The MSG1 non-DNA-binding transactivator binds to the p300/CBP coactivators, enhancing their functional link to the Smad transcription factors

Cited2 is a key regulator of placental development and plasticity

The biology of trophoblast cell lineage development and placentation is characterized by the involvement of several known transcription factors. Central to the action of a subset of these transcriptional regulators is CBP-p300 interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2). CITED2 acts as a coregulator modulating transcription factor activities and affecting placental development and adaptations to physiological stressors. These actions of CITED2 on the trophoblast cell lineage and placentation are conserved across the mouse, rat, and human. Thus, aspects of CITED2 biology in hemochorial placentation can be effectively modeled in the mouse and rat. In this review, we present information on the conserved role of CITED2 in the biology of placentation and discuss the use of CITED2 as a tool to discover new insights into regulatory mechanisms controlling placental development.

Exploring the role of CITED transcriptional regulators in the control of macrophage polarization

Macrophages are tissue resident innate phagocytic cells that take on contrasting phenotypes, or polarization states, in response to the changing combination of microbial and cytokine signals at sites of infection. During the opening stages of an infection, macrophages adopt the proinflammatory, highly antimicrobial M1 state, later shifting to an anti-inflammatory, pro-tissue repair M2 state as the infection resolves. The changes in gene expression underlying these transitions are primarily governed by nuclear factor kappaB (NF-κB), Janus kinase (JAK)/signal transducer and activation of transcription (STAT), and hypoxia-inducible factor 1 (HIF1) transcription factors, the activity of which must be carefully controlled to ensure an effective yet spatially and temporally restricted inflammatory response. While much of this control is provided by pathway-specific feedback loops, recent work has shown that the transcriptional co-regulators of the CBP/p300-interacting transactivator with glutamic acid/aspartic acid-rich carboxy-terminal domain (CITED) family serve as common controllers for these pathways. In this review, we describe how CITED proteins regulate polarization-associated gene expression changes by controlling the ability of transcription factors to form chromatin complexes with the histone acetyltransferase, CBP/p300. We will also cover how differences in the interactions between CITED1 and 2 with CBP/p300 drive their contrasting effects on pro-inflammatory gene expression.

TGF-β signaling in health, disease, and therapeutics

Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.

Roles and signaling pathways of CITED1 in tumors: overview and novel insights

CBP/p300 interacting transactivator with Glu/Asp-rich carboxy-terminal domain 1 (CITED1) is a transcriptional activator belonging to the non-DNA-binding transcription co-regulator family. It regulates diverse pathways, including the transforming growth factor/bone morphogenetic protein/SMAD, estrogen, Wnt-β-catenin, and androgen-AR signaling pathways, by binding to CBP/p300 co-activators through its conserved transactivation domain CR2. CITED1 plays an important role in embryonic development and a certain regulatory role in the occurrence and development of various tumors. In this article, the biological characteristics, expression regulation, participating signaling pathways, and potential roles of CITED1 in the clinical diagnosis and treatment of tumors are reviewed.

Identification of HSPA8 as an interacting partner of MAB21L2 and an important factor in eye development

BACKGROUND

Pathogenic variants in human MAB21L2 result in microphthalmia, anophthalmia, and coloboma. The exact molecular function of MAB21L2 is currently unknown. We conducted a series of yeast two-hybrid (Y2H) experiments to determine protein interactomes of normal human and zebrafish MAB21L2/mab21l2 as well as human disease-associated variant MAB21L2-p.(Arg51Gly) using human adult retina and zebrafish embryo libraries.

RESULTS

These screens identified klhl31, tnpo1, TNPO2/tnpo2, KLC2/klc2, and SPTBN1/sptbn1 as co-factors of MAB21L2/mab21l2. Several factors, including hspa8 and hspa5, were found to interact with MAB21L2-p.Arg51Gly but not wild-type MAB21L2/mab21l2 in Y2H screens. Further analyses via 1-by-1 Y2H assays, co-immunoprecipitation, and mass spectrometry revealed that both normal and variant MAB21L2 interact with HSPA5 and HSPA8. In situ hybridization detected co-expression of hspa5 and hspa8 with mab21l2 during eye development in zebrafish. Examination of zebrafish mutant hspa8hi138Tg identified reduced hspa8 expression associated with severe ocular developmental defects, including small eye, coloboma, and anterior segment dysgenesis. To investigate the effects of hspa8 deficiency on the mab21l2Arg51_Phe52del allele, corresponding zebrafish double mutants were generated and found to be more severely affected than single mutant lines.

CONCLUSION

This study identifies heat shock proteins as interacting partners of MAB21L2/mab21l2 and suggests a role for this interaction in vertebrate eye development.

Estradiol regulates leptin sensitivity to control feeding via hypothalamic Cited1

Until menopause, women have a lower propensity to develop metabolic diseases than men, suggestive of a protective role for sex hormones. Although a functional synergy between central actions of estrogens and leptin has been demonstrated to protect against metabolic disturbances, the underlying cellular and molecular mechanisms mediating this crosstalk have remained elusive. By using a series of embryonic, adult-onset, and tissue/cell-specific loss-of-function mouse models, we document an unprecedented role of hypothalamic Cbp/P300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 1 (Cited1) in mediating estradiol (E2)-dependent leptin actions that control feeding specifically in pro-opiomelanocortin (Pomc) neurons. We reveal that within arcuate Pomc neurons, Cited1 drives leptin's anorectic effects by acting as a co-factor converging E2 and leptin signaling via direct Cited1-ERα-Stat3 interactions. Together, these results provide new insights on how melanocortin neurons integrate endocrine inputs from gonadal and adipose axes via Cited1, thereby contributing to the sexual dimorphism in diet-induced obesity.

Regulation of macrophage IFNγ-stimulated gene expression by the transcriptional coregulator CITED1

Macrophages serve as a first line of defense against microbial pathogens. Exposure to interferon-γ (IFNγ) increases interferon-stimulated gene (ISG) expression in these cells, resulting in enhanced antimicrobial and proinflammatory activity. Although this response must be sufficiently vigorous to ensure the successful clearance of pathogens, it must also be carefully regulated to prevent tissue damage. This is controlled in part by CBP/p300-interacting transactivator with glutamic acid/aspartic acid-rich carboxyl-terminal domain 2 (CITED2), a transcriptional coregulator that limits ISG expression by inhibiting STAT1 and IRF1. Here, we show that the closely related Cited1 is an ISG, which is expressed in a STAT1-dependent manner, and that IFNγ stimulates the nuclear accumulation of CITED1 protein. In contrast to CITED2, ectopic CITED1 enhanced the expression of a subset of ISGs, including Ccl2, Ifit3b, Isg15 and Oas2. This effect was reversed in a Cited1-null cell line produced by CRISPR-based genomic editing. Collectively, these data show that CITED1 maintains proinflammatory gene expression during periods of prolonged IFNγ exposure and suggest that there is an antagonistic relationship between CITED proteins in the regulation of macrophage inflammatory function. This article has an associated First Person interview with the first author of the paper.

Irradiation induces DJ-1 secretion from esophageal squamous cell carcinoma cells to accelerate metastasis of bystander cells via a TGF-β1 positive feedback loop

Background

Radiation-induced bystander effect (RIBE) can promote tumor metastasis contributing to the failure of radiotherapy for esophageal squamous cell carcinoma (ESCC). Aberrant expression of DJ-1 has been identified in ESCC; however, the relationship between DJ-1 and RIBE in ESCC remains unknown.

Methods

We detected DJ-1 in the serum and cell supernatants by enzyme-linked immunosorbent assay (ELISA) and evaluated tumor metastasis by phenotypic experiments in vivo and in vitro. RNA-seq, mass spectrometry, western blot (WB), immunoprecipitation (IP), and dual-luciferase reporter assays were performed to explore the underlying mechanisms.

Results

DJ-1 was highly expressed in the serum of patients with ESCC receiving radiotherapy and was significantly overexpressed in the medium of ESCC cells receiving irradiation. DJ-1 promoted tumor metastasis via the TGF-β1 pathway. Mechanistic studies revealed that DJ-1 bound to HSC70 to promote Smad3 phosphorylation and nuclear aggregation in a protein-interaction manner, which activated the transcription of Thrombospondin-1 (TSP1). Subsequently, the activation of TGF-β1 by TSP1 re-promoted Smad3 phosphorylation and nuclear aggregation, constituting a positive feedback loop to strengthen the metastasis of ESCC cells, which was effectively blocked by LY2109761 and LSKL. Moreover, higher levels of serum DJ-1 in patients with ESCC were related to a poorer prognosis of radiotherapy.

Conclusions

Irradiation can induce ESCC cells secreting DJ-1. Secreted DJ-1 enters bystander cells to initiate activation of the TGF-β1 pathway via the DJ-1/HSC70/Smad3 signaling axis. The TSP1/TGF-β1/Smad3 positive feedback pathway constitutes the core pathway that promotes ESCC metastasis. DJ-1 is a useful biomarker for predicting the efficacy of radiotherapy and a potential therapeutic target for reversing RIBE in ESCC.

Graphical Abstract

Schematic diagram showing the underlying mechanism that irradiation-induced secretion of DJ-1 accelerates the metastasis of bystander ESCC cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02471-6.

TGFB1/INHBA Homodimer/Nodal-SMAD2/3 Signaling Network: A Pivotal Molecular Target in PDAC Treatment

Pancreatic cancer remains a grueling disease that is projected to become the second-deadliest cancer in the next decade. Standard treatment of pancreatic cancer is chemotherapy, which mainly targets the differentiated population of tumor cells; however, it paradoxically sets the roots of tumor relapse by the selective enrichment of intrinsically chemoresistant pancreatic cancer stem cells that are equipped with an indefinite capacity for self-renewal and differentiation, resulting in tumor regeneration and an overall anemic response to chemotherapy. Crosstalk between pancreatic tumor cells and the surrounding stromal microenvironment is also involved in the development of chemoresistance by creating a supportive niche, which enhances the stemness features and tumorigenicity of pancreatic cancer cells. In addition, the desmoplastic nature of the tumor-associated stroma acts as a physical barrier, which limits the intratumoral delivery of chemotherapeutics. In this review, we mainly focus on the transforming growth factor beta 1 (TGFB1)/inhibin subunit beta A (INHBA) homodimer/Nodal-SMAD2/3 signaling network in pancreatic cancer as a pivotal central node that regulates multiple key mechanisms involved in the development of chemoresistance, including enhancement of the stem cell-like properties and tumorigenicity of pancreatic cancer cells, mediating cooperative interactions between pancreatic cancer cells and the surrounding stroma, as well as regulating the deposition of extracellular matrix proteins within the tumor microenvironment.

SRF Fusions Other Than With RELA Expand the Molecular Definition of SRF-fused Perivascular Tumors

Pericytic tumors encompass several entities sharing morphologic and immunohistochemical features. A subset of perivascular myoid tumors associated with the SRF-RELA fusion gene was previously described. Herein, we report a series of 13 tumors belonging to this group, in which we have identified new fusion genes by RNA-sequencing, thus expanding the molecular spectrum of this entity. All patients except 1 were children and infants. The tumors, frequently located in the head (n=8), had a mean size of 38 mm (range 10 to 150 mm) and were mostly (n=9) well-circumscribed. Exploration of the follow-up data (ranging from 3 to 68 mo) confirmed the benign behavior of these tumors. These neoplasms presented a spectrum of morphologies, ranging from perivascular patterns to myoid appearance. Tumor cells presented mitotic figures but without marked atypia. Some of these tumors could mimic sarcoma. The immunohistochemical profiles confirmed a pericytic differentiation with the expression of the smooth muscle actin and the h-caldesmon, as well as the frequent positivity for pan-cytokeratin. The molecular analysis identified the expected SRF-RELA fusion gene, in addition to other genetic alterations, all involving SRF fused to CITED1, CITED2, NFKBIE, or NCOA2. The detection of SRF-NCOA2 fusions in spindle cell rhabdomyosarcoma of the infant has previously been described, representing a risk of misdiagnosis, although the cases reported herein did not express MyoD1. Finally, clustering analyses confirmed that this group of SRF-fused perivascular myoid tumors forms a distinct entity, different from other perivascular tumors, spindle cell rhabdomyosarcomas of the infant, and smooth muscle tumors.

Atypical Neocortical Development in the Cited2 Conditional Knockout Leads to Behavioral Deficits Associated with Neurodevelopmental Disorders

The mammalian neocortex develops from a single layer of neuroepithelial cells to form a six-layer heterogeneous mosaic of differentiated neurons and glial cells. This process requires a complex choreography of temporally and spatially restricted transcription factors and epigenetic regulators. Even subtle disruptions in this regulation can alter the way the neocortex forms and functions, leading to a neurodevelopmental disorder. One epigenetic regulator that is essential for the precise development of the neocortex is CITED2 (CBP/p300 Interacting Transactivator with ED-rich termini). Cited2 is highly expressed by intermediate progenitor cells in the subventricular zone during the generation of the superficial layers of the neocortex. A forebrain-specific conditional knockout of Cited2 (cKO) exhibits reduced proliferation of intermediate progenitor cells embryonically, leading to reduced thickness of the superficial layers and reduced corpus callosum (CC) volume postnatally. Further, the Cited2 cKO display disruptions in balanced neocortical arealization, with a specific reduction in the somatosensory neocortical length, and dysregulation of precise, area-specific neuronal connectivity. Here, we explore the behavioral consequences resulting from this aberrant neocortical development. We demonstrate that Cited2 cKO mice display decreased maternal separation-induced ultrasonic vocalizations (USVs) as neonates, and an increase in rearing behavior and lack of habituation following repeated acoustic startle as adults. They do not display alterations in anxiety-like behavior, overall locomotor activity, or social interactions. Together with the morphological, molecular, and connectivity disruptions, these results identify the Cited2 cKO neocortex as an ideal system to study mechanisms underlying neurodevelopmental and neuroanatomical disruptions with relevance to human neurodevelopmental disorders.

A Multi-Strategy Sequencing Workflow in Inherited Retinal Dystrophies: Routine Diagnosis, Addressing Unsolved Cases and Candidate Genes Identification

The management of unsolved inherited retinal dystrophies (IRD) cases is challenging since no standard pipelines have been established. This study aimed to define a diagnostic algorithm useful for the diagnostic routine and to address unsolved cases. Here, we applied a Next-Generation Sequencing-based workflow, including a first step of panel sequencing (PS) followed by clinical-exome sequencing (CES) and whole-exome sequencing (WES), in 46 IRD patients belonging to 42 families. Twenty-six likely causal variants in retinal genes were found by PS and CES. CES and WES allowed proposing two novel candidate loci (WDFY3 and a X-linked region including CITED1), both abundantly expressed in human retina according to RT-PCR and immunohistochemistry. After comparison studies, PS showed the best quality and cost values, CES and WES involved similar analytical efforts and WES presented the highest diagnostic yield. These results reinforce the relevance of panels as a first step in the diagnostic routine and suggest WES as the next strategy for unsolved cases, reserving CES for the simultaneous study of multiple conditions. Standardizing this algorithm would enhance the efficiency and equity of clinical genetics practice. Furthermore, the identified candidate genes could contribute to increase the diagnostic yield and expand the mutational spectrum in these disorders.

Intracellular Cryptococcus neoformans disrupts the transcriptome profile of M1- and M2-polarized host macrophages

Macrophages serve as a first line of defense against infection with the facultative intracellular pathogen, Cryptococcus neoformans (Cn). However, the ability of these innate phagocytic cells to destroy ingested Cn is strongly influenced by polarization state with classically (M1) activated macrophages better able to control cryptococcal infections than alternatively (M2) activated cells. While earlier studies have demonstrated that intracellular Cn minimally affects the expression of M1 and M2 markers, the impact on the broader transcriptome associated with these states remains unclear. To investigate this, an in vitro cell culture model of intracellular infection together with RNA sequencing-based transcriptome profiling was used to measure the impact of Cn infection on gene expression in both polarization states. The gene expression profile of both M1 and M2 cells was extensively altered to become more like naive (M0) macrophages. Gene ontology analysis suggested that this involved changes in the activity of the Janus kinase-signal transducers and activators of transcription (JAK-STAT), p53, and nuclear factor-κB (NF-κB) pathways. Analyses of the principle polarization markers at the protein-level also revealed discrepancies between the RNA- and protein-level responses. In contrast to earlier studies, intracellular Cn was found to increase protein levels of the M1 marker iNos. In addition, common gene expression changes were identified that occurred post-Cn infection, independent of polarization state. This included upregulation of the transcriptional co-regulator Cited1, which was also apparent at the protein level in M1-polarized macrophages. These changes constitute a transcriptional signature of macrophage Cn infection and provide new insights into how Cn impacts gene expression and the phenotype of host phagocytes.

CITED4 Protects Against Adverse Remodeling in Response to Physiological and Pathological Stress

RATIONALE

Cardiac CITED4 (CBP/p300-interacting transactivators with E [glutamic acid]/D [aspartic acid]-rich-carboxylterminal domain4) is induced by exercise and is sufficient to cause physiological hypertrophy and mitigate adverse ventricular remodeling after ischemic injury. However, the role of endogenous CITED4 in response to physiological or pathological stress is unknown.

OBJECTIVE

To investigate the role of CITED4 in murine models of exercise and pressure overload.

METHODS AND RESULTS

We generated cardiomyocyte-specific CITED4 knockout mice (C4KO) and subjected them to an intensive swim exercise protocol as well as transverse aortic constriction (TAC). Echocardiography, Western blotting, qPCR, immunohistochemistry, immunofluorescence, and transcriptional profiling for mRNA and miRNA (microRNA) expression were performed. Cellular crosstalk was investigated in vitro. CITED4 deletion in cardiomyocytes did not affect baseline cardiac size or function in young adult mice. C4KO mice developed modest cardiac dysfunction and dilation in response to exercise. After TAC, C4KOs developed severe heart failure with left ventricular dilation, impaired cardiomyocyte growth accompanied by reduced mTOR (mammalian target of rapamycin) activity and maladaptive cardiac remodeling with increased apoptosis, autophagy, and impaired mitochondrial signaling. Interstitial fibrosis was markedly increased in C4KO hearts after TAC. RNAseq revealed induction of a profibrotic miRNA network. miR30d was decreased in C4KO hearts after TAC and mediated crosstalk between cardiomyocytes and fibroblasts to modulate fibrosis. miR30d inhibition was sufficient to increase cardiac dysfunction and fibrosis after TAC.

CONCLUSIONS

CITED4 protects against pathological cardiac remodeling by regulating mTOR activity and a network of miRNAs mediating cardiomyocyte to fibroblast crosstalk. Our findings highlight the importance of CITED4 in response to both physiological and pathological stimuli.

Revealing the Interactions Between Diabetes, Diabetes-Related Diseases, and Cancers Based on the Network Connectivity of Their Related Genes

Diabetes-related diseases (DRDs), especially cancers pose a big threat to public health. Although people have explored pathological pathways of a few common DRDs, there is a lack of systematic studies on important biological processes (BPs) connecting diabetes and its related diseases/cancers. We have proposed and compared 10 protein-protein interaction (PPI)-based computational methods to study the connections between diabetes and 254 diseases, among which a method called DIconnectivity_eDMN performs the best in the sense that it infers a disease rank (according to its relation with diabetes) most consistent with that by literature mining. DIconnectivity_eDMN takes diabetes-related genes, other disease-related genes, a PPI network, and genes in BPs as input. It first maps genes in a BP into the PPI network to construct a BP-related subnetwork, which is expanded (in the whole PPI network) by a random walk with restart (RWR) process to generate a so-called expanded modularized network (eMN). Since the numbers of known disease genes are not high, an RWR process is also performed to generate an expanded disease-related gene list. For each eMN and disease, the expanded diabetes-related genes and disease-related genes are mapped onto the eMN. The association between diabetes and the disease is measured by the reachability of their genes on all eMNs, in which the reachability is estimated by a method similar to the Kolmogorov-Smirnov (KS) test. DIconnectivity_eDMN achieves an area under receiver operating characteristic curve (AUC) of 0.71 for predicting both Type 1 DRDs and Type 2 DRDs. In addition, DIconnectivity_eDMN reveals important BPs connecting diabetes and DRDs. For example, "respiratory system development" and "regulation of mRNA metabolic process" are critical in associating Type 1 diabetes (T1D) and many Type 1 DRDs. It is also found that the average proportion of diabetes-related genes interacting with DRDs is higher than that of non-DRDs.

CITED1 promotes proliferation of papillary thyroid cancer cells via the regulation of p21 and p27

Background

It has been reported that CBP/p300-Interacting Transactivator with glutamic acid [E]/aspartic acid [D]-rich C-terminal domain 1 (CITED1) is overexpressed in papillary thyroid cancer (PTC). However, the functional significance and underlying mechanisms of CITED1 in PTC are largely unknown.

Methods

The Cancer Genome Atlas dataset and real-time PCR were used to determine the expression of CITED1 in PTC. The role of CITED1 in PTC cell proliferation was determined conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, and flow cytometry assays in vitro, and a subcutaneous xenotransplantation tumor model in nude mice was established to analyze tumor growth in vivo. We studied the potential mechanisms underlying the contribution of CITED1 to PTC proliferation using western blotting and luciferase assays.

Results

We found that CITED1 was highly expressed in PTC. In vitro and in vivo experiments demonstrated that CITED1 was involved in PTC cell proliferation and tumorigenesis. Then, gain- and loss-of-function experiments revealed that CITED1 decreased the expression of p21 and p27, and thereby increased the phosphorylation of pRb as well as E2F1 transcriptional activity.

Conclusions

Our results suggest that CITED1 is overexpressed in PTC and that CITED1 promotes the proliferation of PTC cells via the regulation of p21 and p27, which indicates that CITED1 might be a potential therapeutic target in the treatment of PTC.

Transcription coactivator Cited1 acts as an inducer of trophoblast-like state from mouse embryonic stem cells through the activation of BMP signaling

Trophoblast lineages, precursors of the placenta, are essential for post-implantation embryo survival. However, the regulatory network of trophoblast development remains incompletely understood. Here, we report that Cited1, a transcription coactivator, is a robust inducer for trophoblast-like state from mouse embryonic stem cells (ESCs). Depletion of Cited1 in ESCs compromises the trophoblast lineage specification induced by BMP signaling. In contrast, overexpression of Cited1 in ESCs induces a trophoblast-like state with elevated expression of trophoblast marker genes in vitro and generation of trophoblastic tumors in vivo. Furthermore, global transcriptome profile analysis indicates that ectopic Cited1 activates a trophoblast-like transcriptional program in ESCs. Mechanistically, Cited1 interacts with Bmpr2 and Smad4 to activate the Cited1–Bmpr2–Smad1/5/8 axis in the cytoplasm and Cited1–Smad4–p300 complexes in the nucleus, respectively. Collectively, our results show that Cited1 plays an important role in regulating trophoblast lineage specification through activating the BMP signaling pathway.

Comprehensive profiling of transcriptional networks specific for lactogenic differentiation of HC11 mammary epithelial stem-like cells

The development of mammary gland as a lactogenic tissue is a highly coordinated multistep process. The epithelial cells of lactiferous tubules undergo profound changes during the developmental window of puberty, pregnancy, and lactation. Several hormones including estrogen, progesterone, glucocorticoids and prolactin act in concert, and orchestrate the development of mammary gland. Understanding the gene regulatory networks that coordinate proliferation and differentiation of HC11 Mammary Epithelial stem-like Cells (MEC) under the influence of lactogenic hormones is critical for elucidating the mechanism of lactogenesis in detail. In this study, we analyzed transcriptome profiles of undifferentiated MEC (normal) and compared them with Murine Embryonic Stem Cells (ESC) using next-generation mRNA sequencing. Further, we analyzed the transcriptome output during lactogenic differentiation of MEC following treatment with glucocorticoids (primed state) and both glucocorticoids and prolactin together (prolactin state). We established stage-specific gene regulatory networks in ESC and MEC (normal, priming and prolactin states). We validated the top up-and downregulated genes in each stage of differentiation of MEC by RT-PCR and found that they are comparable with that of RNA-seq data. HC11 MEC display decreased expression of Pou5f1 and Sox2, which is crucial for the differentiation of MEC, which otherwise ensure pluripotency to ESC. Cited4 is induced during priming and is involved in milk secretion. MEC upon exposure to both glucocorticoids and prolactin undergo terminal differentiation, which is associated with the expression of several genes, including Xbp1 and Cbp that are required for cell growth and differentiation. Our study also identified differential expression of transcription factors and epigenetic regulators in each stage of lactogenic differentiation. We also analyzed the transcriptome data for the pathways that are selectively activated during lactogenic differentiation. Further, we found that selective expression of chromatin modulators (Dnmt3l, Chd9) in response to glucocorticoids suggests a highly coordinated stage-specific lactogenic differentiation of MEC.

The Super-Enhancer-Derived alncRNA-EC7/Bloodlinc Potentiates Red Blood Cell Development in trans

Enhancer-derived RNAs are thought to act locally by contributing to their parent enhancer function. Whether large domains of clustered enhancers (super-enhancers) also produce cis-acting RNAs, however, remains unclear. Unlike typical enhancers, super-enhancers form large spans of robustly transcribed chromatin, amassing capped and polyadenylated RNAs that are sufficiently abundant to sustain trans functions. Here, we show that one such RNA, alncRNA-EC7/Bloodlinc, is transcribed from a super-enhancer of the erythroid membrane transporter SLC4A1/BAND3 but diffuses beyond this site. Bloodlinc localizes to trans-chromosomal loci encoding critical regulators and effectors of terminal erythropoiesis and directly binds chromatin-organizing and transcription factors, including the chromatin attachment factor HNRNPU. Inhibiting Bloodlinc or Hnrnpu compromises the terminal erythropoiesis gene program, blocking red cell production, whereas expressing Bloodlinc ectopically stimulates this program and can promote erythroblast proliferation and enucleation in the absence of differentiation stimuli. Thus, Bloodlinc is a trans-acting super-enhancer RNA that potentiates red blood cell development.

Identification of a Novel Serum Biomarker for Tuberculosis Infection in Chinese HIV Patients by iTRAQ-Based Quantitative Proteomics

Tuberculosis (TB) is a major comorbidity in HIV patients as well as a serious co-epidemic. Traditional detection methods are not effective or sensitive for the detection of Mycobacterium tuberculosis at the early stage. TB has become a major cause of lethal on HIV patients. We employed isobaric tags for relative and absolute quantitation (iTRAQ) technology to identify the different host responses in HIV-noTB and HIV-TB patients’ sera. Given the diversity of HIV subtypes, which results in a variety of host responses in different human populations, we focused on the Chinese patients. Of the 25 proteins identified, 7 were increased and 18 were decreased in HIV-TB co-infected patients. These proteins were found to be involved in host immune response processes. We identified a candidate protein, endoglin (ENG), which showed an 4.9 times increase by iTRAQ and 11.5 times increase by ELISA. ENG demonstrated the diagnostic efficacy and presented a novel molecular biomarker for TB in HIV-infected Chinese patients. This study provides new insight into the challenges in the diagnosis and effective management of patients with HIV-TB.

Melanocyte-specific gene 1 promotes melanoma progression by enhancing the expression of Bcl-2

Malignant melanoma is a class of highly malignant tumors derived from melanocytes. At present, the dysregulated gene expression involved in the progression of melanoma has attracted much attention. In the present study, the gene expression profile of human melanoma tissue was screened using a cDNA microarray, and it was identified that melanocyte-specific gene 1 (MSG1) was significantly overexpressed in melanoma tissue compared with paired nevus tissues. The overexpression of MSG1 in melanoma was subsequently confirmed using immunohistochemistry in a set of melanoma tissues. It was additionally identified that the overexpression of MSG1 may promote cell viability and inhibit cell apoptosis in human melanoma A375 cells, thus promoting melanoma progression. Mechanistically, following screening of the expression of apoptosis-associated proteins, MSG1 was demonstrated to enhance the expression of the apoptosis inhibitor B-cell lymphoma 2 (Bcl-2) to inhibit melanoma cell apoptosis. Therefore, it was concluded that the overexpression of MSG1 inhibits apoptosis by enhancing Bcl-2 expression in malignant melanoma, thus promoting melanoma progression.

Hsp70 May Be a Molecular Regulator of Schistosome Host Invasion

Schistosomiasis is a debilitating disease that affects over 240 million people worldwide and is considered the most important neglected tropical disease following malaria. Free-swimming freshwater cercariae, one of the six morphologically distinct schistosome life stages, infect humans by directly penetrating through the skin. Cercariae identify and seek the host by sensing chemicals released from human skin. When they reach the host, they burrow into the skin with the help of proteases and other contents released from their acetabular glands and transform into schistosomula, the subsequent larval worm stage upon skin infection. Relative to host invasion, studies have primarily focused on the nature of the acetabular gland secretions, immune response of the host upon exposure to cercariae, and cercaria-schistosomulum transformation methods. However, the molecular signaling pathways involved from host-seeking through the decision to penetrate skin are not well understood. We recently observed that heat shock factor 1 (Hsf1) is localized to the acetabular glands of infectious schistosome cercariae, prompting us to investigate a potential role for heat shock proteins (HSPs) in cercarial invasion. In this study, we report that cercarial invasion behavior, similar to the behavior of cercariae exposed to human skin lipid, is regulated through an Hsp70-dependent process, which we show by using chemical agents that target Hsp70. The observation that biologically active protein activity modulators can elicit a direct and clear behavioral change in parasitic schistosome larvae is itself interesting and has not been previously observed. This finding suggests a novel role for Hsp70 to act as a switch in the cercaria-schistosomulum transformation, and it allows us to begin elucidating the pathways associated with cercarial host invasion. In addition, because the Hsp70 protein and its structure/function is highly conserved, the model that Hsp70 acts as a behavior transitional switch could be relevant to other parasites that also undergo an invasion process and can apply more broadly to other organisms during morphological transitions. Finally, it points to a new function for HSPs in parasite/host interactions.

Parasitic schistosome worms cause morbid disease in over 240 million individuals worldwide. Acute infections with these worms can lead to Katayama fever, while chronic infections can lead to portal hypertension, enlarged abdomen, and liver damage. The infective larval stage, called cercariae, are free-swimming and can detect, seek, and penetrate human skin to enter the human host circulatory system, eventually developing into egg-laying adult worms that cause schistosomiasis. Molecular pathways associated with the initial cercarial invasion of the host, however, are largely unknown, especially with respect to the parasite-specific signals involved in host detection and subsequent decision to invade. Here, we describe a role for Hsp70 in cercarial invasion behavior. To date, only generic stimulation with skin lipid, linoleic acid or L-arginine are known to induce cercarial invasion behavior; thus, we can begin an initial investigation of molecular requirements for host invasion and environment transition for schistosomes and possibly other parasitic organisms.

The role of carrier ligands of platinum(II) anticancer complexes in the protein recognition of Pt-DNA adducts

In order to systematically investigate the influence of carrier ligands on the interaction of Pt-DNA adducts with damage recognition proteins, a series of DNA probes containing 1,2-GG platinum compound crosslinks using cisplatin, oxaliplatin, (S,S-DACH)PtCl2 and (cis-1,4-DACH)PtCl2 (kiteplatin) has been constructed. These complexes share similar DNA binding properties although they exhibit quite different cytotoxicity. It is revealed that HMGB1 (high-mobility group protein B1) was the most commonly found protein that recognizes all Pt(II)-DNA probes and prefers cisplatin-DNA probes more than the others. Interestingly, an important component of the replication protein A complex, RPA2, was found to bind to kiteplatin much more tightly than other proteins. These results may be important for the interpretation of the roles of carrier ligands in platinum(II)-based anticancer complexes.

Laminins and Nidogens in the Pericellular Matrix of Chondrocytes: Their Role in Osteoarthritis and Chondrogenic Differentiation

The aim of this study was to investigate the role of laminins and nidogen-2 in osteoarthritis (OA) and their potential to support chondrogenic differentiation. We applied immunohistochemistry, electron microscopy, siRNA, quantitative RT-PCR, Western blot, and proteome analysis for the investigation of cartilage tissue and isolated chondrocytes in three-dimensional culture obtained from patients with late-stage knee OA and nidogen-2 knockout mice. We demonstrate that subunits of laminins appear in OA cartilage and that nidogen-2-null mice exhibit typical osteoarthritic features. Chondrogenic progenitor cells (CPCs) produced high levels of laminin-α1, laminin-α5, and nidogen-2 in their pericellular matrix, and laminin-α1 enhanced collagen type II and reduced collagen type I expression by cultured CPCs. Nidogen-2 increased SOX9 gene expression. Knockdown of nidogen-2 reduced SOX9 expression, whereas it up-regulated RUNX2 expression. This study reveals that the influence of the pericellular matrix on CPCs is important for the expression of the major regulator transcription factors, SOX9 and RUNX2. Our novel findings that laminins and nidogen-2 drive CPCs toward chondrogenesis may help in the elucidation of new treatment strategies for cartilage tissue regeneration.

TGF-β-Induced Transcription Sustains Amoeboid Melanoma Migration and Dissemination

Cell migration underlies metastatic dissemination of cancer cells, and fast “amoeboid” migration in the invasive fronts of tumors is controlled by high levels of actomyosin contractility. How amoeboid migration is regulated by extracellular signals and sustained over time by transcriptional changes is not fully understood. Transforming growth factor β (TGF-β) is well known to promote epithelial-to-mesenchymal transition (EMT) and contribute to metastasis, but melanocytes are neural crest derivatives that have undergone EMT during embryonic development. Surprisingly, we find that in melanoma, TGF-β promotes amoeboid features such as cell rounding, membrane blebbing, high levels of contractility, and increased invasion. Using genome-wide transcriptomics, we find that amoeboid melanoma cells are enriched in a TGF-β-driven signature. We observe that downstream of TGF-β, SMAD2 and its adaptor CITED1 control amoeboid behavior by regulating the expression of key genes that activate contractile forces. Moreover, CITED1 is highly upregulated during melanoma progression, and its high expression is associated with poor prognosis. CITED1 is coupled to a contractile-rounded, amoeboid phenotype in a panel of 16 melanoma cell lines, in mouse melanoma xenografts, and in 47 human melanoma patients. Its expression is also enriched in the invasive fronts of lesions. Functionally, we show how the TGF-β-SMAD2-CITED1 axis promotes different steps associated with progression: melanoma detachment from keratinocytes, 2D and 3D migration, attachment to endothelial cells, and in vivo lung metastatic initial colonization and outgrowth. We propose a novel mechanism by which TGF-β-induced transcription sustains actomyosin force in melanoma cells and thereby promotes melanoma progression independently of EMT.

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TGF-β-SMAD promotes amoeboid migration in melanoma

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Downstream of TGF-β, the adaptor CITED1 controls actomyosin contractility

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Amoeboid features correlate with CITED1 levels in cell lines, xenografts, and patients

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TGF-β-SMAD-CITED1 transcriptional network controls melanoma metastatic ability

Zeb2: A multifunctional regulator of nervous system development

Zinc finger E-box binding homeobox (Zeb) 2 is a transcription factor, identified due its ability to bind Smad proteins, and consists of multiple functional domains which interact with a variety of transcriptional co-effectors. The complex nature of the Zeb2, both at its genetic and protein levels, underlie its multifunctional properties, with Zeb2 capable of acting individually or as part of a transcriptional complex to repress, and occasionally activate, target gene expression. This review introduces Zeb2 as an essential regulator of nervous system development. Zeb2 is expressed in the nervous system throughout its development, indicating its importance in neurogenic and gliogenic processes. Indeed, mutation of Zeb2 has dramatic neurological consequences both in animal models, and in humans with Mowat-Wilson syndrome, which results from heterozygous ZEB2 mutations. The mechanisms by which Zeb2 regulates the induction of the neuroectoderm (CNS primordium) and the neural crest (PNS primordium) are reviewed herein. We then describe how Zeb2 acts to direct the formation, delamination, migration and specification of neural crest cells. Zeb2 regulation of the development of a number of cerebral regions, including the neocortex and hippocampus, are then described. The diverse molecular mechanisms mediating Zeb2-directed development of various neuronal and glial populations are reviewed. The role of Zeb2 in spinal cord and enteric nervous system development is outlined, while its essential function in CNS myelination is also described. Finally, this review discusses how the neurodevelopmental defects of Zeb2 mutant mice delineate the developmental dysfunctions underpinning the multiple neurological defects observed in Mowat-Wilson syndrome patients.

Expression of the CTCFL Gene during Mouse Embryogenesis Causes Growth Retardation, Postnatal Lethality, and Dysregulation of the Transforming Growth Factor β Pathway

CTCFL, a paralog of CTCF, also known as BORIS (brother of regulator of imprinted sites), is a testis-expressed gene whose function is largely unknown. Its product is a cancer testis antigen (CTA), and it is often expressed in tumor cells and also seen in two benign human vascular malformations, juvenile angiofibromas and infantile hemangiomas. To understand the function of Ctcfl, we created tetracycline-inducible Ctcfl transgenic mice. We show that Ctcfl expression during embryogenesis results in growth retardation, eye malformations, multiorgan pathologies, vascular defects, and neonatal death. This phenotype resembles prior mouse models that perturb the transforming growth factor β (TGFB) pathway. Embryonic stem (ES) cells with the Ctcfl transgene reproduce the phenotype in ES cell-tetraploid chimeras. Transcriptome sequencing of the Ctcfl ES cells revealed 14 genes deregulated by Ctcfl expression. Bioinformatic analysis revealed the TGFB pathway as most affected by embryonic Ctcfl expression. Understanding the consequence of Ctcfl expression in nontesticular cells and elucidating downstream targets of Ctcfl could explain the role of its product as a CTA and its involvement in two, if not more, human vascular malformations.

Arabidopsis proteome responses to the smoke-derived growth regulator karrikin

Karrikins are butenolide plant growth regulators in smoke from burning plant material that have proven ability to promote germination and seedling photomorphogenesis. However, the molecular mechanisms underlying these processes are unclear. Here we provide the first proteome-wide analysis of early responses to karrikin in plants (Arabidopsis seedlings). Image analysis of two-dimensionally separated proteins, Rubisco-depleted proteomes and phosphoproteomes, together with LC-MS profiling, detected >1900 proteins, 113 of which responded to karrikin treatment. All the differentially abundant proteins (except HSP70-3) are novel karrikin-responders, and most are involved in photosynthesis, carbohydrate metabolism, redox homeostasis, transcription control, proteosynthesis, protein transport and processing, or protein degradation. Our data provide functionally complementary information to previous identifications of karrikin-responsive genes and evidence for a novel karrikin signalling pathway originating in chloroplasts. We present an updated model of karrikin signalling that integrates proteomic data and is supported by growth response observations.

BIOLOGICAL SIGNIFICANCE

Karrikin has shown promising potential in agricultural applications, yet this process is poorly understood at the molecular level. To the best of our knowledge, this is the first survey of early global proteomic responses to karrikin in plants (Arabidopsis seedlings). The combination of label-free LC-MS profiling and 2-DE analyses provided highly sensitive snapshots of protein abundance and quantitative information on proteoform-level changes. These results present evidence of proteasome-independent karrikin signalling pathways and provide novel targets for detailed mechanistic studies using, e.g., mutants and transgenic plants.

Loss of CITED1, an MITF regulator, drives a phenotype switch in vitro and can predict clinical outcome in primary melanoma tumours

CITED1 is a non-DNA binding transcriptional co-regulator whose expression can distinguish the ‘proliferative’ from ‘invasive’ signature in the phenotype-switching model of melanoma. We have found that, in addition to other ‘proliferative’ signature genes, CITED1 expression is repressed by TGFβ while the ‘invasive’ signature genes are upregulated. In agreement, CITED1 positively correlates with MITF expression and can discriminate the MITF-high/pigmentation tumour molecular subtype in a large cohort (120) of melanoma cell lines. Interestingly, CITED1 overexpression significantly suppressed MITF promoter activation, mRNA and protein expression levels while MITF was transiently upregulated following siRNA mediated CITED1 silencing. Conversely, MITF siRNA silencing resulted in CITED1 downregulation indicating a reciprocal relationship. Whole genome expression analysis identified a phenotype shift induced by CITED1 silencing and driven mainly by expression of MITF and a cohort of MITF target genes that were significantly altered. Concomitantly, we found changes in the cell-cycle profile that manifest as transient G1 accumulation, increased expression of CDKN1A and a reduction in cell viability. Additionally, we could predict survival outcome by classifying primary melanoma tumours using our in vitro derived ‘CITED1-silenced’ gene expression signature. We hypothesize that CITED1 acts a regulator of MITF, functioning to maintain MITF levels in a range compatible with tumourigenesis.

Protective effects of transforming growth factor β2 in intestinal epithelial cells by regulation of proteins associated with stress and endotoxin responses

Transforming growth factor (TGF)-β2 is an important anti-inflammatory protein in milk and colostrum. TGF-β2 supplementation appears to reduce gut inflammatory diseases in early life, such as necrotizing enterocolitis (NEC) in young mice. However, the molecular mechanisms by which TGF-β2 protects immature intestinal epithelial cells (IECs) remain to be more clearly elucidated before interventions in infants can be considered. Porcine IECs PsIc1 were treated with TGF-β2 and/or lipopolysaccharide (LPS), and changes in the cellular proteome were subsequently analyzed using two-dimensional gel electrophoresis-MS and LC-MS-based proteomics. TGF-β2 alone induced the differential expression of 13 proteins and the majority of the identified proteins were associated with stress responses, TGF-β and Toll-like receptor 4 signaling cascades. In particular, a series of heat shock proteins had similar differential trends as previously shown in the intestine of NEC-resistant preterm pigs and young mice. Furthermore, LC-MS-based proteomics and Western blot analyses revealed 20 differentially expressed proteins following treatment with TGF-β2 in LPS-challenged IECs. Thirteen of these proteins were associated with stress response pathways, among which five proteins were altered by LPS and restored by TGF-β2, whereas six were differentially expressed only by TGF-β2 in LPS-challenged IECs. Based on previously reported biological functions, these patterns indicate the anti-stress and anti-inflammatory effects of TGF-β2 in IECs. We conclude that TGF-β2 of dietary or endogenous origin may regulate the IEC responses against LPS stimuli, thereby supporting cellular homeostasis and innate immunity in response to bacterial colonization, and the first enteral feeding in early life.

What do we know about the cardiac benefits of exercise?

Exercise has long been considered an essential element for sustaining cardiovascular health. A vast literature of clinical studies suggests that exercise serves as an effective intervention for the primary and secondary prevention of cardiovascular disease, although the optimal nature, intensity, and duration of exercise for maximizing these cardiovascular benefits remain unclear. On a molecular level, exercise induces physiologic growth of the heart primarily by driving cardiomyocyte hypertrophy, notably through the interconnected IGF-1-PI3K-AKT1 and C/EBPβ-CITED4 pathways. Here, we explore the range of clinical evidence supporting the cardiovascular benefits of exercise and outline the molecular pathways that play major roles in regulating these protective effects.

Pokemon (FBI-1) interacts with Smad4 to repress TGF-β-induced transcriptional responses

Pokemon, an important proto-oncoprotein, is a transcriptional repressor that belongs to the POK (POZ and Krüppel) family. Smad4, a key component of TGF-β pathway, plays an essential role in TGF-β-induced transcriptional responses. In this study, we show that Pokemon can interact directly with Smad4 both in vitro and in vivo. Overexpression of Pokemon decreases TGF-β-induced transcriptional activities, whereas knockdown of Pokemon increases these activities. Interestingly, Pokemon does not affect activation of Smad2/3, formation of Smads complex, or DNA binding activity of Smad4. TGF-β1 treatment increases the interaction between Pokemon and Smad4, and also enhances the recruitment of Pokemon to Smad4-DNA complex. In addition, we also find that Pokemon recruits HDAC1 to Smad4 complex but decreases the interaction between Smad4 and p300/CBP. Taken together, all these data suggest that Pokemon is a new partner of Smad4 and plays a negative role in TGF-β pathway.

Differential protective effects of extra virgin olive oil and corn oil in liver injury: a proteomic study

Extra virgin olive oil (EVOO) presents benefits against chronic liver injury induced by hepatotoxins such as carbon tetrachloride (CCl4); however, the protective mechanisms remain unclear. In the present study, a two-dimensional gel based proteomic approach was constructed to explore the mechanisms. Rats are injected with CCl4 twice a week for 4 weeks to induce liver fibrosis, and were fed laboratory chow plus 20% (w/w) of either corn oil or EVOO over the entire experimental period. Histological staining, MDA assay and fibrogenesis marker gene analysis illustrate that the CCl4-treated animals fed EVOO have a lower fibrosis and lipid peroxidation level in the liver than the corn oil fed group. The proteomic study indicates that the protein expression of thioredoxin domain-containing protein 12, peroxiredoxin-1, thiosulphate sulphurtransferase, calcium-binding protein 1, Annexin A2 and heat shock cognate 71 kDa protein are higher in livers from EVOO-fed rats with the CCl4 treatment compared with those from rats fed with corn oil, whereas the expression of COQ9, cAMP-dependent protein kinase type I-alpha regulatory subunit, phenylalanine hydroxylase and glycerate kinase are lower. Our findings confirmed the benefits of EVOO against chronic liver injury, which may be attributable to the antioxidant effects, hepatocellular function regulation and hepatic metabolism modification effects of EVOO.

Nuclear translocation of CBP/p300-interacting protein CITED1 induced by parathyroid hormone requires serine phosphorylation at position 79 in its 63-84 domain

The transcriptional cofactor CITED1 inhibits osteoblastic differentiation and blunts the stimulation of osteoblastic differentiation by parathyroid hormone (PTH). In the MC3T3-E1 osteoblastic cell line, we found that CITED1 was located predominantly in the cytoplasm and that hPTH(1-34) increased translocation of CITED1 from the cytoplasm to the nucleus. This response to hPTH(1-34) was not observed when all 9 serine residues within the 63-84 domain of CITED1 were mutated to alanines (CITED1 9S>A) or when a single serine to alanine mutation was made at position 79 (CITED1 S(79)>A). CITED1 containing mutations of these 9 serines to glutamic acid (9S>E) retained the same nuclear translocation response to hPTH(1-34) as the wild type CITED1. ALP activity and formation of mineralized nodules were inhibited in cells transfected with pcDNA3-CFP-CITED1 or with pcDNA3-CFP-CITED1 9S>E with or without hPTH(1-34) treatment (all P<0.05); these changes were not observed using CITED1 9S>A. Cells exposed to intermittent treatment with hPTH(1-34) expressed more ALP2, Runx2 and osteocalcin than vehicle-treated cells. These effects of hPTH(1-34) were inhibited in cells transfected with pcDNA3-CFP-CITED1 or pcDNA3-CFP-CITED1 9S>E, but were slightly enhanced by the alanine mutants. PKC activator (TPA) increased nuclear translocation of CITED1, whereas a PKC inhibitor (Go6983) blunted the effect of hPTH(1-34) on the nuclear translocation of wildtype CITED1 but not of CITED1 S(79)>E. The data indicated that serine phosphorylation at position 79 in the 63-84 domain is associated with PKC activation, and is required for both CITED1 nuclear translocation induced by PTH and the negative effects of CITED1 on osteoblastic differentiation and mineralization.

Evaluation of CITED1, SIX1, and CD56 protein expression for identification of blastemal elements in Wilms tumor

OBJECTIVES

Successful further treatment of Wilms tumors (WTs) after preoperative chemotherapy and surgery depends on correct histopathologic risk stratification, including quantification of remaining blastemal elements. In the present study, we assessed the usefulness of protein markers for the detection of WT blastema.

METHODS

Expression of the candidate blastemal protein markers CITED1, SIX1, and CD56 was evaluated by immunofluorescence regarding sensitivity and specificity for staining blastema in a tissue microarray containing cores from 30 WTs, a small number of rarer pediatric renal neoplasms, and normal postnatal kidney.

RESULTS

CITED1, SIX1, and CD56 were expressed in blastema in 100%, 89%, and 74%, respectively, of the WTs with this component present. However, they were also expressed in 64%, 25%, and 79%, respectively, of epithelial WT elements and 48%, 52%, and 62%, respectively, of stromal WT elements.

CONCLUSIONS

SIX1 showed the highest specificity, CITED1 the highest sensitivity, and CD56 low specificity and sensitivity for detection of postchemotherapy WT blastema. Cytokeratin staining proved to be a useful way to determine rudimentary tubular elements not readily recognized by routine staining.

Analysis of the sperm head protein profiles in fertile men: consistency across time in the levels of expression of heat shock proteins and peroxiredoxins

We investigated the identity and quantitative variations of proteins extracted from human sperm heads using a label-free Gel-MS approach. Sperm samples were obtained from three men with high sperm counts at three different time points. This design allowed us to analyse intra-individual and inter-individual variations of the human sperm head proteome. Each time point was analyzed in triplicate to minimize any background artifactual effects of the methodology on the variation analyses. Intra-individual analysis using the spectral counting method revealed that the expression levels of 90% of the common proteins identified in three samples collected at various time-points, separated by several months, had a coefficient of variation of less than 0.5 for each man. Across individuals, the expression level of more than 80% of the proteins had a CV under 0.7. Interestingly, 83 common proteins were found within the core proteome as defined by the intra- and inter-variation analyses set criteria (CV<0.7). Some of these uniformly expressed proteins were chaperones, peroxiredoxins, isomerases, and cytoskeletal proteins. Although there is a significant level of inter-individual variation in the protein profiles of human sperm heads even in a well-defined group of men with high sperm counts, the consistent expression levels of a wide range of proteins points to their essential role during spermatogenesis.

Cited1 deficiency suppresses intestinal tumorigenesis

Conditional deletion of Apc in the murine intestine alters crypt-villus architecture and function. This process is accompanied by multiple changes in gene expression, including upregulation of Cited1, whose role in colorectal carcinogenesis is unknown. Here we explore the relevance of Cited1 to intestinal tumorigenesis. We crossed Cited1 null mice with Apc(Min/+) and AhCre(+)Apc(fl/fl) mice and determined the impact of Cited1 deficiency on tumour growth/initiation including tumour multiplicity, cell proliferation, apoptosis and the transcriptome. We show that Cited1 is up-regulated in both human and murine tumours, and that constitutive deficiency of Cited1 increases survival in Apc(Min/+) mice from 230.5 to 515 days. However, paradoxically, Cited1 deficiency accentuated nearly all aspects of the immediate phenotype 4 days after conditional deletion of Apc, including an increase in cell death and enhanced perturbation of differentiation, including of the stem cell compartment. Transcriptome analysis revealed multiple pathway changes, including p53, PI3K and Wnt. The activation of Wnt through Cited1 deficiency correlated with increased transcription of β-catenin and increased levels of dephosphorylated β-catenin. Hence, immediately following deletion of Apc, Cited1 normally restrains the Wnt pathway at the level of β-catenin. Thus deficiency of Cited1 leads to hyper-activation of Wnt signaling and an exaggerated Wnt phenotype including elevated cell death. Cited1 deficiency decreases intestinal tumourigenesis in Apc(Min/+) mice and impacts upon a number of oncogenic signaling pathways, including Wnt. This restraint imposed by Cited1 is consistent with a requirement for Cited1 to constrain Wnt activity to a level commensurate with optimal adenoma formation and maintenance, and provides one mechanism for tumour repression in the absence of Cited1.

CITED1 expression in liver development and hepatoblastoma

Hepatoblastoma, the most common pediatric liver cancer, consists of epithelial mixed embryonal/fetal (EMEF) and pure fetal histologic subtypes, with the latter exhibiting a more favorable prognosis. Few embryonal histology markers that yield insight into the biologic basis for this prognostic discrepancy exist. CBP/P-300 interacting transactivator 1 (CITED1), a transcriptional co-activator, is expressed in the self-renewing nephron progenitor population of the developing kidney and broadly in its malignant analog, Wilms tumor (WT). In this current study, CITED1 expression is detected in mouse embryonic liver initially on post-coitum day 10.5 (e10.5), begins to taper by e14.5, and is undetectable in e18.5 and adult livers. CITED1 expression is detected in regenerating murine hepatocytes following liver injury by partial hepatectomy and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Importantly, while CITED1 is undetectable in normal human adult livers, 36 of 41 (87.8%) hepatoblastoma specimens express CITED1, where it is enriched in EMEF specimens compared to specimens of pure fetal histology. CITED1 overexpression in Hep293TT human hepatoblastoma cells induces cellular proliferation and upregulates the Wnt inhibitors Kringle containing transmembrane protein 1 (KREMEN1) and CXXC finger protein 4 (CXXC4). CITED1 mRNA expression correlates with expression of CXXC4 and KREMEN1 in clinical hepatoblastoma specimens. These data show that CITED1 is expressed during a defined time course of liver development and is no longer expressed in the adult liver but is upregulated in regenerating hepatocytes following liver injury. Moreover, as in WT, this embryonic marker is reexpressed in hepatoblastoma and correlates with embryonal histology. These findings identify CITED1 as a novel marker of hepatic progenitor cells that is re-expressed following liver injury and in embryonic liver tumors.

Comprehensive review on the HSC70 functions, interactions with related molecules and involvement in clinical diseases and therapeutic potential

Heat shock cognate protein 70 (HSC70) is a constitutively expressed molecular chaperone which belongs to the heat shock protein 70 (HSP70) family. HSC70 shares some of the structural and functional similarity with HSP70. HSC70 also has different properties compared with HSP70 and other heat shock family members. HSC70 performs its full functions by the cooperation of co-chaperones. It interacts with many other molecules as well and regulates various cellular functions. It is also involved in various diseases and may become a biomarker for diagnosis and potential therapeutic targets for design, discovery, and development of novel drugs to treat various diseases. In this article, we provide a comprehensive review on HSC70 from the literatures including the basic general information such as classification, structure and cellular location, genetics and function, as well as its protein association and interaction with other proteins. In addition, we also discussed the relationship of HSC70 and related clinical diseases such as cancer, cardiovascular, neurological, hepatic and many other diseases and possible therapeutic potential and highlight the progress and prospects of research in this field. Understanding the functions of HSC70 and its interaction with other molecules will help us to reveal other novel properties of this protein. Scientists may be able to utilize this protein as a biomarker and therapeutic target to make significant advancement in scientific research and clinical setting in the future.

Gene expression profile of human thyroid cancer in relation to its mutational status

This review describes the gene expression profile changes associated with the presence of different mutations that contribute to thyroid cell carcinogenesis. The results are discussed in the context of thyroid cancer biology and of the implications for disease prognosis, while the diagnostic aspect has been omitted. For papillary thyroid cancer (PTC), the most characteristic gene expression profile is associated with the presence of BRAF mutation. BRAF-associated PTC differ profoundly from RET/PTC or RAS-associated cancers. Simultaneously, they retain many characteristic gene expression features common for all PTCs, induced by the alternative mutations activating MAPK pathway. Although the difference between papillary and follicular thyroid cancer (FTC) is significant at the gene expression profile level, surprisingly, the RAS-related signature of FTC is not well specified. PAX8/peroxisome proliferator-activated receptor γ (PPARγ) rearrangements, which occur in FTC as an alternative to the RAS mutation, are associated with specific changes in gene expression. Furthermore, the difference between well-differentiated thyroid cancers and poorly differentiated and anaplastic thyroid cancers is mainly a reflection of tumor degree of differentiation and may not be attributed to the presence of characteristic mutations.

Identification of estradiol/ERα-regulated genes in the mouse pituitary

Estrogen acts to prime the pituitary prior to the GnRH-induced LH surge by undiscovered mechanisms. This study aimed to identify the key components that mediate estrogen action in priming the pituitary. RNA extracted from the pituitaries of metestrous (low estrogen) and proestrus (high estrogen) stage mice, as well as from ovariectomized wild-type and estrogen receptor α (ERα) knockout mice treated with 17β-estradiol (E(2)) or vehicle, was used for gene expression microarray. Microarray data were then aggregated, built into a functional electronic database, and used for further characterization of E(2)/ERα-regulated genes. These data were used to compile a list of genes representing diverse biological pathways that are regulated by E(2) via an ERα-mediated pathway in the pituitary. This approach substantiates ERα regulation of membrane potential regulators and intracellular vesicle transporters, among others, but not the basic components of secretory machinery. Subsequent characterization of six selected genes (Cacna1a, Cacna1g, Cited1, Abep1, Opn3, and Kcne2) confirmed not only ERα dependency for their pituitary expression but also the significance of their expression in regulating GnRH-induced LH secretion. In conclusion, findings from this study suggest that estrogen primes the pituitary via ERα by equipping pituitary cells with critical cellular components that potentiate LH release on subsequent GnRH stimulations.

xCITED2 Induces Neural Genes in Animal Cap Explants of Xenopus Embryos

Neural tissue is arisen from presumptive ectoderm via inhibition of bone morphogenetic protein (BMP) signaling during Xenopus early development. Previous studies demonstrate that ectopic expression of dominant negative BMP4 receptor (DNBR) produces neural tissue in animal cap explants (AC) and also increases the expression level of various genes involved in neurogenesis. To investigate detail mechanism of neurogenesis in transcriptional level, we analyzed RNAs increased by DNBR using total RNA sequencing analysis and identified several candidate genes. Among them, xCITED2 (Xenopus CBP/p300-interacting transcription activator) was induced 4.6 fold by DNBR and preferentially expressed in neural tissues at tadpole stage. Ectopic expression of xCITED2 induced anterior neural genes without mesoderm induction and reduced BMP downstream genes, an eye specific marker and posterior neural marker. Taken together, these results suggest that xCITED2 may have a role in the differentiation of anterior neural tissue during Xenopus early development.

Functional characterization of two CITED3 homologs (gcCITED3a and gcCITED3b) in the hypoxia-tolerant grass carp, Ctenopharyngodon idellus

Background

CITED proteins belong to a family of non-DNA-binding transcriptional co-regulators that are characterized by a conserved ED-rich domain at the C-terminus. This family of genes is involved in the regulation of a variety of transcriptional responses through interactions with the CBP/p300 integrators and various transcription factors. In fish, very little is known about the expression and functions of CITEDs.

Results

We have characterized two closely related but distinct CITED3 genes, gcCited3a and gcCited3b, from the hypoxia-tolerant grass carp. The deduced gcCITED3a and gcCITED3b proteins share 72% amino acid identity, and are highly similar to the CITED3 proteins of both chicken and Xenopus. Northern blot analysis indicates that the mRNA expression of gcCited3a and gcCited3b is strongly induced by hypoxia in the kidney and liver, respectively. Luciferase reporter assays demonstrated that both gene promoters are activated by gcHIF-1. Further, ChIP assays comparing normal and hypoxic conditions reveal differential in vivo binding of gcHIF-1 to both gene promoters in kidney and liver tissues. HRE-luciferase reporter assays demonstrated that both gcCITED3a and gcCITED3b proteins inhibit gcHIF-1 transcriptional activity, and GST pull-down assays confirmed that both proteins bind specifically to the CH1 domain of the grass carp p300 protein.

Conclusion

The grass carp gcCITED3a and gcCITED3b genes are differentially expressed and regulated in different fish organs in response to hypoxic stress. This is the first report demonstrating in vivo regulation of two closely-related CITED3 isogenes by HIF-1, as well as CITED3 regulation of HIF-1 transcriptional activity in fish. Overall, our findings suggest that unique molecular mechanisms operate through these two gcCITED3 isoforms that likely play an important regulatory role in the hypoxic response in the grass carp.

Progesterone receptor-induced gene expression in primary mouse granulosa cell cultures

The progesterone receptor (PGR) is induced by luteinizing hormone (LH) in granulosa cells of preovulatory follicles, and the PGR-A isoform is essential for ovulation based on the phenotypes of Pgr isoform-specific knockout mice. Although several genes regulated by PGR-A in vivo have been identified, whether these genes are primary targets of PGR-A or if their expression also depends on other signaling molecules that are induced by the LH surge has not been resolved. Therefore, to identify genes that are either induced or repressed by PGR in the absence of LH-mediated signaling cascades, we infected primary cultures of mouse granulosa cells with either PGR-A or PGR-B adenoviral vectors without or with R-5020 as a PGR ligand. Total RNA was extracted from infected cells at 16 h and analyzed by Affymetrix Mouse 430 2.0 microarrays. PGR-A in the presence or absence of ligand significantly induced approximately 50 genes 2-fold or more (local pooled error test at P <or= 0.01). Fewer and different genes were induced by PGR-B in the absence of ligand. Edn1, Apoa1, and Cited1 were primarily regulated by PGR-A as verified by additional RT-PCR analyses, suppression by the PGR antagonist RU486, and the lack of induction by protein kinase A, protein kinase C, or epidermal growth factor (EGF)-like factors pathways. PGR regulation of these genes was confirmed further by gene expression analyses in hormonally primed Pgr mutant mouse ovaries. Because Edn1, Apoa1, and Cited1 are known to regulate angiogenesis, PGR may affect the neovascularization of follicles that is initiated with ovulation.

Termination of TGF-beta superfamily signaling through SMAD dephosphorylation--a functional genomic view

The transforming growth factor-beta (TGF-beta) and related growth factors activate a broad range of cellular responses in metazoan organisms via autocrine, paracrine, and endocrine modes. They play key roles in the pathogenesis of many diseases especially cancer, fibrotic diseases, autoimmune diseases and cardiovascular diseases. TGF-beta receptor-mediated phosphorylation of R-SMADs represents the most critical step in the TGF-beta signaling pathways that triggers a cascade of intracellular events from SMAD complex assembly in the cytoplasm to transcriptional control in the nucleus. Conversely, dephosphorylation of R-SMADs is a key mechanism for terminating TGF-beta signaling. Our labs have recently taken an integrated approach combining functional genomics, biochemistry and development biology to describe the isolation and functional characterization of protein phosphatase PPM1A in controlling TGF-beta signaling. This article briefly reviews how dynamic phosphorylation and dephosphorylation of SMADs control or fine-tune the signaling strength and duration and ultimately the physiological consequences in TGF-beta signaling.

Identification of the molecular mechanisms for dedifferentiation at the invasion front of colorectal cancer by a gene expression analysis

PURPOSE

The aim of this study is to identify gene expression signatures that accompany dedifferentiation at the cancer invasion front in colorectal cancer.

EXPERIMENTAL DESIGN

Two types of colorectal cancer were selected. Both types were well-differentiated adenocarcinomas at the superficial lesion. One type showed a dedifferentiated phenotype at the invasion front (type A, 13 samples); the other showed almost no dedifferentiated cancer cells at the invasion front (type B, 12 samples). Laser microdissection was combined with a cDNA microarray analysis to investigate the superficial lesions and the invasion front in colorectal cancers.

RESULTS

Eighty-three genes were differentially expressed between types A and B in the superficial lesions, and the samples of superficial lesions were divided correctly into two clusters by these genes. Interestingly, the samples of the invasion front were also divided into the two same clusters by these genes. The text mining method selected 10 genes involved in potential mechanisms causing dedifferentiation of cancer cells at the invasion front. The potential mechanisms include the networks of transforming growth factor-beta, Wnt, and Hedgehog signals. The expression levels of 10 genes were calculated by quantitative reverse transcription-PCR and 8 genes were confirmed to be significantly differentially expressed between two types (P < 0.05). The gene expression profiles of 8 genes divided 12 test cases into two clusters with one misclassification.

CONCLUSIONS

The molecular mechanisms constructed with 8 genes from three networks of transforming growth factor-beta, Wnt, and Hedgehog signals were found to correlate with dedifferentiation at the invasion front of colorectal cancer.

Possible involvement of BRAFV600E in altered gene expression in papillary thyroid cancer

Somatic mutations in BRAF, especially BRAFV600E, are frequently identified in papillary thyroid cancer (PTC) tumors. It has been established that expression levels of numbers of genes are characteristically altered in PTC, however, the link between BRAF mutation and gene expression patterns are still elusive. In the present study, we analyzed relative expression levels of the wild type BRAF and BRAFV600E mRNA by using quantitative PCR (qPCR) and cDNAPCR- RFLP in 19 PTC specimens and adjacent normal thyroid tissues. BRAFV600E mRNA was detected in 17 out of 19 PTC specimens, and the expression levels were valuable among the specimens, suggesting alternative expression of BRAFV600E in each cell and/or alternative population of BRAFV600E-positive clones in the tumor. We then analyzed expression levels of 20 genes by qPCR, and analyzed for possible correlation with expression levels of BRAFV600E mRNA. Expression levels of fibronectin, vimentin and CITED1 (Cbp/p300 interacting protein with glutamic acid and aspartic acid rich carboxyl terminal domain) were positively correlated with those of BRAFV600E, suggesting pathophysiological links between activated BRAF and overexpression of these genes. Among these genes expression of vimentin was decreased by inhibiting BRAF expression in NPA cells that express BRAFV600E by means of siRNA, suggesting activated BRAF positively regulate expression of vimentin. Collectively, our analyses illustrated the possibilities that variable expression of BRAFV600E may modify characters of PTC through its effects on gene expression.