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1.
FEBS Lett ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38697949

ABSTRACT

Lipid metabolism hinges on a balance between lipogenesis and fatty acid oxidation (FAO). Disruptions in this balance can induce endoplasmic reticulum (ER) stress triggering the unfolded protein response (UPR) and contribute to metabolic diseases. The UPR protein, Luman or CREB3, has recently been implicated in metabolic regulation-CREB3 knockout mice exhibit resistance to diet-induced obesity and altered insulin sensitivity. Here, we show that CREB3 activated PPARGC1A transcription from a 1 kb promoter region. An increase in CREB3 expression correlated inversely with endogenous PPARGC1A mRNA levels and genes involved in FAO. As PGC-1α encoded by PPARGC1A is a master regulator of mitochondrial biogenesis and energy homeostasis, these findings demonstrate that CREB3 is a transcriptional regulator of PGC-1α, underlining the potential role of CREB3 in energy metabolism.

2.
Am J Clin Exp Urol ; 11(1): 27-39, 2023.
Article in English | MEDLINE | ID: mdl-36923723

ABSTRACT

BACKGROUND: Risk factors for prostate cancer include age, environment, race and ethnicity. Genetic variants in cyclic-adenosine-monophosphate-response-element-binding protein 3 regulatory factor (CREBRF) gene are frequently observed in Pacific Islanders, a population with elevated prostate cancer incidence. CREBRF has been shown to play a role in other cancers, however its function in prostate homeostasis and tumorigenesis has not been previously explored. We determined the incidence of CREBRF alterations in publicly available databases and examined the impact of CREBRF deletion on the murine prostate in order to determine whether CREBRF impacts prostate physiology or pathophysiology. METHODS: Alterations in CREBRF were identified in prostate cancer patients via in silico analysis of several publicly available datasets through cBioPortal. Male Crebrf knockout and wild-type littermate mice were generated and examined for prostate defects at 4 months of age. Immunohistochemical staining of murine prostate sections was used to determine the impact of Crebrf knockout on proliferation, apoptosis, inflammation and blood vessel density in the prostate. Serum adipokine levels were measured using a Luminex Multiplex Assay. RESULTS: CREBRF alterations were identified in up to 4.05% of prostate tumors and the mutations identified were categorized as likely damaging. Median survival of prostate cancer patients with genetic alterations in CREBRF was 41.23 months, compared to 131 months for patients without these changes. In the murine model, the prostates of Crebrf knockout mice had reduced epithelial proliferation and increased TUNEL+ apoptotic cells. Circulating adipokines PAI-1 and MCP-1 were also altered in Crebrf knockout mice compared to age-matched controls. CONCLUSIONS: Prostate cancer patients with genetic alterations in CREBRF had a significantly decreased overall survival suggesting that wild type CREBRF may play a role in limiting prostate tumorigenesis and progression. The murine knockout model demonstrated that CREBRF could modulate proliferation and apoptosis and macrophage density in the prostate. Serum levels of adipokines PAI-1 and MCP-1 were also altered and may contribute to the phenotypic changes observed in the prostates of Crebrf knockout mice. Future studies focused on populations susceptible to CREBRF mutations and mechanistic studies will be required to fully elucidate the potential role of CREBRF in prostate tumorigenesis.

3.
Mitochondrion ; 69: 10-17, 2023 03.
Article in English | MEDLINE | ID: mdl-36627030

ABSTRACT

In mammalian cells, mitochondrial respiration produces reactive oxygen species (ROS) such as superoxide (O2-), which is then converted by the SOD1 enzyme into hydrogen peroxide (H2O2), the predominant form of cytosolic ROS. ROS at high levels can be toxic, but below this threshold are important for physiological processes acting as a second messenger similar to Ca2+. Mitochondrial Ca2+ influx from the ER increases ATP and ROS production, while ATP and ROS can regulate Ca2+ homeostasis, leading to an intricate interplay between Ca2+, ROS, and ATP synthesis. The Unfolded Protein Response (UPR) proteins ATF6α and XBP1 contribute to protection from oxidative stress through upregulation of Sod1 and Catalase genes. Here, UPR-associated protein CREB3 is shown to play a role in balancing Ca2+, ROS, and ATP homeostasis. Creb3-deficient mouse embryonic fibroblast cells (MEF-/-) were susceptible to H2O2-induced oxidative stress while having a functioning antioxidant gene expression response compared to MEF+/+. MEF-/- cells also contained elevated basal cytosolic ROS levels, which was attributed to drastically increased basal mitochondrial respiration and spare respiratory capacity relative to MEF+/+. MEF-/- cells also showed an increase in endoplasmic reticulum Ca2+ release and mitochondrial Ca2+ levels hinting at a potential cause for MEF-/- cell mitochondrial dysfunction. These results suggest that CREB3 is essential for maintaining proper Ca2+, ATP, and ROS homeostasis in mammalian cells.


Subject(s)
Hydrogen Peroxide , Transcription Factors , Animals , Mice , Adenosine Triphosphate/metabolism , Calcium/metabolism , Fibroblasts/metabolism , Homeostasis , Hydrogen Peroxide/toxicity , Hydrogen Peroxide/metabolism , Mammals , Oxidative Stress , Reactive Oxygen Species/metabolism , Superoxide Dismutase-1/metabolism , Transcription Factors/metabolism
4.
VideoGIE ; 7(7): 250-252, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35815163

ABSTRACT

Video 1EUS-guided gallbladder drainage followed by rendezvous ERCP.

5.
Int J Obes (Lond) ; 46(8): 1446-1455, 2022 08.
Article in English | MEDLINE | ID: mdl-35637262

ABSTRACT

BACKGROUND: The endoplasmic reticulum senses alterations to cellular homeostasis that activates the unfolded protein response (UPR). UPR proteins are known to aid in regulating glucose and lipid metabolism. CREB3 is a UPR-associated transcription factor whose potential role in regulating energy metabolism remains unclear. METHODS: Eight-week-old wild-type (WT) and Creb3+/- mice were placed on control and high-fat diets (HFD) for 8 weeks, and metabolic phenotypes characterized by weekly weighing, indirect calorimetry, body composition scans, glucose tolerance tests, plasma analysis, tissue lipid quantifications and gene/protein expression analysis. RESULTS: HFD weight gain in Creb3+/- males was reduced by 34% (p < 0.0001) and females by 39.5% (p = 0.014) from their WT counterparts. No differences were found in HFD food intake or total fecal lipids between genotypes. Creb3+/- mice had increased energy expenditure and respiratory exchange ratios (p = 0.002) relative to WT. Creb3+/- mice had significant reductions in absolute fat and lean tissue, while Creb3+/- females had significant reductions in body fat% and increased lean% composition (p < 0.0001) compared to WT females. Creb3+/- mice were protected from HFD-induced basal hyperglycemia (males p < 0.0001; females p = 0.0181). Creb3+/- males resisted HFD-induced hepatic lipid accumulation (p = 0.025) and glucose intolerance compared to WT (p < 0.0001) while Creb3+/- females were protected from lipid accumulation in skeletal muscle (p = 0.001). Despite the metabolic differences of Creb3+/- mice on HFD, lipid plasma profiles did not significantly differ from WT. Fasted Creb3+/- mice additionally revealed upregulation of hepatic energy expenditure and gluconeogenic genes such as Pgc-1a and Gr (glucocorticoid receptor) (p < 0.05), respectively. CONCLUSIONS: Reduced expression of CREB3 increased energy expenditure and the respiratory exchange ratio, and protected mice from HFD-induced weight gain, basal hyperglycemia, and sex-specific tissue lipid accumulation. We postulate that CREB3 is a novel key regulator of diet-induced obesity and energy metabolism that warrants further investigation as a potential therapeutic target in metabolic disorders.


Subject(s)
Cyclic AMP Response Element-Binding Protein , Diet, High-Fat , Energy Metabolism , Obesity , Animals , Cyclic AMP Response Element-Binding Protein/genetics , Cyclic AMP Response Element-Binding Protein/metabolism , Diet, High-Fat/adverse effects , Energy Metabolism/genetics , Female , Glucose Intolerance/genetics , Lipid Metabolism , Lipids , Male , Mice , Mice, Inbred C57BL , Obesity/genetics , Obesity/metabolism , Transcription Factors/metabolism , Weight Gain
6.
Water Sci Technol ; 84(6): 1527-1540, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34559086

ABSTRACT

Life Cycle Assessment was used to evaluate onsite wastewater treatment systems (OWTS): aerobic treatment unit (ATU) with reinforced concrete (C.ATU) and HDPE (H.ATU) tank; and constructed wetland (CW) with three biochar concentrations in the substrate (0%; 10, and 20% v:v), dubbed CW.BC0, CW.BC10 and CW.BC20, respectively. CML 2001 in SimaPro® was used to evaluate the impacts of the treatment of 1 m3 wastewater. The OWTS were compared on their overall environmental performance scores (OEP). ATUs have higher impacts on human toxicity, eutrophication, freshwater and marine ecotoxicity. The CW.BC20 has the lowest global warming impact (GWP) while CW.BC0 has the highest. Electricity consumption was the largest contributor to the impacts of the ATUs. PVC pipes, coir peat, geomembrane, and electronic devices were the biggest contributors to the impacts of the CWs. The OEP of the CWs were almost a third of the ATUs' (6.07E-03). Changes in electricity sources were tested according to the 2030-Australian targets; increasing renewables share improves the OEP of ATUs by 39%; nevertheless, CWs continue to outperform the ATUs. Variations in biochar biodegradation had a small effect on the OEP of CWs; being relevant only to GWP. This study provides a reference to policy makers for better evaluation of OWTS.


Subject(s)
Water Purification , Wetlands , Animals , Australia , Humans , Life Cycle Stages , Waste Disposal, Fluid , Wastewater
7.
PLoS One ; 16(9): e0251895, 2021.
Article in English | MEDLINE | ID: mdl-34520472

ABSTRACT

Obesity and diabetes have strong heritable components, yet the genetic contributions to these diseases remain largely unexplained. In humans, a missense variant in Creb3 regulatory factor (CREBRF) [rs373863828 (p.Arg457Gln); CREBRFR457Q] is strongly associated with increased odds of obesity but decreased odds of diabetes. Although virtually nothing is known about CREBRF's mechanism of action, emerging evidence implicates it in the adaptive transcriptional response to nutritional stress downstream of TORC1. The objectives of this study were to generate a murine model with knockin of the orthologous variant in mice (CREBRFR458Q) and to test the hypothesis that this CREBRF variant promotes obesity and protects against diabetes by regulating energy and glucose homeostasis downstream of TORC1. To test this hypothesis, we performed extensive phenotypic analysis of CREBRFR458Q knockin mice at baseline and in response to acute (fasting/refeeding), chronic (low- and high-fat diet feeding), and extreme (prolonged fasting) nutritional stress as well as with pharmacological TORC1 inhibition, and aging to 52 weeks. The results demonstrate that the murine CREBRFR458Q model of the human CREBRFR457Q variant does not influence energy/glucose homeostasis in response to these interventions, with the exception of possible greater loss of fat relative to lean mass with age. Alternative preclinical models and/or studies in humans will be required to decipher the mechanisms linking this variant to human health and disease.


Subject(s)
DNA-Binding Proteins/genetics , Diet/adverse effects , Glucose/metabolism , Obesity/genetics , Polymorphism, Single Nucleotide , Animals , Body Mass Index , Diet/classification , Disease Models, Animal , Energy Metabolism , Female , Gene Knock-In Techniques , Genetic Predisposition to Disease , Male , Mice , Mutation, Missense , Obesity/metabolism
8.
Endocrinology ; 161(11)2020 11 01.
Article in English | MEDLINE | ID: mdl-32901804

ABSTRACT

Glucocorticoid signaling controls many key biological functions ranging from stress responses to affective states. The putative transcriptional coregulator CREB3 regulatory factor (CREBRF) reduces glucocorticoid receptor levels in vitro, suggesting that CREBRF may impact behavioral and physiological outputs. In the present study, we examined adult male and female mice with global loss of CREBRF (CrebrfKO) for anxiety-like behaviors and circulating glucocorticoids in response to various acute stress conditions. Results demonstrate that both male and female CrebrfKO mice have preserved locomotor activity but reduced anxiety-like behaviors during the light-dark box and elevated plus maze. These behavioral phenotypes were associated with lower plasma corticosterone after restraint stress. Further studies using unhandled female mice also demonstrated a loss of the diurnal circulating corticosterone rhythm in CrebrfKO mice. These results suggest that CREBRF impacts anxiety-like behavior and circulating glucocorticoids in response to acute stressors and serves as a basis for future mechanistic studies to define the impact of CREBRF in glucocorticoid-associated behavioral and physiological responses.


Subject(s)
Anxiety/genetics , DNA-Binding Proteins/genetics , Glucocorticoids/blood , Animals , Anxiety/blood , Behavior, Animal/physiology , Corticosterone/blood , Down-Regulation/genetics , Female , Hypothalamo-Hypophyseal System/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Pituitary-Adrenal System/metabolism , Stress, Psychological/blood , Stress, Psychological/genetics
9.
Dig Dis ; 38(6): 484-489, 2020.
Article in English | MEDLINE | ID: mdl-32088711

ABSTRACT

BACKGROUND/AIMS: Serious gastrointestinal (GI) pathologies are common in older adults compared to young adults (≤40 years). Data on the diagnostic yield (DY) of colonoscopy in young adults with lower GI symptoms are lacking. We aimed to evaluate the overall DY of colonoscopy; and the DY stratified by the presence or absence of bright red blood per rectum (BRBPR) in young adults ≤40 years. METHODS: We reviewed diagnostic colonoscopies performed in young adults by 18 gastroenterologists at 2 different institutions from -October 2016 to April 2019. Patients with familial colorectal cancer (CRC) syndromes were excluded. DY was calculated based on the proportion of abnormal colonoscopy defined as having inflammatory bowel disease (IBD), microscopic colitis (MC), advanced adenoma, or CRC. RESULTS: We included 454 patients, mean (SD) age was 31 (3) years, 162 (36%) were males and mean (SD) BMI was 30 (8.5). BRBPR was the indication for colonoscopy in 194 (43%) patients, 260 (57%) patients had colonoscopy for other lower GI symptoms (abdominal pain, chronic diarrhea, constipation) but without BRBPR. Overall DY of colonoscopy in young adults with lower GI symptoms was 15%; IBD was seen in 43 (10%) patients, MC 10 (2%), and advanced neoplasia/CRC 20 (4%). Overall DY in patients with BRBPR was significantly higher than in patients without BRBPR (22 vs. 11%, p = 0.001). The DY for IBD was also higher in young adults with BRBPR versus without BRBPR (15 vs. 6%, p = 0.003). The DY of patients with both BRBPR and abdominal pain was 34%, for BRBPR and diarrhea was 40%, and for all 3 symptoms of BRBPR, diarrhea, and abdominal pain was 52%. CONCLUSIONS: Significant proportion of young adults with BRBPR have abnormal pathology (22%) justifying evaluation by colonoscopy. For other lower GI symptoms without BRBPR, the necessity of endoscopic evaluation should be determined clinically on a case-to-case basis due to the low overall DY.


Subject(s)
Colonoscopy , Gastrointestinal Diseases/diagnosis , Adult , Cohort Studies , Colitis/diagnosis , Colorectal Neoplasms/diagnosis , Female , Humans , Inflammatory Bowel Diseases/diagnosis , Male , Risk Assessment , Young Adult
10.
Front Mol Neurosci ; 11: 352, 2018.
Article in English | MEDLINE | ID: mdl-30337854

ABSTRACT

LUMAN/CREB3, originally identified through its interaction with a cell cycle regulator HCFC1, is a transcription factor involved in the unfolded protein response during endoplasmic reticulum stress. Previously using gene knockout mouse models, we have shown that LUMAN modulates the glucocorticoid (GC) response leading to enhanced glucocorticoid receptor (GR) activity and lower circulating GC levels. Consequently, the stress response is dysregulated, leading to a blunted stress response in the Luman-deficient mice. One question that remained was how LUMAN deficiency affected the stress response at the cellular level leading to the changes in the physiological stress response. Here, we found that LUMAN interacts with GR through a putative nuclear receptor box site and can activate GR in the absence of a ligand. Further investigation showed that, when activated, LUMAN binds to the glucocorticoid response element (GRE), increasing the activity of GR exponentially compared to GR-ligand binding alone. On the other hand, we also found that in the absence of LUMAN, cells were more sensitive to cellular stress, exhibiting decreased secretory capacity. Hence our current data suggest that LUMAN may function both as a transcriptional cofactor of GR and a hormone secretion regulator, and through this, plays a role in stress sensitivity and reactivity to stress.

11.
Mol Cell Endocrinol ; 439: 95-104, 2017 01 05.
Article in English | MEDLINE | ID: mdl-27789393

ABSTRACT

Altered glucocorticoid sensitivity is believed to contribute to a number of human diseases, including inflammatory and autoimmune conditions as well as disorders characterized by abnormal hypothalamic-pituitary-adrenal axis (HPA) function. LUMAN (or CREB3), originally identified through its interaction with a cell cycle regulator HCFC1, is an endoplasmic reticulum membrane-bound transcription factor that is involved in the unfolded protein response. Here we demonstrate that LUMAN changes the glucocorticoid response by modulating the expression of the glucocorticoid receptor leading to an overall increase in GR activity. Luman-deficient mice exhibited a blunted stress response characterized by low levels of both anxiety and depressive-like behaviour in addition to low circulating corticosterone levels. These mice also have reduced dendritic branching in the CA3 region of the hippocampus, consistent with increased GR responses. These findings are consistent with the notion that elevated GR activities are the primary cause of the observed phenotype in these LUMAN-deficient mice. We thus postulate that LUMAN is a key regulator of GR-mediated signaling and modulates HPA axis reactivity.


Subject(s)
Cyclic AMP Response Element-Binding Protein/metabolism , Glucocorticoids/pharmacology , Stress, Physiological , Animals , Animals, Newborn , Behavior, Animal/drug effects , Body Weight/drug effects , CA3 Region, Hippocampal/metabolism , Corticosterone/metabolism , Cyclic AMP Response Element-Binding Protein/deficiency , Dendrites/drug effects , Dendrites/metabolism , Mice, Inbred C57BL , Receptors, Glucocorticoid/metabolism , Stress, Physiological/drug effects , Survival Analysis
12.
Eur J Cell Biol ; 95(12): 611-622, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28029379

ABSTRACT

The recently identified Luman/CREB3-binding partner LRF (Luman/CREB3 recruitment factor) was shown to localize to discrete sub-nuclear foci. Luman is implicated in herpes simplex virus-1 (HSV-1) latency/reactivation and the unfolded protein response (UPR) pathway; therefore, we sought to characterize the formation of the LRF nuclear foci in the context of cellular signaling and HSV-1 replication. Here, we mapped the nuclear foci-targeting sequence to the central region containing the first leucine zipper (a.a.415-519), and found that the integrity of the whole region appears essential for LRF foci formation. LRF foci integrity was unaffected by inhibition of cellular DNA replication and translation, however, disruption of transcription resulted in altered LRF localization. When compared to other cellular and viral foci LRF co-localized with the nuclear receptor co-activator GRIP1, while the HSV-1 gene products ICP4, ICP27 and VP13/14 disrupted foci formation to varying degrees. Interestingly, cells over-expressing LRF were resistant to productive HSV-1 infection and this resistance was dependent upon protein targeting and an N-terminal transactivation domain. When LRF knockdown cells were subjected to primary infection, HSV-1 gene expression and progeny virus yield were enhanced by ∼3 fold compared to wildtype cells. Taken together, these results indicate that LRF is a key regulator that may act direct or indirectly as a repressor of essential genes required for productive viral infection.


Subject(s)
Cyclic AMP Response Element-Binding Protein/metabolism , DNA-Binding Proteins/metabolism , Herpesvirus 1, Human/physiology , Transcription Factors/metabolism , Virus Replication/physiology , Animals , COS Cells , Chlorocebus aethiops , HEK293 Cells , HeLa Cells , Humans , Mice , NIH 3T3 Cells , Tumor Suppressor Proteins/metabolism , Unfolded Protein Response , Vero Cells
13.
Virology ; 497: 251-261, 2016 10.
Article in English | MEDLINE | ID: mdl-27498408

ABSTRACT

Deoxyuridine 5'-triphosphate pyrophosphatase (dUTPase), a ubiquitous enzyme that catalyzes the hydrolysis of dUTP to dUMP and found in many viruses, has yet to be identified in fowl adenovirus 9 (FAdV-9). By a multiple alignment of dUTPase amino acid sequences, FAdV-9 ORF1 contained the five conserved motifs that define the protein family, and encoded a functional dUTPase. Moreover, transcription and protein expression patterns were characterized, indicating that dUTPase was transcribed from 2h post-infection (h.p.i.) and translated from 6h.p.i., and both continued to the late phase of virus infection. An HA-tagged dUTPase recombinant virus was generated, and dUTPase was found to be localized in both the cytoplasm and nucleus in chicken hepatoma cells (CH-SAH). A dUTPase knockout virus was generated and compared with the wild-type virus, showing that dUTPase upregulated the expression of type I interferons, but was not required for viral DNA or virus replication in CH-SAH cells.


Subject(s)
Adenoviridae/enzymology , Adenoviridae/genetics , Pyrophosphatases/genetics , Pyrophosphatases/metabolism , Adenoviridae/classification , Amino Acid Sequence , Animals , Cytokines/genetics , Enzyme Activation , Genome, Viral , Mutation , Open Reading Frames , Protein Biosynthesis , Protein Transport , Pyrophosphatases/chemistry , RNA, Messenger/genetics , Transcription, Genetic
14.
BMC Vet Res ; 11: 191, 2015 Aug 08.
Article in English | MEDLINE | ID: mdl-26253169

ABSTRACT

BACKGROUND: Many species of frogs secrete cutaneous antimicrobial peptides that are capable of killing Batrachochytrium dendrobatidis. Some of these species are nonetheless susceptible to chytridiomycosis, suggesting that host factors causing dysregulation of this innate immune response may be important in pathogenesis. Since stresses, such as from environmental perturbations, are a potential cause of such dysregulation, this study investigated the effect of glucocorticoid on cutaneous gene expression of these antimicrobial peptides. RESULTS: Northern leopard frogs (Lithobates pipiens) were injected with either the corticosteroid methylprednisolone or saline every 48 h. Norepinephrine-elicited cutaneous secretions were collected every 8 days for 40 days. Gene expression of antimicrobial peptides (brevinin-1P and ranatuerin-2P) in the cutaneous secretions was measured relative to the reference genes EF1-α and RPL8 using quantitative RT-PCR. Corticosteroid treatment was associated with a significant increase in brevinin-1P gene expression, which was most notable at 24-40 days of corticosteroid administration. Ranatuerin-2P expression followed a similar but non-significant trend. CONCLUSION: This treatment protocol, including corticosteroid-administration and frequent norepinephrine-induced secretion, increased AMP gene expression in the skin of L. pipiens under these experimental conditions. The findings do not support the hypothesis that environmental stress predisposes frogs to chytridiomycosis by causing glucocorticoid-induced suppression of antimicrobial peptide defences.


Subject(s)
Antimicrobial Cationic Peptides/metabolism , Gene Expression Regulation/drug effects , Methylprednisolone/pharmacology , Rana pipiens/metabolism , Skin/metabolism , Amphibian Proteins/genetics , Amphibian Proteins/metabolism , Animals , Glucocorticoids/pharmacology , Skin/drug effects
15.
Neuropharmacology ; 75: 191-200, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23911746

ABSTRACT

In numerous species social learning is predominant and adaptive, yet, we know little of its neurobiological mechanisms. Social learning is modulated by motivations and emotions, in a manner that is often sexually dimorphic. Additionally, stress hormones acutely modulate the related social cognitive process of social recognition. Whether this is true even for social learning is currently unknown. We investigated the acute effects of the stress hormone corticosterone (CORT) on the social transmission of food preferences (STFP) in male and female mice. During a brief social interaction an observer (OBS) acquires a food preference from a same-sex demonstrator (DEM). CORT (1.0, 2.5, 5.0 mg/kg), its ethanol vehicle (0.1%), and saline solution (0.9%) were administered intraperitoneally to the OBS, 10 min before a 30-min social interaction. Levels of plasma CORT were assessed in other mice that had received the same doses of CORT and either had or had not gone through a 30 min social interaction 10 min post-treatment. Exogenous CORT elicited levels of plasma level comparable to those seen at the peak of the circadian cycle and facilitated the STFP with males responding more than females both in terms of the duration of the food preference and the minimum effective dose. CORT also sexually dimorphically inhibited feeding, with females showing a greater dose-response than males. Saline solution and ethanol vehicles also sexually dimorphically facilitated the STFP and reduced feeding, but less than CORT did. These results indicate that CORT facilitates social learning, like social recognition. Hence, CORT may generally increase social information processing.


Subject(s)
Corticosterone/pharmacology , Feeding Behavior/drug effects , Interpersonal Relations , Learning/drug effects , Sex Characteristics , Analysis of Variance , Animals , Corticosterone/blood , Dose-Response Relationship, Drug , Eating/drug effects , Enzyme-Linked Immunosorbent Assay , Feeding Behavior/physiology , Female , Food Preferences/drug effects , Food Preferences/physiology , Learning/physiology , Male , Mice , Time Factors
16.
Biochim Biophys Acta ; 1829(9): 921-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23583719

ABSTRACT

Luman/CREB3 (also called LZIP) is an endoplasmic reticulum (ER)-bound transcription factor that has been implicated in the ER stress response. In this study, we used the region of Luman containing the basic DNA-binding domain as bait in a yeast two-hybrid screen and identified the Jun activation domain-binding protein 1 (JAB1) or the COP9 signalosome complex unit 5 (CSN5) as an interacting protein. We confirmed their direct binding by glutathione S-transferase pull-down assays, and verified the existence of such interaction in the cellular environment by mammalian two-hybrid and co-immunoprecipitation assays. Deletion mapping studies revealed that the MPN domain in JAB1 was essential and sufficient for the binding. JAB1 also colocalized with Luman in transfected cells. More interestingly, the nuclear form of Luman was shown to promote the translocation of JAB1 into the nucleus. We found that overexpression of JAB1 shortened the half-life of Luman by 67%, and repressed its transactivation function on GAL4 and unfolded protein response element (UPRE)-containing promoters. We therefore propose that JAB1 is a novel binding partner of Luman, which negatively regulates the activity of Luman by promoting its degradation.


Subject(s)
Cyclic AMP Response Element-Binding Protein/antagonists & inhibitors , Intracellular Signaling Peptides and Proteins/physiology , Peptide Hydrolases/physiology , Animals , Base Sequence , COP9 Signalosome Complex , COS Cells , Chlorocebus aethiops , Cyclic AMP Response Element-Binding Protein/metabolism , DNA Primers , HEK293 Cells , Humans , Protein Binding , Proteolysis , Reverse Transcriptase Polymerase Chain Reaction , Transcriptional Activation , Two-Hybrid System Techniques , Vero Cells
17.
J Reprod Dev ; 59(3): 245-51, 2013.
Article in English | MEDLINE | ID: mdl-23400243

ABSTRACT

Luman/CREB3 recruitment factor (LRF or CREBRF) was identified as a regulator of Luman (or CREB3) that is involved in the unfolded protein response during endoplasmic reticulum stress. Luman is implicated in a multitude of functions ranging from viral infection and immunity to cancer. The biological function of LRF, however, is unknown. In this paper, we report that uteri of pregnant mice and embryos displayed enhanced LRF expression at all stages, and the expressed LRF was found to be localized specifically at implantation sites. On the other hand, uteri of mice induced for delayed implantation or pseudopregnant mice showed low levels of LRF expression, suggesting that LRF mediates uterine receptivity during implantation. Further, expression of LRF was found to be modulated by steroid hormones such as progesterone and estradiol. This study thereby identifies a potential role for LRF in the process of implantation in uteri and development of preimplantation embryos in mice.


Subject(s)
Blastocyst/metabolism , Cyclic AMP Response Element-Binding Protein/metabolism , DNA-Binding Proteins/metabolism , Embryo Implantation/physiology , Gene Expression Regulation, Developmental , Transcription Factors/metabolism , Uterus/physiology , Animals , Decidua/metabolism , Estradiol/metabolism , Female , Mice , Pregnancy , Pregnancy, Animal , Progesterone/metabolism , Real-Time Polymerase Chain Reaction , Signal Transduction , Steroids/metabolism , Time Factors
18.
Mol Cell Biol ; 32(24): 5140-50, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23071095

ABSTRACT

The hypothalamic-pituitary-adrenal (HPA) axis is a major part of the neuroendocrine system in animal responses to stress. It is known that the HPA axis is attenuated at parturition to prevent detrimental effects of glucocorticoid secretion including inhibition of lactation and maternal responsiveness. Luman/CREB3 recruitment factor (LRF) was identified as a negative regulator of CREB3 which is involved in the endoplasmic reticulum stress response. Here, we report a LRF gene knockout mouse line that has a severe maternal behavioral defect. LRF(-/-) females lacked the instinct to tend pups; 80% of their litters died within 24 h, while most pups survived if cross-fostered. Prolactin levels were significantly repressed in lactating LRF(-/-) dams, with glucocorticoid receptor (GR) signaling markedly augmented. In cell culture, LRF repressed transcriptional activity of GR and promoted its protein degradation. LRF was found to colocalize with the known GR repressor, RIP140/NRIP1, which inhibits the activity by GR within specific nuclear punctates that are similar to LRF nuclear bodies. Furthermore, administration of prolactin or the GR antagonist RU486 restored maternal responses in mutant females. We thus postulate that LRF plays a critical role in the attenuation of the HPA axis through repression of glucocorticoid stress signaling during parturition and the postpartum period.


Subject(s)
Cyclic AMP Response Element-Binding Protein/metabolism , Maternal Behavior/physiology , Prolactin/physiology , Receptors, Glucocorticoid/metabolism , Animals , Base Sequence , Cyclic AMP Response Element-Binding Protein/deficiency , Cyclic AMP Response Element-Binding Protein/genetics , Female , Hypothalamo-Hypophyseal System/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Models, Biological , Pituitary-Adrenal System/metabolism , Pregnancy , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction
19.
Biol Chem ; 390(3): 215-23, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19090724

ABSTRACT

Porcine reproductive and respiratory syndrome (PRRS) virus is an RNA virus that replicates in the cytoplasm, but the viral nucleocapsid (N) protein localizes specifically in the nucleus and nucleolus of virus-infected cells. Nuclear localization of N is non-essential for PRRSV replication in cultured cells but has been shown to modulate the pathogenesis of virus in pigs, suggesting that N plays an accessory role in the nucleus during infection. We identified by yeast two-hybrid screening the inhibitor of MyoD family-a (I-mfa) domain-containing protein (HIC) as a cellular partner for PRRS virus (PRRSV) N protein. This protein is a homolog of human HIC, a recently identified cellular transcription factor. The specific interaction of PRRSV N with HIC was confirmed in cells by mammalian two-hybrid assay and co-immunoprecipitation and in vitro by GST pull-down assay. HIC is a zinc-binding protein and confocal microscopy demonstrated co-localization of N with the HIC-p40 isomer in the nucleus and nucleolus, and in the cytoplasm with HIC-p32, which is the N-terminal truncation of HIC-p40. The porcine homolog of HIC is universally expressed in pig tissues including alveolar macrophages. The interaction of viral capsid with the cellular transcription factor implicates a possible regulation of host cell gene expression by the N protein during PRRSV infection.


Subject(s)
MyoD Protein/antagonists & inhibitors , Nucleocapsid Proteins/metabolism , Porcine respiratory and reproductive syndrome virus/metabolism , Viral Proteins/metabolism , Animals , Base Sequence , Cell Line , DNA Primers , Protein Binding , Reverse Transcriptase Polymerase Chain Reaction , Swine , Zinc/metabolism
20.
Regul Pept ; 131(1-3): 66-73, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16084604

ABSTRACT

Visceral pain/hypersensitivity is a cardinal symptom of functional gastrointestinal disorders. With their peripheral and central (spinal) projections, sensory neurons in the dorsal root ganglia (DRG) are the "gateway" for painful signals emanating from both somatic and visceral structures. In contrast to somatic pain, the neurochemical pathways involved in visceral pain/hypersensitivity have not been well studied. We hypothesized the neuropeptide changes in spinal cord and DRG during visceral pain would mirror similar changes in somatic nociception. Noxious (painful) colorectal distension (CRD) was done by distending a rectal balloon up to 60 mm Hg phasically for 1 h in Sprague-Dawley rats. The spinal content of calcitonin gene-related peptide (CGRP), substance P (SP), galanin and vasoactive intestinal peptide (VIP) as well as their mRNAs in DRG were measured at 0, 4 and 24 h after the CRD. Visceromotor reflex (VMR) was measured by recording the electromyogram at the abdominal muscle in response to CRD. Distal colorectum was removed for evaluating the presence of inflammation. No significant evidence of histological inflammation was seen in the colonic mucosa/submucosa after repeated CRD, which is confirmed by myeloperoxidase assay. The spinal content of CGRP and SP decreased significantly 4 h after CRD, while galanin and VIP levels increased gradually and reached highest level at 24 h (p<0.05). The mRNAs in DRG of the neuropeptides were significantly upregulated after CRD (p<0.05). VMR recording showed the rat's colon became hypersensitive 4 h after CRD, a sequence parallel to the spinal changes of CGRP and SP in timeframe. Noxious mechanical distension of the colorectum causes an acute change in the spinal levels of excitatory neurotransmitters (CGRP and SP), probably reflecting central release of these peptides from sensory neurons and contributing to the hypersensitivity following the noxious CRD. This is followed by a slower change in the levels of the inhibitory neurotransmitter galanin and VIP. Such stimulation results in significant alternation of the gene expression in DRG, reflecting the plasticity of the neuronal response. In the absence of visceral inflammation, the aforementioned neuropeptides are important mediators in the processing of visceral pain/hypersensitivity.


Subject(s)
Colon/pathology , Ganglia, Spinal/metabolism , Neuropeptides/metabolism , Pain/metabolism , Rectum/pathology , Spinal Cord/metabolism , Animals , Calcitonin Gene-Related Peptide/genetics , Calcitonin Gene-Related Peptide/metabolism , Dilatation, Pathologic , Galanin/genetics , Galanin/metabolism , Ganglia, Spinal/chemistry , Humans , Male , Neuropeptides/genetics , Protein Precursors/genetics , Protein Precursors/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Reflex , Spinal Cord/chemistry , Substance P/genetics , Substance P/metabolism , Tachykinins/genetics , Tachykinins/metabolism , Vasoactive Intestinal Peptide/metabolism , Visceral Afferents/metabolism
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