TCF7L2 Expression Research Articles

Three-dimensional chromatin landscapes in somatotroph tumour.

The three-dimensional (3D) genome architecture plays a critical role inregulating gene expression. However, the specific alterations in thisarchitecture within somatotroph tumors and their implications for gene expression remain largely unexplored. We employed Hi-C and RNA-seq analyses to compare the 3D genomic structures of somatotroph tumors with normal pituitary tissue. This comprehensive approachenabled the characterization of A/B compartments, topologically associateddomains (TADs), and chromatin loops, integrating these with gene expression patterns. We observed a decrease in both the frequency of chromosomal interactions andthe size of TADs in tumor tissue compared to normal tissue. Conversely, the number of TADs and chromatin loops was found to be increased in tumors. Integrated analysis of Hi-C and RNA-seq data demonstrated that changes inhigher-order chromat in structure were associated with alterations in gene expression. Specifically, genes in A compartments showed higher density and increased expression relative to those in B compartments. Moreover, the weakand enhanced insulation boundaries were identified, and the associated genes were enriched in the Wnt/β-Catenin signaling pathway. We identified the gainedand lost loops in tumor and integrated these differences with transcriptional changes to examine the functional relevance of the identified loops. Notably, we observed an enhanced insulation boundary and a greater number of loops in the TCF7L2 gene region within tumors, which was accompanied by an upregulation of TCF7L2 expression. Subsequently, TCF7L2 expression was confirmed through qRT-PCR, and upregulated TCF7L2 prompted cell proliferation and growth hormone (GH) secretion in vitro. Our results provide comprehensive 3D chromatin architecture maps of somatotroph tumors and offer a valuable resource for furthering the understanding of the underlying biology and mechanisms of gene expression regulation.

BRD4-binding enhancer promotes CRC progression by interacting with YY1 to activate the Wnt pathway through upregulation of TCF7L2

Colorectal carcinoma (CRC), one of the most life-threatening cancer types, is associated with aberrant expression of epigenetic modifiers and activation of the Wnt pathway. However, the role of epigenetic regulators in driving cancer cell proliferation and their potential as therapeutic targets affecting the Wnt pathway remain unclear. In this study, BRD4 was found to promote the progression of CRC both in vitro and in vivo. The expression of BRD4 correlated with shortened CRC patient survival. In addition, BRD4 function was strongly correlated with the Wnt pathway, but rather through regulation of TCF7L2 at transcriptional levels. BRD4 and H3K27ac have overlapping occupancies in the cis-regulatory elements of TCF7L2, suggesting enhancer-based epigenetic regulation. Numerous YY1 binding sites were found in the abovementioned region. YY1 recruited BRD4 to bind to cis-regulatory elements of TCF7L2, thereby regulating the expression of TCF7L2. Altogether, this study validates that BRD4 performs a canonical epigenetic regulatory function in CRC and can be used in the treatment of Wnt pathway-dependent CRC or other malignancies with clinically available bromodomain inhibitors.

To unravel the role of TCF7L2 (Transcription Factor 7 like 2) variants in type 2 diabetes mellitus

Predisposition to diabetes is attributed to a large number of genes. TCF7L2 is one of the most significant candidate genes among them, and it is crucial for beta-cell activity and blood glucose regulation. According to previous research, TCF7L2 has been implicated in T2DM in various Indian tribes. Many studies have discovered a link between TCF7L2 gene variations and vulnerability to T2DM. These results suggest that changes in TCF7L2 expression are not only associated with insulin resistance but also with risk for genotypes connected to poor beta cell activity. TCF7L2 drives the conventional Wnt signalling pathway and functions as a nuclear ligand for beta catenin. Wnt signalling is necessary for intestinal endocrine L-cells to emit GLP-1 (glucagon-like peptide-1). As a result, a blockage in this route would cause less GLP-1 to be released, which might have an impact on the release of insulin after meals contributing to T2DM as a result. The molecular processes through which the TCF7L2 gene increases the susceptibility of T2DM will therefore be of significant interest, as will the identification of possible therapeutic targets that may be employed to treat and prevent the illness as a result of the gene variations.

Expression of TCF7L2 in midbrain Vglut2-positive neurons.

Expression of TCF7L2 in midbrain Vglut2-positive neurons.

345 The Role of TCF7L2 in Hepatic Metabolic Zonation

OBJECTIVES/GOALS: Single nucleotide polymorphisms in the transcription factor 7-like 2 (TCF7L2) gene are associated with Type 2 Diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD). The metabolic function of TCF7L2 in the liver remains to be fully elucidated, but we hypothesized that TCF7L2 contributes to NAFLD through regulation of zonal metabolic pathways. METHODS/STUDY POPULATION: Using single nuclei RNA sequencing, we examined Tcf7l2 expression in periportal (PP) hepatocytes around the portal triad and pericentral (PC) hepatocytes surrounding the central vein of the liver. To visualize TCF7L2 transcriptional activity we used a TCF reporter mice, which expresses an H2B-eGFP fusion protein downstream of the conserved TCF DNA binding site. We disrupted Tcf7l2 transcriptional activity in mouse liver by breeding mice with a floxed Tcf7l2 exon 11, which encodes part of the DNA binding domain (DBD), to albumin-Cre mice (Hep-TCF7L2ΔDBD). Eight-week-old mice were fed a choline-deficient amino acid-defined high fat (CDAHFD) diet for 8 weeks. In liver samples harvested from these mice, we examined disruption to several key zonated metabolic pathways, and quantified the development of fibrosis. RESULTS/ANTICIPATED RESULTS: Single nuclei analysis revealed that Tcf7l2 mRNA was expressed primarily in parenchymal cells of the liver but was ubiquitous across the liver lobule. However, in immunofluorescence analysis of TCF reporter mice, the transcriptional activity of TCF7L2 was highly restricted to PC hepatocytes. Classic PC hepatocyte markers, including glutamine synthetase (Glul), were absent in Hep-TCF7L2ΔDBD mice. Following the CDAHFD, Hep-TCF7L2ΔDBD mice developed more severe fibrosis in histological analysis, and expressed elevated levels of genes involved in fibrogenesis, collagen synthesis and TGFβsignaling. Hep-TCF7L2ΔDBD mice also displayed hepatic cholesterol accumulation following the CDAHFD, which was likely the result of impaired pericentral bile acid synthesis. DISCUSSION/SIGNIFICANCE: Our results suggest that TCF7L2 plays an important role in the regulation of zonated metabolic pathways, which may contribute to the development of fibrosis. Ongoing analyses are exploring the mechanisms regulating the zonal transcriptional activity of TCF7L2.

TCF7L2 acts as a molecular switch in midbrain to control mammal vocalization through its DNA binding domain but not transcription activation domain

Vocalization is an essential medium for social signaling in birds and mammals. Periaqueductal gray (PAG) a conserved midbrain structure is believed to be responsible for innate vocalizations, but its molecular regulation remains largely unknown. Here, through a mouse forward genetic screening we identified one of the key Wnt/β-catenin effectors TCF7L2/TCF4 controls ultrasonic vocalization (USV) production and syllable complexity during maternal deprivation and sexual encounter. Early developmental expression of TCF7L2 in PAG excitatory neurons is necessary for the complex trait, while TCF7L2 loss reduces neuronal gene expressions and synaptic transmission in PAG. TCF7L2-mediated vocal control is independent of its β-catenin-binding domain but dependent of its DNA binding ability. Patient mutations associated with developmental disorders, including autism spectrum disorders, disrupt the transcriptional repression effect of TCF7L2, while mice carrying those mutations display severe USV impairments. Therefore, we conclude that TCF7L2 orchestrates gene expression in midbrain to control vocal production through its DNA binding but not transcription activation domain.

Rotational night shift work adversely affects expression of TCF7L2 and PPAR-γ genes among healthcare workers with normal glucose tolerance

Rotational night shift work adversely affects expression of TCF7L2 and PPAR-γ genes among healthcare workers with normal glucose tolerance

FGF9 Promotes Expression of HAS2 in Palatal Elevation via the Wnt/β-Catenin/TCF7L2 Pathway.

Fgf9 mutation was found in cleft palate patients. Our previous study indicated that Fgf9 promotes timely elevation of palate by regulating hyaluronic acid (HA) accumulation at embryonic day 13.5 (E13.5). HA is synthesized by hyaluronic acid synthases (HAS) isoforms 1, 2, or 3. However, how FGF9 regulates HA in palatogenesis is still unclear. Using Ddx4-Cre mice, we generated the Fgf9-/- mouse model (with exon 2 deletion). Immunohistochemistry was used to detect the location and expression of HAS2 in WT and the Fgf9-/- palate at E13.5. We also predicted the association between Fgf9 and Has2 within the developing palate by performing a bioinformatics analysis. The expression of β-catenin, HAS2, and TCF7L2 were verified by Western blotting after knockout of Fgf9. Rescue experiments were performed by ELISA in vitro. Fgf9-/- mice exhibited 100% penetrance of the cleft palate. A knockout of Fgf9 confirmed that HAS2 and TCF7L2 expression was positively correlated with FGF9. TCF7L2 binds to the Has2 promoter, exhibiting the high specificity predicted by JASPAR. Additionally, increased HA expression by BML-284, TCF-dependent agonist, was blocked in Fgf9-/- palate because of the significant decline in TCF7L2 expression. FGF9 promotes HAS2 expression via Wnt/β-catenin/TCF7L2 pathway with TCF7L2 activating transcription of Has2 in the palate.

Coronarin A modulated hepatic glycogen synthesis and gluconeogenesis via inhibiting mTORC1/S6K1 signaling and ameliorated glucose homeostasis of diabetic mice.

Promotion of hepatic glycogen synthesis and inhibition of hepatic glucose production are effective strategies for controlling hyperglycemia in type 2 diabetes mellitus (T2DM), but agents with both properties were limited. Herein we report coronarin A, a natural compound isolated from rhizomes of Hedychium gardnerianum, which simultaneously stimulates glycogen synthesis and suppresses gluconeogenesis in rat primary hepatocytes. We showed that coronarin A (3, 10 μM) dose-dependently stimulated glycogen synthesis accompanied by increased Akt and GSK3β phosphorylation in rat primary hepatocytes. Pretreatment with Akt inhibitor MK-2206 (2 μM) or PI3K inhibitor LY294002 (10 μM) blocked coronarin A-induced glycogen synthesis. Meanwhile, coronarin A (10 μM) significantly suppressed gluconeogenesis accompanied by increased phosphorylation of MEK, ERK1/2, β-catenin and increased the gene expression of TCF7L2 in rat primary hepatocytes. Pretreatment with β-catenin inhibitor IWR-1-endo (10 μM) or ERK inhibitor SCH772984 (1 μM) abolished the coronarin A-suppressed gluconeogenesis. More importantly, we revealed that coronarin A activated PI3K/Akt/GSK3β and ERK/Wnt/β-catenin signaling via regulation of a key upstream molecule IRS1. Coronarin A (10, 30 μM) decreased the phosphorylation of mTOR and S6K1, the downstream target of mTORC1, which further inhibited the serine phosphorylation of IRS1, and subsequently increased the tyrosine phosphorylation of IRS1. In type 2 diabetic ob/ob mice, chronic administration of coronarin A significantly reduced the non-fasting and fasting blood glucose levels and improved glucose tolerance, accompanied by the inhibited hepatic mTOR/S6K1 signaling and activated IRS1 along with enhanced PI3K/Akt/GSK3β and ERK/Wnt/β-catenin pathways. These results demonstrate the anti-hyperglycemic effect of coronarin A with a novel mechanism by inhibiting mTORC1/S6K1 to increase IRS1 activity, and highlighted coronarin A as a valuable lead compound for the treatment of T2DM.

P10.22.A Prognostic role ofTCF7L2 in glioblastoma

Abstract Background Glioblastoma is the most common and devastating brain cancer and despite maximal surgical resection, chemotherapy and radiotherapy, the five-year survival rate is less than 7%. The TCF7L2 gene encodes transcription factor 7-like 2, a main effector of Wnt/β-Catenin signaling pathway involved in cancer development and progression. Aberrant activation of the TCF7L2 gene is one of the primary events in tumorigenesis by maintaining stem-cell characteristics, however its role in glioblastoma is poorly studied. Material and Methods The expression of TCF7L2 was analyzed by qRT-PCR in a series of consecutive glioblastoma samples from patients that underwent surgical resection. Secondary or recurrent glioblastomas were excluded from the analysis. All patients underwent radio- and chemotherapy according to the protocol. Housekeeping gene RPL13 was used as reference gene. The 2-ΔCT method was used to calculate the relative expression of TCF7L2 to the reference gene. Results A total of 49 glioblastoma samples were included in the study. The mean survival period was 58.2 weeks. The median value of TCF7L2 expression was used as a cut-off point for the survival analysis. There were no statistically significant differences regarding the clinical and histopathological factors between the groups with low and high expression of TCF7L2. By using the Kaplan-Meier analysis, we observed that patients with overexpression of TCF7L2 had a decreased survival rate compared to patients with low levels of TCF7L2 (38.8 weeks vs. 77.34 weeks, p = 0.001). Conclusion These results demonstrate that glioblastoma patients with high levels of TCF7L2 have a poorer survival rate and TCF7L2 might be a useful prognostic factor for these patients. However, further studies are needed to elucidate the mechanisms through which TCF7L2 affects the prognosis and its implication as a possible therapeutic target. This work was supported by an ERA PerMed grant - ERAPERMED2018-270 (PerProGlio).

SOX transcription factors direct TCF-independent WNT/β-catenin responsive transcription to govern cell fate in human pluripotent stem cells.

WNT/β-catenin signaling controls gene expression across biological contexts from development and stem cell homeostasis to diseases including cancer. How β-catenin is recruited to distinct enhancers to activate context-specific transcription is unclear, given that most WNT/ß-catenin-responsive transcription is thought to be mediated by TCF/LEF transcription factors (TFs). With time-resolved multi-omic analyses, we show that SOX TFs can direct lineage-specific WNT-responsive transcription during the differentiation of human pluripotent stem cells (hPSCs) into definitive endoderm and neuromesodermal progenitors. We demonstrate that SOX17 and SOX2 are required to recruit β-catenin to lineage-specific WNT-responsive enhancers, many of which are not occupied by TCFs. At TCF-independent enhancers, SOX TFs establish a permissive chromatin landscape and recruit a WNT-enhanceosome complex to activate SOX/ß-catenin-dependent transcription. Given that SOX TFs and the WNT pathway are critical for specification of most cell types, these results have broad mechanistic implications for the specificity of WNT responses across developmental and disease contexts.

Liraglutide stimulates the β-catenin signaling cascade in mouse epididymal fat tissue.

Although canonical Wnt signaling pathway activation was shown to negatively regulate adipogenesis, recent investigations suggest that Wnt pathway effectors TCF7L2 and β-catenin (β-cat) in adipose tissues are also involved in energy homeostasis during adulthood. In assessing the metabolic beneficial effect of GLP-1-based diabetes drugs in high-fat diet (HFD)-challenged mice, we observed that liraglutide treatment affected the expression of a battery of adipose tissue-specific genes, including those that encode adiponectin and leptin, mainly in epididymal white adipose tissue (eWAT). Fourteen-week HFD challenge repressed TCF7L2 and β-cat S675 phosphorylation in eWAT, while such repression was reversed by liraglutide treatment (150 µg/kg body weight daily) during weeks 10-14. In Glp1r-/-mice, liraglutide failed in stimulating TCF7L2 or β-cat in eWAT. We detected Glp1r expression in mouse eWAT and its level is enriched in its stromal vascular fraction (SVF). Mouse eWAT-SVF showed reduced expression of Tcf7l2 and its Tcf7l2 level could not be stimulated by liraglutide treatment; while following adipogenic differentiation, rat eWAT-SVF showed elevated Tcf7l2 expression. Direct in vitro liraglutide treatment in eWAT-SVF stimulated CREB S133, β-cat S675 phosphorylation, and cellular cAMP level. Thus, cAMP/β-cat signaling cascade can be stimulated by liraglutide in eWAT via GLP-1R expressed in eWAT-SVF.

TCF7l2, a nuclear marker that labels premyelinating oligodendrocytes and promotes oligodendroglial lineage progression.

Clinical and basic neuroscience research is greatly benefited from the identification and characterization of lineage specific and developmental stage-specific markers. In the glial research community, histological markers that specifically label newly differentiated premyelinating oligodendrocytes are still scarce. Premyelinating oligodendrocyte markers, especially those of nuclear localization, enable researchers to easily quantify the rate of oligodendrocyte generation regardless of developmental ages. We propose that the transcription factor 7-like 2 (TCF7l2, mouse gene symbol Tcf7l2) is a useful nuclear marker that specifically labels newly generated premyelinating oligodendrocytes and promotes oligodendroglial lineage progression. Here, we highlight the controversial research history of TCF7l2 expression and function in oligodendroglial field and discuss previous experimental data justifying TCF7l2 as a specific nuclear marker for premyelinating oligodendrocytes during developmental myelination and remyelination. We conclude that TCF7l2 can be used alone or combined with pan-oligodendroglial lineage markers to identify newly differentiated or newly regenerated oligodendrocytes and quantify the rate of oligodendrocyte generation.

Role of Toothbrushes as Gene Expression Profiling Tool for Oral Cancer Screening in Tobacco and Alcohol Users.

Aim: The use of toothbrushes was investigated as a potential RNA source and gene expression profiling tool for oral cancer screening in tobacco and alcohol users. Methodology: A total of 20 subjects were selected on the basis of inclusion and exclusion criteria. They were divided into two groups: group I—healthy controls (n = 6); group II—individuals who consume tobacco and alcohol (n = 14). After the volunteers brushed their teeth using a soft-bristle toothbrush with ~0.5 gm of toothpaste, the toothbrushes were collected, and the gene expression of BAX, BCL2, CDK4, CKDN2A, GNB3, and TCF7L2 was assessed. Results: The gene expression of BAX decreased significantly in alcoholics and smokers (0.13867 ± 0.12014), while the gene expression of BCL2 increased in alcoholics and smokers (1.91001 ± 0.90425) in comparison with healthy controls (p = 0.0054 and p = 0.0055). Although there was increased expression of CDK4, CKDN2A, and TCF7L2 and decreased expression of GNB3 in smokers and alcoholics, the results were not significant. Conclusions: A toothbrush is a good source of RNA, and gene expression analysis can be performed using the genetic material retrieved from toothbrushes, which can aid in the early diagnosis of oral squamous cell carcinoma among tobacco and alcohol users. Further studies with a larger sample size and different durations of toothbrush use should be conducted to explore the role of toothbrushes as a noninvasive tool for disease diagnosis.

Extracellular vesicles derived from bone marrow mesenchymal stem cells alleviate neurological deficit and endothelial cell dysfunction after subarachnoid hemorrhage via the KLF3-AS1/miR-83-5p/TCF7L2 axis

BackgroundNew data are accumulating on the effects of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) in cerebrovascular diseases. We explored the potential role of KLF3-AS1-containing bone marrow MSC-EVs (BMSC-EVs) in a rat model of subarachnoid hemorrhage (SAH). MethodsA rat model of SAH was established by endovascular perforation method, into which KLF3-AS1-containing EVs from BMSCs or miR-183-5p mimic were injected. Further, brain microvascular endothelial cells (BMECs) were induced by oxyhemoglobin (OxyHb) to simulate in vitro setting, which were co-cultured with KLF3-AS1-containing EVs from BMSCs. Effects of KLF3-AS1 on neurological deficits in vivo and endothelial cell dysfunction in vitro were investigated. We also performed bioinformatics analysis to predict downstream factors miR-183-5p and TCF7L2, which were verified by RIP, RNA pull-down and luciferase activity assays. ResultsBMSC-EVs was demonstrated to alleviate neurological deficits in SAH rats and endothelial cell dysfunction in OxyHb-induced BMECs. In addition, BMSC-EVs were shown to deliver KLF3-AS1 to BMECs, where KLF3-AS1 bound to miR-183-5p and miR-183-5p targeted TCF7L2. In vivo results confirmed that BMSC-EVs regulated the KLF3-AS1/miR-183-5p/TCF7L2 signaling axis to attenuate neurological deficit and endothelial dysfunction after SAH. ConclusionOverall, KLF3-AS1 delivered by BMSC-EVs upregulate TCF7L2 expression by binding to miR-138-5p, thus attenuating neurological deficits and endothelial dysfunction after SAH.

TCF7L2 plays a complex role in human adipose progenitor biology, which might contribute to genetic susceptibility to type 2 diabetes

IntroductionNon-coding genetic variation at TCF7L2 is the strongest genetic determinant of type 2 diabetes (T2D) risk in humans. TCF7L2 encodes a transcription factor mediating the nuclear effects of WNT signaling in adipose tissue (AT). In vivo studies in transgenic mice have highlighted important roles for TCF7L2 in adipose tissue biology and systemic metabolism. ObjectiveTo map the expression of TCF7L2 in human AT, examine its role in human adipose cell biology in vitro, and investigate the effects of the fine-mapped T2D-risk allele at rs7903146 on AT morphology and TCF7L2 expression. MethodsEx vivo gene expression studies of TCF7L2 in whole and fractionated human AT. In vitro TCF7L2 gain- and/or loss-of-function studies in primary and immortalized human adipose progenitor cells (APCs) and mature adipocytes (mADs). AT phenotyping of rs7903146 T2D-risk variant carriers and matched controls. ResultsAdipose progenitors (APs) exhibited the highest TCF7L2 mRNA abundance compared to mature adipocytes and adipose-derived endothelial cells. Obesity was associated with reduced TCF7L2 transcript levels in whole subcutaneous abdominal AT but paradoxically increased expression in APs. In functional studies, TCF7L2 knockdown (KD) in abdominal APs led to dose-dependent activation of WNT/β-catenin signaling, impaired proliferation and dose-dependent effects on adipogenesis. Whilst partial KD enhanced adipocyte differentiation, near-total KD impaired lipid accumulation and adipogenic gene expression. Over-expression of TCF7L2 accelerated adipogenesis. In contrast, TCF7L2-KD in gluteal APs dose-dependently enhanced lipid accumulation. Transcriptome-wide profiling revealed that TCF7L2 might modulate multiple aspects of AP biology including extracellular matrix secretion, immune signaling and apoptosis. The T2D-risk allele at rs7903146 was associated with reduced AP TCF7L2 expression and enhanced AT insulin sensitivity. ConclusionsTCF7L2 plays a complex role in AP biology and has both dose- and depot-dependent effects on adipogenesis. In addition to regulating pancreatic insulin secretion, genetic variation at TCF7L2 might also influence T2D risk by modulating AP function.

T-cell factor 7L2 is a novel regulator of osteoblast functions that acts in part by modulation of hypoxia signaling.

T-cell-like factor (TCF)7l2, a key effector of canonical Wnt signaling, is highly expressed in bone but nothing is known about its role in regulating osteoblast function. To test this, we generated mice with conditional disruption of Tcf7l2 gene in osteoblast lineages using Tcf7l2 floxed and Col1α2-Cre mice. Skeletal parameters were evaluated using heterozygous conditional knockdown (HCKD) mice since homozygous conditional knockout died during pregnancy or immediately after birth. At 5 wk of age, trabecular bone mass of long bones was reduced by 35% as measured by microcomputed tomography (μCT). Histology data showed a 42% reduction in femur trabecular bone mass caused by reduced bone formation. Knockdown of Tcf7l2 expression in osteoblasts decreased proliferation and differentiation by 20%-40%. Expression levels of genes (Hif1α, Vegf, and β-catenin) targeted by TCF7L2 were decreased by 50% in Tcf7l2-deficient osteoblasts and bones of HCKD mice. We found that the Hif1α gene promoter contained multiple putative TCF7L2 motifs and stabilization of HIF1α protein levels rescued expression of TCF7L2 target genes and alkaline phosphatase (ALP) activity in Tcf7l2-deficient osteoblasts. Furthermore, Tcf7l2 overexpression increased proliferation in the presence of canonical Wnt3a that was not affected by β-catenin inhibitor providing evidence for a noncanonical signaling in mediating TCF7L2 effects. Tcf7l2 expression was increased in response to mechanical strain (MS) in vitro and in vivo, and disruption of Tcf7l2 expression in osteoblasts reduced MS-induced ALP activity by 35%. We conclude that Tcf7l2, a mechanoresponsive gene, is an important regulator of osteoblast function acting, in part, via hypoxia signaling.NEW & NOTEWORTHY TCF7L2 is expressed by bone but it was not known whether TCF7L2 expression influenced bone development. By using a mouse model with conditional disruption of Tcf7l2 in osteoblast lineage cells, we have demonstrated for the first time, that TCF7L2 plays an important role in regulating osteoblasts via a noncanonical pathway.

Activation of WNT/CTNNB1/TCF7L2 in Epstein-Barr virus–positive gastric cancer regulates epithelial mesenchymal transition

Gastric cancer (GC) is the fifth most frequently diagnosed malignant tumour and the third leading cause of cancer-related death. EBV infection is one of the major causes of GC, accounting for approximately 10% of GC cases. Studies revealed that EBV infection could induce malignancy through multilevel mechanisms, including epigenetics state alterations, miRNA regulations, etc. However, it is poorly understood if EBV positive GC has any characteristic oncogenic singling activation. By comparing the transcriptomic of EB positive and negative cell lines, TCGA GC samples, and GC single cells, we identified that canonical WNT signalling is commonly activated in EBV positive GC. Next, we proved that the WNT activation is crucial for the invasiveness of the GC via regulating epithelial-mesenchymal transition (EMT) gene expressions. Then we confirmed that the WNT signalling activation in EBV + GC is through the WNT/CTNNB1 (β-catenin)/TCF7L2 axis with the expression of TCF7L2 indicating worse outcome and more metastasis in EBV+ GCs. Finally, we found that KLF5 is potentially involved as a cooperative transcription factor in the early phase of the EMT process through single-cell pseudotime analysis.

Role of the hydrogen sulfide-releasing donor ADT-OH in the regulation of mammal neural precursor cells.

Neural precursor cells (NPCs) generate new neurons to supplement neuronal loss as well as to repair damaged neural circuits. Therefore, NPCs have potential applications in a variety of neurological diseases, such as spinal cord injury, traumatic brain injury, and glaucoma. Specifically, improving NPCs proliferation and manipulating their differentiated cell types can be a beneficial therapy for a variety of these diseases. ADT-OH is a slow-releasing organic H2 S donor that produces a slow and continuous release of H2 S to maintain normal brain functions. In this study, we aimed to explore the effect of ADT-OH on NPCs. Our results demonstrated that ADT-OH promotes self-renewal and antiapoptosis ability of cultured NPCs. Additionally, it facilitates more NPCs to differentiate into neurons and oligodendrocytes, while inhibiting their differentiation into astrocytes. Furthermore, it enhances axonal growth. Moreover, we discovered that the mRNA and protein expression of β-catenin, TCF7L2, c-Myc, Ngn1, and Ngn2, which are key genes that regulate NPCs self-renewal and differentiation, were increased in the presence of ADT-OH. Altogether, these results indicate that ADT-OH may be a promising drug to regulate the neurogenesis of NPCs, and needs to be studied in the future for clinical application potential.

Role of Ciliary Protein Intraflagellar Transport Protein 88 in the Regulation of Cartilage Thickness and Osteoarthritis Development in Mice.

Mechanical and biologic cues drive cellular signaling in cartilage development, health, and disease. Primary cilia proteins, which are implicated in the transduction of biologic and physiochemical signals, control cartilage formation during skeletal development. This study was undertaken to assess the influence of the ciliary protein intraflagellar transport protein 88 (IFT88) on postnatal cartilage from mice with conditional knockout of the Ift88 gene (Ift88-KO). Ift88fl/fl and aggrecanCreERT2 mice were crossed to create a strain of cartilage-specific Ift88-KO mice (aggrecanCreERT2 ;Ift88fl/fl ). In these Ift88-KO mice and Ift88fl/fl control mice, tibial articular cartilage thickness was assessed by histomorphometry, and the integrity of the cartilage was assessed using Osteoarthritis Research Society International (OARSI) damage scores, from adolescence through adulthood. In situ mechanisms of cartilage damage were investigated in the microdissected cartilage sections using immunohistochemistry, RNAScope analysis, and quantitative polymerase chain reaction. Osteoarthritis (OA) was induced in aggrecanCreERT2 ;Ift88fl/fl mice and Ift88fl/fl control mice using surgical destabilization of the medial meniscus (DMM). Following tamoxifen injection and DMM surgery, the mice were given free access to exercise on a wheel. Deletion of Ift88 resulted in progressive reduction in the thickness of the medial tibial cartilage in adolescent mice, as well as marked atrophy of the cartilage in mice during adulthood. In aggrecanCreERT2 ;Ift88fl/fl mice at age 34 weeks, the median thickness of the medial tibial cartilage was 89.42 μm (95% confidence interval [95% CI] 84.00-93.49), whereas in Ift88fl/fl controls at the same age, the median cartilage thickness was 104.00 μm (95% CI 100.30-110.50; P < 0.0001). At all time points, the median thickness of the calcified cartilage was reduced. In some mice, atrophy of the medial tibial cartilage was associated with complete, spontaneous degradation of the cartilage. Following DMM, aggrecanCreERT2 ;Ift88fl/fl mice were found to have increased OARSI scores of cartilage damage. In articular cartilage from maturing mice, atrophy was not associated with obvious increases in aggrecanase-mediated destruction or chondrocyte hypertrophy. Of the 44 candidate genes analyzed, only Tcf7l2 expression levels correlated with Ift88 expression levels in the microdissected cartilage. However, RNAScope analysis revealed that increased hedgehog (Hh) signaling (as indicated by increased expression of Gli1) was associated with the reductions in Ift88 expression in the tibial cartilage from Ift88-deficient mice. Wheel exercise restored both the articular cartilage thickness and levels of Hh signaling in these mice. Our results in a mouse model of OA demonstrate that IFT88 performs a chondroprotective role in articular cartilage by controlling the calcification of cartilage via maintenance of a threshold of Hh signaling during physiologic loading.