Functional analysis of Tcl1 using Tcl1-deficient mouse embryonic stem cells

B-1 derived anti-Thy-1 B cells in old aged mice develop lymphoma/leukemia with high expression of CD11b and Hamp2 that different from TCL1 transgenic mice

Human old aged unmutated chronic lymphocytic leukemia U-CLL are the TCL1+ZAP70+CD5+ B cells. Since CD5 makes the BCR signaling tolerance, ZAP70 increased in U-CLL not only TCL1+ alone. In mice, TCL1 (TCL1A) is the negative from neonate to old aged, as TC-. VH8-12/Vk21-5 is the anti-thymocyte/Thy-1 autoreactive ATA B cell. When ATA μκTg generation in mice, ATA B cells are the neonate generated CD5+ B cells in B-1, and in the middle age, CD5+ can be down or continuously CD5+, then, old aged CLL/lymphoma generation with increased CD11b in TC-ZAP70-CD5- or TC-ZAP70+CD5+. In this old aged TC-ATA B microarray analysis showed most similar to human CLL and U-CLL, and TC-ZAP70+CD5+ showed certain higher present as U-CLL. Original neonate ATA B cells showed with several genes down or further increase in old aged tumor, and old aged T-bet+CD11c+, CTNNB1hi, HMGBhi, CXCR4hi, DPP4hi and decreased miR181b. These old aged increased genes and down miR181b are similar to human CLL. Also, in old age ATA B cell tumor, high CD38++CD44++, increased Ki67+ AID+, and decreased CD180- miR15Olow are similar to U-CLL. In this old aged ATA B, increased TLR7,9 and Wnt10b. TC+Tg generated with ATAμκTg mice occurred middle age tumor as TC+ZAP70-CD5+ or TC+ZAP70+CD5+, with high NF-kB1, TLR4,6 and Wnt5b,6 without increased CD11b. Since neonatal state to age with TC+Tg continuously, middle age CLL/lymphoma generation is not similar to old aged generated, however, some increased in TC+ZAP70+ are similar to the old age TC- ATA B tumor. Then, TC- ATA B old age tumor showed some difference to human CLL. ATA B cells showed CD11b+CD22++, CD24 down, and hepcidin Hamp2++ with iron down. This mouse V8-12 similar to human V2-5, and V2-5 showed several cancers with macrophages/neutrophils generated hepcidin+ ironlow or some showed hepcidin- iron+ with tumor, and mouse V8-12 with different Vk19-17 generate MZ B cells strongly increased macrophage++ in old aged and generated intestine/colon tumor. Conclusion, neonate generated TC-ATA B1 cells in old aged tumor generation are CD11b+ in the leukemia CLL together with lymphoma cancer with hepcidin-related Hamp2++ in B-1 cell generation to control iron.

Zfp296 knockout enhances chromatin accessibility and induces a unique state of pluripotency in embryonic stem cells

The Zfp296 gene encodes a zinc finger-type protein. Its expression is high in mouse embryonic stem cells (ESCs) but rapidly decreases following differentiation. Zfp296-knockout (KO) ESCs grew as flat colonies, which were reverted to rounded colonies by exogenous expression of Zfp296. KO ESCs could not form teratomas when transplanted into mice but could efficiently contribute to germline-competent chimeric mice following blastocyst injection. Transcriptome analysis revealed that Zfp296 deficiency up- and down-regulates a distinct group of genes, among which Dppa3, Otx2, and Pou3f1 were markedly downregulated. Chromatin immunoprecipitation sequencing demonstrated that ZFP296 binding is predominantly seen in the vicinity of the transcription start sites (TSSs) of a number of genes, and ZFP296 was suggested to negatively regulate transcription. Consistently, chromatin accessibility assay clearly showed that ZFP296 binding reduces the accessibility of the TSS regions of target genes. Zfp296-KO ESCs showed increased histone H3K9 di- and trimethylation. Co-immunoprecipitation analyses revealed interaction of ZFP296 with G9a and GLP. These results show that ZFP296 plays essential roles in maintaining the global epigenetic state of ESCs through multiple mechanisms including activation of Dppa3, attenuation of chromatin accessibility, and repression of H3K9 methylation, but that Zfp296-KO ESCs retain a unique state of pluripotency while lacking the teratoma-forming ability.

Single paternal dexamethasone challenge programs offspring metabolism and reveals multiple candidates in RNA-mediated inheritance

Single traumatic events that elicit an exaggerated stress response can lead to the development of neuropsychiatric conditions. Rodent studies suggested germline RNA as a mediator of effects of chronic environmental exposures to the progeny. The effects of an acute paternal stress exposure on the germline and their potential consequences on offspring remain to be seen. We find that acute administration of an agonist for the stress-sensitive Glucocorticoid receptor, using the common corticosteroid dexamethasone, affects the RNA payload of mature sperm as soon as 3 hr after exposure. It further impacts early embryonic transcriptional trajectories, as determined by single-embryo sequencing, and metabolism in the offspring. We show persistent regulation of tRNA fragments in sperm and descendant 2-cell embryos, suggesting transmission from sperm to embryo. Lastly, we unravel environmentally induced alterations in sperm circRNAs and their targets in the early embryo, highlighting this class as an additional candidate in RNA-mediated inheritance of disease risk.

T Cell Leukemia/Lymphoma 1A is essential for mouse epidermal keratinocytes proliferation promoted by insulin-like growth factor 1

T Cell Leukemia/Lymphoma 1A is expressed during B-cell differentiation and, when over-expressed, acts as an oncogene in mouse (Tcl1a) and human (TCL1A) B-cell chronic lymphocytic leukemia (B-CLL) and T-cell prolymphocytic leukemia (T-PLL). Furthermore, in the murine system Tcl1a is expressed in the ovary, testis and in pre-implantation embryos, where it plays an important role in blastomere proliferation and in embryonic stem cell (ESC) proliferation and self-renewal. We have also observed that Tcl1-/- adult mice exhibit alopecia and deep ulcerations. This finding has led us to investigate the role of TCL1 in mouse skin and hair follicles. We have found that TCL1 is expressed in the proliferative structure (i.e. the secondary hair germ) and in the stem cell niche (i.e. the bulge) of the hair follicle during regeneration phase and it is constitutively expressed in the basal layer of epidermis where it is required for the correct proliferative–differentiation program of the keratinocytes (KCs). Taking advantage of the murine models we have generated, including the Tcl1-/- and the K14-TCL1 transgenic mouse, we have analysed the function of TCL1 in mouse KCs and the molecular pathways involved. We provide evidence that in the epidermal compartment TCL1 has a role in the regulation of KC proliferation, differentiation, and apoptosis. In particular, the colony-forming efficiency (CFE) and the insulin-like growth factor 1 (IGF1)-induced proliferation are dramatically impaired, while apoptosis is increased, in KCs from Tcl1-/- mice when compared to WT. Moreover, the expression of differentiation markers such as cytokeratin 6 (KRT6), filaggrin (FLG) and involucrin (IVL) are profoundly altered in mutant mice (Tcl1-/-). Importantly, by over-expressing TCL1A in basal KCs of the K14-TCL1 transgenic mouse model, we observed a significant rescue of cell proliferation, differentiation and apoptosis of the mutant phenotype. Finally, we found TCL1 to act, at least in part, via increasing phospho-ERK1/2 and decreasing phospho-P38 MAPK. Hence, our data demonstrate that regulated levels of Tcl1a are necessary for the correct proliferation and differentiation of the interfollicular KCs.

Overlapping functions of Krüppel-like factor family members: targeting multiple transcription factors to maintain the naïve pluripotency of mouse embryonic stem cells

Krüppel-like factors (Klfs) have a pivotal role in maintaining self-renewal of mouse embryonic stem cells (mESCs). The functions of three Klf family members (Klf2, Klf4 and Klf5) have been identified, and are suggested to largely overlap. For further dissection of their functions, we applied an inducible knockout system for these Klf family members and assessed the effects of combinatorial loss of function. As a result, we confirmed that any one of Klf2, Klf4 and Klf5 was sufficient to support self-renewal, whereas the removal of all three compromised it. The activity of any single transcription factor, except for a Klf family member, was not sufficient to restore self-renewal of triple-knockout mESCs. However, some particular combinations of transcription factors were capable of the restoration. The triple-knockout mESCs were successfully captured at primed state. These data indicate that the pivotal function of a Klf family member is transduced into the activation of multiple transcription factors in a naïve-state-specific manner.

A Role for KLF4 in Promoting the Metabolic Shift via TCL1 during Induced Pluripotent Stem Cell Generation

Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is accompanied by morphological, functional, and metabolic alterations before acquisition of full pluripotency. Although the genome-wide effects of the reprogramming factors on gene expression are well documented, precise mechanisms by which gene expression changes evoke phenotypic responses remain to be determined. We used a Sendai virus-based system that permits reprogramming to progress in a strictly KLF4-dependent manner to screen for KLF4 target genes that are critical for the progression of reprogramming. The screening identified Tcl1 as a critical target gene that directs the metabolic shift from oxidative phosphorylation to glycolysis. KLF4-induced TCL1 employs a two-pronged mechanism, whereby TCL1 activates AKT to enhance glycolysis and counteracts PnPase to diminish oxidative phosphorylation. These regulatory mechanisms described here highlight a central role for a reprogramming factor in orchestrating the metabolic shift toward the acquisition of pluripotency during iPSC generation.

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KLF4 upregulates Tcl1 expression by directly binding to its enhancer and promoter

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TCL1 enhances glycolysis by activating AKT during reprogramming

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TCL1 reduces oxidative phosphorylation by counteracting PnPase during reprogramming

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TCL1 promotes the metabolic shift to facilitate reprogramming

T-cell leukemia/lymphoma-1A predicts the clinical outcome for patients with stage II/III colorectal cancer

T-cell leukemia/lymphoma-1A (TCL1A) as a stem cell marker is abundantly expressed in embryonic stem cells and has been identified as an oncogene in various hematological malignancies such as chronic lymphocytic leukemia and B-cell lymphoma. However, with regard to its role in solid tumors, few studies are available and less are for colorectal cancer (CRC). In this study, we aim to investigate the expression and clinical significance of TCL1A in a cohort of 278 stage II/III CRC patients. As a result, we find TCL1A expression is higher in CRC tissues than that in adjacent normal tissues, and significantly correlated with tumor differentiation, TNM stage and Ki-67 positive rate. The prognostic analysis suggests that TCL1A expression is an independent factor affecting CRC-specific and disease-free survival of these patients. Furthermore, we find stage II/III patients with high TCL1A expression have a significantly higher rate of postoperative local recurrence and metastasis than those with low TCL1A expression. Finally, through subgroup analysis, we find TCL1A expression can stratify the outcome of stage II/III patients who received standard adjuvant chemotherapy. Taken together, our findings suggest TCL1A is not only a useful biomarker for prognostic evaluation in stage II/III CRC patients, but also a promising therapeutic target for improving their clinical outcome.

Key Molecular Drivers of Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is an adult neoplastic disease of B cells characterized by variable clinical outcomes. Although some patients have an aggressive form of the disease and often encounter treatment failure and short survival, others have more stable disease with long-term survival and little or no need for theraphy. In the past decade, significant advances have been made in our understanding of the molecular drivers that affect the natural pathology of CLL. The present review describes what is known about these key molecules in the context of their role in tumor pathogenicity, prognosis, and therapy.

Continual removal of H3K9 promoter methylation by Jmjd2 demethylases is vital for ESC self-renewal and early development

Chromatin-associated proteins are essential for the specification and maintenance of cell identity. They exert these functions through modulating and maintaining transcriptional patterns. To elucidate the functions of the Jmjd2 family of H3K9/H3K36 histone demethylases, we generated conditional Jmjd2a/Kdm4a, Jmjd2b/Kdm4b and Jmjd2c/Kdm4c/Gasc1 single, double and triple knockout mouse embryonic stem cells (ESCs). We report that while individual Jmjd2 family members are dispensable for ESC maintenance and embryogenesis, combined deficiency for specifically Jmjd2a and Jmjd2c leads to early embryonic lethality and impaired ESC self-renewal, with spontaneous differentiation towards primitive endoderm under permissive culture conditions. We further show that Jmjd2a and Jmjd2c both localize to H3K4me3-positive promoters, where they have widespread and redundant roles in preventing accumulation of H3K9me3 and H3K36me3. Jmjd2 catalytic activity is required for ESC maintenance, and increased H3K9me3 levels in knockout ESCs compromise the expression of several Jmjd2a/c targets, including genes that are important for ESC self-renewal. Thus, continual removal of H3K9 promoter methylation by Jmjd2 demethylases represents a novel mechanism ensuring transcriptional competence and stability of the pluripotent cell identity.

TCL1 transgenic mouse model as a tool for the study of therapeutic targets and microenvironment in human B-cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy with a mature phenotype. In spite of its relatively indolent nature, no radical cure is as yet available. CLL is not associated with either a unique cytogenetic or a molecular defect, which might have been a potential therapeutic target. Instead, several factors are involved in disease development, such as environmental signals which interact with genetic abnormalities to promote survival, proliferation and an immune surveillance escape. Among these, PI3-Kinase signal pathway alterations are nowadays considered to be clearly important. The TCL1 gene, an AKT co-activator, is the cause of a mature T-cell leukemia, as well as being highly expressed in all B-CLL. A TCL1 transgenic mouse which reproduces leukemia with a distinct immunophenotype and similar to the course of the human B-CLL was developed several years ago and is widely used by many groups. This is a review of the CLL biology arising from work of many independent investigators who have used TCL1 transgenic mouse model focusing on pathogenetic, microenviroment and therapeutic targets.

An HDAC2-TET1 switch at distinct chromatin regions significantly promotes the maturation of pre-iPS to iPS cells

The maturation of induced pluripotent stem cells (iPS) is one of the limiting steps of somatic cell reprogramming, but the underlying mechanism is largely unknown. Here, we reported that knockdown of histone deacetylase 2 (HDAC2) specifically promoted the maturation of iPS cells. Further studies showed that HDAC2 knockdown significantly increased histone acetylation, facilitated TET1 binding and DNA demethylation at the promoters of iPS cell maturation-related genes during the transition of pre-iPS cells to a fully reprogrammed state. We also found that HDAC2 competed with TET1 in the binding of the RbAp46 protein at the promoters of maturation genes and knockdown of TET1 markedly prevented the activation of these genes. Collectively, our data not only demonstrated a novel intrinsic mechanism that the HDAC2-TET1 switch critically regulates iPS cell maturation, but also revealed an underlying mechanism of the interplay between histone acetylation and DNA demethylation in gene regulation.