Hormonal Induction Research Articles

Hormonal induction and roles of Disabled-2 in lactation and involution.

Disabled-2 (Dab2) is a widely expressed endocytic adaptor that was first isolated as a 96 KDa phospho-protein, p96, involved in MAPK signal transduction. Dab2 expression is lost in several cancer types including breast cancer, and Dab2 is thought to have a tumor suppressor function. In mammary epithelia, Dab2 was induced upon pregnancy and further elevated during lactation. We constructed mutant mice with a mosaic Dab2 gene deletion to bypass early embryonic lethality and to investigate the roles of Dab2 in mammary physiology. Loss of Dab2 had subtle effects on lactation, but Dab2-deficient mammary glands showed a strikingly delayed cell clearance during involution. In primary cultures of mouse mammary epithelial cells, Dab2 proteins were also induced by estrogen, progesterone, and/or prolactin. Dab2 null mammary epithelial cells were refractory to growth suppression induced by TGF-beta. However, Dab2 deletion did not affect Smad2 phosphorylation; rather TGF-beta-stimulated MAPK activation was enhanced in Dab2-deficient cells. We conclude that Dab2 expression is induced by hormones and Dab2 plays a role in modulating TGF-beta signaling to enhance apoptotic clearance of mammary epithelial cells during involution.

Roles of plant hormones in the regulation of host-virus interactions.

SummaryHormones are tuners of plant responses to biotic and abiotic stresses. They are involved in various complicated networks, through which they modulate responses to different stimuli. Four hormones primarily regulate plant defence to pathogens: salicylic acid (SA), jasmonic acid (JA), ethylene (Et) and abscisic acid (ABA). In susceptible plants, viral infections result in hormonal disruption, which manifests as the simultaneous induction of several antagonistic hormones. However, these antagonistic hormones may exhibit some sequential accumulation in resistant lines. Virus propagation is usually restricted by the activation of the small interfering RNA (siRNA) antiviral machinery and/or SA signalling pathway. Several studies have investigated these two systems, using different model viruses. However, the roles of hormones other than SA, especially those with antagonistic properties, such as ABA, have been neglected. Increasing evidence indicates that hormones control components of the small RNA system, which regulates many processes (including the siRNA antiviral machinery and the microRNA system) at the transcriptional or post‐transcriptional level. Consequently, cross‐talk between the antagonistic SA and ABA pathways modulates plant responses at multiple levels. In this review, we summarize recent findings on the different roles of hormones in the regulation of plant–virus interactions, which are helping us to elucidate the fine tuning of viral and plant systems by hormones.

X-box binding protein 1 is a novel key regulator of peroxisome proliferator-activated receptor γ2.

X-box binding protein 1 (XBP1), a transcription factor of the unfolded protein response, plays various roles in many biological processes. We examined its pro-adipogenic activity and target genes during adipogenic differentiation in wild-type and genetically modified 3T3-L1 cells. Signalling pathways that contribute to Xbp1 mRNA splicing, and the correlation of the transcriptionally active XBP1 isoform (XBP1s) level with body mass index and the level of peroxisome proliferator-activated receptor γ2 (PPARγ2) in human adipose tissues were also examined. The mRNA and nuclear protein expression levels of XBP1s increased immediately following hormonal induction of adipogenesis, reaching a peak at 6 h. Results from cDNA microarray and gene expression analyses using genetically modified cells indicated that PPARγ2 was a principal target of XBP1s. The XBP1s-specific binding motif, which is distinct from the CCAAT/enhancer-binding protein α binding site, was identified in the PPARγ2 promoter by site-directed mutagenesis. Fetal bovine serum, insulin, 3-isobutyl-1-methylxanthine and dexamethasone contributed independently to Xbp1 mRNA splicing. In human subcutaneous adipose tissues, the levels of both Xbp1s and Pparγ2 mRNA increased proportionally with body mass index, and there was a significant positive correlation between the two genes. These data suggest for the first time that positive regulation of PPARγ2 is a principal mechanism of XBP1s-mediated adipogenesis in 3T3-L1 cells.

Spawn quality and GnRHa induction efficiency in longfin yellowtail (Seriola rivoliana) broodstock kept in captivity

Abstract The longfin yellowtail ( Seriola rivoliana ) is a preferred species for aquaculture diversification in the Canary Islands. The aim of the present study was obtain a large number of spawns whit hormonal induction, which would provide reliable numbers of juveniles for the sustainable development of longfin yellowtail culture. Two females with oocytes bigger than 500 μ, and four males, previously captured from the wild were used for this study. Females and males of 10.7 ± 1.4 and 8.5 ± 0.9 kg body weight and 86.2 ± 5.3 and 78.9 ± 1.9 cm total length, respectively, were acclimated in 10 m 3 tanks. Fish were injected three times per month between June and November with 20 μg kg − 1 of GnRHa. During the experimental period, temperature ranged from 21.9 ± 0.2 °C in June to 23.5 ± 0.4 °C in November. Broodstock feeding consisted in Atlantic mackerel ( Scomber scombrus ) at 2% BW, three times per week. A total of 20,189,700 eggs (944,326 eggs female kg − 1 ) were obtained with fifteen injections and 33 spawns (2.2 ± 0.7 spawns per injection). A significant positive was found, between the numbers of eggs obtained each month and the average monthly temperature. Latency period was approximately of 28 h and 30 min. A highly significant negative statistical relation ( P − 1 of GnRHa every 10 days in fluent males and 500 μm oocytes bearing females of longfin yellowtail broodstock were successful to obtain a high induction efficiency and excellent spawn quality.

Effect of doses and time post-injection on hormonal induction of spermiation in Bufo calamita (Anura: Bufonidae)

Effect of doses and time post-injection on hormonal induction of spermiation in Bufo calamita (Anura: Bufonidae)

Influence of hormonal induction and broodstock feeding on longfin yellowtailSeriola rivolianamaturation, spawning quality and egg biochemical composition

To optimize broodstock management for Seriola rivoliana, a survey over 5 years was performed to evaluate the effects of successive hormonal inductions with GnRHa or dietary regime on spawning quality. Running males and females with an oocyte diameter > 500 μm were injected with GnRHa. The spawning quality was compared among consecutive years and different moments along the spawning season. Besides, three different feeding regimes were tested. Spawning quality parameters were not significantly affected by time along the spawning season, whereas they were clearly influenced by diet. Particularly, broodfish fed the mackerel regime (M) showed a significantly higher number of eggs than other treatments. Besides, dietary protein content significantly improved broodstock fecundity of S. rivoliana. Moreover, hatching rates were also higher in broodfish fed mackerel and the dietary docosahexaenoic acid (DHA) levels significantly increased this parameter. Despite polar lipids were not significantly affected, neutral lipids fatty acid composition of S. rivoliana eggs showed higher 18:2n-6 in eggs, whereas ARA content was not affected. The results of this study denoted the high fecundity and good spawning quality of S. rivoliana broodfish and suggested the importance of high protein, energy and DHA levels in broodstock diets.

Follicle stimulating hormone (FSH) induction of aromatase and luteinizing hormone receptor (LHR) is dependent, in part, on the protein kinase a regulatory-rho-guanine nucleotide exchange factor AKAP13

FSH drives ovarian folliculogenesis via protein kinase A (PKA). The PKA anchoring protein 13 (AKAP13) is highly expressed in the human ovarian follicle and is known to regulate PKA activation through binding of RII regulatory subunits. We previously reported that expression of AKAP13 was induced during follicular development in mice and humans1. Since FSH leads to activation of PKA, we sought to determine the role of AKAP13 in FSH receptor signaling in COV434, an FSH-responsive human granulosa cell line.

Dephosphorylation of CCAAT/enhancer-binding protein β by protein phosphatase 2A containing B56δ is required at the early time of adipogenesis

It is known that protein phosphatase 2A (PP2A) expression is increased in high-fat diet (HFD)-induced obese mice, but the role of PP2A in adipogenesis as well as obesity remains to be addressed. In this study, the role of PP2A in adipogenesis was explored. Preadipocytes were treated with okadaic acid (OA) during adipogenesis and the degree of adipogenesis was determined. The OA treatment blocked adipogenesis at the early time of adipogenesis, but not at the late time. In the early time of adipogenesis, CCAAT/enhancer-binding protein β (C/EBPβ) activation is preceded by the expression of key adipogenic transcription factors including PPARγ and C/EBPα, which function at the late time of adipogenesis, and then C/EBPβ is degraded. However, the inhibition of PP2A by OA treatment sustained phosphorylation of C/EBPβ and delayed its degradation. In turn, PPARγ and C/EBPα activation was altered. Among the various regulatory B56 subunits consisting of PP2A holoenzyme, B56δ was directly bound to C/EBPβ and was responsible for the dephosphorylation of C/EBPβ by PP2A.Taken together, these findings suggest that the phosphorylation of C/EBPβ after hormonal induction has to be inactivated by PP2A containing B56δ at the early time of adipogenesis to allow the completion of adipogenesis.

Ovarian insufficiency and pubertal development after hematopoietic stem cell transplantation in childhood.

Ovarian insufficiency (OI) and infertility are common and devastating late effects of cancer treatment and hematopoietic stem cell transplantation (HSCT). In children, gonadal insufficiency may subsequently lead to abnormal pubertal development. The aim of this study was to assess the cumulative incidence of OI and the need for hormonal induction of pubertal development after HSCT in childhood. We additionally assessed HSCT-related risk factors for OI. A single center cohort study was undertaken of female patients transplanted during childhood, surviving at least 2 years post-HSCT and who were at least 10 years old at initiation of the study. Of 141 eligible patients, 109 were included and hormone levels and clinical data of these patients during follow-up were collected. Risk factors for OI were analyzed by multivariate Cox regression analysis. Cumulative incidence of OI was 56% at a median follow-up of 7.2 years. Eight patients, initially diagnosed with OI, showed recovery of ovarian function over time. Hormonal induction of puberty was necessary in 44% of females who were pre-pubertal or pubertal at HSCT. In multivariate analysis, more advanced pubertal stage at HSCT was associated with OI. We found a trend for an association of busulfan with OI in patients conditioned with chemotherapy only. The incidence of OI after HSCT was high and associated with more advanced pubertal stage at HSCT. Almost half of the females who were pre-pubertal or pubertal at HSCT required hormonal induction of pubertal development.

The antioxidant system of sterlet seminal fluid in testes and Wolffian ducts

Oxidative stress is a possible source of spermatozoa function deterioration. Seminal fluid (SF) protects spermatozoa against reactive oxygen species (ROS) attack during development in testes and transit through the reproductive tract. Spermatozoa curvilinear velocity and percent of motile cells as well as changes in thiobarbituric acid-reactive substance (TBARS) content, superoxide dismutase, and catalase activity, and uric acid concentration in SF were evaluated in sterlet sperm collected from testes 24 h after hormone induction of spermiation and from Wolffian ducts at 12, 24, 36, and 60 h after hormone injection (HI). While testicular spermatozoa motility was not initiated in activating medium, Wolffian duct sperm showed low motility at 12 h, significant increase at 24 and 36 h, and decrease at 60 h. Testicular SF was characterized by the highest level of TBARS and activity of studied enzymes compared with SF from Wolffian duct sperm at 24 h post-HI. In fluid from Wolffian duct sperm, a significant increase in TBARS content was shown at 36-60 h post-HI. In contrast to testicular SF, in SF from Wolffian duct sperm, this increase was not counterbalanced by changes in the studied variables of antioxidant system. This may be the source of the observed decrease in spermatozoa motility parameters 60 h post-HI. The results may confirm a dual role of ROS in fish sperm physiology. The data with respect to decrease in sturgeon spermatozoa motility parameters at 60 h post-HI should be taken into account in artificial sturgeon propagation.

Post-embryonic organogenesis and plant regeneration from tissues: two sides of the same coin?

Plants have extraordinary developmental plasticity as they continuously form organs during post-embryonic development. In addition they may regenerate organs upon in vitro hormonal induction. Advances in the field of plant regeneration show that the first steps of de novo organogenesis through in vitro culture in hormone containing media (via formation of a proliferating mass of cells or callus) require root post-embryonic developmental programs as well as regulators of auxin and cytokinin signaling pathways. We review how hormonal regulation is delivered during lateral root initiation and callus formation. Implications in reprograming, cell fate and pluripotency acquisition are discussed. Finally, we analyze the function of cell cycle regulators and connections with epigenetic regulation. Future work dissecting plant organogenesis driven by both endogenous and exogenous cues (upon hormonal induction) may reveal new paradigms of common regulation.

Neoadjuvant endocrine treatment in breast cancer: analysis of daily practice in large cancer center to facilitate decision making

BackgroundTo examine outcomes of neoadjuvant endocrine therapy in daily practice to inform decision making. MethodsWe retrospectively selected 204 patients who received neoadjuvant endocrine therapy with T2 (≥30 mm) or T3 tumors, examining subsequent breast-sparing surgery and long-term outcomes. ResultsNeoadjuvant endocrine therapy was administered for 7.3 months (median) and breast-sparing surgery was achievable in 53% of patients. Smaller initial tumor size and modified version of the Scarff–Bloom and Richardson grades 1 to 2 were associated with breast-sparing surgery. Disease progression during treatment was 6.9%; actuarial risk of local relapse was 3% at 5 years and 15% at 10 years. Five- and 10-year metastasis relapse-free survival was 78% and 63%, respectively. Grade 3, negative progesterone receptors, and absence or slow response to neoadjuvant therapy were associated prognostic factors. ConclusionThese daily practice data provide important information about feasibility, efficacy, and long-term results of neoadjuvant endocrine therapy and can be used to inform patients for decision making between mastectomy and endocrine induction therapy.

Multiple mechanisms of PAHs toxicity in Daphnia magna: effects of an AhR agonist and competitor on genes involved in toxicant pathways (1138.11)

Understanding the mechanistic pathways underlying the toxicity of chemicals can provide more biologically relevant models to extrapolate adverse outcomes. Mechanistically based models should provide more efficient means to screen untested compounds and predict exposure to untested species. We evaluated the relationship between reproductive outcomes in Daphnia magna and expression of biomarkers after exposure to polyaromatic hydrocarbons (PAHs). These biomarkers include Daphnia magna homologs of ARNT (aryl hydrocarbon nuclear translator), CYP4 (Cytochrome P450 Family 4), COX (cyclooxygenase), retinoid‐X‐receptor (RXR), and juvenile hormone esterase (JHE). To assess physiological endpoints we monitored reproductive changes in a 14‐day chronic exposure. Exposure to benzo(a)pyrene resulted in altered reproduction and was correlated with increases in RXR and decreases in VTG and CYP4 genes. We then conducted exposures with a known cytochrome P450 inhibitor, PBO (piperonyl butoxide and phenanthrene. PBO alone induced ARNT, JHE, COX, RXR, and CYP4 more than phenanthrene alone. In combination with PBO, phenanthrene did not induce JHE, RXR, and downregulated phase I detoxification pathway genes ARNT and CYP4. CYP450 activity (ARNT) does not have a role in induction of developmental hormones (JHE). These results indicate that Daphnia toxicant control mechanisms are operating through multiple pathways that influence reproduction and survival.

Expression, subcellular localization and protein‑protein interaction of four isoforms of EcR/USP in the common cutworm

Ecdysone receptor (EcR) and ultraspiracle (USP) form heterodimers to mediate ecdysteroid signaling during molting and metamorphosis. Various EcR/USP heterodimers have been reported. However, it is unclear what kind of EcR/USP combination is adopted by lepidopteran insects during the larval-pupal metamorphosis and whether the EcR/USP heterodimer varies among different tissues. To address these questions, two isoforms of each EcR and USP were cloned from the common cutworm, their messenger RNA expression patterns were examined by real-time quantitative polymerase chain reaction in different tissues during the larval-pupal metamorphosis and in the midgut in response to hormonal induction. Furthermore, their subcellular localization and protein-protein interaction were explored by transient expression and far-western blotting, respectively. All the four genes were significantly up-regulated in prepuae and/or pupae. The expression profiles of EcRB1 and USP1 were nearly identical to each other in the epidermis, fat body and midgut, and a similar situation also applied to EcRA and USP2. The three genes responded to 20-hydroxyecdysone (20E) induction except for USP2, and USP1 could be up-regulated by both 20E and juvenile hormone. The four proteins mainly localized in the nucleus and the nuclear localization was promoted by 20E. The protein-protein interaction between each EcR and USP was found in vitro. These results suggest that two types of EcR/USP heterodimer (EcRA/USP2 and EcRB1/USP1) may exist simultaneously in the common cutworm, and the latter should play more important roles during the larval-pupal metamorphosis. In addition, the types of EcR/USP heterodimer do not vary in the tissues which undergo histolysis and regeneration during metamorphosis.

Thyroid hormone induction of human cholesterol 7 alpha-hydroxylase (Cyp7a1) in vitro

Thyroid hormone (TH) modulates serum cholesterol by acting on TH receptor β1 (TRβ1) in liver to regulate metabolic gene sets. In rodents, one important TH regulated step involves induction of Cyp7a1, an enzyme in the cytochrome P450 family, which enhances cholesterol to bile acid conversion and plays a crucial role in regulation of serum cholesterol levels. Current models suggest, however, that Cyp7a1 has lost the capacity to respond to THs in humans. We were prompted to re-examine TH effects on cholesterol metabolic genes in human liver cells by a recent study of a synthetic TH mimetic which showed that serum cholesterol reductions were accompanied by increases in a marker for bile acid synthesis in humans. Here, we show that TH effects upon cholesterol metabolic genes are almost identical in mouse liver, mouse and human liver primary cells and human hepatocyte cell lines. Moreover, Cyp7a1 is a direct TR target gene that responds to physiologic TR levels through a set of distinct response elements in its promoter. These findings suggest that THs regulate cholesterol to bile acid conversion in similar ways in humans and rodent experimental models and that manipulation of hormone signaling pathways could provide a strategy to enhance Cyp7a1 activity in human patients.

Preservation and Transportation of Hepatocyte Monolayers in A No Spill Format at Non Freezing Temperatures

Hepatocyte monolayers were preserved under a gelatin overlay at 10°C. Morphological changes were observed after 4 days, as structure less areas at the cell periphery. The changes could be prevented by adding sucrose (0.05M) to the gel. Cell viability remained high for 7 days. Cell spreading occurred rapidly when the cells were reactivated. Basal enzyme levels were maintained during the preservation period. The hormonal induction of tyrosine aminotransferase was stable for 4 days but declined subsequently. Sucrose addition extended the period of preservation where induction was evident. The method provides a robust system that allows preservation in the absence of potentially deleterious chemicals. Time is allowed to send cells anywhere in the World in a no spill format whist arriving at their destination as if freshly produced.

Tributyltin affects adipogenic cell fate commitment in mesenchymal stem cells by a PPARγ independent mechanism

The food contaminant tributyltin (TBT) is an endocrine disrupting compound (EDC) promoting adipogenic differentiation in vitro and in vivo. Although prenatal TBT exposure has been shown to induce obesity, the underlying mechanisms and the role of the transcription factor PPARγ are not clarified yet.At different stages of adipogenesis, multipotent murine mesenchymal stem cells (MSC), C3H10T1/2, were exposed to TBT and analyzed for adipogenic differentiation, PPARγ promoter activation and PPARγ1, PPARγ2, Pref-1 and SOX9 expression. Depending on the exposure window, TBT promoted subsequent adipogenesis independently and dependently from PPARγ. In undifferentiated MSC, TBT exposure induced a transcriptional PPARγ-independent repression of Pref-1 and SOX9, which are both suppressors of adipogenic cell fate commitment. During hormonal induction TBT additionally enhanced adipogenic differentiation by PPARγ signaling.The impact of TBT on early cell fate development documents a novel mechanistic insight in the development of adipocytes derived from MSC and its susceptibility to EDC.

Infecciones por bacterias poco comunes y oncogénesis bacteriana

The recovery of an unusual organism in the clinical microbiology laboratory may be an indicator of an immunological abnormality in the patient. For instance, an important relationship between Clostridium septicum and colon carcinoma as well as between leukemia or lymphoma with species frequently considered contaminants (Bacillus spp., Corynebacterium spp.) or others rarely isolated from different contexts (Capnocytophaga spp.) were described. Some bacteria are almost exclusively isolated from AIDS patients (Rhodococcus equi). Campylobacter spp., Aeromonas spp., group G and mitis group streptococci were more frequently isolated in individuals suffering from any type of cancer than in other patients. Furthermore, some other bacteria can be considered markers of an undetected cancer that can be found mostly in neutropenic patients rather than in immunologically normal individuals. Possible mechanisms of bacterial oncogenesis include a modification of the inflammatory response, antigen-derived lymphoproliferation, and induction of hormones that increase epithelial cell proliferation. Typical examples of the above are: gastric adenocarcinoma induced by Helicobacter pylori, the association between group bovis bacteremia and colon carcinoma and the mucosa-associated lymphoid tissue (MALT) related to Helicobacter species (gastric MALT) and Chlamydophila spp. (ocular MALT). Isolation of any of these pathogens should require a thorough search for possible malignant diseases.

A Comorbid Major Depression in Patients with Panic Disorder Affects the HPA Axis Response in the DEX-CRH Test

Panic disorder (PD) has been associated with an altered reactivity of the hypothalamic-pituitary-adrenocortical (HPA) system in the dexamethasone-corticotropin-releasing-hormone (DEX-CRH) test. Recent findings showed that the duration of the PD and the severity of psychopathology are prominent moderators of the HPA-axis reactivity under hormonal stress induction. As major depression (MD) often occurs as comorbidity in patients with PD, a secondary MD might influence the reactivity of HPA-axis in the DEX-CRH test. For this study, the DEX-CRH test was implemented to observe the adreno-corticotropin-hormone (ACTH) and the cortisol release. The sample included 20 patients diagnosed with PD (mean age = 32.20 years, SD = 9.98), 20 patients with PD and comorbid MD (mean age = 37.63 years, SD = 11.31) in a Structured Clinical Interview (SCID), and 20 healthy controls (mean age = 31.97 years, SD = 10.53) matched by age and gender. The ACTH and the cortisol release increased significantly in all three groups due to the CRH injection (p < .001). The two anxiety patient groups differed in the cortisol response pattern, however, not in the ACTH. Patients with pure PD showed a lower CRH-induced cortisol release than healthy controls (p < .038) and patients with a comorbid major depression (p = .001); the latter showed the highest cortisol release in DEX-CRH test. Duration (AUCg: r = .353, p = .030; AUCi: r = .339, p = .037) and severity of psychopathology (AUCg: r = .496, p = .026; AUCi: r = .463, p = .040) significantly correlated with the cortisol release. Patients with/without comorbid MD showed some dissociation between the central and the peripheral HPA-axis functionality under the DEX-CRH test. Furthermore, it seems that a secondary depressive disorder is the decisive factor in explaining an increased reactivity of HPA-axis in patients with PD.

Identification of anti-adipogenic proteins in adult bovine serum suppressing 3T3-L1 preadipocyte differentiation

Adipocyte differentiation is a complex developmental process forming adipocytes from various precursor cells. The murine 3T3-L1 preadipocyte cell line has been most frequently used in the studies of adipocyte differentiation. Differentiation of 3T3-L1 preadipocytes includes a medium containing fetal bovine serum (FBS) with hormonal induction. In this study, we observed that differentiation medium containing adult bovine serum (ABS) instead of FBS did not support differentiation of preadipocytes. Impaired adipocyte differentiation was due to the presence of a serum protein factor in ABS that suppresses differentiation of preadipocytes. Using a proteomic analysis, alpha-2-macroglobulin and paraoxonase/arylesterase 1, which were previously shown to suppress differentiation of preadipocytes, were identified as anti-adipogenic proteins. Although their functional mechanisms have not yet been elucidated, the anti-adipogenic effects of these proteins are discussed. [BMB Reports 2013; 46(12): 582-587]