly expressed in lineage negative hematopoietic stem cells (HSCs). To understand the role of CREB in hematopoietic progenitors and leukemia cells, we examined the effects of RNA interference (RNAi) to knock down CREB expression in vitro and in vivo. Transduction of primary HSCs or myeloid leukemia cells with lentiviral CREB shRNAs resulted in decreased proliferation of stem cells, cell- cycle abnormalities, and inhibition of CREB transcription. Mice that received transplants of bone marrow transduced with CREB shRNA had decreased committed progenitors compared with control mice. Mice injected with Ba/F3 cells expressing either Bcr-Abl wild-type or T315I mutation with CREB shRNA had delayed leukemic infiltration by bioluminescence imaging and prolonged median survival. Our results suggest that CREB is critical for normal myelopoiesis and leukemia cell proliferation

O-GlcNAcylation of core components of the translation initiation machinery regulates protein synthesis

Protein synthesis is essential for cell growth, proliferation, and survival. Protein synthesis is a tightly regulated process that involves multiple mechanisms. Deregulation of protein synthesis is considered as a key factor in the development and progression of a number of diseases, such as cancer. Here we show that the dynamic modification of proteins by O-linked β-N-acetyl-glucosamine (O-GlcNAcylation) regulates translation initiation by modifying core initiation factors eIF4A and eIF4G, respectively. Mechanistically, site-specific O-GlcNAcylation of eIF4A on Ser322/323 disrupts the formation of the translation initiation complex by perturbing its interaction with eIF4G. In addition, O-GlcNAcylation inhibits the duplex unwinding activity of eIF4A, leading to impaired protein synthesis, and decreased cell proliferation. In contrast, site-specific O-GlcNAcylation of eIF4G on Ser61 promotes its interaction with poly(A)-binding protein (PABP) and poly(A) mRNA. Depletion of eIF4G O-GlcNAcylation results in inhibition of protein synthesis, cell proliferation, and soft agar colony formation. The differential glycosylation of eIF4A and eIF4G appears to be regulated in the initiation complex to fine-tune protein synthesis. Our study thus expands the current understanding of protein synthesis, and adds another dimension of complexity to translational control of cellular proteins

Interaction of cyclin-dependent kinase 12/CrkRS with cyclin K1 is required for the phosphorylation of the C-terminal domain of RNA polymerase II

CrkRS (Cdc2-related kinase, Arg/Ser), or cyclin-dependent kinase 12 (CKD12), is a serine/threonine kinase believed to coordinate transcription and RNA splicing. While CDK12/CrkRS complexes were known to phosphorylate the C-terminal domain (CTD) of RNA polymerase II (RNA Pol II), the cyclin regulating this activity was not known. Using immunoprecipitation and mass spectrometry, we identified a 65-kDa isoform of cyclin K (cyclin K1) in endogenous CDK12/CrkRS protein complexes. We show that cyclin K1 complexes isolated from mammalian cells contain CDK12/CrkRS but do not contain CDK9, a presumed partner of cyclin K. Analysis of extensive RNA-Seq data shows that the 65-kDa cyclin K1 isoform is the predominantly expressed form across numerous tissue types. We also demonstrate that CDK12/CrkRS is dependent on cyclin K1 for its kinase activity and that small interfering RNA (siRNA) knockdown of CDK12/CrkRS or cyclin K1 has similar effects on the expression of a luciferase reporter gene. Our data suggest that cyclin K1 is the primary cyclin partner for CDK12/CrkRS and that cyclin K1 is required to activate CDK12/CrkRS to phosphorylate the CTD of RNA Pol II. These properties are consistent with a role of CDK12/CrkRS in regulating gene expression through phosphorylation of RNA Pol II

Rosette-forming glioneuronal tumor: a pineal region case with IDH1 and IDH2 mutation analyses and literature review of 43 cases

Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a mixed glio-neuronal neoplasm recently codified by the World Health Organization WHO Classification of Central Nervous System (CNS) Tumors (2007). To date, 43 cases have been described in the literature; most occurring in the fourth ventricle region. We report the fourth case involving the pineal region in a 16-year-old female with signs of increased intracranial pressure (ICP). A stereotactic biopsy of the mass was followed by a debulking procedure. Both specimens revealed classic RGNT histology. The patient had stable scans 7 months post-resection. The clinical, radiological and histopathologic features of the previously described 43 cases are reviewed along with our illustrative case. Mean age of patients was 30 ± 12.8 years with 1.9:1 female to male ratio. The most common presenting signs related to increased ICP and posterior fossa involvement, including: headache (62.8%), ataxia (39.5%) and vomiting and vertigo (both 16.3%). This tumor usually presents with cystic changes (54.5%) with focal enhancement (60.9%) and hydrocephalus (43.2%). Microcalcifications and satellite lesions were common radiographic observations. All reported cases had the classic biphasic pattern. Rosenthal fibers and eosinophilic granular bodies are each present in approximately two thirds of cases. Ki-67 labeling index is consistently low (mean (%): 1.8 ± 0.75 SD). The isocitrate dehydrogenase 1 or 2 mutation found in low grade diffuse gliomas is not identified in this RGNT case. Reported outcome is nearly uniformly excellent after complete or subtotal resection. A solitary report of recurrence after 10 years and the limited experience with this entity suggest that long term follow up is advisable

Finfish and aquatic invertebrate pathology resources for now and the future

Utilization of finfish and aquatic invertebrates in biomedical research and as environmental sentinels has grown dramatically in recent decades. Likewise the aquaculture of finfish and invertebrates has expanded rapidly worldwide as populations of some aquatic food species and threatened or endangered aquatic species have plummeted due to overharvesting or habitat degradation. This increasing intensive culture and use of aquatic species has heightened the importance of maintaining a sophisticated understanding of pathology of various organ systems of these diverse species. Yet, except for selected species long cultivated in aquaculture, pathology databases and the workforce of highly trained pathologists lag behind those available for most laboratory animals and domestic mammalian and avian species. Several factors must change to maximize the use, understanding, and protection of important aquatic species: 1) improvements in databases of abnormalities across species; 2) standardization of diagnostic criteria for proliferative and nonproliferative lesions; and 3) more uniform and rigorous training in aquatic morphologic pathology

Finfish and aquatic invertebrate pathology resources for now and the future

Utilization of finfish and aquatic invertebrates in biomedical research and as environmental sentinels has grown dramatically in recent decades. Likewise the aquaculture of finfish and invertebrates has expanded rapidly worldwide as populations of some aquatic food species and threatened or endangered aquatic species have plummeted due to overharvesting or habitat degradation. This increasing intensive culture and use of aquatic species has heightened the importance of maintaining a sophisticated understanding of pathology of various organ systems of these diverse species. Yet, except for selected species long cultivated in aquaculture, pathology databases and the workforce of highly trained pathologists lag behind those available for most laboratory animals and domestic mammalian and avian species. Several factors must change to maximize the use, understanding, and protection of important aquatic species: 1) improvements in databases of abnormalities across species; 2) standardization of diagnostic criteria for proliferative and nonproliferative lesions; and 3) more uniform and rigorous training in aquatic morphologic pathology