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Aberrant activation of sonic hedgehog (SHH) signaling and its effector transcriptional factor GLI1 are essential for oncogenesis of SHH-dependent medulloblastoma (MB SHH ) and basal cell carcinoma (BCC). Here, we show that SHH inactivates p38α (MAPK14) in a smoothened-dependent manner, conversely, p38α directly phosphorylates GLI1 on Ser937/Ser941 (human/mouse) to induce GLI1’s proteasomal degradation and negates the transcription of SHH signaling. As a result, Gli1 S941E loss-of-function knock-in significantly reduces the incidence and severity of smoothened-M2 transgene-induced spontaneous MB SHH , whereas Gli1 S941A gain-of-function knock-in phenocopies Gli1 transgene in causing BCC-like proliferation in skin. Correspondingly, phospho-Ser937-GLI1, a destabilized form of GLI1, positively correlates to the overall survival rate of children with MB SHH . Together, these findings indicate that SHH-induced p38α inactivation and subsequent GLI1 dephosphorylation and stabilization in controlling SHH signaling and may provide avenues for future interventions of MB SHH and BCC. Upregulation of GLI1 of has previously been reported in sonic hedgehog (SHH) driven medulloblastoma and basal cell carcinoma (BCC). Here, the authors find that SHH-inactivation of p38 results in stabilization of the transcription factor GLI1 via dephosphorylation at Ser937, resulting in expression of SHH genes and presenting a potential therapy strategy for medulloblastoma and BCC.

Preeclampsia (PE), a pregnancy-specific syndrome with the major molecular determinants of placenta-borne oxidative stress and consequently impaired nitric oxide (NO) generation, has been considered to be one of the leading causes of maternal morbidity as well as mortality and preterm delivery worldwide. Several medical conditions have been found to be associated with increased PE risk, however, the treatment of PE remains unclear. Here, we report that Tianma Gouteng Decoction (TGD), which is used clinically for hypertension treatment, regulates oxidative stress and NO production in human extravillous trophoblast-derived TEV-1 cells. In human preeclamptic placental explants, reactive oxygen species (ROS) levels were elevated and NO production was inhibited, while TGD treatment at different periods effectively down-regulated the H 2 O 2 -induced ROS levels and significantly up-regulated the H 2 O 2 -suppressed NO production in human TEV-1 cells. Mechanistically, TGD enhanced the activity of total nitric oxide synthase (TNOS), which catalyze L-arginine oxidation into NO, and simultaneously , TGD promoted the expression of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS), two isoforms of nitric oxide synthetases (NOS) in human placenta, resulting in the increased NO generation. More importantly, TGD administration not only increased the weight gain during pregnancy and revealed a hypotensive effect, but also improved the placental weight gain and attenuated fetal growth restriction in an NG-nitro-L-arginine methyl ester (L-NAME)-induced mouse PE-like model. Our results thereby provide new insights into the role of TGD as a potentially novel treatment for PE.

Large tumour suppressor (LATS) 1/2, the core kinases of Hippo signalling, are critical for maintaining tissue homeostasis. Here, we investigate the role of SUMOylation in the regulation of LATS activation. High cell density induces the expression of components of the SUMOylation machinery and enhances the SUMOylation and activation of Lats1 but not Lats2, whereas genetic deletion of the SUMOylation E2 ligase, Ubc9 , abolishes this Lats1 activation. Moreover, SUMOylation occurs at the K830 (mouse K829) residue to activate LATS1 and depends on the PIAS1/2 E3 ligase. Whereas the K830 deSUMOylation mutation of LATS1 found in the human metastatic prostate cancers eliminates the kinase activity by attenuating the formation of the phospho-MOB1/phospho-LATS1 complex. As a result, the LATS1(K830R) transgene phenocopies Yap transgene to cause the oversized livers in mice, whereas Lats1(K829R) knock-in phenocopies the deletion of Lats1 in causing the reproductive and endocrine defects and ovary tumours in mice. Thus, SUMOylation-mediated LATS1 activation is an integral component of Hippo signalling in the regulation of tissues homeostasis.

The Wnt/β-catenin signaling pathway appears to be particularly important for bone homeostasis, whereas nuclear accumulation of β-catenin requires the activation of Rac1, a member of the Rho small GTPase family. The aim of the present study was to investigate the role of RhoA/Rho kinase (Rock)-mediated Wnt/β-catenin signaling in the regulation of aging-associated bone loss. We find that Lrp5/6-dependent and Lrp5/6-independent RhoA/Rock activation by Wnt3a activates Jak1/2 to directly phosphorylate Gsk3β at Tyr216, resulting in Gsk3β activation and subsequent β-catenin destabilization. In line with these molecular events, RhoA loss- or gain-of-function in mouse embryonic limb bud ectoderms interacts genetically with Dkk1 gain-of-function to rescue the severe limb truncation phenotypes or to phenocopy the deletion of β-catenin , respectively. Likewise, RhoA loss-of-function in pre-osteoblasts robustly increases bone formation while gain-of-function decreases it. Importantly, high RhoA/Rock activity closely correlates with Jak and Gsk3β activities but inversely correlates with β-catenin signaling activity in bone marrow mesenchymal stromal cells from elderly male humans and mice, whereas systemic inhibition of Rock therefore activates the β-catenin signaling to antagonize aging-associated bone loss. Taken together, these results identify RhoA/Rock-dependent Gsk3β activation and subsequent β-catenin destabilization as a hitherto uncharacterized mechanism controlling limb outgrowth and bone homeostasis.

The nuclear translocation of transcriptional factor Gli is indispensable for Hedgehog (Hh) signaling activation, whose deregulation causes cancer progressions; however, the mechanisms governing Gli nuclear translocation are poorly understood. Here, we report that the Gli translocation in response to Hh requires Rac1 activation. C3H10T1/2 cell line and mouse embryonic fibroblasts were used to explore the molecular mechanisms underlying Rac1 activity in regulation of Hh signaling transduction. Transgenic mouse strains and human medulloblastoma (MB) tissue samples were utilized to examine the role of Rac1 in Hh-directed limb bud development and MB progression. We show that upon the binding of Hh to receptor Patched1 (Ptch1), receptor Smoothened (Smo) dissociates from Ptch1 and binds to Vav2, resulting in the increased phosphorylation levels of Vav2 at Y172, which further activates Rac1. The role of Rac1 is dependent on the regulation of phosphorylation levels of KIF3A at S689 and T694, which in turn affects IFT88 stability and subsequently dampens SuFu-Gli complex formation, leading to the release of Gli from the complex and the consequent translocation of Gli into the nucleus. Moreover, Vav2 phospho-Y172 levels are up-regulated in mouse cerebellum and human Shh type MB tissues, whereas deficiency of in mouse embryonic limb bud ectoderm ( ) impedes Hh activation by disruption of Gli nuclear translocation. Together, our results uncover the Rac1 activation and the subsequent Gli translocation as a hitherto uncharacterized mechanism controlling Hh signaling and may provide targets for therapeutic intervention of this signaling pathway.

Acute myeloid leukemia (AML) is a malignant blood cancer resulting from leukemia stem cells (LSCs) supplanting normal stem cells. Platelet-derived growth factors (PDGFs) are important for LSCs but have not been studied in the development of AML. In this study, transcriptome data of PDGFs were sourced from The Cancer Genome Atlas (TCGA) and GTEx databases, and relevant differential expression and prognosis analysis were performed using R software packages and online tools (UCSC-Xena Shiny tools, GEPIA2, Kaplan-Meier Plotter databases, etc.). Then, we focused on PDGFD expression in AML, along with its clinical and diagnostic importance, drug resistance studies, and association with immunotherapy. The real-time quantitative polymerase chain reaction (RT-qPCR) was performed to verify the expression and clinical characteristics of PDGFD. Analyses of public data and clinical samples revealed that PDGFD expression was upregulated compared with other PDGF genes, and only this upregulation was associated with poor prognosis in AML. High expression of PDGFD showed a significant positive correlation with intermediate-high cytogenetic risk, NPM1 mutation, FLT3-ITD mutation, and unfavorable prognosis. ROC curve analysis indicated that PDGFD holds substantial diagnostic potential for AML patients. Functional enrichment analysis revealed the role of PDGFD in calcium and Rap1 signaling pathways. Additionally, PDGFD expression exhibited a significant positive correlation with natural killer cells and dendritic cells. Furthermore, we propose that MiR-203-3p targeting PDGFD has potential anti-leukemic effects in AML. In conclusion, PDGFD serves as a possible diagnostic and prognostic biomarker, as well as a target for cellular immunotherapy in AML.