Factor Of T-cells Research Articles

Pharmacological mechanism of Sishen Wan® attenuated experimental chronic colitis by inhibiting wnt/β-catenin pathway

Ethnopharmacological relevanceSishen Wan (SSW) is a commercial and frequently used Chinese patent medicine listed in the Chinese Pharmacopeia, which is usually used to treat chronic colitis. Aim of the studyWe explored the pharmacological mechanism of Sishen Wan attenuated experimental chronic colitis by inhibiting Wnt/β-catenin pathway. Materials and methodsExperimental chronic colitis was induced by trinitrobenzene sulfonic acid (TNBS). The therapeutic effect of SSW were analyzed by index of colonic weight, colonic length, pathological score. Cytokines expression were analyzed by ELISA, while the apoptosis level was checked by TUNEL staining. These proteins of Wnt/β-catenin signaling pathway was analyzed by Western blot assay. ResultsRats with TNBS-induced chronic colitis were treated by SSW for 10 days. The efficacy of SSW was demonstrated by improved macroscopic and microscopic colonic damage. SSW increased the level of ATP in colonic mucosa, while SSW inhibited β-catenin, ubiquitination of Nemo-like-kinase-associated ring finger protein and T-cell factor, and expression of Wnt/β-catenin downstream proteins (including c-Myc, cyclo-oxygenase-2, cyclin D1, survivin, signal transducer and activator of transcription 3 and zipper-interacting protein kinase), and improved lymphoid enhancer factor ubiquitination and β-TrCP activity, followed by excessive apoptosis of colonic epithelial cells. ConclusionsSSW effectively attenuated experimental chronic colitis induced by TNBS, which was realized by inhibition of the Wnt/β-catenin signaling pathway.

Shikonin inhibits triple-negative breast cancer-cell metastasis by reversing the epithelial-to-mesenchymal transition via glycogen synthase kinase 3β-regulated suppression of β-catenin signaling

Triple-negative breast cancer (TNBC) is characterized by elevated metastasis, low survival, and poor response to therapy. Although many specific and effective agents for treating TNBC have been investigated, promising therapeutic options remain elusive. Here, we screened the inhibitory activities of three main components of Lithospermum erythrorhizon Sieb. et Zucc (shikonin, acetylshikonin, and β,β-dimethylacrylshikonin) on TNBC cells. The results revealed that shikonin potently decreased the viabilities of TNBC MDA-MB-231 and 4T1 cells but showed less cytotoxicity to normal mammary epithelial MCF-12A cells. Additionally, shikonin reversed the epithelial-to-mesenchymal transition (EMT) in MDA-MB-231 and 4T1 cells. Shikonin depressed cell migration and invasion, upregulated E-cadherin levels, downregulated N-cadherin, vimentin, and Snail levels, and reorganized the cytoskeletal proteins F-actin and vimentin. Shikonin reversed EMT by inhibiting activation of β-catenin signaling through attenuating β-catenin expression, nuclear accumulation, binding to T-cell factor consensus oligos, and transcription of its targeted EMT-related genes. Moreover, shikonin upregulated glycogen synthase kinase 3β (GSK-3β) levels, leading to enhanced phosphorylation and decreased levels of β-catenin. Furthermore, shikonin administration significantly inhibited lung metastasis of MDA-MB-231 cells in NOD/SCID mice accompanied by low systemic toxicity. Histological analysis confirmed that shikonin elevated levels of E-cadherin, phosphorylated β-catenin, and GSK-3β, and decreased levels of vimentin and β-catenin in pulmonary metastatic foci. These results indicated that shikonin potently inhibits TNBC metastasis by targeting the EMT via GSK-3β-regulated suppression of β-catenin signaling, which highlights the importance of shikonin as a potential candidate for novel anticancer therapeutics against TNBC.

FRI-373-Mismatch in C-locus Eplets between donor and recipient as independent factor of acute T-cell mediated rejection in liver transplantation

FRI-373-Mismatch in C-locus Eplets between donor and recipient as independent factor of acute T-cell mediated rejection in liver transplantation

Wnt/β-Catenin Pathway Is Involved in Cadmium-Induced Inhibition of Osteoblast Differentiation of Bone Marrow Mesenchymal Stem Cells.

Cadmium is a common environmental pollutant that causes bone damage. However, the effects of cadmium on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) and its mechanism of action in this process are unclear. Here, we determined the effects of cadmium chloride (CdCl2) on the osteogenic differentiation of BMMSCs and the potential mechanism involved in this process. As determined in the present investigation, CdCl2, in a concentration-dependent manner, affected the viability of BMMSCs and their cytoskeletons. Exposure to 0.1 or 0.2 µM CdCl2 inhibited osteogenic differentiation of BMMSCs, which was reflected in the down-regulation of osteoblast-related genes (ALP, OCN, Runx2, OSX, and OPN); in suppression of the protein expression of alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2); and in decreased ALP activity and capacity for mineralization. Moreover, mRNA microarray was performed to determine the roles of these factors in BMMSCs treated with CdCl2 in comparison to control BMMSCs. As determined with the microarrays, the Wingless-type (Wnt), mothers against decapentaplegic and the C. elegans gene Sam (SMAD), and Janus kinase-Signal Transducers and Activators of Transcription (JAK-STAT) signaling pathways were involved in the effects caused by CdCl2. Moreover, during differentiation, the protein levels of Wnt3a, β-catenin, lymphoid enhancer factor 1 (LEF1), and T-cell factor 1 (TCF1) were reduced by CdCl2. The current research shows that CdCl2 suppresses the osteogenesis of BMMSCs via inhibiting the Wnt/β-catenin pathway. The results establish a previously unknown mechanism for bone injury induced by CdCl2.

WNT3a and WNT5a Transported by Exosomes Activate WNT Signaling Pathways in Human Cardiac Fibroblasts.

WNT signaling plays an important role in fibrotic processes in the heart. Recently, exosomes have been proposed as novel extracellular transporters for WNT proteins. In this study, we analyzed whether WNT3a and WNT5a carried by exosomes could activate downstream molecular pathways in human cardiac fibroblasts. Exosomes were isolated from conditioned medium of control, WNT3a- and WNT5a-producing L cells by differential ultracentrifugations. Obtained exosomes showed size ranging between 20–150 nm and expressed exosomal markers ALG-2-interacting protein X (ALIX) and CD63. Treatment with WNT3a-rich exosomes inhibited activity of glycogen synthase kinase 3β (GSK3β), induced nuclear translocation of β-catenin, and activated T-cell factor (TCF)/lymphoid enhancer factor (LEF) transcription factors as well as expression of WNT/β-catenin responsive genes in cardiac fibroblasts, but did not coactivate extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and activator protein 1 (AP-1) signaling pathways. In contrast, exosomes produced by WNT5a-producing L cells failed to activate β-catenin-dependent response, but successfully triggered phosphorylation of ERK1/2 and JNK and stimulated IL-6 production. In conclusion, exosomes containing WNT proteins can functionally contribute to cardiac fibrosis by activating profibrotic WNT pathways on cardiac fibroblasts and may represent a novel mechanism of spreading profibrotic signals in the heart.

β-Catenin and Yes-Associated Protein 1 Cooperate in Hepatoblastoma Pathogenesis

Hepatoblastoma (HB), the most common pediatric primary liver neoplasm, shows nuclear localization of β-catenin and yes-associated protein 1 (YAP1) in almost 80% of the cases. Co-expression of constitutively active S127A-YAP1 and ΔN90 deletion-mutant β-catenin (YAP1-ΔN90-β-catenin) causes HB in mice. Because heterogeneity in downstream signaling is being identified owing to mutational differences even in the β-catenin gene alone, we investigated if co-expression of point mutants of β-catenin (S33Y or S45Y) with S127A-YAP1 led to similar tumors as YAP1-ΔN90-β-catenin. Co-expression of S33Y/S45Y-β-catenin and S127A-YAP1 led to activation of Yap and Wnt signaling and development of HB, with 100% mortality by 13 to 14 weeks. Co-expression with YAP1-S45Y/S33Y-β-catenin of the dominant-negative T-cell factor 4 or dominant-negative transcriptional enhanced associate domain 2, the respective surrogate transcription factors, prevented HB development. Although histologically similar, HB in YAP1-S45Y/S33Y-β-catenin, unlike YAP1-ΔN90-β-catenin HB, was glutamine synthetase (GS) positive. However, both ΔN90-β-catenin and point-mutant β-catenin comparably induced GS-luciferase reporter invitro. Finally, using a previously reported 16-gene signature, it was shown that YAP1-ΔN90-β-catenin HB tumors exhibited genetic similarities with more proliferative, less differentiated, GS-negative HB patient tumors, whereas YAP1-S33Y/S45Y-β-catenin HB exhibited heterogeneity and clustered with both well-differentiated GS-positive and proliferative GS-negative patient tumors. Thus, we demonstrate that β-catenin point mutants can also collaborate with YAP1 in HB development, albeit with a distinct molecular profile from the deletion mutant, which may have implications in both biology and therapy.

MicroRNA-33-3p involved in selenium deficiency-induced apoptosis via targeting ADAM10 in the chicken kidney.

Selenium (Se) deficiency induces typical clinical and pathological changes and causes various pathological responses at the molecular level in several different chicken organs; the kidney is one of the target organs of Se deficiency. To explore the mechanisms that underlie the effects of microRNA-33-3p (miR-33-3p) on Se deficiency-induced kidney apoptosis, 60 chickens were randomly divided into two groups (30 chickens per group). We found that Se deficiency increased the expression of miR-33-3p in the chicken kidney. A disintegrin and metalloprotease domain 10 (ADAM10) was verified to be a target of miR-33-3p in the chicken kidney. The overexpression of miR-33-3p decreased the expression levels of β-catenin, cyclinD1, T-cell factor (TCF), c-myc, survivin, and Bcl-2; it increased the expression levels of E-cadherin, Bak, Bax, and caspase-3; and it increased the number of chicken kidney cells in the G0/G1 phase. In addition, Se deficiency caused the ultrastructure of the kidney to develop apoptotic characteristics. The results of flow cytometry analysis and AO/EB staining showed that the number of apoptotic chicken kidney cells increased in the miR-33-3p mimic group. All these results suggest that Se deficiency-induced cell cycle arrest and apoptosis in vivo and in vitro in the chicken kidney via the regulation of miR-33-3p, which targets ADAM10.

LncCCAT1 Promotes Breast Cancer Stem Cell Function through Activating WNT/β-catenin Signaling.

Background: Breast cancer stem cells (BCSCs) play an essential role in facilitating breast cancer relapse and metastasis. The underlying mechanism, however, remains incompletely understood. In the current study, we investigated the clinical significance, biological function and mechanism of a long noncoding RNA CCAT1 (LncCCAT1) in BCSCs.Methods: Firstly, lncRNAs expression in poorly differentiated breast cancer tissues and BCSCs were measured by lncRNA microarray and confirmed in breast cancer tissues and cell lines. The functional roles and mechanisms of LncCCAT1 were further investigated by gain and loss of function assays in vitro and in vivo.Results: LncCCAT1 is markedly upregulated in breast cancer tissues BCSCs and is correlated with poor outcomes in breast cancer patients. Overexpression of LncCCAT1 contributes to the proliferation, stemness, migration and invasion capacities of BCSCs. Mechanistic investigation suggests that LncCCAT1 can interact with miR-204/211, miR-148a/152 and Annexin A2(ANXA2), then upregulate T-cell factor 4 (TCF4) or promote translocation of β-catenin to the nucleus where it activates TCF4, leading to the activation of wingless/integrated (Wnt) signaling. Furthermore, TCF4 can also bind to the promoter of LncCCAT1 to promote LncCCAT1 transcription, thus forming a positive feedback regulatory circuit of LncCCAT1-TCF4-LncCCAT1 in BCSCs.Conclusions: LncCCAT1 plays an important role in breast cancer progression and may serve as a novel target for breast cancer diagnosis and therapy.

Ammonia-N exposure alters neurohormone levels in the hemolymph and mRNA abundance of neurohormone receptors and associated downstream factors in the gills of Litopenaeus vannamei.

Effects of ammonia-N (0.05, 2, 10 and 20 mg l-1) on the neuroendocrine regulation of ammonia transport were investigated in Litopenaeus vannamei The results showed that corticotrophin-releasing hormone, adrenocorticotropic hormone, dopamine, noradrenaline and 5-hydroxytryptamine concentrations in all ammonia-N groups increased significantly between 3 and 12 h. Cortisol increased significantly between 3 and 24 h. All hormones except crustacean hyperglycemic hormone were reduced to control levels. mRNA abundance of guanylyl cyclase increased significantly during the experiment. Dopamine receptor D4 and α2 adrenergic receptor mRNA abundance in treatments decreased significantly at the beginning, and eventually returned to the control level, whereas mRNA abundance of the 5-HT7 receptor increased significantly only within the first 12 h. Changes in protein kinase (PKA, PKG) mRNA abundance were similar to the patterns of biogenic amines and crustacean hyperglycemic hormone, peaking at 6 and 12 h, respectively, whereas PKC mRNA abundance decreased within 24 h. 14-3-3 protein, FXYD2 and cAMP-response element binding protein mRNA abundance increased significantly and peaked at 6 h. β-catenin and T-cell factor mRNA abundance increased significantly throughout the experiment and peaked at 12 h. The upregulation of Rh protein, K+ channel, Na+/K+-ATPase, V-type H+-ATPase and vesicle associated membrane protein (VAMP) mRNA, together with downregulation of Na+/K+/2Cl- cotransporter mRNA, indicated an adjustment of general branchial ion-/ammonia-regulatory mechanisms. Meanwhile, hemolymph ammonia concentration was significantly increased in most ammonia-N exposure groups. Histological investigation revealed the hepatopancreatic damage caused by ammonia-N. Results suggest that hormones, biogenic amines and Wnt/β-catenin play a principal role in adapting to ammonia-N exposure and facilitating ammonia transport.

A serine in exon 11 determines the full transcriptional activity of TCF-4 in lung carcinoma cells

Activation of T cell factor-4 (TCF-4) is causally linked to the development of lung carcinoma, while the mechanism of sequence-dependent TCF-4 activity is still obscure. Using reverse transcription-polymerase chain reaction (RT-PCR), here, we demonstrated that sequences of exon 11 in TCF-4 were present in lung carcinoma cells but not in normal lung epithelial cells. Loss of exon 11 in TCF-4 inhibited TCF-4-induced cell growth of lung carcinoma and prolonged the survival time of Lewis lung carcinoma (LLC) tumor-bearing mice. Mechanistically, loss of exon 11 in TCF-4 attenuated the binding activity between TCF-4 protein and its canonical binding site, inhibited TOP/FOP luciferase activity and suppressed mRNA expression of Wnt signaling targets. By performing truncated and site-directed mutations, we further demonstrated that the 16th amino acid serine in exon 11 was responsible for TCF-4-mediated Wnt signaling. In vivo experiments indicated that a mutation of the 16th amino acid serine in exon 11 of TCF-4 could mimic the anti-tumor effect of Wnt signaling inhibitor. Taken together, we identified a serine determining the transcriptional activity of TCF-4 in lung carcinoma cells, and sequencing of TCF-4 mRNA might be an effective strategy to evaluate the Wnt pathway activation and prognosis in lung cancer.

Analysis of Immunologic Function Changes in Lichen Planus After Clinical Treatment.

BackgroundLichen planus (LP) is a common chronic superficial skin lesion that causes chronic or sub-acute inflammatory disorders. LP can affect the oral cavity, skin, mucous membrane, and other body parts, and features include repeat attacks and long duration, leading to lower quality of life. This study aimed to analyze the changes of immunologic function before and after treatment of LP.Material/MethodsThirty cutaneous LP patients were selected. Peripheral blood was collected in the morning before and after treatment. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient method. Flow cytometry was used to detect T cell subpopulation CD4+ T cells and CD8+ T to calculate CD4+ T/CD8+ T ratio. Enzyme-linked immunosorbent assay (ELISA) was adopted to detect the helper T-cell (Th) factor IL-2, IFN-γ, IL-4, IL-6, IL-17, and IL-22 levels.ResultsCompared with before treatment, the expressions of CD4+ T cells and CD8+ T cells were decreased, while the proportion of CD4+ T/CD8+ T were significantly elevated after treatment. IL-2 and IFN-γ secretion were markedly increased, whereas IL-4, IL-6, IL-17, and IL-22 were significantly reduced after treatment (P<0.05).ConclusionsLP treatment reduces the distribution of CD4+ T cells and CD8+ T cells, and promotes the changes of Th1, Th2, and Th17 cytokines secretion.

Wnt/β-Catenin Signaling Pathway Governs a Full Program for Dopaminergic Neuron Survival, Neurorescue and Regeneration in the MPTP Mouse Model of Parkinson's Disease.

Wingless-type mouse mammary tumor virus (MMTV) integration site (Wnt) signaling is one of the most critical pathways in developing and adult tissues. In the brain, Wnt signaling contributes to different neurodevelopmental aspects ranging from differentiation to axonal extension, synapse formation, neurogenesis, and neuroprotection. Canonical Wnt signaling is mediated mainly by the multifunctional β-catenin protein which is a potent co-activator of transcription factors such as lymphoid enhancer factor (LEF) and T-cell factor (TCF). Accumulating evidence points to dysregulation of Wnt/β-catenin signaling in major neurodegenerative disorders. This review highlights a Wnt/β-catenin/glial connection in Parkinson’s disease (PD), the most common movement disorder characterized by the selective death of midbrain dopaminergic (mDAergic) neuronal cell bodies in the subtantia nigra pars compacta (SNpc) and gliosis. Major findings of the last decade document that Wnt/β-catenin signaling in partnership with glial cells is critically involved in each step and at every level in the regulation of nigrostriatal DAergic neuronal health, protection, and regeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD, focusing on Wnt/β-catenin signaling to boost a full neurorestorative program in PD.

Loss of endogenous RNF43 function enhances proliferation and tumour growth of intestinal and gastric cells.

Ring finger protein 43 (RNF43) is an E3 ubiquitin ligase that has been described to be frequently mutated in gastrointestinal cancers. RNF43 downregulation was associated with distant metastasis, TNM stage and poorer survival in patients with gastric and colorectal cancers. Functional analysis has shown that overexpressed RNF43 negatively regulates Wnt signalling by ubiquitinating Frizzled receptors and targeting them for degradation and by sequestering T-cell factor 4 (TCF4) to the nuclear membrane, thereby inhibiting Wnt-mediated transcription. In the stomach, RNF43 overexpression was shown to impair stem-like properties and to be negatively correlated with expression of Wnt-target genes. In this study, we show that RNF43 knockdown enhances the tumourigenic potential of gastric and colorectal cancer cell lines in vitro and in vivo. Thus, loss of RNF43 leads to increased proliferation and anchorage-independent growth as well as increased invasive capacity. In a xenograft model, RNF43 depletion enhanced tumour growth. Furthermore, we established two mouse models in which mutations in the RING domain of RNF43 were introduced. In the intestine and colon, loss of Rnf43 did not induce changes in epithelial architecture or proliferation. In contrast, in the stomach, thickening of the mucosa, hyperplasia and cellular atypia were observed in these mice. Notably, this was independent of elevated Wnt signalling. Together, our results show that RNF43 plays a tumour suppressive role in gastric and colorectal cancer cells and that the loss of its function alters gastric tissue homeostasis in vivo.

HPV-18 E6 Oncoprotein and Its Spliced Isoform E6*I Regulate the Wnt/β-Catenin Cell Signaling Pathway through the TCF-4 Transcriptional Factor.

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation and its aberrant activation in cervical cancer has been described. Persistent infection with high risk human papillomavirus (HR-HPV) is the most important factor for the development of this neoplasia, since E6 and E7 viral oncoproteins alter cellular processes, promoting cervical cancer development. A role of HPV-16 E6 in Wnt/β-catenin signaling has been proposed, although the participation of HPV-18 E6 has not been previously studied. The aim of this work was to investigate the participation of HPV-18 E6 and E6*I, in the regulation of the Wnt/β-catenin signaling pathway. Here, we show that E6 proteins up-regulate TCF-4 transcriptional activity and promote overexpression of Wnt target genes. In addition, it was demonstrated that E6 and E6*I bind to the TCF-4 (T cell factor 4) and β-catenin, impacting TCF-4 stabilization. We found that both E6 and E6*I proteins interact with the promoter of Sp5, in vitro and in vivo. Moreover, although differences in TCF-4 transcriptional activation were found among E6 intratype variants, no changes were observed in the levels of regulated genes. Furthermore, our data support that E6 proteins cooperate with β-catenin to promote cell proliferation.

Hsa-miR-106b-5p Negatively Regulates LEF1

Aberrant expression of the genes involved in Wnt signaling pathway, one of the most important developing pathways, is observed in many malignancies. Reports show that Wnt/β-catenin activation is critical for cancer development, angiogenesis, migration, and invasion. LEF1 belongs to the T cell Factor (TCF)/LEF family of transcription factors and plays the role of nuclear effector in the Wnt/β-catenin signaling pathway. LEF1 has central role as a transcription factor in the Wnt/β-catenin signaling pathway which makes it an ideal target for therapeutic treatment in dealing with cancer proliferation. It can act as an oncogene or a tumor suppressor in cellular context dependent manner. miRNAs are aberrantly expressed in cancers and can act as tumor suppressors or oncomirs depending upon the type of carcinomas. Studies show that miRNAs can be used as novel agents for targeted cancer therapy. miR-106b, which belong to miR-17-92 paralog cluster, is reported to be overexpressed in multiple tumor types including medulloblastomas, breast, colon, kidney, gastric, lung cancer and HCC. In this study we have demonstrated that over-expression of miR-106b-5p down-regulates the endogenous expression of LEF1 in HEK293FT cells, thereby affecting the expression of N-Myc, downstream gene of Wnt signaling. Therefore, our results suggest that miR-106b-5p plays a significant role in suppressing the carcinomas resulted due to the over-expression of LEF1 and/or activation of Wnt pathway and may prove to be a potential target for novel cancer therapy. It may helpful in developing therapeutic strategies for cancer treatments.

Epidermal growth factor can signal via β-catenin to control proliferation of mesenchymal stem cells independently of canonical Wnt signalling

Bone marrow mesenchymal stem/stromal cells (MSCs) maintain bone homeostasis and repair through the ability to expand in response to mitotic stimuli and differentiate into skeletal lineages. Signalling mechanisms that enable precise control of MSC function remain unclear. Here we report that by initially examining differences in signalling pathway expression profiles of individual MSC clones, we identified a previously unrecognised signalling mechanism regulated by epidermal growth factor (EGF) in primary human MSCs. We demonstrate that EGF is able to activate β-catenin, a key component of the canonical Wnt signalling pathway. EGF is able to induce nuclear translocation of β-catenin in human MSCs but does not drive expression of Wnt target genes or T cell factor (TCF) activity in MSC reporter cell lines. Using an efficient Design of Experiments (DoE) statistical analysis, with different combinations and concentrations of EGF and Wnt ligands, we were able to confirm that EGF does not influence the Wnt/β-catenin pathway in MSCs. We show that the effects of EGF on MSCs are temporally regulated to initiate early “classical” EGF signalling mechanisms (e.g via mitogen activated protein kinase) with delayed activation of β-catenin. By RNA-sequencing, we identified gene sets that were exclusively regulated by the EGF/β-catenin pathway, which were distinct from classical EGF-regulated genes. However, subsets of classical EGF gene targets were significantly influenced by EGF/β-catenin activation. These signalling pathways cooperate to enable EGF-mediated proliferation of MSCs by alleviating the suppression of cell cycle pathways induced by classical EGF signalling.

Hypermethylation of Secreted Frizzled Related Protein 1 gene promoter in different astrocytoma grades

AimTo identify the involvement of Secreted Frizzled Related Protein 1 (SFRP1) promoter hypermethylation in different malignancy grades of astrocytoma and assess its association with beta-catenin, lymphoid-enhancer factor 1, and T-cell factor 1.MethodsTwenty-six astrocytoma samples were collected from 2008-2015. Promoter hypermethylation was evaluated by methylation-specific polymerase-chain-reaction and protein expression by immunohistochemistry and stereological analysis. The staining intensity was scored by comparing immunoreactivity with normal tissue and by using 10% and 50% cut-offs.ResultsSFRP1 promoter methylation was found in 32% of astrocytomas. The number of hypermethylated samples increased in higher astrocytoma grades and was the highest in glioblastoma (P = 0.042 compared to other astrocytoma grades). There was 45.8% of samples with the lack of or weak expression of SFRP1 protein and 29.2% with strong expression. Samples with methylated promoter expressed significantly less SFRP1 than samples with unmethylated promoter (P = 0.031). Beta-catenin expression levels were elevated. Yet, glioblastomas with unmethylated SFRP1 promoter had significantly less beta-catenin (P = 0.033). Strong expression of lymphoid-enhancer factor 1 was associated to higher astrocytoma grades (P = 0.006).ConclusionSFRP1 gene was epigenetically silenced in glioblastomas when compared to low astrocytoma grades, which may suggest that the lack of its protein is involved in astrocytoma progression.

Wnt Effector TCF4 Is Dispensable for Wnt Signaling in Human Cancer Cells.

T-cell factor 4 (TCF4), together with β-catenin coactivator, functions as the major transcriptional mediator of the canonical wingless/integrated (Wnt) signaling pathway in the intestinal epithelium. The pathway activity is essential for both intestinal homeostasis and tumorigenesis. To date, several mouse models and cellular systems have been used to analyze TCF4 function. However, some findings were conflicting, especially those that were related to the defects observed in the mouse gastrointestinal tract after Tcf4 gene deletion, or to a potential tumor suppressive role of the gene in intestinal cancer cells or tumors. Here, we present the results obtained using a newly generated conditional Tcf4 allele that allows inactivation of all potential Tcf4 isoforms in the mouse tissue or small intestinal and colon organoids. We also employed the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system to disrupt the TCF4 gene in human cells. We showed that in adult mice, epithelial expression of Tcf4 is indispensable for cell proliferation and tumor initiation. However, in human cells, the TCF4 role is redundant with the related T-cell factor 1 (TCF1) and lymphoid enhancer-binding factor 1 (LEF1) transcription factors.

Alternative pre-mRNA splicing switch controls hESC pluripotency and differentiation

Alternative splicing (AS) of pre-mRNAs is a ubiquitous process in mammals that is tightly regulated in a cell type- and cell state-dependent manner. However, the details of how splicing is regulated to impact specific cell fate decisions remains incompletely understood. A study by Yamazaki and colleagues (pp. 1161-1174) in this issue of Genes & Development provides exciting new insight into the role and regulation of splicing in the maintenance of pluripotency of human embryonic stem cells (hESCs). In brief, they show that AS of several genes is robustly regulated upon differentiation of hESCs. One of these genes, T-cell factor 3 (TCF3), is regulated at least in part through the activity of heterogeneous nuclear ribonucleoproteins H1 and F (hnRNP H/F) to control the mutually exclusive expression of the encoded E12 and E47 transcription regulators. The investigators demonstrate that reduced expression of hnRNP H/F favors expression of E47, which in turn decreases E-cadherin expression to promote hESC differentiation. In contrast, high levels of hnRNP H/F induce expression of E12 to maintain pluripotency. Thus, this work provides at least one new link between AS and control of human stem cell fate and suggests a broader role of splicing in pluripotency.

Protective effects of 2,3,5,4‐tetrahydroxystilbene‐2‐o‐β‐D‐glucoside against osteoporosis: Current knowledge and proposed mechanisms

The aim of this study was to explore the mechanism underlying the protective effects of 2,3,5,4-tetrahydroxystilbene-2-o-β-D-glucoside (TSG) against osteoporosis. MC3T3-E1 mouse osteoblast precursor cells were used to analyze the protective effects of TSG on osteoblast apoptosis and differential inhibition induced by oxidative stress to determine the gene expression of forkhead transcription factor FKHRL1 (FoxO3a), T cell factors (TCFs), and downstream genes. A mouse model was used to assess the protective effects of TSG on ovariectomy-induced osteoporosis as well as on Cell Counting Kit-8 (CCK) gene expression, including that of FoxO3a. The mechanism underlying the protective effects of TSG against osteoporosis was further explored using high-throughput sequencing data. A CCK-8 assay in MC3T3-E1 cells and hematoxylin and eosin staining in mouse tissue indicated that cell viability and bone tissue development were inhibited by oxidative stress and ovariectomy and that TSG neutralized or attenuated this effect. The expression levels of FoxO3a, TCF, and downstream genes and the indices of oxidative stress were the same in MC3T3-E1 cells and the bone tissues of the mouse model. Bioinformatics analysis indicated that the cardiac muscle contraction and chemokine signaling pathway were disturbed in MC3T3-E1 cells treated with hydrogen peroxide. Gene ontology-biological process analysis revealed the influence of TSG treatment. Osteoporosis and cardiac diseases appear to share a common mechanism. In addition to Wnt/FoxO3a signaling, the immune system and the chemokine signaling pathway may contribute to the protective mechanism of TSG.