Huang W, Eickhoff JC, Mehraein-Ghomi F, Church DR, Wilding G, Basu HS.
PMID: 25893668 | DOI: 10.1002/pros.22996.
Abstract INTRODUCTION: Prostate cancer (PCa) in many patients remains indolent for the rest of their lives, but in some patients, it progresses to lethal metastatic disease. Gleason score is the current clinical method for PCa prognosis. It cannot reliably identify aggressive PCa, when GS is ≤ 7. It is shown that oxidative stress plays a key role in PCa progression. We have shown that in cultured human PCa cells, an activation of spermidine/spermine N1 -acetyl transferase (SSAT; EC 2.3.1.57) enzyme initiates a polyamine oxidation pathway and generates copious amounts of reactive oxygen species in polyamine-rich PCa cells. METHOD: We used RNA in situ hybridization and immunohistochemistry methods to detect SSAT mRNA and protein expression in two tissue microarrays (TMA) created from patient's prostate tissues. We analyzed 423 patient's prostate tissues in the two TMAs. RESULTS: Our data show that there is a significant increase in both SSAT mRNA and the enzyme protein in the PCa cells as compared to their benign counterpart. This increase is even more pronounced in metastatic PCa tissues as compared to the PCa localized in the prostate. In the prostatectomy tissues from early-stage patients, the SSAT protein level is also high in the tissues obtained from the patients who ultimately progress to advanced metastatic disease. DISCUSSION: Based on these results combined with published data from our and other laboratories, we propose an activation of an autocrine feed-forward loop of PCa cell proliferation in the absence of androgen as a possible mechanism of castrate-resistant prostate cancer growth.
Molecular Vision 2015; 21:428-442
Sun N, Shibata B, Hess JF, FitzGerald PG.
PMID: 25991907
Purpose: Several properties of ocular tissue make fixation for light microscopy problematic. Because the eye is spherical, immersion fixation necessarily results in a temporal gradient of fixation, with surfaces fixing more rapidly and thoroughly than interior structures. The problem is compounded by the fact that the layers of the eye wall are compositionally quite different, resulting in different degrees of fixation-induced shrinkage and distortion. Collectively, these result in non-uniform preservation, as well as buckling and/or retinal detachment. This gradient problem is most acute for the lens, where the density of proteins can delay fixation of the central lens for days, and where the fixation gradient parallels the age gradient of lens cells, which complicates data interpretation. Our goal was to identify a simple method for minimizing some of the problems arising from immersion fixation, which avoided covalent modification of antigens, retained high quality structure, and maintained tissue in a state that is amenable to common cytochemical techniques. Methods: A simple and inexpensive derivative of the freeze-substitution approach was developed and compared to fixation by immersion in formalin. Preservation of structure, immunoreactivity, GFP and tdTomato fluorescence, lectin reactivity, outer segment auto fluorescence, Click-iT chemistry, compatibility with in situ hybdrdization, and the ability to rehydrate eyes after fixation by freeze substitution for subsequent cryo sectioning were assessed. Results: An inexpensive and simple variant of the freeze substitution approach provides excellent structural preservation for light microscopy, and essentially eliminates ocular buckling, retinal detachment, and outer segment auto-fluorescence, without covalent modification of tissue antigens. The approach shows a notable improvement in preservation of immunoreactivity. TdTomato intrinsic fluorescence is also preserved, as is compatibility with in situ hybridization, lectin labeling, and the Click-iT chemistry approach to labeling the thymidine analog EdU. On the negative side, this approach dramatically reduced intrinsic GFP fluorescence. Conclusions: A simple, cost-effective derivative of the freeze substitution process is described that is of particular value in the study of rodent or other small eyes, where fixation gradients, globe buckling, retinal detachment, differential shrinkage, autofluorescence, and tissue immunoreactivity have been problematic.
Dalbøgea LS, Pedersena SL, Sechera T, Holstb B, Vranga N, Jelsinga J.
PMID: 25895852 | DOI: 10.1016/j.peptides.2015.04.010
Neuromedin U (NMU) is a gut-brain peptide, implicated in energy and glucose homeostasis via the peripherally expressed NMU receptor 1 (NMUR1) and the central NMUR2. We investigated the effects of a lipidated NMU analog on gastric emptying (GE), glucose homeostasis and food intake to evaluate the use of a NMU analog as drug candidate for treatment of obesity and diabetes. Finally mRNA expression of NMU and NMUR1 in the gut and NMUR2 in the hypothalamus was investigated using a novel chromogen-based in situ hybridization (ISH) assay. Effects on food intake (6 and 18 h post dosing) were addressed in both mice and rats. The effects on GE and glycaemic control were assessed in mice, immediately after the first dose and after seven days of bidaily (BID) dosing. The lipidated NMU analog exerted robust reductions in GE and food intake in mice and improved glycaemic control when measured immediately after the first dose. No effects were observed after seven days BID. In rats, the analog induced only a minor effect on food intake. NMU mRNA was detected in the enteric nervous system throughout the gut, whereas NMUR1 was confined to the lamina propria. NMUR2 was detected in the paraventricular (PVN) and arcuate nuclei (ARC) in mice, with a reduced expression in ARC in rats. In summary, the anorectic effect of the lipidated NMU is partly mediated by a decrease in gastric emptying which is subject to tachyphylaxis after continuous dosing. Susceptibility to NMU appears to be species specific.
Guenther CA, Wang Z, Li E, Tran MC, Logan CY, Nusse R, Pantalena-Filho L, Yang GP, Kingsley DM.
PMID: 25886903 | DOI: 10.1016/j.bone.2015.04.010.
Bone morphogenetic proteins (BMPs) are key signaling molecules required for normal development of bones and other tissues. Previous studies have shown that null mutations in the mouse Bmp5 gene alter the size, shape and number of multiple bone and cartilage structures during development. Bmp5 mutations also delay healing of rib fractures in adult mutants, suggesting that the same signals used to pattern embryonic bone and cartilage are also reused during skeletal regeneration and repair. Despite intense interest in BMPs as agents for stimulating bone formation in clinical applications, little is known about the regulatory elements that control developmental or injury-induced BMP expression. To compare the DNA sequences that activate gene expression during embryonic bone formation and following acute injuries in adult animals, we assayed regions surrounding the Bmp5 gene for their ability to stimulate lacZ reporter gene expression in transgenic mice. Multiple genomic fragments, distributed across the Bmp5 locus, collectively coordinate expression in discrete anatomic domains during normal development, including in embryonic ribs. In contrast, a distinct regulatory region activated expression following rib fracture in adult animals. The same injury control region triggered gene expression in mesenchymal cells following tibia fracture, in migrating keratinocytes following dorsal skin wounding, and in regenerating epithelial cells following lung injury. The Bmp5 gene thus contains an "injury response" control region that is distinct from embryonic enhancers, and that is activated by multiple types of injury in adult animals.
Nat Neurosci. 2015 Apr 13.
Wang DV, Yau HJ, Broker CJ, Tsou JH, Bonci A, Ikemoto S.
PMID: 25867120 | DOI: 10.1038/nn.3998.
Sharp wave-associated field oscillations (∼200 Hz) of the hippocampus, referred to as ripples, are believed to be important for consolidation of explicit memory. Little is known about how ripples are regulated by other brain regions. We found that the median raphe region (MnR) is important for regulating hippocampal ripple activity and memory consolidation. We performed in vivo simultaneous recording in the MnR and hippocampus of mice and found that, when a group of MnR neurons was active, ripples were absent. Consistently, optogenetic stimulation of MnR neurons suppressed ripple activity and inhibition of these neurons increased ripple activity. Notably, using a fear conditioning procedure, we found that photostimulation of MnR neurons interfered with memory consolidation. Our results demonstrate a critical role of the MnR in regulating ripples and memory consolidation.
Mol Cancer. 2015 Apr 8;14(1):77.
Koizume S, Ito S, Nakamura Y, Yoshihara M, Furuya M, Yamada R, Miyagi E, Hirahara F, Takano Y, Miyagi Y.
PMID: 25879517 | DOI: 10.1186/s12943-015-0351-z.
BACKGROUND: Elucidation of the molecular mechanisms by which cancer cells overcome hypoxia is potentially important for targeted therapy. Complexation of hypoxia-inducible factors (HIFs) with aryl hydrocarbon receptor nuclear translocators can enhance gene expression and initiate cellular responses to hypoxia. However, multiple molecular mechanisms may be required for cancer cells to adapt to diverse microenvironments. We previously demonstrated that a physical interaction between the ubiquitously expressed transcription factor Sp1 and HIF2 is a major cause of FVII gene activation in poor prognostic ovarian clear cell carcinoma (CCC) cells under hypoxia. Furthermore, it was found that FVII activation is synergistically enhanced when serum-starved cells are cultured under hypoxic conditions. In this study, we investigated whether HIFs and transcription factor Sp1 cooperate to activate multiple genes in CCC cells under conditions of serum starvation and hypoxia (SSH) and then contribute to malignant phenotypes. METHODS: To identify genes activated under hypoxic conditions in an Sp1-dependent manner, we first performed cDNA microarray analyses. We further investigated the molecular mechanisms of synergistic gene activations including the associated serum factors by various experiments such as real-time RT-PCR, western blotting and chromatin immunoprecipitation. The study was further extended to animal experiments to investigate how it contributes to CCC progression in vivo. RESULTS: ICAM1 is one such gene dramatically induced by SSH and is highly induced by SSH and its synergistic activation involves both the mTOR and autonomously activated TNFα-NFκB axes. We identified long chain fatty acids (LCFA) as a major class of lipids that is associated with albumin, a serum factor responsible for synergistic gene activation under SSH. Furthermore, we found that ICAM1 can be induced in vivo to promote tumor growth. CONCLUSION: Sp1 and HIFs collaborate to activate genes required for the adaptation of CCC cells to severe microenvironments, such as LCFA starvation and hypoxia. This study highlights the importance of transcriptional regulation under lipid starvation and hypoxia in the promotion of CCC tumor growth.
Nat Commun. 2015 Apr 10;6:6810.
Boo K, Bhin J, Jeon Y, Kim J, Shin HJ, Park JE, Kim K, Kim CR, Jang H, Kim IH, Kim VN, Hwang D, Lee H, Baek SH.
PMID: 25857206 | DOI: 10.1038/ncomms7810
The actions of transcription factors, chromatin modifiers and noncoding RNAs are crucial for the programming of cell states. Although the importance of various epigenetic machineries for controlling pluripotency of embryonic stem (ES) cells has been previously studied, how chromatin modifiers cooperate with specific transcription factors still remains largely elusive. Here, we find that Pontin chromatin remodelling factor plays an essential role as a coactivator for Oct4 for maintenance of pluripotency in mouse ES cells. Genome-wide analyses reveal that Pontin and Oct4 share a substantial set of target genes involved in ES cell maintenance. Intriguingly, we find that the Oct4-dependent coactivator function of Pontin extends to the transcription of large intergenic noncoding RNAs (lincRNAs) and in particular linc1253, a lineage programme repressing lincRNA, is a Pontin-dependent Oct4 target lincRNA. Together, our findings demonstrate that the Oct4-Pontin module plays critical roles in the regulation of genes involved in ES cell fate determination.
Am J Respir Crit Care Med. 2015 Apr 6.
Roos AB, Sandén C, Mori M, Bjermer L, Stampfli MR, Erjefält JS.
PMID: 25844618
Abstract RATIONALE: End-stage chronic obstructive pulmonary disease (COPD) is associated with an accumulation of pulmonary lymphoid follicles. Interleukin (IL)-17A is implicated in COPD and pulmonary lymphoid neogenesis in response to microbial stimuli. We hypothesized that IL-17A is increased in peripheral lung tissue during end-stage COPD and also directly contributes to cigarette smoke-induced lymphoid neogenesis. OBJECTIVE: Characterize the tissue expression and functional role of IL-17A in end-stage COPD. METHODS: Automated immune-detection of IL-17A and IL-17F was performed in lung tissue specimens collected from patients with GOLD stage I-IV COPD, as well as smoking and never-smoking controls. In parallel, Il17a-/- mice and WT controls were exposed to cigarette smoke for 24 weeks and pulmonary lymphoid neogenesis was assessed. MEASUREMENTS AND MAIN RESULTS: Tissue expression of IL-17A and IL-17F was increased in COPD and correlated with lung function decline. IL-17A was significantly elevated in severe-very severe COPD (GOLD III/IV), compared to both smokers and never-smokers without COPD. While CD3+ T cells expressed IL-17A in very severe COPD, the majority of IL-17A+ cells were identified as tryptase+ mast cells. Attenuated lymphoid neogenesis and reduced expression of the B cell attracting chemokine C-X-C motif ligand (CXCL)12 was observed in cigarette smoke-exposed Il17a-/- mice. CXCL12 was also highly expressed in lymphoid follicles in COPD lungs, and the pulmonary expression was significantly elevated in end-stage COPD. CONCLUSION: IL-17A in the peripheral lung of patients with severe-very severe COPD may contribute to disease progression and development of lymphoid follicles via activation of CXCL12.
Nat Commun. 2015 Apr 7;6:6613.
Wang T, Chai R, Kim GS, Pham N, Jansson L, Nguyen DH, Kuo B, May LA, Zuo J, Cunningham LL, Cheng AG.
PMID: 25849379 | DOI: 10.1038/ncomms7613.
Recruitment of endogenous progenitors is critical during tissue repair. The inner ear utricle requires mechanosensory hair cells (HCs) to detect linear acceleration. After damage, non-mammalian utricles regenerate HCs via both proliferation and direct transdifferentiation. In adult mammals, limited transdifferentiation from unidentified progenitors occurs to regenerate extrastriolar Type II HCs. Here we show that HC damage in neonatal mouse utricle activates the Wnt target gene Lgr5 in striolar supporting cells. Lineage tracing and time-lapse microscopy reveal that Lgr5+ cells transdifferentiate into HC-like cells in vitro. In contrast to adults, HC ablation in neonatal utricles in vivo recruits Lgr5+ cells to regenerate striolar HCs through mitotic and transdifferentiation pathways. Both Type I and II HCs are regenerated, and regenerated HCs display stereocilia and synapses. Lastly, stabilized ß-catenin in Lgr5+ cells enhances mitotic activity and HC regeneration. Thus Lgr5 marks Wnt-regulated, damage-activated HC progenitors and may help uncover factors driving mammalian HC regeneration.
The Journal of Neuroscience, 8 April 2015, 35(14): 5625-5639
Rubio FJ, Liu QR, Li X, Cruz FC, Leão RM, Warren BL, Kambhampati S, Babin KR, McPherson KB, Cimbro R, Bossert JM, Shaham Y, Hope BT.
PMID: 25855177 | DOI: 10.1523/JNEUROSCI.4997-14.2015
Context-induced reinstatement of drug seeking is a well established animal model for assessing the neural mechanisms underlying context-induced drug relapse, a major factor in human drug addiction. Neural activity in striatum has previously been shown to contribute to context-induced reinstatement of heroin, cocaine, and alcohol seeking, but not yet for methamphetamine seeking. In this study, we found that context-induced reinstatement of methamphetamine seeking increased expression of the neural activity marker Fos in dorsal but not ventral striatum. Reversible inactivation of neural activity in dorsolateral but not dorsomedial striatum using the GABA agonists muscimol and baclofen decreased context-induced reinstatement. Based on our previous findings that Fos-expressing neurons play a critical role in conditioned drug effects, we assessed whether context-induced reinstatement was associated with molecular alterations selectively induced within context-activated Fos-expressing neurons. We used fluorescence-activated cell sorting to isolate reinstatement-activated Fos-positive neurons from Fos-negative neurons in dorsal striatum and used quantitative PCR to assess gene expression within these two populations of neurons. Context-induced reinstatement was associated with increased expression of the immediate early genes Fos and FosB and the NMDA receptor subunit gene Grin2a in only Fos-positive neurons. RNAscope in situ hybridization confirmed that Grin2a, as well as Grin2b, expression were increased in only Fos-positive neurons from dorsolateral, but not dorsomedial, striatum. Our results demonstrate an important role of dorsolateral striatum in context-induced reinstatement of methamphetamine seeking and that this reinstatement is associated with unique gene alterations in Fos-expressing neurons.
The FASEB Journal 29.1 Supplement (2015): 685-19.
Over activation of renin angiotensin system (RAS) signaling in cardiovascular control centers of the brain causes inflammatory responses that are associated with the onset of neurogenic hypertension. The (pro)renin receptor (PRR) is an early component of RAS, that binds (pro)renin resulting in an increase in angiotensin II (Ang-II) generation and ensuing neurogenic hypertension. Additionally, activation of the PRR leads to Ang-II independent signaling that has been hypothesized to similarly initiate hypertensive and proinflammatory responses. Here, we sought to identify which cell types co-localize with the PRR in the paraventricular nucleus of the hypothalamus (PVN), an important brain region in regulating systemic blood pressure and neuroendocrine responses. To characterize which cell types contained the PRR we performed RNAscope in situ hybridization (ISH) coupled with immunohistochemistry for cell-type-specific markers on perfused mouse brains. Dense localization of PRR mRNA to the PVN was observed and these mRNAs were predominantly localized to cells labeled with the neuronal-specific marker, HuC/D. PRR mRNAs were also localized to cells expressing the microglial (Iba-1) and astroglial (GFAP) markers. However, the expression of PRR mRNAs within these cell-types was less robust. Subsequent ISH studies in corticotrophin-releasing hormone and angiotensin type-1 receptor reporter mice localized PRR to these specific neuronal phenotypes. Phenotyping PVN-localized cells in this manner works towards understanding the mechanisms PRR binding may play in affecting neurogenic hypertension.
Steinckwich N, Myers P, Janardhan KS, Flagler ND, King D, Petranka JG, Putney JW.
PMID: 25837581 | DOI: fj.14-265215.
Stromal interaction molecule 1 (STIM1) is a Ca2+ sensor protein that initiates store-operated calcium entry (SOCE). STIM1 is known to be involved in the chemoattractant signaling pathway for FPR1 in cell lines, but its role in in vivo functioning of neutrophils is unclear. Plaque-type psoriasis is a chronic inflammatory skin disorder associated with chemoattractants driving neutrophils into the epidermis. We investigated the involvement of STIM1 in neutrophil chemotaxis in vitro, as well as during chronic psoriatic inflammation. To this end, we used conditional knockout (KO) mice lacking STIM1 in cells of myeloid lineage (STIM1fl/fl LysM-cre). We demonstrate that STIM1 is required for chemotaxis because of multiple chemoattractants in mouse neutrophils in vitro. Using an imiquimod-induced psoriasis-like skin model, we show that KO mice had less neutrophil infiltration in the epidermis than controls, whereas neither chemoattractant production in the epidermis nor macrophage migration was decreased. KO mice displayed a more rapid reversal of the outward signs of psoriasis (plaques). Thus, KO of STIM1 impairs neutrophil contribution to psoriatic inflammation. Our data provide new insights to our understanding of how STIM1 orchestrates the cellular behavior underlying chemotaxis and illustrate the important role of SOCE in a disease-related pathologic model.-Steinckwich, N., Myers, P., Janardhan, K. S., Flagler, N. D., King, D., Petranka, J. G., Putney, J. W. Role of the store-operated calcium entry protein, STIM1, in neutrophil chemotaxis and infiltration into a murine model of psoriasis-inflamed skin.