CRH-R splicing in estrogen-sensitive breast cancer

Alternative pre-mRNA splicing contributes in the acquired genomic alterations involved in the pathobiology of cancer development and progression.1 In normal biological systems, this mechanism allows protein complexity and diversity by increasing gene coding capacity and promoting expression of several related proteins with diverse and even antagonistic functions. However, in pathological settings such as cancer, mutations in splicing regulatory elements and/or alterations in the cellular splicing machinery can change splicing patterns and result in the generation of aberrantly spliced pre-mRNAs that favor development of the malignant state

Corticotropin-releasing hormone interacts with interleukin-1 to regulate prostaglandin H synthase-2 expression in human myometrium during pregnancy and labor

Context: The onset of labor appears to involve the activation of myometrial inflammatory pathways, and transcription factors such as nuclear factor-κB (NF-κB) control expression of the contraction-associated proteins required to induce a procontractile phenotype. These responses might involve CRH, which integrates immune and neuroendocrine systems. Objectives: In human myometrium we investigated cyclooxygenase 2 (PGHS2) expression and regulation by CRH and the proinflammatory cytokine IL-1β before and after labor. Design: Myometrial tissues obtained from pregnant women at term before (n = 12) or during labor (n = 10) and pathological cases of choriamnionitis-associated term labor (n = 5) were used to isolate primary myocytes and investigate in vitro, CRH effects on basal and IL-1β regulated p65 activation and PGHS2 expression. Results: In nonlaboring myometrial cells, CRH was unable to induce NF-κB nuclear translocation; however, it altered the temporal dynamics of IL-1β-driven NF-κB nuclear entry by initially delaying entry and subsequently prolonging retention. These CRH-R1-driven effects were associated with a modest inhibitory action in the early phase (within 2 hours) of IL-1β stimulated PGHS2 mRNA expression, whereas prolonged stimulation for 6–18 hours augmented the IL-1β effects. The early-phase effect required intact protein kinase A activity and was diminished after the onset of labor. The presence of chorioamnionitis led to exaggerated PGHS2 mRNA responses to IL-1β but diminished effects of CRH. Conclusions: CRH is involved in the inflammatory regulation of PGHS2 expression before and during labor; these actions might be important in priming and preparing the myometrium for labor and cellular adaptive responses to inflammatory mediator

The onset of labor alters corticotropin-releasing hormone type 1 receptor variant expression in human myometrium : putative role of interleukin-1ß

CRH targets the human myometrium during pregnancy. The efficiency of CRH actions is determined by expression of functional receptors (CRH-R), which are dynamically regulated. Studies in myometrial tissue biopsies using quantitative RT-PCR demonstrated that the onset of labor, term or preterm, is associated with a significant 2- to 3-fold increase in CRH-R1 mRNA levels. Detailed analysis of myometrial CRH-R1 mRNA variants showed a decline of the pro-CRH-R1 mRNA encoding the CRH-R1ß variant during labor and increased mRNA levels of CRH-R1d mRNA. Studies in myometrial cells identified IL-1ß as an important regulator of myometrial CRH-R1 gene expression because prolonged treatment of myometrial cells with IL-1ß (1 ng/ml) for 18 h induced expression of CRH-R1 mRNA levels by 1.5- to 2-fold but significantly attenuated CRH-R1ß mRNA expression by 70%. In contrast, IL-1ß had no effect on CRH-R1d mRNA expression. Studies using specific inhibitors suggest that ERK1/2, p38 MAPK, and downstream nuclear translocation of nuclear factor-B mediate IL-1ß effects on myometrial CRH-R1 gene. However, the increased CRH-R1 mRNA expression was associated with a dampening of the receptor efficacy to activate the adenylyl cyclase/cAMP signaling cascade. Thus, our findings suggest that IL-1ß is an important regulator of CRH-R1 expression and functional activity, and this interaction might play a role in the transition of the uterus from quiescence to active contractions necessary for the onset of parturition

Actin cytoskeleton-dependent regulation of corticotropin-releasing factor receptor heteromers

Stress responses are highly nuanced and variable, but how this diversity is achieved by modulating receptor function is largely unknown. Corticotropin-releasing factor receptors (CRFRs), class B G protein–coupled receptors, are pivotal in mediating stress responses. Here we show that the two known CRFRs interact to form heteromeric complexes in HEK293 cells coexpressing both CRFRs and in vivo in mouse pancreas. Coimmunoprecipitation and mass spectrometry confirmed the presence of both CRF1R and CRF2βR, along with actin in these heteromeric complexes. Inhibition of actin filament polymerization prevented the transport of CRF2βR to the cell surface but had no effect on CRF1R. Transport of CRF1R when coexpressed with CRF2βR became actin dependent. Simultaneous stimulation of cells coexpressing CRF1R+CRF2βR with their respective high-affinity agonists, CRF+urocortin2, resulted in approximately twofold increases in peak Ca2+responses, whereas stimulation with urocortin1 that binds both receptors with 10-fold higher affinity did not. The ability of CRFRs to form heteromeric complexes in association with regulatory proteins is one mechanism to achieve diverse and nuanced function

The corticotrophin-releasing factor/urocortin system regulates white fat browning in mice through paracrine mechanisms

Objectives: The corticotrophin-releasing factor (CRF)/urocortin system is expressed in the adipose tissue of mammals, but its functional role in this tissue remains unknown. Methods: Pharmacological manipulation of the activity of CRF receptors, CRF1 and CRF2, was performed in 3T3L1 white pre-adipocytes and T37i brown pre-adipocytes during in vitro differentiation. The expression of genes of the CRF/urocortin system and of markers of white and brown adipocytes was evaluated along with mitochondrial biogenesis and cellular oxygen consumption. Metabolic evaluation of corticosterone-deficient or supplemented Crhr1-null (Crhr1−/−) mice and their wild-type controls was performed along with gene expression analysis carried out in white (WAT) and brown (BAT) adipose tissues. Results: Peptides of the CRF/urocortin system and their cognate receptors were expressed in both pre-adipocyte cell lines. In vitro pharmacological studies showed an inhibition of the expression of the CRF2 pathway by the constitutive activity of the CRF1 pathway. Pharmacological activation of CRF2 and, to a lesser extent, inhibition of CRF1 signaling induced molecular and functional changes indicating transdifferentiation of white pre-adipocytes and differentiation of brown pre-adipocytes. Crhr1−/− mice showed increased expression of CRF2 and its agonist Urocortin 2 in adipocytes that was associated to brown conversion of WAT and activation of BAT. Crhr1−/− mice were resistant to diet-induced obesity and glucose intolerance. Restoring physiological circulating corticosterone levels abrogated molecular changes in adipocytes and the favorable phenotype of Crhr1−/− mice. Conclusions: Our findings suggest the importance of the CRF2 pathway in the control of adipocyte plasticity. Increased CRF2 activity in adipocytes induces browning of WAT, differentiation of BAT and is associated with a favorable metabolic phenotype in mice lacking CRF1. Circulating corticosterone represses CRF2 activity in adipocytes and may thus regulate adipocyte physiology through the modulation of the local CRF/urocortin system. Targeting CRF receptor signaling specifically in the adipose tissue may represent a novel approach to tackle obesity

Corticotropin-releasing factor receptors couple to multiple g-proteins to activate diverse intracellular signaling pathways in mouse hippocampus: role in neuronal excitability and associative learning

Corticotropin-releasing factor (CRF) exerts a key neuroregulatory control on stress responses in various regions of the mammalian brain, including the hippocampus. Using hippocampal slices, extracts, and whole animals, we investigated the effects of human/rat CRF (h/rCRF) on hippocampal neuronal excitability and hippocampus-dependent learning in two mouse inbred strains, BALB/c and C57BL/6N. Intracellular recordings from slices revealed that application of h/rCRF increased the neuronal activity in both mouse inbred strains. Inhibition of protein kinase C (PKC) by bisindolylmaleimide I (BIS-I) prevented the h/rCRF effect only in hippocampal slices from BALB/c mice but not in slices from C57BL/6N mice. Inhibition of cAMP-dependent protein kinase (PKA) by H-89 abolished the h/rCRF effect in slices from C57BL/6N mice, with no effect in slices from BALB/c mice. Accordingly, h/rCRF elevated PKA activity in hippocampal slices from C57BL/6N mice but increased only PKC activity in the hippocampus of BALB/c mice. These differences in h/rCRF signal transduction were also observed in hippocampal membrane suspensions from both mouse strains. In BALB/c mice, hippocampal CRF receptors coupled to Gq/11 during stimulation by h/rCRF, whereas they coupled to Gs, Gq/11, and Gi in C57BL/6N mice. As expected on the basis of the slice experiments, h/rCRF improved context-dependent fear conditioning of BALB/c mice in behavioral experiments, and BIS-I prevented this effect. However, although h/rCRF increased neuronal spiking in slices from C57BL/6N mice, it did not enhance conditioned fear. These results indicate that the CRF system activates different intracellular signaling pathways in mouse hippocampus and may have distinct effects on associative learning depending on the mouse strain investigated

Synthesis of N4-aryl-β-d-glucopyranosylcytosines: a methodology study

A number of leaving groups, including arylsulfonates, triazoles, 3-nitrotriazoles, and tetrazoles, have been studied for the substitution reaction by aryl and alkyl amines at the 4-position of β-d-glucopyranosyluracils. Examination of the stability, ease of purification and reactivity in the substitution reaction led to a number of optimized conditions with the most convenient involving substitution of triazole derivatives under microwave conditions in the presence of silica gel. Under these conditions, a number of N4-aryl-substituted β-d-glucopyranosylcytosines were prepared as potential inhibitors of glycogen phosphorylase, a molecular target for type-2 diabetes mellitus

The identification of mitochondrial DNA variants in glioblastoma multiforme

Background: Mitochondrial DNA (mtDNA) encodes key proteins of the electron transfer chain (ETC), which produces ATP through oxidative phosphorylation (OXPHOS) and is essential for cells to perform specialised functions. Tumor-initiating cells use aerobic glycolysis, a combination of glycolysis and low levels of OXPHOS, to promote rapid cell proliferation and tumor growth. Glioblastoma multiforme (GBM) is an aggressively malignant brain tumor and mitochondria have been proposed to play a vital role in GBM tumorigenesis. Results: Using next generation sequencing and high resolution melt analysis, we identified a large number of mtDNA variants within coding and non-coding regions of GBM cell lines and predicted their disease-causing potential through in silico modeling. The frequency of variants was greatest in the D-loop and origin of light strand replication in non-coding regions. ND6 was the most susceptible coding gene to mutation whilst ND4 had the highest frequency of mutation. Both genes encode subunits of complex I of the ETC. These variants were not detected in unaffected brain samples and many have not been previously reported. Depletion of HSR-GBM1 cells to varying degrees of their mtDNA followed by transplantation into immunedeficient mice resulted in the repopulation of the same variants during tumorigenesis. Likewise, de novo variants identified in other GBM cell lines were also incorporated. Nevertheless, ND4 and ND6 were still the most affected genes. We confirmed the presence of these variants in high grade gliomas. Conclusions: These novel variants contribute to GBM by rendering the ETC. partially dysfunctional. This restricts metabolism to anaerobic glycolysis and promotes cell proliferation

Conceptualization and treatment of schizophrenia in Lacanian psychoanalysis: towards a clinic of the sinthome

Schizophrenia is rarely referred to in Lacan’s scholarship, and even more rarely in the socalled later Lacan. Yet the French psychoanalyst’s teaching on knotting and the theory of the sinthome of the 1970s can be utilized for the theoretical and clinical approach to this psychotic type. The gradual emphasis on the real in Lacan’s teaching can act as a guide both for its conceptualization and for the treatment supported by those clinicians who see schizophrenic subjects. My investigation of the conceptual history of schizophrenia led to the conclusion that despite psychiatric scholars having noted from early on an aspect that pertains to the real – schizophrenic discourse – this was disregarded, having been deemed one of the condition’s numerous morbid outcomes. In the same way, early psychoanalysts emphasized the aspect of subjectivity that Lacan calls the imaginary in the treatment of schizophrenia, trying, thus, to address it via a mechanism typical of the other major psychotic type, paranoia. This approach does not seem consonant with Freud’s reading of the two types, although he never elaborated upon their differentiation beyond the early 1910s. In fact, although the suggested Lacanian approach to schizophrenia derives from the last decade of Lacan’s teaching, it has roots in Freud’s view of psychosis of the mid-1910s and early 1920s. I have attempted to create a paradigm for the impact of those findings in examining the case of the late-19th-century Greek poet, writer and scholar Georgios Vizyenos. I argue that Vizyenos was characterized by a schizophrenic’s relation to the body, language, and the social bond. In his life and work, examined in detail, we see how the cause, triggering, and temporary treatment of his psychosis are linked to a concept with a direct relation to the real: ‘child’. Testimonies from Vizyenos’ childhood show his resistance to semblance, which had specific effects upon his body. It is, then, demonstrated how in late adolescence and mature life the subject renamed himself and acquired a sense of his body thanks to a ‘modified’ narcissism that did not resemble the coordinates of the paranoiac’s ego. This construction is approached through the later Lacan’s theories of the sinthome and the escabeau. Finally, it is shown how that invention was temporary, with Vizyenos being unable, in the end, to avoid the return of jouissance to the subject’s body. The theoretical and clinical implications of the study of Vizyenos’ case are discussed in relation to the contemporary Lacanian approach to schizophrenia. It is suggested that the singular character of the subject’s relation to the real could lead us to cross schizophrenia with a bar, schizophrenia, as Lacan did for the signifier ‘woman’ in his later teaching. Thus, the sinthomatic approach, which emphasizes the subject’s relation to the real rather than the universal subscription to Oedipus, does not seem unsuitable for the treatment of subjects who are schizophrenic. This is argued at greater length by comparing it with psychoanalytic orientations that place more emphasis on the use of the imaginary or the symbolic