Role of the Transcriptional Coactivator CBP/p300 in Linking Basic Helix-Loop-Helix and CREB Responses for Follicle-Stimulating Hormone-Mediated Activation of the Transferrin Promoter in Sertoli Cells

Sertoli cells are the epithelial cells responsible for the onset of pubertal development and the maintenance of spermatogenesis in the adult. Transferrin is one of the major secretory products expressed by differentiated Sertoli cells. Investigation of the transcriptional control of transferrin gene expression provides insight regarding the regulation of Sertoli cell differentiation. The optimal activation of the mouse transferrin promoter (mTf) by FSH requires the synergistic actions of the cAMP response element-binding protein (CREB) binding to the cAMP response element-like proximal region II (PRII) and the basic helix-loop-helix (bHLH) binding to the E-box. Proximal region II alone is sufficient for cAMP-mediated activation. The proximity of the PRII and E-box (220 base pairs apart) suggests the possibility of interaction between CREB and bHLH proteins. Such an interaction can be mediated by transcriptional integrators such as CREB-binding protein (CBP) and/or p300 and may stabilize the binding of trans-acting factors to their respective cis-elements. Such an interaction may also provide a mechanism for cell-specific promoter activation. The hypothesis tested in this study was that CBP/p300 is required for the synergistic activation of the transferrin promoter involving PRII and E-box through the formation of a ternary complex. In the Sertoli cells, both CBP and p300 proteins are expressed. The effect of CBP/p300 on transferrin promoter activation and, hence, Sertoli cell function was studied by using antisense oligonucleotides (AS-oligo). In the presence of CBP/p300 AS-oligo, activity of the FSH-induced mTf-chloramphenicol acetyl transferase (CAT) was significantly lower as compared to the respective controls. Interestingly, AS-oligo had no effect on cAMP-induced activation of the transferrin promoter reporter construct (mTf-CAT). Mutations in the E-box (EB*) significantly reduced the FSH response. The presence of AS-oligo had no further effect on the FSH-mediated activation of the EB*-mTf-CAT construct but reduced cAMP-mediated activation. Mutations in the CRE-like PRII (PRII*) also significantly reduced the FSH response. Activation of the PRII*-mTf-CAT in response to cAMP was completely abolished. The presence of AS-oligo had no further effect on the FSH- or cAMP-mediated activation of the PRII*-mTf-CAT construct. In Sertoli cells, CBP/p300 was coimmunoprecipitated with CREB and the bHLH protein E47. These observations suggest that CBP/p300 appears to be involved in regulating FSH-mediated activation of the transferrin promoter by linking bHLH and CREB activities

Privacy-Preserving Eye Videos using Rubber Sheet Model

Video-based eye trackers estimate gaze based on eye images/videos. As security and privacy concerns loom over technological advancements, tackling such challenges is crucial. We present a new approach to handle privacy issues in eye videos by replacing the current identifiable iris texture with a different iris template in the video capture pipeline based on the Rubber Sheet Model. We extend to image blending and median-value representations to demonstrate that videos can be manipulated without significantly degrading segmentation and pupil detection accuracy.Comment: Will be published in ETRA 20 Short Papers, June 2-5, 2020, Stuttgart, Germany Copyright 2020 Association for Computing Machiner

Role of Winged Helix Transcription Factor (WIN) in the Regulation of Sertoli Cell Differentiated Functions: WIN Acts as an Early Event Gene for Follicle-Stimulating Hormone

Members of the winged helix transcription factor family are known to regulate epithelial cell differentiation by regulating cell-specific gene expression. rWIN is a newly discovered member of the winged helix family shown to be present in the adult rat testis. In the testis the human homolog of rWIN, HFH-11, was localized to the germ cells (i.e. spermatocytes and spermatids) undergoing spermatogenesis. In the present study we show that rWIN is also expressed in testicular Sertoli cells. Sertoli cells are the epithelial component of the semi-niferous tubule and provide both the cytoarchitectural support and the microenvironment for developing germ cells. The presence of rWIN in Sertoli cells was confirmed by Northern blot and RT-PCR analysis. The rWIN transcript size in the Sertoli cells was different from the germ cell transcript that is probably due to alternative splicing or modifications of the 3-untranslated region. At least two spliced variants of rWIN were observed in the Sertoli cells corresponding to the deletion of an exon in the DNA-binding region. Long term stimulation of cultured Sertoli cells with the gonadotropin FSH down-regulated rWIN expression. In contrast, short-term stimulation (2 h) transiently up-regulated rWIN expression. The FSH-induced transient stimulation of rWIN precedes expression of the transferrin gene that is a marker of Sertoli cell differentiation. FSH-induced transferrin promoter activity was inhibited when cultured Sertoli cells were treated with an antisense oligonucleotide to rWIN. Interestingly , the constitutive overexpression of the DNA-binding domain of rWIN also down-regulated transferrin promoter activity. Analysis of the transferrin promoter with various deletion mutations suggested that rWIN acts at an upstream gene of the transferrin promoter. The results indicate that a transient up-regulation of rWIN in part mediates the ability of FSH to activate the transferrin promoter, which can be inhibited with a rWIN antisense oligonucleotide or constitutive expression of the rWIN DNA-binding domain. The current study demonstrates that rWIN acts as an early event gene for FSH actions on Sertoli cells and that rWIN appears to have a role in the regulation of Sertoli cell differentiated functions. (Endocrinology 141: 2758 –2766, 2000

Anti-Tac(Fv)-PE40, a single chain antibody Pseudomonas fusion protein directed at interleukin 2 receptor bearing cells

Anti-Tac(Fv)-PE40 is a chimeric single chain immunotoxin in which anti-Tac variable heavy and light chains held together by a peptide linker are attached to PE40, a truncated form of Pseudomonas exotoxin. This molecule was shown to be extremely cytotoxic for interleukin 2 (IL2) receptor bearing cells in tissue culture (Chaudhary, V. K., Queen, C., Junghans, R. P., Waldmann, T. A., FitzGerald, D. J., and Pastan, I. (1989) Nature 339, 394-397). Here we describe various forms of anti-Tac(Fv)-PE40 protein in which the order of the variable domains of anti-Tac has been switched and also three different types of peptide linkers have been used. All these proteins were purified to near homogeneity and were found to have similar cytotoxic activities against various human cells expressing the p55 subunit of the IL2 receptor. Anti-Tac(Fv)-PE40 was also found to have a very potent suppressive activity against phytohemagglutinin-activated human lymphoblasts and in a human mixed lymphocyte reaction. Anti-Tac(Fv)-PE40 appeared in the blood rapidly in mice after intraperitoneal administration and could be detected in the blood for up to 8 h. Anti-Tac(Fv)-PE40 warrants evaluation as an anti-tumor and immunosuppressive agent in humans

Disseminated peritoneal hydatidosis following blunt abdominal trauma: A case report

A middle age lady presented with abdominal pain was diagnosed to have multiple peritoneal and hepatic hydatid cysts on CT scan. Retrospectively she was found to have suffered blunt abdominal trauma