Depletion of Mob1a/b causes intestinal epithelia degeneration by suppressing Wnt and activating BMP/Tgfβ signaling
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE103338 | GEO | 2017/09/01
SECONDARY ACCESSION(S): PRJNA401696
REPOSITORIES: GEO
Similar Datasets
Project description:The Hippo pathway is involved in intestinal epithelial homeostasis with Wnt, BMP, Notch, and EGF signaling. We investigated the relationship between Hippo and other signaling pathways and the role of MOB kinase activator 1A/1B (MOB1A/B) in intestinal homeostasis. Mice with intestinal epithelial cell (IEC)-specific depletion of MOB1A/B showed hyperproliferation in IECs, defects in secretory lineage differentiation and loss of intestinal stem cells and eventually died at 10-12 days after tamoxifen treatment. In MOB1A/B-depleted IECs, expression of Wnt target genes were downregulated but Bmp2 and Tgfbr2 were transcriptionally activated with enhanced YAP activity. In in vivo and in vitro experiments with several signaling inhibitors, it has been shown that the BMP inhibitor LDN193189 or TGF-? inhibitor SB431542 had effects on partial restoration of the intestinal degenerative phenotype. Treatment with these inhibitors restored differentiation of secretory lineage cells in MOB1A/B-deficient mice, but not ISC pools in the crypt region. These studies reveal that IEC-specific depletion of MOB1A/B induced overexpression of Bmp2 and Tgfbr2 and inhibited Wnt activity, finally leading to loss of ISCs and functional epithelia in the mouse intestine. These results suggest that MOB1A/B has an essential function for intestinal epithelial homeostasis by regulating YAP, Wnt activity, and BMP/TGF-? signaling.
| S-EPMC6197243 | biostudies-literature
Project description:BackgroundThe clinical healing environment after a posterior spinal arthrodesis surgery is one of the most clinically challenging bone-healing environments across all orthopedic interventions due to the absence of a contained space and the need to form de novo bone. Our group has previously reported that sclerostin in expressed locally at high levels throughout a developing spinal fusion. However, the role of sclerostin in controlling bone fusion remains to be established.MethodsWe computationally identified two FDA-approved drugs, as well as a single novel small-molecule drug, for their ability to disrupt the interaction between sclerostin and its receptor, LRP5/6. The drugs were tested in several in vitro biochemical assays using murine MC3T3 and MSCs, assessing their ability to (1) enhance canonical Wnt signaling, (2) promote the accumulation of the active (non-phosphorylated) form of β-catenin, and (3) enhance the intensity and signaling duration of BMP signaling. These drugs were then tested subcutaneously in rats as standalone osteoinductive agents on plain collagen sponges. Finally, the top drug candidates (called VA1 and C07) were tested in a rabbit posterolateral spine fusion model for their ability to achieve a successful fusion at 6 wk.ResultsWe show that by controlling GSK3b phosphorylation our three small-molecule inhibitors (SMIs) simultaneously enhance canonical Wnt signaling and potentiate canonical BMP signaling intensity and duration. We also demonstrate that the SMIs produce dose-dependent ectopic mineralization in vivo in rats as well as significantly increase posterolateral spine fusion rates in rabbits in vivo, both as standalone osteogenic drugs and in combination with autologous iliac crest bone graft.ConclusionsFew if any osteogenic small molecules possess the osteoinductive potency of BMP itself - that is, the ability to form de novo ectopic bone as a standalone agent. Herein, we describe two such SMIs that have this unique ability and were shown to induce de novo bone in a stringent in vivo environment. These SMIs may have the potential to be used in novel, cost-effective bone graft substitutes for either achieving spinal fusion or in the healing of critical-sized fracture defects.FundingThis work was supported by a Veteran Affairs Career Development Award (IK2-BX003845).
| S-EPMC10431921 | biostudies-literature
Project description:Colorectal cancer (CRC) is one of the most common cancers, but the mechanisms underlying its initiation and progression are largely unknown. TGIF1 (TGFB induced factor homeobox 1) is a transcriptional corepressor that belongs to the three-amino acid loop extension (TALE) superclass of atypical homeodomains. It has been reported that TGIF1 is highly expressed in mammary cancer and non-small cell lung cancer and can enhance tumor progression. However, the role of TGIF1 in colorectal cancer remains unknown. Here, we report that TGIF1 is significantly upregulated in colorectal cancers, and its high expression predicts poor prognosis. Overexpression of TGIF1 markedly promotes the proliferation of colorectal cancer cells both in vivo and in vitro. In addition, TGIF1 activates Wnt/β-catenin signaling, and the homeodomain is indispensable for Wnt activation and β-catenin interaction. Taken together, our results suggest that TGIF1 is a novel colorectal tumor promoter and indicate that TGIF1 enhances colorectal cancer tumorigenesis through activating Wnt signaling.
| S-EPMC5642548 | biostudies-literature
Project description:Background:Gukang capsule (GKC) is a traditional Chinese medicine formulation which has been used extensively in the clinical treatment of bone fractures. However, the mechanisms underlying its effects on fracture healing remain unclear. Methods:In this study we used a rabbit radius fracture model, and we measured the serum content of bone alkaline phosphatase (ALP), calcium, and phosphorus and examined pathology of the fracture site as indicators of the fracture healing effects of GKC. SaOS-2 human osteosarcoma cells were used to measure (i) ALP activity, (ii) ornithine transcarbamylase (OTC), calcium, and mineralization levels, (iii) the expression of osteogenic-related genes, that is, runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2), collagen I (COL-I), osteopontin (OPN), OTC, and osterix (Osx), and (iv) the expression of key proteins in the Wnt/?-catenin and BMP/SMAD signaling pathways to study the mechanisms by which GKC promotes fracture healing. Results:We found that GKC effectively promotes radius fracture healing in rabbits and enhances ALP activity, increases OTC and calcium levels, and stimulates the formation of mineralized nodules in SaOS-2?cells. Moreover, COL-I, OTC, Osx, BMP2, and OPN expression levels were higher in SaOS-2?cells treated with GKC than control cells. GKC upregulates glycogen synthase kinase 3? (GSK3?) phosphorylation and Smad1/5 and ?-catenin protein levels, thereby activating Wnt/?-catenin and BMP/Smad signaling pathways. Inhibitors of the Wnt/?-catenin and BMP/Smad signaling pathways (DKK1 and Noggin, respectively) suppress the osteogenic effects of GKC. Conclusions:GKC promotes fracture healing by activating the Wnt/?-catenin and BMP/Smad signaling pathways and increasing osteoprotegerin (OPG) secretion by osteoblasts (OBs), which prevents receptor activator of nuclear factor kappa B ligand (RANKL) binding to RANK.
| S-EPMC7545469 | biostudies-literature
Project description:Bardet-Biedl syndrome (BBS) is a heterogeneous disease characterized by deficiencies in various organs that are caused by defects in genes involved in the genesis, structural maintenance, and protein trafficking of cilia. Leucine zipper transcription factor-like 1 (LZTFL1) has been identified as a BBS protein (BBS17), because patients with mutations in this gene exhibit the common BBS phenotypes. In this study, we generated a knockout mouse model to investigate the effects of LZTFL1 depletion. Lztfl1 knockout mice were born with low birth weight, reached similar weight to those of wild-type mice at 10 weeks of age, and later gained more weight than their wild-type counterparts. LZTFL1 was localized to the primary cilium of kidney cells, and the absence of LZTFL1 increased the ciliary localization of BBS9. Moreover, in the retinas of Lztfl1 knockout mice, the photoreceptor outer segment was shortened, the distal axoneme of photoreceptor connecting cilium was significantly enlarged, and rhodopsin was targeted to the outer nuclear layer. TUNEL assay showed that many of these abnormal photoreceptor cells in Lztfl1 knockout mice underwent apoptosis. Interestingly, the absence of LZTFL1 caused an abnormal increase of the adaptor protein complex 1 (AP1) in some photoreceptor cells. Based on these data, we conclude that LZTFL1 is a cilium protein and regulates animal weight and photoreceptor connecting cilium function probably by controlling microtubule assembly and protein trafficking in cilia.
| S-EPMC4925197 | biostudies-literature
Project description:Spondylocarpotarsal synostosis (SCT) is an autosomal recessive disorder characterized by progressive vertebral fusions and caused by loss of function mutations in Filamin B (FLNB). FLNB acts as a signaling scaffold by linking the actin cytoskleteon to signal transduction systems, yet the disease mechanisms for SCT remain unclear. Employing a Flnb knockout mouse, we found morphologic and molecular evidence that the intervertebral discs (IVDs) of Flnb-/-mice undergo rapid and progressive degeneration during postnatal development as a result of abnormal cell fate changes in the IVD, particularly the annulus fibrosus (AF). In Flnb-/-mice, the AF cells lose their typical fibroblast-like characteristics and acquire the molecular and phenotypic signature of hypertrophic chondrocytes. This change is characterized by hallmarks of endochondral-like ossification including alterations in collagen matrix, expression of Collagen X, increased apoptosis, and inappropriate ossification of the disc tissue. We show that conversion of the AF cells into chondrocytes is coincident with upregulated TGFβ signaling via Smad2/3 and BMP induced p38 signaling as well as sustained activation of canonical and noncanonical target genes p21 and Ctgf. These findings indicate that FLNB is involved in attenuation of TGFβ/BMP signaling and influences AF cell fate. Furthermore, we demonstrate that the IVD disruptions in Flnb-/-mice resemble aging degenerative discs and reveal new insights into the molecular causes of vertebral fusions and disc degeneration.
| S-EPMC4809497 | biostudies-literature
Project description:A full understanding of the key regulators controlling periodontal development and homeostasis is necessary for the design of improved periodontal regenerative therapies. Small leucine-rich proteoglycans (SLRPs) are extracellular matrix molecules suggested to regulate collagen organization and cell signaling. Mice with double-deficiency of 2 SLRPs, fibromodulin and biglycan (dKO), acquire skeletal abnormalities, but their roles in regulating the periodontium remain undefined and were the focus of our studies. Transmission electron microscopy studies showed abnormal collagen fibrils in the periodontal ligament (PDL) and altered remodeling of alveolar bone in dKO mice. Immunohistochemistry (IHC) revealed increased staining of SLRPs (asporin, lumican, and decorin) and dentin matrix protein-1 (DMP1, a mechanosensory/osteocyte marker), while osteoblast markers, bone sialoprotein and osteopontin, remained unchanged. Disruption of homeostasis was further evidenced by increased expression of receptor-activator of nuclear factor-κB ligand (RANKL) and elevated numbers of osteoclasts, especially noted around the alveolar bone of molars (buccal side) and incisors. Polymerase chain reaction (PCR) array revealed hyperactive transforming growth factors beta/bone morphogenetic protein (TGFβ/BMP) signaling in dKO PDL tissues, which was further confirmed by elevated expression of phosphorylated Smad5 (p-Smad5) by IHC in dKO PDL. These studies highlight the importance of SLRPs in maintaining periodontal homeostasis through regulation of TGFβ/BMP signaling, matrix turnover, and collagen organization.
| S-EPMC4126226 | biostudies-literature
Project description:The β-catenin mutation is frequently observed in hepatoblastoma (HB), but the underlying mechanism by which Wnt/β-catenin signaling induces HB tumor formation is unknown. We found that expression of growth regulation by estrogen in breast cancer 1 (GREB1) depends on Wnt/β-catenin signaling in HB patients. GREB1 was localized to the nucleus where it bound Smad2/3 in a competitive manner with p300 and inhibited TGFβ signaling, thereby promoting HepG2 HB cell proliferation. Forced expression of β-catenin, YAP, and c-Met induced HB-like mouse liver tumor (BYM mice), with an increase in GREB1 expression and HB markers. Depletion of GREB1 strongly suppressed marker gene expression and HB-like liver tumorigenesis, and instead enhanced TGFβ signaling in BYM mice. Furthermore, antisense oligonucleotides for GREB1 suppressed the formation of HepG2 cell-induced tumors and HB-like tumors in vivo. We propose that GREB1 is a novel target molecule of Wnt/β-catenin signaling and required for HB progression.
2019-07-18 | GSE133976 | GEO
Project description:SMAD4 constrains progression of Pten-null prostate cancer and serves as a common downstream node of transforming growth factor β (TGFβ) and bone morphogenetic protein (BMP) pathways. Here, we dissected the roles of TGFβ receptor II (TGFBR2) and BMP receptor II (BMPR2) using a Pten-null prostate cancer model. These studies demonstrated that the molecular actions of TGFBR2 result in both SMAD4-dependent constraint of proliferation and SMAD4-independent activation of apoptosis. In contrast, BMPR2 deletion extended survival relative to Pten deletion alone, establishing its promoting role in BMP6-driven prostate cancer progression. These analyses reveal the complexity of TGFβ-BMP signaling and illuminate potential therapeutic targets for prostate cancer.
| S-EPMC5795781 | biostudies-literature
Project description:Platelet-derived growth factor-BB (PDGF-BB) is a cytokine involved in tissue repair and tumor progression. It has been found to have expression differences between normal and degenerative intervertebral discs. However, it is not clear whether PDGF-BB has a protective effect on intervertebral disc degeneration (IDD). In this experiment, we treated nucleus pulposus cells (NPCs) with IL-1β to simulate an inflammatory environment and found that the extracellular matrix (ECM) anabolic function of NPCs in an inflammatory state was inhibited. Moreover, the induction of IL-1β also enhanced the expression of NLRP3 and the cleavage of caspase-1 and IL-1β, which activated the pyroptosis of NPCs. In this study, we studied the effect of PDGF-BB on IL-1β-treated NPCs and found that PDGF-BB not only significantly promotes the ECM anabolism of NPCs, but also inhibits the occurrence of pyroptosis and the production of pyroptosis products of NPCs. Consistent with this, when we used imatinib to block the PDGF-BB receptor, the above-mentioned protective effect disappeared. In addition, we found that PDGF-BB can also promote the ECM anabolism of NPCs by regulating the ERK, JNK, PI3K/AKT signaling pathways, but not the P38 signaling pathway. In vivo studies, mice that blocked PDGF-BB receptors showed more severe histological manifestations of intervertebral disc degeneration. In summary, our results indicate that PDGF-BB participates in inhibiting the occurrence and development of IDD by inhibiting pyroptosis and regulating the MAPK signaling pathway.
| S-EPMC8795915 | biostudies-literature