Cell-specific Transcription Factor Research Articles

백선피(白鮮皮) 추출물이 DNCB로 유발된 NC/Nga 생쥐의 아토피 피부염에 미치는 영향

Objectives Dictamni Radicis Cortex extracts (DRC) has been known to suppress allergic reaction, however the cellular target of DRC and its mode of action remain unclear. The purpose of this study is to investigate the effects of Dictamni Radicis Cortex extracts on DNCB induced atopic dermatitis-like skin lesions of NC/Nga mouse. Methods This study was designed to investigate the effects of DRC extract in the DNP-IgE-induced activation of MC/9 murine mast cell lines in vitro and in the DNCB-induced activation of NC/Nga mouse in vivo. For this investigation, We examined IL-4, IL-5, IL-6, IL-13, TNF-<TEX>${\alpha}$</TEX> and GM-CSF mRNA expression by Real-time PCR, IL-13, MIP-<TEX>$1{\alpha}$</TEX> production by ELISA analysis and manifestations of NFAT1, NFAT2, AP-1 and NF-<TEX>${\kappa}B$</TEX> p65 transcription factors by western blotting in vitro. Then, we examined WBC, eosinophil and neutrophil in NC/Nga mouse, IL-5, IL-13 in serum, IFN-<TEX>${\gamma}$</TEX>, IL-4 in the spleenocyte culture supernatant, the absolute cell numbers of <TEX>$CD4^+$</TEX>, <TEX>$CD8^+$</TEX>, <TEX>$^+Gr-1^+CD11b$</TEX>, <TEX>$B220^+CD23^+$</TEX> in the ALN, PBMCs and dorsal skin, IL-5, IL-13 in the dorsal skin by Real-time PCR and the distribution of mast cells by H&E and toluidine blue. Results In vitro the mRNA expression of IL-4, IL-5, IL-6, IL-13, TNF-<TEX>${\alpha}$</TEX>, GM-CSF and IL-13, MIP-<TEX>$1{\alpha}$</TEX> production by ELISA analysis were completely abolished by DRC and the western blot analysis decreased the expression of mast cell-specific transcription factors including NFAT-1, NF-<TEX>${\kappa}B$</TEX> p65. In vivo DRC oral adminstration also decreased the counts of WBC, eosinophils and inflammatory cytokines such as IL-13 and IgE in the serum. DRC oral adminstration elevated IL-4 level in the spleenocyte culture supernatant. DRC oral adminstration decreased total ALN cells, total skin cells, cell numbers of <TEX>$CD4^+$</TEX>, <TEX>$B220^+CD23^+$</TEX> in the ALN, <TEX>$^+Gr-1^+CD11b$</TEX> in the PBMCs and <TEX>$CD4^+$</TEX>, <TEX>$CD8^+$</TEX> in the dorsal skin. The mRNA expression of IL-5, IL-13, thickness of epidermis, inflammation immune cells and mast cells were abolished by DRC in the dorsal skin. Conclusions Histological examination showed that infiltration levels of immune cells in the skin of AD-induced NC/Nga mouse were much improved by DRC oral adminstration. These results, therefore, suggest that DRC can regulate molecular mediators and immune cells that are functionally associated with atopic dermatitis induced in NC/Nga mouse, and may play an important role in recovering AD symptoms.

Alterations of T helper lymphocyte subpopulations in sepsis, severe sepsis, and septic shock: a prospective observational study.

Circulating lymphocyte number was significantly decreased in patients with sepsis. However, it remains unknown which severity phase (sepsis, severe sepsis, and septic shock) does it develop and what happen on each subpopulation. Eight patients with differing severities of sepsis (31 sepses, 33 severe sepses, and 16 septic shocks) were enrolled. Quantitative real-time polymerase chain reaction (RT-PCR) of Th1, Th2, and Th17; regulatory T (Treg) cell-specific transcription factor T-bet; GATA-3; RORgammat (RORγt); forkhead box P3 (FOXP3); and IL-17 mRNA were performed, and the enzyme-linked immunosorbent assay (ELISA) was used to detect serum interferon (IFN)-γ, IL-4, and IL-10. In this study, the Th1, Th2, Treg transcription factors, and related cytokines IFN-γ, IL-4, and IL-10 levels of sepsis and severe sepsis patients in peripheral blood were significantly higher than those of the normal controls. Except for IL-17, the T-bet, GATA-3, and IFN-γ levels of septic shock patients were lower than those of sepsis patients. We also observed that the proportions of Th17/Treg in the sepsis and septic shock groups were inversed. From the above, the inflammatory response especially the adaptive immune response is still activated in sepsis and severe sepsis, but significant immunosuppression was developed in septic shock. In addition, the proportion of Th17/Treg inversed may be associated with the illness aggravation of patients with sepsis.

MiR26a modulates Th17/T reg balance in the EAE model of multiple sclerosis by targeting IL6.

A number of different microRNAs (miRNAs) have been implicated in various autoimmune diseases, including multiple sclerosis (MS). T helper (Th)17 and regulatory T cells (Tregs) have likewise been implicated as key players in MS, and a functional imbalance of these cell types is increasingly recognized as a key etiological factor in the disease. Although specific panels of transcription factors and cytokines are known to regulate the Th17/Treg balance, the role of noncoding RNAs remains poorly understood. The inflammatory cytokine, interleukin (IL)6, appears to play a critical role in both the development of the Th17 response and the inhibition of Treg functions. In this research, an IL6-associated miRNA, miR26a, was identified, and its normally downregulated expression was shown to be highly correlated with disease severity in patients suffering from MS as well as in C57BL/6 mice with experimental autoimmune encephalomyelitis (EAE; a well-established animal model of human MS). Using the EAE model system, in vivo silencing of miR26a was found to result in increased expression of Th17-related cytokines and increased severity of EAE, while overexpression of miR26a was found to result in reduced expression of Th17-related cytokines and a milder form of EAE. By contrast, Treg cell-specific transcription factor, Foxp3, was found to be positively correlated with miR26a expression. Finally, miR26a was found to downregulate Th17 and to upregulate Treg cell function through its targeting of IL6. Taken together, our data indicate an important role for miR26a in maintaining the Th17 and Treg cell balance in MS that involves repression of IL6 expression.

Macrophage-inducible C-type lectin Mincle-expressing dendritic cells contribute to control of splenic Mycobacterium bovis BCG infection in mice.

The macrophage-inducible C-type lectin Mincle has recently been identified to be a pattern recognition receptor sensing mycobacterial infection via recognition of the mycobacterial cell wall component trehalose-6',6-dimycolate (TDM). However, its role in systemic mycobacterial infections has not been examined so far. Mincle-knockout (KO) mice were infected intravenously with Mycobacterium bovis BCG to mimic the systemic spread of mycobacteria under defined experimental conditions. After intravenous infection with M. bovis BCG, Mincle-KO mice responded with significantly higher numbers of mycobacterial CFU in spleen and liver, while reduced granuloma formation was observed only in the spleen. At the same time, reduced Th1 cytokine production and decreased numbers of gamma interferon-producing T cells were observed in the spleens of Mincle-KO mice relative to the numbers in the spleens of wild-type (WT) mice. The effect of adoptive transfer of defined WT leukocyte subsets generated from bone marrow cells of zDC(+/DTR) mice (which bear the human diphtheria toxin receptor [DTR] under the control of the classical dendritic cell-specific zinc finger transcription factor zDC) to specifically deplete Mincle-expressing classical dendritic cells (cDCs) but not macrophages after diphtheria toxin application on the numbers of splenic and hepatic CFU and T cell subsets was then determined. Adoptive transfer experiments revealed that Mincle-expressing splenic cDCs rather than Mincle-expressing macrophages contributed to the reconstitution of attenuated splenic antimycobacterial immune responses in Mincle-KO mice after intravenous challenge with BCG. Collectively, we show that expression of Mincle, particularly by cDCs, contributes to the control of splenic M. bovis BCG infection in mice.

Abstract 484: Identification of FOXM1 as therapeutic target in Philadelphia chromosome-positive acute lymphoblastic leukemia

Abstract Introduction: The BCR-ABL1 tyrosine kinase induces malignant transformation of B cells at the pre-B cell checkpoint and induces Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL). In a genome-wide search, we identified FOXM1 as a transcription factor that is specifically upregulated at the pre-B cell checkpoint. FOXM1 is a forkhead box transcription factor and a key regulator of cell growth by promoting cell cycle progression. Results: We transformed murine pre-B cells with a retroviral BCR-ABL1 expression vector and observed upregulation of Foxm1 protein levels. Consistent with this, FOXM1 protein levels in patient-derived Ph+ ALL samples are ∼10-fold higher than in healthy B cells and B cell precursors (n=5; P=0.01). In a cohort of 83 Ph+ ALL patients, the FOXM1 promoter region was significantly de-methylated compared to normal pre-B cells (n=12; P=2.4x10e-7). In order to evaluate a potential predictive value of FOXM1 expression in ALL cells, we correlated FOXM1 mRNA levels with clinical outcome. High FOXM1 expression correlates with shorter overall survival in patients with ALL (n=12, P=0.05) and was predictive of a higher risk of relapse (n=21; P=7.3x10e-5). To study the functional role of FOXM1 in Ph+ ALL, we developed a genetic model for Foxm1 loss-of-function using Foxm1fl/fl mice. Cre-mediated, inducible deletion of Foxm1 decreases ALL cell viability (n=3; P=0.001) and reduced proliferative capacity (n=3; S-phase Foxm1+/+ 59% vs 42% for Foxm1-/-; P=0.0004). The ability to form colonies in vitro was significantly decreased by deletion of Foxm1 (n=3, P=8.9x10e-6). Injection of 1x10e5 Foxm1+/+ or Foxm1-/- leukemic cells into NOD/SCID mice revealed reduced leukemogenesis in vivo (n=7; P=0.0035). In contrast, normal B cell precursors were unaffected by Foxm1 deletion both, in vitro and in vivo. In addition, Foxm1-deleted ALL cells revealed a strikingly higher sensitivity towards Imatinib in dose-response curves compared to control cells (IC50=420 nM for Foxm1+/+ vs 160 nM for Foxm1-/-). Mechanistically, we found that FOXM1 decreased levels of reactive oxygen species via upregulation of the antioxidant response molecule catalase. As potential therapeutic agents to target FOXM1, we evaluated the effects of a previously described ARF peptide (AA 26-44) and the natural occurring antibiotic Thiostrepton. Both bind and inhibit the function of FOXM1, and induced apoptosis in Ph+ ALL. Patient-derived Ph+ ALL cells were xenografted into NOD/SCID recipients and then treated with Thiostrepton i.v. for 7 consecutive days. Thiostrepton-treatment resulted in significantly prolonged overall survival (29 vs 35 days; n=7; P=0.0014) and reduced leukemia burden as measured by luciferase bioimaging, as compared to vehicle controls. Conclusion: Taken together, our data identify the pre-B cell-specific transcription factor FOXM1 as a novel therapeutic target for the treatment of TKI-resistant Ph+ ALL. Citation Format: Maike V. Buchner, Eugene Park, Lars Klemm, Huimin Geng, Dragana Kopanja, Pradip Raychaudhuri, Markus Müschen. Identification of FOXM1 as therapeutic target in Philadelphia chromosome-positive acute lymphoblastic leukemia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 484. doi:10.1158/1538-7445.AM2014-484

Transcriptional regulation and T cell exhaustion.

This review highlights the control of transcriptional networks, including induction of inhibitory receptors, by T cell-specific transcription factors in exhausted T cells that accumulate in chronic viral infections including HIV. Transcriptional profiling has established distinct molecular phenotypes for exhausted CD4 and CD8 T cells in chronic viral infection models. There exists a subset of transcription factors associated with exhaustion, notably Blimp-1, basic leucine zipper transcription factor, ATF-like and Helios. Epigenetic phenomena are likely important in regulating gene expression networks during exhaustion as illustrated by programmed death 1 promoter methylation patterns. Following chronic viral infections, CD4 and CD8 T cells defined functionally and phenotypically as exhausted have distinct transcriptional profiles. These studies have identified a core set of transcription factors that have been implicated in promoting exhaustion. However, no single factor appears to be an exhaustion determining factor, suggesting that T cell exhaustion reflects a combinatorial mechanism with multiple transcription factors interacting to influence the development of functionally exhausted T cells as well as different T effector populations.

Conversion of adipose-derived stem cells into natural killer-like cells with anti-tumor activities in nude mice.

Efforts to develop peripheral blood-derived nature killer (NK) cells into therapeutic products have been hampered by these cells' low abundance and histoincompatibility. On the other hand, derivation of NK-like cells from more abundant cell sources such as embryonic stem cells (ESCs) and umbilical cord blood (UCB) requires the selection of rare CD34+ cells. Thus, we sought to convert adipose-derived stem cells (ADSCs), which are abundant and natively CD34+, into NK-like cells. When grown in hematopoietic induction medium, ADSCs formed sphere clusters and expressed hematopoietic markers CD34, CD45, and KDR. Further induction in NK cell-specific medium resulted in a population of cells that expressed NK cell marker CD56, and thus termed ADSC-NK. Alternatively, the hematopoietically induced ADSCs were transduced with NK cell-specific transcription factor E4BP4 prior to induction in NK cell-specific medium. This latter population of cells, termed ADSC-NKE, expressed CD56 and additional NK cell markers such as CD16, CD94, CD158, CD314, FasL, and NKp46. ADSC-NKE was as potent as NK leukemia cell NKL in killing breast cancer cell MCF7 and prostate cancer cells DU145, PC3, LnCap, DuPro, C4–2 and CWR22, but exhibited no killing activity toward normal endothelial and smooth muscle cells. In nude mice test ADSC-NKE was able to significantly delay the progression of tumors formed by MCF7 and PC3. When injected into immunocompetent rats, ADSC-NKE was detectable in bone marrow and spleen for at least 5 weeks. Together, these results suggest that ADSCs can be converted into NK-like cells with anti-tumor activities.

Murine gammaherpesvirus 68 reactivation from B cells requires IRF4 but not XBP-1.

Gammaherpesviruses display tropism for B cells and, like all known herpesviruses, exhibit distinct lytic and latent life cycles. One well-established observation among members of the gammaherpesvirus family is the link between viral reactivation from latently infected B cells and plasma cell differentiation. Importantly, a number of studies have identified a potential role for a CREB/ATF family member, X-box binding protein 1 (XBP-1), in trans-activating the immediate early BZLF-1 or BRLF1/gene 50 promoters of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), respectively. XBP-1 is required for the unfolded protein response and has been identified as a critical transcription factor in plasma cells. Here, we demonstrate that XBP-1 is capable of trans-activating the murine gammaherpesvirus 68 (MHV68) RTA promoter in vitro, consistent with previous observations for EBV and KSHV. However, we show that in vivo there does not appear to be a requirement for XBP-1 expression in B cells for virus reactivation. The MHV68 M2 gene product under some experimental conditions plays an important role in virus reactivation from B cells. M2 has been shown to drive B cell differentiation to plasma cells, as well as interleukin-10 (IL-10) production, both of which are dependent on M2 induction of interferon regulatory factor 4 (IRF4) expression. IRF4 is required for plasma cell differentiation, and consistent with a role for plasma cells in MHV68 reactivation from B cells, we show that IRF4 expression in B cells is required for efficient reactivation of MHV68 from splenocytes. Thus, the latter analyses are consistent with previous studies linking plasma cell differentiation to MHV68 reactivation from B cells. The apparent independence of MHV68 reactivation from XBP-1 expression in plasma cells may reflect redundancy among CREB/ATF family members or the involvement of other plasma cell-specific transcription factors. Regardless, these findings underscore the importance of in vivo studies in assessing the relevance of observations made in tissue culture models. All known herpesviruses establish a chronic infection of their respective host, persisting for the life of the individual. A critical feature of these viruses is their ability to reactivate from a quiescent form of infection (latency) and generate progeny virus. In the case of gammaherpesviruses, which are associated with the development of lymphoproliferative disorders, including lymphomas, reactivation from latently infected B lymphocytes occurs upon terminal differentiation of these cells to plasma cells-the cell type that produces antibodies. A number of studies have linked a plasma cell transcription factor, XBP-1, to the induction of gammaherpesvirus reactivation, and we show here that indeed in tissue culture models this cellular transcription factor can trigger expression of the murine gammaherpesvirus gene involved in driving virus reactivation. However, surprisingly, when we examined the role of XBP-1 in the setting of infection of mice-using mice that lack a functional XBP-1 gene in B cells-we failed to observe a role for XBP-1 in virus reactivation. However, we show that another cellular factor essential for plasma cell differentiation, IRF4, is critical for virus reactivation. Thus, these studies point out the importance of studies in animal models to validate findings from studies carried out in cell lines passaged in vitro.

Adipose tissue-derived mesenchymal stem cells in long-term dialysis patients display downregulation of PCAF expression and poor angiogenesis activation.

We previously demonstrated that mesenchymal stem cells (MSCs) differentiate into functional kidney cells capable of urine and erythropoietin production, indicating that they may be used for kidney regeneration. However, the viability of MSCs from dialysis patients may be affected under uremic conditions. In this study, we isolated MSCs from the adipose tissues of end-stage kidney disease (ESKD) patients undergoing long-term dialysis (KD-MSCs; mean: 72.3 months) and from healthy controls (HC-MSCs) to compare their viability. KD-MSCs and HC-MSCs were assessed for their proliferation potential, senescence, and differentiation capacities into adipocytes, osteoblasts, and chondrocytes. Gene expression of stem cell-specific transcription factors was analyzed by PCR array and confirmed by western blot analysis at the protein level. No significant differences of proliferation potential, senescence, or differentiation capacity were observed between KD-MSCs and HC-MSCs. However, gene and protein expression of p300/CBP-associated factor (PCAF) was significantly suppressed in KD-MSCs. Because PCAF is a histone acetyltransferase that mediates regulation of hypoxia-inducible factor-1α (HIF-1α), we examined the hypoxic response in MSCs. HC-MSCs but not KD-MSCs showed upregulation of PCAF protein expression under hypoxia. Similarly, HIF-1α and vascular endothelial growth factor (VEGF) expression did not increase under hypoxia in KD-MSCs but did so in HC-MSCs. Additionally, a directed in vivo angiogenesis assay revealed a decrease in angiogenesis activation of KD-MSCs. In conclusion, long-term uremia leads to persistent and systematic downregulation of PCAF gene and protein expression and poor angiogenesis activation of MSCs from patients with ESKD. Furthermore, PCAF, HIF-1α, and VEGF expression were not upregulated by hypoxic stimulation of KD-MSCs. These results suggest that the hypoxic response may be blunted in MSCs from ESKD patients.

L-Cysteine inhibits root elongation through auxin/PLETHORA and SCR/SHR pathway in Arabidopsis thaliana.

L-Cysteine plays a prominent role in sulfur metabolism of plants. However, its role in root development is largely unknown. Here, we report that L-cysteine reduces primary root growth in a dosage-dependent manner. Elevating cellular L-cysteine level by exposing Arabidopsis thaliana seedlings to high L-cysteine, buthionine sulphoximine, or O-acetylserine leads to altered auxin maximum in root tips, the expression of quiescent center cell marker as well as the decrease of the auxin carriers PIN1, PIN2, PIN3, and PIN7 of primary roots. We also show that high L-cysteine significantly reduces the protein level of two sets of stem cell specific transcription factors PLETHORA1/2 and SCR/SHR. However, L-cysteine does not downregulate the transcript level of PINs, PLTs, or SCR/SHR, suggesting that an uncharacterized post-transcriptional mechanism may regulate the accumulation of PIN, PLT, and SCR/SHR proteins and auxin transport in the root tips. These results suggest that endogenous L-cysteine level acts to maintain root stem cell niche by regulating basal- and auxin-induced expression of PLT1/2 and SCR/SHR. L-Cysteine may serve as a link between sulfate assimilation and auxin in regulating root growth.

GTS-21, an α7-nicotinic acetylcholine receptor agonist, modulates Th1 differentiation in CD4+ T cells from patients with rheumatoid arthritis.

GTS-21 (also known as DMBX-anabaseine), a selective α7 nicotinic acetylcholine receptor (α7nAChR) agonist, has previously been found to inhibit the inflammation associated with rheumatoid arthritis (RA). RA is an autoimmune disease, where an abnormal immune system plays a critical role in the occurrence and development of synovium inflammation and bone damage. However, prior to this study, the immunological mechanism by which GTS-21 protects against RA had not been elucidated. In the present study, the effects of GTS-21 on T helper 1 (Th1) cells, which have an important role in the inflammation associated with RA, were investigated. Peripheral blood mononuclear cells (PBMCs) and cluster of differentiation (CD)4+ T cells were separated from patients with RA, and the effects of GTS-21 on PBMCs stimulated with anti-CD3/-CD28 antibodies and CD4+ T cells were investigated in the context of Th1-cell differentiation. ELISA was used to analyze interferon (IFN)-γ expression and flow cytometric analysis was used to detect the percentage of IFN-γ+ CD3+CD8− T cells. In addition, western blotting was employed to detect the levels of the T-box transcription factor TBX21, which is a Th1 cell-specific transcription factor. The present study showed that GTS-21 reduced IFN-γ production in PBMCs from patients with RA. Under conditions of Th1-cell differentiation, GTS-21 reduced the percentage of IFNγ+CD3+CD8− T cells and IFN-γ production in the culture supernatant and also inhibited the expression of the Th1 cell-specific transcription factor TBX21. The effects of GTS-21 were blocked by the α7nAchR antagonist α-bungarotoxin, which increased the expression of IFN-γ and TBX21. This study demonstrated that GTS-21 is able to inhibit RA Th1-cell differentiation through activation of the α7nAchR.

Progress in early pancreas development and reprogramming of terminally differentiated cells into β cells

Type 1 diabetes mellitus (T1DM) is an autoimmune disease in which the immune system attacks insulin-secreting β cells, thus leading to an absolute deficiency of insulin. Patients must rely on exogenous insulin, which cannot effectively prevent diabetes complications. Generation of insulin-secreting cells by reprogramming of pluripotent stem cells or somatic cells is a potential approach for the treatment of T1DM. These cells can be used for cell therapy and drug screening, and may eventually provide a cure for the disease. Significant progress has been made in generating insulin-secreting cells through the expression of β cell specific transcription factors in stem cells or somatic cells. In this review, we summarize recent research progress in early pancreas development, β cell specific transcription factors and reprogramming of terminally differentiated cells into β cells.

R-Spondin2 Activates Hepatic Stellate Cells and Promotes Liver Fibrosis

The development of liver fibrosis is the fundamental stage toward a number of mortal complications of liver diseases, including cirrhosis and hepatocellular carcinoma. Canonical Wnt pathway is crucial in diverse biological processes and mediates the progression and regression of liver fibrosis. As a potent Wnt pathway agonist, the role of roof plate-specific spondin-2 (R-Spondin2) in the hepatic fibrosis has not been well elucidated. The purpose of this study was to investigate whether R-Spondin2 contributes to hepatic stellate cells (HSCs) activation, the key event in liver fibrogenesis. Human liver tissues, hepatic fibrosis mouse model, and freshly isolated mice HSCs were used. Protein expression and transcriptional level were analyzed by Western-blot assays and real-time PCR, respectively. Exogenous stimulation with recombinant R-Spondin2 and knockdown of R-Spondin2 were performed to investigate functionality. Nuclear β-catenin level and T cell-specific transcription factors activity were analyzed, and HSC proliferation was tested by MTT assay. Overexpression of R-Spondin2 was observed in both human fibrotic liver tissues and hepatic fibrosis mouse model. Exogenous stimulation with R-Spondin2 in the freshly isolated mice HSCs induced a dose-dependent increase in Wnt pathway activities, HSC proliferation, and the expression of α-smooth muscle actin (α-SMA) and Collagen I. Additionally, Wnt pathway activities, HSC proliferation, and the expressions of α-SMA and Collagen I decreased in the R-Spondin2 knockdown HSCs. These findings suggest that R-Spondin2 may promote HSC activation by enhancing the canonical Wnt pathway.

Itm2a, a target gene of GATA-3, plays a minimal role in regulating the development and function of T cells.

The integral membrane protein 2a (Itm2a) is one of the BRICHOS domain-containing proteins and is structurally related to Itm2b and Itm2c. It is expressed preferentially in the T lineage among hematopoietic cells and is induced by MHC-mediated positive selection. However, its transcriptional regulation and function are poorly understood. Here we showed Itm2a to be a target gene of GATA-3, a T cell-specific transcription factor. Deficiency of Itm2a had little impact on the development and function of polyclonal T cells but resulted in a partial defect in the development of thymocytes bearing a MHC class I-restricted TCR, OT-I. In addition, Itm2a-deficient mice displayed an attenuated T helper cell-dependent immune response in vivo. We further demonstrated that Itm2b but not Itm2c was also expressed in T cells, and was induced upon activation, albeit following a kinetic different from that of Itm2a. Thus, functional redundancy between Itm2a and Itm2b may explain the minimal phenotype of Itm2a deficiency.

Cellular reprogramming for pancreatic β‐cell regeneration: clinical potential of small molecule control

Recent scientific breakthroughs in stem cell biology suggest that a sustainable treatment approach to cure diabetes mellitus (DM) can be achieved in the near future. However, the transplantation complexities and the difficulty in obtaining the stem cells from adult cells of pancreas, liver, bone morrow and other cells is a major concern. The epoch-making strategy of transcription-factor based cellular reprogramming suggest that these barriers could be overcome, and it is possible to reprogram any cells into functional β cells. Contemporary biological and analytical techniques help us to predict the key transcription factors needed for β-cell regeneration. These β cell-specific transcription factors could be modulated with diverse reprogramming protocols. Among cellular reprogramming strategies, small molecule approach gets proclaimed to have better clinical prospects because it does not involve genetic manipulation. Several small molecules targeting certain epigenetic enzymes and/or signaling pathways have been successful in helping to induce pancreatic β-cell specification. Recently, a synthetic DNA-based small molecule triggered targeted transcriptional activation of pancreas-related genes to suggest the possibility of achieving desired cellular phenotype in a precise mode. Here, we give a brief overview of treating DM by regenerating pancreatic β-cells from various cell sources. Through a comprehensive overview of the available transcription factors, small molecules and reprogramming strategies available for pancreatic β-cell regeneration, this review compiles the current progress made towards the generation of clinically relevant insulin-producing β-cells.

Excess IL-1 Signaling Enhances the Development of Th17 Cells by Downregulating TGF-β–Induced Foxp3 Expression

IL-1R antagonist-deficient (Il1rn(-/-)) mice develop autoimmune arthritis in which IL-17A plays a crucial role. Although many studies have shown that Th17 cell differentiation is dependent on TGF-β and IL-6, we found that Th17 cells developed normally in Il1rn(-/-)Il6(-/-) mice in vivo. Then, we analyzed the mechanisms of Th17 cell differentiation in Il1rn(-/-)Il6(-/-) mice. We found that IL-21 production was increased in the lymph nodes of Il1rn(-/-) mice, naive Il6(-/-) CD4(+) T cells differentiated into Th17 cells when cultured with TGF-β and IL-21, and the differentiation was greatly enhanced when IL-1 was added to the culture. Th17 cell differentiation was not induced by either TGF-β or IL-1 alone or in combination. IL-21 induced IL-1R expression in naive CD4(+) T cells, and IL-1 inhibited TGF-β-induced Foxp3 expression, resulting in the promotion of Th17 cell differentiation. Furthermore, IL-1 augmented the expression of Th17 cell-specific transcription factors such as Nfkbiz and Batf. These results indicate that excess IL-1 signaling can overcome the requirement of IL-6 in the differentiation of Th17 cells by suppressing Foxp3 expression and inducing Th17 cell-specific transcription factors.

RNA Polymerase III Transcriptomes in Human Embryonic Stem Cells and Induced Pluripotent Stem Cells, and Relationships with Pluripotency Transcription Factors

Recent genomic approaches have revealed that the repertoire of RNA Pol III-transcribed genes varies in different human cell types, and that this variation is likely determined by a combination of the chromatin landscape, cell-specific DNA-binding transcription factors, and collaboration with RNA Pol II. Although much is known about this regulation in differentiated human cells, there is presently little understanding of this aspect of the Pol III system in human ES cells. Here, we determine the occupancy profiles of Pol III components in human H1 ES cells, and also induced pluripotent cells, and compare to known profiles of chromatin, transcription factors, and RNA expression. We find a relatively large fraction of the Pol III repertoire occupied in human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs). In ES cells we find clear correlations between Pol III occupancy and active chromatin. Interestingly, we find a highly significant fraction of Pol III-occupied genes with adjacent binding events by pluripotency factors in ES cells, especially NANOG. Notably, in human ES cells we find H3K27me3 adjacent to but not overlapping many active Pol III loci. We observe in all such cases, a peak of H3K4me3 and/or RNA Pol II, between the H3K27me3 and Pol III binding peaks, suggesting that H3K4me3 and Pol II activity may “insulate” Pol III from neighboring repressive H3K27me3. Further, we find iPSCs have a larger Pol III repertoire than their precursors. Finally, the active Pol III genome in iPSCs is not completely reprogrammed to a hESC like state and partially retains the transcriptional repertoire of the precursor. Together, our correlative results are consistent with Pol III binding and activity in human ES cells being enabled by active/permissive chromatin that is shaped in part by the pluripotency network of transcription factors and RNA Pol II activity.

Expression of miR-155 in peripheral blood and skin lesions from as well as its relationship with Th17 cells in patients with atopic dermatitis

Objective To detect the expressions of miR-155,T helper type 17 (Thl7) cells,and Th17 cellspecific transcription factor RORγt and effector cytokine interleukin (IL)-17 in peripheral blood and skin lesions from,and to evaluate their relationship in,patients with atopic dermatitis (AD).Methods Peripheral blood was obtained from 37 patients with AD and 33 age-and sex-matched healthy controls,and biopsy specimens from the lesional and perilesional skin of five patients with severe AD as well as from the normal skin of five healthy human controls.Real-time fluorescence-based reverse transcription (RT)-PCR was employed to measure the mRNA expression levels of miR-155,RORγt and IL-17 in peripheral blood mononuclear cells (PBMCs) and skin specimens,flow cytometry to detect the percentage of Th17 cells in PBMCs,enzyme-linked immunosorbent assay (ELISA) to determine the plasma concentration of IL-17.Statistical analysis was done using independent sample's t test,one-way analysis of variance followed by the least significant difference test,and linear correlation analysis.Results Compared with the healthy controls,the patients with AD showed a significant increase in Th17 cell percentage (1.78％ ± 0.52％ vs.0.47％ ± 0.15％,P＜ 0.01),mRNA expression levels of miR-155 (5.78 ± 1.78 vs.1.82 ± 0.46,P＜ 0.01),RORγt (6.08 ± 1.04 vs.1.64 ± 0.52,P＜ 0.01) and IL-17 (7.09 ± 1.75 vs.1.71 ± 0.46,P＜ 0.01),as well as in the plasma concentration of IL-17 ((2.51 ± 6.15) pg/ml vs.(11.80 ± 2.24) pg/ml,P＜ 0.01).There was a sequential decrease in the expression levels of miR-155,RORγt and IL-17 mRNA from lesional skin,perilesional skin to normal skin (F =41.803,17.040 and 37.064 respectively,all P ＜ 0.01).The miR-155 mRNA expression level in PBMCs was positively correlated with the SCORing Atopic Dermatitis (SCORAD) index,Th17 cell percentage,RORγt and IL-17 mRNA expression levels as well as IL-17 plasma concentration (r =0.405,0.426,0.402,0.410 and 0.408 respectively,all P ＜ 0.05).Similarly,the miR-155 expression level was positively correlated with RORγt and IL-17 mRNA expression levels in lesional and paralesional specimens (r =0.428 and 0.435 respectively,both P ＜ 0.05).Conclusion The up-regulated expression of miR-155,Th17 cells and their effector cytokine IL-17 may be associated with the development of AD. Key words: Dermatitis, atopic; miR-155; Th17 cells

Repositioning monocyte TFRN into fibroblasts.

Repositioning of cell-specific Transcription Factor Regulatory Networks (TFRNs) into another cell type is a pragmatic approach to elicit desired functions in impaired cells and also to investigate transcription regulations underlying cellular functions. However, a systematic method to identify a set of transcription factors (TFs) which can efficiently promote TFRN in a foreign cell type is lacking. Here, we demonstrate a perturbation-matrix method for the identification and repositioning of monocyte TFRNs in dermal fibroblasts.

Integrin α6β4 Identifies Human Distal Lung Epithelial Progenitor Cells with Potential as a Cell-Based Therapy for Cystic Fibrosis Lung Disease

To develop stem/progenitor cell-based therapy for cystic fibrosis (CF) lung disease, it is first necessary to identify markers of human lung epithelial progenitor/stem cells and to better understand the potential for differentiation into distinct lineages. Here we investigated integrin α6β4 as an epithelial progenitor cell marker in the human distal lung. We identified a subpopulation of α6β4+ cells that localized in distal small airways and alveolar walls and were devoid of pro-surfactant protein C expression. The α6β4+ epithelial cells demonstrated key properties of stem cells ex vivo as compared to α6β4- epithelial cells, including higher colony forming efficiency, expression of stem cell-specific transcription factor Nanog, and the potential to differentiate into multiple distinct lineages including basal and Clara cells. Co-culture of α6β4+ epithelial cells with endothelial cells enhanced proliferation. We identified a subset of adeno-associated virus (AAVs) serotypes, AAV2 and AAV8, capable of transducing α6β4+ cells. In addition, reconstitution of bronchi epithelial cells from CF patients with only 5% normal α6β4+ epithelial cells significantly rescued defects in Cl- transport. Therefore, targeting the α6β4+ epithelial population via either gene delivery or progenitor cell-based reconstitution represents a potential new strategy to treat CF lung disease.