Regulation Of Hormone Gene Expression Research Articles

Expression of GLOD4 in the Testis of the Qianbei Ma Goat and Its Effect on Leydig Cells.

The expression pattern of GLOD4 in the testis and its regulatory effect on testicular cells was explored in goats to enhance our understanding of spermatogenesis and improve reproduction in breeding rams. In this study, we demonstrated the localization of GLOD4 in testicular cells using immunohistochemistry and subcellular localization analyses. Subsequently, we analyzed the GLOD4 expression pattern in four age-based groups (0, 6, 12, and 18 months old) using real-time quantitative polymerase chain reaction (qRT-PCR) and protein blotting. Finally, we performed GLOD4 silencing and overexpression studies in Leydig cells (LCs) and explored the effects on cell proliferation, the cell cycle, steroid hormone secretion and the expression of candidate testosterone hormone-regulated genes. GLOD4 was mainly expressed in Leydig cells, and the subcellular localization results showed that the GLOD4 protein was mainly localized in the cytoplasm and nucleus. Silencing of GLOD4 significantly suppressed the mRNA expression levels of the testosterone secretion-related genes CYP11A1, 3β-HSD, and CYP17A1 and the mRNA expression levels of cell cycle-related genes CDK6, PCNA, and Cyclin E. Moreover, the cell cycle was blocked at the G2/M phase after GLOD4 silencing, which significantly suppressed testosterone secretion. In contrast, GLOD4 overexpression significantly increased the mRNA expression levels of the testosterone secretion-related genes CYP11A1, 3β-HSD, and CYP17A1 and increased the expression of the cell cycle-related genes CDK6, PCNA, and Cyclin E. Moreover, GLOD4 overexpression promoted the cell cycle from G0/G1 phases to enter the S phase and G2/M phases, promoted the secretion of testosterone. Taken together, our experimental results indicate that GLOD4 may affect the development of cells in Qianbei Ma goats of different ages by influencing the cell cycle, cell proliferation, and testosterone hormone synthesis. These findings enhance our understanding of the functions of GLOD4 in goats.

Cellular Iron Deficiency Disrupts Thyroid Hormone Regulated Gene Expression in Developing Hippocampal Neurons

BackgroundDeveloping neurons have high thyroid hormone and iron requirements to support their metabolically demanding growth. Early-life iron and thyroid-hormone deficiencies are prevalent and often coexist, and each independently increases risk of permanently impaired neurobehavioral function in children. Early-life dietary iron deficiency reduces thyroid-hormone concentrations and impairs thyroid hormone-responsive gene expression in the neonatal rat brain, but it is unclear whether the effect is cell-intrinsic. ObjectivesThis study determined whether neuronal-specific iron deficiency alters thyroid hormone-regulated gene expression in developing neurons. MethodsIron deficiency was induced in primary mouse embryonic hippocampal neuron cultures with the iron chelator deferoxamine (DFO) beginning at 3 d in vitro (DIV). At 11DIV and 18DIV, thyroid hormone-regulated gene messenger ribonucleic acid (mRNA)concentrations indexing thyroid hormone homeostasis (Hairless, mu-crystallin, Type II deiodinase, solute carrier family member 1c1, and solute carrier family member 16a2) and neurodevelopment (neurogranin, Parvalbumin, and Krüppel-like factor 9) were quantified. To assess the effect of iron repletion, DFO was removed at 14DIV from a subset of DFO-treated cultures, and gene expression and adenosine 5'-triphosphate (ATP) concentrations were quantified at 21DIV. ResultsAt 11DIV and 18DIV, neuronal iron deficiency decreased neurogranin, Parvalbumin, and mu-crystallin, and by 18DIV, solute carrier family member 16a2, solute carrier family member 1c1, Type II deiodinase, and Hairless were increased, suggesting cellular sensing of a functionally abnormal thyroid hormone state. Dimensionality reduction with Principal component analysis reveals that thyroid hormone homeostatic genes strongly correlate with and predict iron status. Iron repletion from 14–21DIV did not restore ATP concentration, and Principal component analysis suggests that, after iron repletion, cultures maintain a gene expression signature indicative of previous iron deficiency. ConclusionsThese novel findings suggest there is an intracellular mechanism coordinating cellular iron/thyroid hormone activities. We speculate this is a part of the homeostatic response to acutely match neuronal energy production and growth signaling. However, the adaptation to iron deficiency may cause permanent deficits in thyroid hormone-dependent neurodevelopmental processes even after recovery from iron deficiency.

ASO Visual Abstract: Menstrual Phase and Menopausal Status Classification of Benign Breast Tissue Using Hormone-Regulated Gene Expression and Histomorphology: A Validation Study.

ASO Visual Abstract: Menstrual Phase and Menopausal Status Classification of Benign Breast Tissue Using Hormone-Regulated Gene Expression and Histomorphology: A Validation Study.

Developmental and hormonal regulation of FBN1 and OR4M1 mRNA in bovine granulosa cells

Recent studies have reported hormonal regulation of expression of fibrillin 1 (FBN1), the gene that encodes asprosin, in bovine theca cells, however, hormonal regulation of gene expression of FBN1 and the asprosin receptor, olfactory receptor 4M1 (OR4M1), has not been evaluated in granulosa cells (GC). This study was designed to characterize FBN1 and OR4M1 gene expression in GC during development of bovine dominant ovarian follicles, and to determine the hormonal regulation of FBN1 and OR4M1 mRNA expression in GC. GC FBN1 mRNA abundance was greater (P < 0.05) in medium (5.1–8 mm) estrogen inactive (EI) follicles than in large (>8.1 mm) or small (1–5 mm) EI follicles. In comparison, GC OR4M1 mRNA abundance was greater (P < 0.05) in small EI follicles than in large or medium EI follicles. Abundance of OR4M1 mRNA in GC of follicles collected on days 3 to 4 (early growth phase) and on days 5 to 6 (late growth phase) was similar, whereas FBN1 mRNA abundance was greater (P < 0.05) on days 5 to 6 vs days 3 to 4. Hormonal regulators for FBN1 mRNA abundance in cultured small-follicle GC were identified: TGFβ1 causing a 2.45-fold increase, WNT3A causing a 1.45-fold increase, and IGF1 causing a 65% decrease. Steroids, leptin, insulin, growth hormone, follicle stimulating hormone, fibroblast growth factor 9 and epidermal growth factor had no effect on FBN1 mRNA abundance. Abundance of OR4M1 mRNA in GC was regulated by progesterone with 3.55-fold increase, but other hormones did not affect GC OR4M1 mRNA abundance. Findings indicate that both FBN1 and OR4M1 gene expression are hormonally and developmentally regulated in bovine follicles, and thus may affect asprosin production and its subsequent role in ovarian follicular function in cattle.

Menstrual Phase and Menopausal Status Classification of Benign Breast Tissue Using Hormone-Regulated Gene Expression and Histomorphology: A Validation Study.

The validation of breast cancer risk biomarkers in benign breast samples (BBS) is a long-sought goal, hampered by the fluctuation of gene and protein expression with menstrual phase (MP) and menopausal status (MS). Previously, we identified hormone-related gene expression and histomorphology parameters to classify BBS by MS/MP. We now evaluate both together, to validate our prior results. BBS were obtained from consenting women (86 premenopausal, 55 postmenopausal) undergoing reduction mammoplasty (RM) or contralateral unaffected breast (CUB) mastectomy. MP/MS was defined using classical criteria for menstrual dates and hormone levels on the day of surgery. BBS gene expression was measured with reverse transcription quantitative polymerase chain reaction (RT-qPCR) for three luteal phase (LP) genes (TNFSF11, DIO2, MYBPC1) and four menopausal genes (PGR, GREB1, TIFF1, CCND1). Premenopausal samples were classified into LP or non-LP, using published histomorphology parameters. Logistic regression and receiver-operator curve analysis was performed to assess area under the curve (AUC) for prediction of MP/MS. In all 131 women, menopausal genes plus age>50 years predicted true MS [AUC 0.93, 95% confidence interval (CI) 0.89, 0.97]. Among premenopausal women, high TNFSF11 expression distinguished non-LP from LP samples (AUC 0.80, 95% CI 0.70, 0.91); the addition of histomorphology improved the prediction nonsignificantly (AUC 0.87, 95% CI 0.78, 0.96). In premenopausal subsets, addition of histomorphology improved LP prediction in RM (AUC 0.95, 95% CI 0.87, 1.0), but not in CUB (0.84, 95% CI 0.72, 0.96). Expression of five-gene set accurately predicts menopausal status and menstrual phase in BBS, facilitating the development of breast cancer risk biomarkers using large, archived sample repositories.

Auxin receptors as integrators of developmental and hormonal signals during reproductive development in pea.

Auxins regulate many aspects of plant growth and development. In pea, three of the five TIR1/AFB members (PsTIR1a, PsTIR1b, and PsAFB2) have been implicated in auxin-related responses during fruit/seed development; however, the roles of PsAFB4 and PsAFB6 in these processes are unknown. Using yeast two-hybrid assays, we found that all five pea TIR1/AFB receptor proteins interacted with the pea AUX/IAAs PsIAA6 and/or PsIAA7 in an auxin-dependent manner, a requirement for functional auxin receptors. All five auxin receptors are expressed in young ovaries (pericarps) and rapidly developing seeds, with overlapping and unique developmental and hormone-regulated gene expression patterns. Pericarp PsAFB6 expression was suppressed by seeds and increased in response to deseeding, and exogenous hormone treatments suggest that seed-derived auxin and deseeding-induced ethylene are involved in these responses, respectively. Ethylene-induced elevation of pericarp PsAFB6 expression was associated with 4-Cl-IAA-specific reduction in ethylene responsiveness. In developing seeds, expression of PsTAR2 and PsYUC10 auxin biosynthesis genes was associated with high auxin levels in seed coat and cotyledon tissues, and PsAFB2 dominated the seed tissue transcript pool. Overall, auxin receptors had overlapping and unique developmental and hormone-regulated gene expression patterns during fruit/seed development, suggesting mediation of diverse responses to auxin, with PsAFB6 linking auxin and ethylene signaling.

Abstract P2-11-03: Menstrual phase classification of benign breast tissue using hormone-regulated gene expression and morphology

Abstract Introduction: The use of archived benign breast samples (BBS) for breast cancer risk research is limited by the fact that menstrual luteal phase and menopausal status is either unknown or inaccurate by self-report. As a result, physiologic variation in gene and protein expression cannot be accounted for. We previously showed that morphologic features (PMID: 12481017) and progesterone (P)-related gene expression (PMID: 23512947) in breast specimens can aid in luteal phase classification. Here we report a validation of the concept, in a larger sample size, regarding gene expression, menstrual-specific morphology factors and a combination of both. Methods: BBS were obtained from the contralateral unaffected breast (CUB) of unilateral breast cancer patients and reduction mammoplasty (RM) controls of premenopausal women (n = 81) under IRB approved protocol. Gene expression analysis was performed with 100 ng by qRT-PCR of 21 target genes. Serum concentration of estradiol (E), P, and follicular stimulating hormone (FSH) were measured by enzyme immunoassay and IMMULITE. Subjects were classified using hormone levels as postmenopausal (E&amp;lt; 30 pg/ml and FSH&amp;gt; 30 IU/L) or luteal phase (E&amp;gt;60pg/ml and P&amp;gt;3ng/ml); premenopausal women who did not meet luteal phase hormonal criteria were called non-luteal. A single study pathologist evaluated samples from premenopausal subjects, masked to the menstrual phase of subjects, using histo-morphologic features to categorize subjects as luteal or non-luteal. Gene expression and morphology were evaluated individually and together, through multivariate analysis, for luteal-phase stratification. Receiver operator curve (ROC) analysis was used to assess the accuracy (AUC) for prediction of luteal phase using gene expression, morphology and a combination of both. Results: Our study population, matched by age, included 81 premenopausal subjects (CUB=51, RM=30) with mean age of 42. For luteal phase classification, we identified P-correlated genes; TNFSF11, DI02, and MYBPC1 genes were significantly correlated with serum progesterone levels. ROC analysis results using individual genes, average morphology score and multivariate model is in the table below. The results are reported with the area under the curve (AUC) value along with the confidence interval. The multivariate model consists of the three genes with the average morphology score. Conclusions: We provided preliminary validation for three P-related genes as classifiers of luteal phase status. We find that histomorphologic classification of menstrual phase is more prominent in the RM samples. These findings along with our validation data, for the first time, provide RNA-based classifiers for menstrual phase of BBS, and offer the potential of increasing the robustness and validity of biomarker research by accounting for important physiologic variation in the hormonal milieu of the donor. CUB (n = 51) AUC +/- ciRM (n = 30) AUC +/- ciTNFS11 gene expression0.84 (0.74 – 0.95)0.76 (0.54 – 0.97)DI02 gene expression0.86 (0.75 – 0.96)0.72 (0.49 – 0.96)MYBPC1 gene expression0.80 (0.68 – 0.92)0.67 (0.45 – 0.89)Average morphology score0.67 (0.54 – 0.81)0.87 (0.76 – 0.98)Multivariate model0.89 (0.79 – 0.98)0.948 (0.87 -1.00) Citation Format: Omid Hosseini, Irene Helenowski, Oukseub Lee, Hui Zhang, Jun Wang, Luis Blanco, Seema A Khan. Menstrual phase classification of benign breast tissue using hormone-regulated gene expression and morphology [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-11-03.

PSIV-5 Developmental and hormonal regulation of gene expression of fibrillin-1 (FBN1) and the asprosin receptor, olfactory receptor family 4 subfamily M member 1 (OR4M1), in bovine ovarian cells

Abstract Asprosin is a novel fasting-induced protein associated with insulin resistance and polycystic ovaries in humans. It is encoded by FBN1 gene and produced when FBN1 is cleaved by the enzyme furin. In cattle, the role of asprosin is unknown. To characterize mRNA abundance of FBN1, furin, and the asprosin receptor, OR4M1, in granulosa (GC) and theca cells (TC), and identify hormones regulating FBN1 mRNA expression, GC and TC from small (&amp;lt; 6 mm; SM) and large (&amp;gt;5 mm; LG) follicles were collected from heifers at an abattoir and used for real-time gene expression analysis or in vitro evaluation of hormone regulation. SMTC had 151-fold greater (P &amp;lt; 0.05) FBN1 mRNA abundance than SMGC, and LGTC had 50-fold greater (P &amp;lt; 0.05) FBN1 mRNA than LGGC. In contrast, OR4M1 mRNA abundance was significantly greater (by 81-fold) in SMGC than LGGC and did not differ from SMTC, but LGTC had 9-fold greater (P &amp;lt; 0.05) OR4M1 mRNA abundance than LGGC. Furin mRNA was significantly greater (by 2.6-fold) in SMGC than SMTC but did not differ between LGTC and LGGC. In SMGC, leptin, insulin, GH, FSH, EGF, and steroids had no effect (P &amp;gt;0.10) on FBN1 mRNA abundance. In contrast, TGFB1, WNT3A and FGF9 increased (P &amp;lt; 0.05) and IGF1 significantly decreased SMGC FBN1 mRNA abundance. In LGTC, leptin, insulin, LH, IGF1 and steroids did not significantly affect FBN1 mRNA, but TGFB1, WNT3A, EGF, FGF2 and FGF9 increased (P&amp;lt; 0.05) FBN1 mRNA abundance. Altogether, FBN1 mRNA was more highly expressed in TC than GC and was stimulated by TGFB1, WNT3A and FGF9 in both cell types. Developmental and hormonal regulation of FBN1, furin and OR4M1 along with a greater expression of OR4M1 mRNA in GC than TC suggests that asprosin may be acting as a paracrine regulator of ovarian follicular function in cattle.

Menstrual cycle associated changes in hormone-related gene expression in oestrogen receptor positive breast cancer

The major changes in hormone levels that occur through the menstrual cycle have been postulated to affect the expression of hormone-regulated and proliferation-associated genes (PAGs) in premenopausal ER+ breast cancer. Whilst previous studies have demonstrated differences in gene expression, here, we investigated if there are within patient changes in the expression of oestrogen- and progesterone-regulated genes (ERGs and PRGs) and PAGs in ER+ breast cancer during the menstrual cycle. Samples from 96 patients in two independent prospective studies of the effect of menstrual cycle on ER+ breast cancer were used. Plasma hormone measurements were used to assign tumours to one of three pre-defined menstrual cycle windows: W1 (days 27–35 and 1–6; low oestradiol and low progesterone), W2 (days 7–16; high oestradiol and low progesterone) and W3 (days 17–26; intermediate oestradiol and high progesterone). RNA expression of 50 genes, including 27 ERGs, 11 putative PRGs and seven PAGs was measured. The AvERG (geomean of PGR, GREB1, TFF1 and PDZK1) was used as a composite measure of ERG expression and showed significant changes between the three windows of the menstrual cycle increasing over 2.2-fold between W1 and W2 and decreasing between W2 and W3 and between W3 and W1. Proliferation gene expression also varied significantly, following the same pattern of changes as ERG expression, but the changes were of lower magnitude (1.4-fold increase between W1 and W2). Significant changes in the expression of eight individual ERGs, including GREB1, PGR and TFF1, and two PAGs were observed between W1 and either W2 or W3 with all genes showing higher levels in W2 or W3 (1.3–2.4-fold; FDR 0.016–0.05). The AvProg, a composite measure of PRG expression, increased significantly (1.5-fold) in W3 compared to W1 or W2 but no significant changes were observed for individual PRGs. In conclusion, we observed significant changes in ERG, PRG and PAG expression in ER+ breast tumours during the menstrual cycle that may affect the assessment and interpretation of prominent biomarkers (e.g. PgR) and commonly used multigene prognostic signatures in premenopausal ER+ breast cancer.

Measuring Gene Expression in Bombarded Barley Aleurone Layers with Increased Throughput.

The aleurone layer of barley grains is an important model system for hormone-regulated gene expression in plants. In aleurone cells, genes required for germination or early seedling development are activated by gibberellin (GA), while genes associated with stress responses are activated by abscisic acid (ABA). The mechanisms of GA and ABA signaling can be interrogated by introducing reporter gene constructs into aleurone cells via particle bombardment, with the resulting transient expression measured using enzyme assays. An improved protocol is reported that partially automates and streamlines the grain homogenization step and the enzyme assays, allowing significantly more throughput than existing methods. Homogenization of the grain samples is carried out using an automated tissue homogenizer, and GUS (β-glucuronidase) assays are carried out using a 96-well plate system. Representative results using the protocol suggest that phospholipase D activity may play an important role in the activation of HVA1 gene expression by ABA, through the transcription factor TaABF1.

The effects of di-2-ethylhexyl phthalate on testicular ultrastructure and hormone-regulated gene expression in male rats.

The objective of this study is to determine testicular pathological damage and explore its molecular mechanisms after di-2-ethylhexyl phthalate (DEHP) treatment. A total of 40 healthy 5-week-old male Sprague-Dawley rats were randomly divided into four groups, which received intragastric administration of 0 mg kg-1, 100 mg kg-1, 500 mg kg-1 and 1500 mg kg-1 DEHP for six continuous weeks. After DEHP treatment, the testes wet weight and testes coefficient were calculated, the histopathological changes of the testes were examined by HE staining and the testicular ultrastructure was examined by transmission electron microscopy. The gene expression levels were analyzed by quantitative RT-PCR and the protein expression levels were analyzed by western blotting. Both 500 mg kg-1 and 1500 mg kg-1 DEPH treatments decreased the wet weight of the testes and testes coefficient, due to vacuoles in Sertoli cells, broken mitochondrial ridges, and degranulation. Quantitative RT-PCR showed that the relative gene expression levels of steroidogenic acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) increased in the 100 mg kg-1, 500 mg kg-1, and 1500 mg kg-1 DEHP groups, respectively. Additionally, 17β-hydroxysteroid dehydrogenase (17β-HSD) expression levels were increased in the 1500 mg kg-1 DEHP treatment group. Gonadotropin-releasing hormone (GnRH) expression levels were decreased with 500 mg kg-1 and 1500 mg kg-1 DEHP treatments. DEHP induced serious pathological damage and ultrastructure changes in rat testes, caused endocrine disorders, interfered with the synthesis of male hormones, and ultimately led to male reproductive system dysfunction.

Thyroid hormone regulates fibronectin expression through the activation of the hypoxia inducible factor 1

Thyroid hormones regulate gene expression via both canonical and non-canonical signaling. Hyperthyroidism is associated with elevated plasma levels of fibronectin (FN): in this study we elucidate the molecular mechanism through which triiodothyronine (T3) regulates FN and demonstrate that T3 induces FN expression via a non-canonical pathway by activating hypoxia-inducible factor-1 (HIF-1). We found that T3 treatment increased cellular and secreted FN in human hepatoma cells (HepG2) and human dermal fibroblasts (HF) via the PI3K/Akt/HIF-1 pathway. The inhibition of either Akt phosphorylation with wortmannin or HIF-1 with YC1 in both cell types prevented HIF-1α synthesis and FN positive regulation upon T3 treatment. We showed that HIF-1α overexpression per se was sufficient to up-regulate FN in both cell lines as demonstrated by the transient transfection of both the constitutively active and wild-type forms of HIF-1α. Our data demonstrate the involvement of the PI3K/Akt/HIF-1 pathway in mediating T3 induced FN up-regulation.

Extensive transcriptomic studies on the roles played by abscisic acid and auxins in the development and ripening of strawberry fruits

Strawberry is an ideal model for studying the molecular biology of the development and ripening of non-climacteric fruits. Hormonal regulation of gene expression along all these processes in strawberries is still to be fully elucidated. Although auxins and ABA have been pointed out as the major regulatory hormones, few high-throughput analyses have been carried out to date. The role for ethylene and gibberellins as regulatory hormones during the development and ripening of the strawberry fruit remain still elusive. By using a custom-made and high-quality oligo microarray platform done with over 32,000 probes including all of the genes actually described in the strawberry genome, we have analysed the expression of genes during the development and ripening in the receptacles of these fruits. We classify these genes into two major groups depending upon their temporal and developmental expression. First group are genes induced during the initial development stages. The second group encompasses genes induced during the final maturation and ripening processes. Each of these two groups has been also divided into four sub-groups according their pattern of hormonal regulation. By analyzing gene expression, we clearly show that auxins and ABA are the main and key hormones that combined or independently are responsible of the development and ripening process. Auxins are responsible for the receptacle fruit development and, at the same time¸ prevent ripening by repressing crucial genes. ABA regulates the expression of the vast majority of genes involved in the ripening. The main genes expressed under the control of these hormones are presented and their physiological rule discussed. We also conclude that ethylene and gibberellins do not seem to play a prominent role during these processes.

α-Xylosidase plays essential roles in xyloglucan remodelling, maintenance of cell wall integrity, and seed germination in Arabidopsis thaliana.

Regulation and maintenance of cell wall physical properties are crucial for plant growth and environmental response. In the germination process, hypocotyl cell expansion and endosperm weakening are prerequisites for dicot seeds to complete germination. We have identified the Arabidopsis mutant thermoinhibition-resistant germination 1 (trg1), which has reduced seed dormancy and insensitivity to unfavourable conditions for germination owing to a loss-of-function mutation of TRG1/XYL1, which encodes an α-xylosidase. Compared to those of wild type, the elongating stem of trg1 showed significantly lower viscoelasticity, and the fruit epidermal cells were longitudinally shorter and horizontally enlarged. Actively growing tissues of trg1 over-accumulated free xyloglucan oligosaccharides (XGOs), and the seed cell wall had xyloglucan with a greatly reduced molecular weight. These observations suggest that XGOs reduce xyloglucan size by serving as an acceptor in transglycosylation and eventually enhancing cell wall loosening. TRG1/XYL1 gene expression was abundant in growing wild-type organs and tissues but relatively low in cells at most actively elongating part of the tissues, suggesting that α-xylosidase contributes to maintaining the mechanical integrity of the primary cell wall in the growing and pre-growing tissues. In germinating seeds of trg1, expression of genes encoding specific abscisic acid and gibberellin metabolism enzymes was altered in accordance with the aberrant germination phenotype. Thus, cell wall integrity could affect seed germination not only directly through the physical properties of the cell wall but also indirectly through the regulation of hormone gene expression.

FOXA1 acts upstream of GATA2 and AR in hormonal regulation of gene expression.

Hormonal regulation of gene expression by androgen receptor (AR) is tightly controlled by many transcriptional cofactors, including pioneer factors FOXA1 and GATA2, which, however, exhibit distinct expression patterns and functional roles in prostate cancer. Here, we examined how FOXA1, GATA2, and AR crosstalk and regulate hormone-dependent gene expression in prostate cancer cells. ChIP-seq analysis revealed that FOXA1 reprograms both AR and GATA2 cistrome by preferably recruiting them to FKHD-containing genomic sites. By contrast, GATA2 is unable to shift AR or FOXA1 to GATA motifs. Rather, GATA2 co-occupancy enhances AR and FOXA1 binding to nearby ARE and FKHD sites, respectively. Similarly, AR increases, but not re-programs, GATA2 and FOXA1 cistromes. Concordantly, GATA2 and AR strongly enhance the transcriptional program of each other, whereas FOXA1 regulates GATA2- and AR-mediated gene expression in a context-dependent manner due to its reprogramming effects. Taken together, our data delineated for the first time the distinct mechanisms by which GATA2 and FOXA1 regulate AR cistrome and suggest that FOXA1 acts upstream of GATA2 and AR in determining hormone-dependent gene expression in prostate cancer.

Retinoic Acid Induces Ubiquitination-Resistant RIP140/LSD1 Complex to Fine-Tune Pax6 Gene in Neuronal Differentiation.

Receptor-interacting protein 140 (RIP140) is a wide-spectrum coregulator for hormonal regulation of gene expression, but its activity in development/stem cell differentiation is unknown. Here, we identify RIP140 as an immediate retinoic acid (RA)-induced dual-function chaperone for LSD1 (lysine-specific demethylase 1). RIP140 protects LSD1's catalytic domain and antagonizes its Jade-2-mediated ubiquitination and degradation. In RA-induced neuronal differentiation, the increased RIP140/LSD1 complex is recruited by RA-elevated Pit-1 to specifically reduce H3K4me2 modification on the Pax6 promoter, thereby repressing RA-induction of Pax6. This study reveals a new RA-induced gene repressive mechanism that modulates the abundance, enzyme quality, and recruitment of histone modifier LSD1 to neuronal regulator Pax6, which provides a homeostatic control for RA induction of neuronal differentiation.

In Pursuit of Genes of Glucose Metabolism

If you don't know where you're going, you might wind up someplace else—Yogi Berra My professional journey, once I accepted the fact that I would not play first base for the Chicago Cubs, was not accomplished in a straight line. I entered medical school intending to become a family physician but soon became interested in research. I took an internal medicine residency at the University of California, San Francisco (UCSF), then a long research fellowship in the nascent field of molecular biology at the National Institutes of Health (NIH), and followed that with training in clinical endocrinology at the University of Wisconsin. I spent the next fifteen years dividing my time between the clinic and laboratory at the University of Iowa. Finally, I decided to concentrate on research and spent the next twenty-three years at Vanderbilt University. For the past eleven years, I have been at the University of Iowa, where I helped establish a new diabetes research center. My research journey also had several different directions. Upon reflection, I guess I ended up “someplace else” by choice, and it certainly has been an interesting trip. It is one I unreservedly recommend.

Histone Lysine Methyltransferase SDG8 Is Involved in Brassinosteroid-Regulated Gene Expression in Arabidopsis thaliana

The plant steroid hormones, brassinosteroids (BRs), play important roles in plant growth, development, and responses to environmental stresses. BRs signal through receptors localized to the plasma membrane and other signaling components to regulate the BES1/BZR1 family of transcription factors, which modulates the expression of thousands of genes. How BES1/BZR1 and their interacting proteins function to regulate the large number of genes are not completely understood. Here we report that histone lysine methyltransferase SDG8, implicated in histone 3 lysine 36 di- and trimethylation (H3K36me2 and me3), is involved in BR-regulated gene expression. BES1 interacts with SDG8, directly or indirectly through IWS1, a transcription elongation factor involved in BR-regulated gene expression. The knockout mutant sdg8 displays a reduced growth phenotype with compromised BR responses. Global gene expression studies demonstrated that, while BR regulates about 5000 genes in wild-type plants, the hormone regulates fewer than 700 genes in sdg8 mutant. In addition, more than half of BR-regulated genes are differentially affected in sdg8 mutant. A Chromatin Immunoprecipitation (ChIP) experiment showed that H3K36me3 is reduced in BR-regulated genes in the sdg8 mutant. Based on these results, we propose that SDG8 plays an essential role in mediating BR-regulated gene expression. Our results thus reveal a major mechanism by which histone modifications dictate hormonal regulation of gene expression.

Hormonal crosstalk for root development: a combined experimental and modeling perspective.

Plants are sessile organisms and therefore they must adapt their growth and architecture to a changing environment. Understanding how hormones and genes interact to coordinate plant growth in a changing environment is a major challenge in developmental biology. Although a localized auxin concentration maximum in the root tip is important for root development, auxin concentration cannot change independently of multiple interacting hormones and genes. In this review, we discuss the experimental evidence showing that the POLARIS peptide of Arabidopsis plays an important role in hormonal crosstalk and root growth, and review the crosstalk between auxin and other hormones for root growth with and without osmotic stress. Moreover, we discuss that experimental evidence showing that, in root development, hormones and the associated regulatory and target genes form a network, in which relevant genes regulate hormone activities and hormones regulate gene expression. We further discuss how it is increasingly evident that mathematical modeling is a valuable tool for studying hormonal crosstalk. Therefore, a combined experimental and modeling study on hormonal crosstalk is important for elucidating the complexity of root development.

Evaluation of Reference Genes for RT qPCR Analyses of Structure-Specific and Hormone Regulated Gene Expression in Physcomitrella patens Gametophytes

The use of the moss Physcomitrella patens as a model system to study plant development and physiology is rapidly expanding. The strategic position of P. patens within the green lineage between algae and vascular plants, the high efficiency with which transgenes are incorporated by homologous recombination, advantages associated with the haploid gametophyte representing the dominant phase of the P. patens life cycle, the simple structure of protonemata, leafy shoots and rhizoids that constitute the haploid gametophyte, as well as a readily accessible high-quality genome sequence make this moss a very attractive experimental system. The investigation of the genetic and hormonal control of P. patens development heavily depends on the analysis of gene expression patterns by real time quantitative PCR (RT qPCR). This technique requires well characterized sets of reference genes, which display minimal expression level variations under all analyzed conditions, for data normalization. Sets of suitable reference genes have been described for most widely used model systems including e.g. Arabidopsis thaliana, but not for P. patens. Here, we present a RT qPCR based comparison of transcript levels of 12 selected candidate reference genes in a range of gametophytic P. patens structures at different developmental stages, and in P. patens protonemata treated with hormones or hormone transport inhibitors. Analysis of these RT qPCR data using GeNorm and NormFinder software resulted in the identification of sets of P. patens reference genes suitable for gene expression analysis under all tested conditions, and suggested that the two best reference genes are sufficient for effective data normalization under each of these conditions.