Hedgehog Signaling Research Articles

Pharmacokinetics and Bioavailability Study of a Novel Smoothened Inhibitor TPB15 for Treatment of Triple-Negative Breast Cancer in Rats by High Performance Liquid Chromatography-Mass Spectrometry.

Smoothened (SMO), a key component of the hedgehog signaling pathway, represents a therapeutic target for triple negative breast cancer(TNBC), yet the chemotherapy response rate in TNBC patients is only 40-50%, underscoring the urgent need for the development of novel drugs to effectively treat this condition. The novel compound TPB15, an SMO inhibitor derived from [1,2,4] triazolo [4,3-α] pyridines, demonstrated superior anti-TNBC activity and lower toxicity compared to the first SMO inhibitor vismodegib in both in vitro and in vivo. However, the compound's pharmacokinetic properties remain unclear. The present work aims to develop a simple HPLC-MS/MS method to profile the pharmacokinetics and bioavailability of TPB15 in rats as a ground work for further clinical research. Separation was performed on an Agilent ZORBAX StableBond C18 column by gradient elution using acetonitrile and 0.1% formic acid as mobile phase at a flow rate of 0.3mL/min. Multiple reaction monitoring(MRM) in positive mode with the transitions of m/z 454.2 → 100.0, 248.1 → 121.1 was employed to determine TPB15 and internal standard tinidazole, respectively. The specificity, intra- and inter- day precision and accuracy, extraction recovery, stability, matrix effect, dilution integrity and carryover of the method was validated. The pharmacokinetics and bioavailability studyof TPB15 were carried out on rats through intravenous injection at the dose of 5 mg/kg and oral gavage at the dose of 25 mg/kg, and the pharmacokinetics parameters were calculated by the non-compartment analysis using the pharmacokinetics software DAS 2.1.1. The values of specificity, intra- and inter- day precision and accuracy, extraction recovery, stability, matrix effect, dilution integrity and carryover satisfied the acceptable limits. The lower limit of quantification of this method was 10 ng/mL with a linear range of 10-2000ng/mL. The validated method was then applied to pharmacokinetics and bioavailability studies in rat by dosing with gavage (25mg/kg) and intravenous injection(5mg/kg), and the oral bioavailability of TBP15 in rat was calculated as 16.4 ± 3.5%. The pharmacokinetic parameters were calculated as following: maximum of plasma concentration (Cmax) (PO: 2787.17 ± 279.45µg/L), Time to maximum plasma concentration (Tmax) (PO: 4.20 ± 0.90 h), the area under the concentration-time curve 0 to time (AUC0-t) (PO: 17,373.03 ± 2585.18 ng/mL·h, IV: 21,129.79 ± 3360.84ng/mL·h), the area under the concentration-time curve 0 to infinity (AUC0-∞) (PO: 17,443.85 ± 2597.63 ng/mL·h, IV: 17,443.85 ± 2597.63ng/mL·h), terminal elimination half-life (t1/2) (PO: 7.26 ± 2.16h, IV: 4.78 ± 1.09h). TPB15, a promising candidate for treating TNBC, hasdemonstrated outstanding efficacy and safety in vitro and in vivo. This study established a simple, sensitive, and rapid HPLC-MS/MS bioanalytical method, developed and validated in accordance with FDA and EMA guidelines, for conducting pharmacokinetic and bioavailability studies of TPB15. The results revealed a favorable pharmacokinetic profile owing to its long t1/2. Nevertheless, the next phase of research should include formulation screening to enhance bioavailability, as well as clinical trials, metabolism pathway analysis, and assessment of potential drug-drug interactions.

Molecular mechanism of skeletal muscle loss and its prevention by natural resources.

A skeletal muscle disorder has drawn attention due to the global aging issues. The loss of skeletal muscle mass has been suggested to be from the reduced muscle regeneration by dysfunction of muscle satellite cell/fibro-adipogenic progenitor cells and the muscle atrophy by dysfunction of mitochondria, ubiquitin-proteasome system, and autophagy. In this review, we highlighted the underlying mechanisms of skeletal muscle mass loss including Notch signaling, Wnt/β-catenin signaling, Hedgehog signaling, AMP-activated protein kinase (AMPK) signaling, and mammalian target of rapamycin (mTOR) signaling. In addition, we summarized accumulated studies of natural resources investigating their roles in ameliorating the loss of skeletal muscle mass and demonstrating the underlying mechanisms in vitro and in vivo. In conclusion, following the studies of natural resources exerting the preventive activity in muscle mass loss, the signaling-based approaches may accelerate the development of functional foods for sarcopenia prevention.

Villification of the intestinal epithelium is driven by Foxl1.

The primitive gut tube of mammals initially forms as a simple cylinder consisting of the endoderm-derived, pseudostratified epithelium and the mesoderm-derived surrounding mesenchyme. During mid-gestation a dramatic transformation occurs in which the epithelium is both restructured into its final cuboidal form and simultaneously folded and refolded to create intestinal villi and intervillus regions, the incipient crypts. Here we show that the mesenchymal winged helix transcription factor Foxl1, itself induced by epithelial hedgehog signaling, controls villification by activating BMP and PDGFRa as well as planar cell polarity genes in epithelial-adjacent telocyte progenitors, both directly and in a feed- forward loop with Foxo3. In the absence of Foxl1-dependent mesenchymal signaling, villus formation is delayed, the separation of epithelial cells into mitotic intervillus and postmitotic villus cells impaired, and the differentiation of secretory progenitors blocked. Thus, Foxl1 orchestrates key events during the epithelial transition of the fetal mammalian gut.

Targeting Super-Enhancer-Driven Transcriptional Dependencies Suppresses Aberrant Hedgehog Pathway Activation and Overcomes Smoothened Inhibitor Resistance.

Aberrant activation of the Hedgehog (Hh) signaling pathway plays important roles in oncogenesis and therapeutic resistance in several types of cancer. The clinical application of FDA-approved Hh-targeted smoothened inhibitors (SMOi) is hindered by the emergence of primary or acquired drug resistance. Epigenetic and transcriptional-targeted therapies represent a promising direction for developing improved anti-Hh therapies. In this study, we integrated epigenetic/transcriptional-targeted small-molecule library screening with CRISPR/Cas9 knockout library screening and identified CDK9 and CDK12, two transcription elongation regulators, as therapeutic targets for antagonizing aberrant Hh activation and overcoming SMOi resistance. Inhibition of CDK9 or CDK12 potently suppressed Hh signaling and tumor growth in various SMOi responsive or resistant Hh-driven tumor models. Systemic epigenomic profiling elucidated the Hh-driven super-enhancer (SE) landscape and identified IRS1, encoding a critical component and cytoplasmic adaptor protein of the insulin-like growth factor (IGF) pathway, as an oncogenic Hh-driven SE target gene and effective therapeutic target in Hh-driven tumor models. Collectively, this study identifies SE-driven transcriptional dependencies that represent promising therapeutic vulnerabilities for suppressing the Hh pathway and overcoming SMOi resistance. As CDK9 and IRS inhibitors have already entered human clinical trials for cancer treatment, these findings provide comprehensive preclinical support for developing trials for Hh-driven cancers. Significance: Dissecting transcriptional dependencies driven by super-enhancers uncovers therapeutic targets in Hedgehog-driven cancers and identifies strategies for overcoming resistance to smoothened inhibitors.

Vascular smooth muscle cell-derived exosomes promote osteoblast-to-osteocyte transition via β-catenin signaling

Blood vessel growth and osteogenesis in the skeletal system are coupled; however, fundamental aspects of vascular function in osteoblast-to-osteocyte transition remain unclear. Our study demonstrates that vascular smooth muscle cells (VSMCs), but not endothelial cells, are sufficient to drive bone marrow mesenchymal stromal cell-derived osteoblast-to-osteocyte transition via β-catenin signaling and exosome-mediated communication. We found that VSMC-derived exosomes are loaded with transcripts encoding proteins associated with the osteocyte phenotype and members of the WNT/β-catenin signaling pathway. In contrast, endothelial cell-derived exosomes facilitated mature osteoblast differentiation by reprogramming the TGFB1 gene family and osteogenic transcription factors osterix (SP7) and RUNX2. Notably, VSMCs express significant levels of tetraspanins (CD9, CD63, and CD81) and drive the intracellular trafficking of exosomes with a lower membrane zeta potential than those from other cells. Additionally, the high ATP content within these exosomes supports mineralization mechanisms, as ATP is a substrate for alkaline phosphatase. Osteocyte function was further validated by RNA sequencing, revealing activity in genes related to intermittent mineralization and sonic hedgehog signaling, alongside a significant increase in TNFSF11 levels. Our findings unveil a novel role of VSMCs in promoting osteoblast-to-osteocyte transition, thus offering new insights into bone biology and homeostasis, as well as in bone-related diseases. Clinically, these insights could pave the way for innovative therapeutic strategies targeting VSMC-derived exosome pathways to treat bone-related disorders such as osteoporosis. By manipulating these signaling pathways, it may be possible to enhance bone regeneration and improve skeletal health in patients with compromised bone structure and function.

Constructing condylar cartilage organoid to explore primary cilia functions

An organoid culture system better recapitulates the cellular structure, function, and interaction between cells and the extracellular matrix (ECM) than a two-dimensional (2D) culture system. We here constructed a condylar cartilage organoid to explore the regulatory role of primary cilia. Similar to the natural condylar cartilage, the condylar cartilage organoid exhibited abundant ECM and comprised superficial, proliferative, and hypertrophic zones. Primary cilia in the condylar cartilage organoid were shorter on average than those in the 2D culture chondrocytes, but their average length was equivalent to those in the natural condylar cartilage. Notably, primary cilia in each zone of the condylar cartilage organoid had an average length similar to that of primary cilia in the natural condylar cartilage. According to transcriptomic and biochemical analyses, the expression of cilia-related genes and cilia-related Hedgehog (HH) signaling differed between the condylar cartilage organoid and 2D culture systems. IFT88 knockdown promoted the protein levels of COL-Ⅹ, TRPV4, and HH signaling molecules in the condylar cartilage organoid, but decreased them in the 2D culture system. Notably, the protein levels of COL-Ⅹ, TRPV4, and HH signaling molecules increased in the superficial zone of the si IFT88 condylar cartilage organoid compared with the condylar cartilage organoid. However, the protein levels of aforementioned molecules were not significantly different in proliferative and hypertrophic zones. Collectively, we successfully constructed the condylar cartilage organoid with a better tissue structure and abundant ECM. Moreover, the condylar cartilage organoid is more suitable for exploring primary cilia functions.

GRK2 kinases in the primary cilium initiate SMOOTHENED-PKA signaling in the Hedgehog cascade.

During Hedgehog (Hh) signal transduction in development and disease, the atypical G protein-coupled receptor (GPCR) SMOOTHENED (SMO) communicates with GLI transcription factors by binding the protein kinase A catalytic subunit (PKA-C) and physically blocking its enzymatic activity. Here, we show that GPCR kinase 2 (GRK2) orchestrates this process during endogenous mouse and zebrafish Hh pathway activation in the primary cilium. Upon SMO activation, GRK2 rapidly relocalizes from the ciliary base to the shaft, triggering SMO phosphorylation and PKA-C interaction. Reconstitution studies reveal that GRK2 phosphorylation enables active SMO to bind PKA-C directly. Lastly, the SMO-GRK2-PKA pathway underlies Hh signal transduction in a range of cellular and in vivo models. Thus, GRK2 phosphorylation of ciliary SMO and the ensuing PKA-C binding and inactivation are critical initiating events for the intracellular steps in Hh signaling. More broadly, our study suggests an expanded role for GRKs in enabling direct GPCR interactions with diverse intracellular effectors.

Mesenchymal stem cells-derived exosomes alleviate liver fibrosis by targeting Hedgehog/SMO signaling.

Despite increasing knowledge regarding the cellular and molecular mechanisms of liver fibrogenesis, there is currently no approved drug for the treatment of liver fibrosis. Mesenchymal stem cells (MSCs) are multipotent progenitor cells representing an attractive therapeutic tool for tissue damage and inflammation. This study was designed to determine the protective effect and underlying mechanism of human umbilical cord-derived MSCs (UC-MSCs) on thioacetamide-induced liver fibrosis. Liver fibrosis was induced in mice by intraperitoneal injection of thioacetamide (TAA). Some mice were then given injection of UC-MSCs or UC-MSCs-derived exosomes (UC-MSCs-Exo) via the tail vein. Liver tissues were collected for histologic analysis. We found that administration of UC-MSCs significantly reduced serum alanine aminotransferase and aspartate aminotransferase levels, and attenuated hepatic inflammation and fibrosis. Moreover, the therapeutic effect of UC-MSCs-derived exosomes was similar to that of UC-MSCs. Intriguingly, UC-MSCs-Exo treatment downregulated the expression of smoothened (SMO), a fundamental component of Hedgehog signaling which plays a critical role in fibrogenesis, and subsequently inhibited the activation of hepatic stellate cells, a central driver of fibrosis in experimental and human liver injury. Furthermore, the anti-inflammatory and anti-fibrotic effects of UCMSCs- Exo was reversed by the SMO agonist SAG treatment in mice. Our findings suggest that UC-MSCs-Exo exert therapeutic effects on liver fibrosis, at least in part, through inhibiting the Hedgehog/SMO signaling pathway.

Benzaldehyde stimulates autophagy via the sonic hedgehog signaling pathway in mouse brain astrocytes after treatment with Angiostrongylus cantonensis excretory-secretory products

Autophagy is a vital cellular process responsible for digesting various cytoplasmic organelles. This process plays a crucial role in maintaining cell survival and homeostasis, especially under conditions that cause nutrient deficiency, cellular damage, and oxidative stress. Neuroangiostrongyliasis is an infection caused by the parasitic nematode Angiostrongylus cantonensis and is considered as an emerging disease in many parts of the world. However, effective therapeutic strategies for neuroangiostrongyliasis still need to be further developed. In this study, we investigated the effects of benzaldehyde treatment on autophagy and sonic hedgehog (Shh) signaling in A. cantonensis-infected mice and its mechanisms. First, we found autophagosome generation in the central nervous system after A. cantonensis infection. Next, benzaldehyde combined with albendazole treatment reduced eosinophilic meningitis and upregulated the expression of Shh signaling- and autophagy-related molecules in A. cantonensis-infected mouse brains. In vitro experiments demonstrated that benzaldehyde could induce autophagy via the Shh signaling pathway in A. cantonensis excretory-secretory products (ESPs)-treated mouse astrocytes. Finally, benzaldehyde treatment also decreased lipid droplet accumulation and increased cholesterol production by activating the Shh pathway after ESPs treatment. In conclusion, these findings suggested that benzaldehyde treatment could alleviate brain damage by stimulating autophagy generation through the Shh signaling pathway.

Bitter taste receptors as prognostic markers in adrenocortical carcinoma.

230 Background: Adrenocortical carcinoma (ACC) is a rare malignant neoplasm of the adrenal gland. Progressive forms of this cancer carry a dismal prognosis with 5-year survival rates < 40%. As such, predictors of stage progression and prognostic biomarkers are a must. Taste 2 receptors (TAS2Rs) are localized on the surface of bitter receptor cells. Recent evidence has shown their role as prognostic biomarkers in multiple cancers, such as breast, prostate, and head and neck squamous cell carcinoma. The aim of this study was to elucidate the role of TAS2Rs in ACC. Methods: Differentially expressed genes (DEGs) based on high and low expression groups of TAS2R genes were identified through the 'DESeq2' package on R. Subsequent Gene Set Enrichment Analysis (GSEA) was performed using the 'TCGAbiolinks' package on R and Enrichr online tool. Immune infiltration analysis was conducted using TIMER2.0 and CIBERSORT. Survival analysis with an optimal expression cutoff for overall survival (OS) and a median cutoff for disease-free survival (DFS) based on The Cancer Genome Atlas Adrenocortical carcinoma (TCGA-ACC) data was executed using the 'survival' and 'survminer' R packages and GEPIA2 online tool. Results: Analysis of the TCGA-ACC cohort revealed OS estimates that indicated worse survival in patients with higher TAS2R14, TAS2R19, TAS2R20, and TAS2R30 expression (Table). Further analysis produced consistent results, demonstrating that elevated expressions of TAS2R14 and TAS2R19 are correlated with decreased DFS, with Hazard Ratios (HR) of 2.60 (p = 0.0046) and 2.20 (p = 0.022), respectively. Furthermore, the F-test and stage plots have shown consistent upregulation of selected TAS2R genes across stages I–IV (p < 0.05). RNA-seq analysis revealed 1170 common (579 downregulated, 591 upregulated) DEGs between high and low TAS2R14 and TAS2R19 expression groups. GSEA showed upregulated genes in high expressers have relations to hedgehog signaling, epithelial to mesenchymal transition, TGF-B signaling, and organization of the extracellular matrix. On the other hand, down-regulated genes showed functions in metabolic reprogramming, chemokine receptor binding, MHC protein complex, and chemokine-mediated inflammation. GSEA on co-expressed genes showed pathways related to ferroptosis, autolysosome activity, and iron homeostasis and metabolism. Immune infiltration analysis revealed significantly increased CD4+, naïve and plasma B cell infiltration with higher TAS2R14 and TAS2R19 expression (Rho > 0.25, p < 0.05), in addition to increased M1 macrophage infiltration with higher TAS2R19 expression (Rho = 0.28, p < 0.05). Conclusions: TAS2R genes are potentially involved in modulating carcinogenic processes, including stage progression, metastasis and invasion, immune regulation, and metabolic processes. This modulation may explain the poorer prognostic outcomes in ACC patients with elevated TAS2R expression. Further validation in external cohorts is necessary to confirm these results. [Table: see text]

Genomic landscape of hepatocellular carcinoma in Egyptian patients by whole exome sequencing

BackgroundHepatocellular carcinoma (HCC) is the most common primary liver cancer. Chronic hepatitis and liver cirrhosis lead to accumulation of genetic alterations driving HCC pathogenesis. This study is designed to explore genomic landscape of HCC in Egyptian patients by whole exome sequencing.MethodsWhole exome sequencing using Ion Torrent was done on 13 HCC patients, who underwent surgical intervention (7 patients underwent living donor liver transplantation (LDLT) and 6 patients had surgical resection}.ResultsMutational signature was mostly S1, S5, S6, and S12 in HCC. Analysis of highly mutated genes in both HCC and Non-HCC revealed the presence of highly mutated genes in HCC (AHNAK2, MUC6, MUC16, TTN, ZNF17, FLG, MUC12, OBSCN, PDE4DIP, MUC5b, and HYDIN). Among the 26 significantly mutated HCC genes—identified across 10 genome sequencing studies—in addition to TCGA, APOB and RP1L1 showed the highest number of mutations in both HCC and Non-HCC tissues. Tier 1, Tier 2 variants in TCGA SMGs in HCC and Non-HCC (TP53, PIK3CA, CDKN2A, and BAP1). Cancer Genome Landscape analysis revealed Tier 1 and Tier 2 variants in HCC (MSH2) and in Non-HCC (KMT2D and ATM). For KEGG analysis, the significantly annotated clusters in HCC were Notch signaling, Wnt signaling, PI3K-AKT pathway, Hippo signaling, Apelin signaling, Hedgehog (Hh) signaling, and MAPK signaling, in addition to ECM-receptor interaction, focal adhesion, and calcium signaling. Tier 1 and Tier 2 variants KIT, KMT2D, NOTCH1, KMT2C, PIK3CA, KIT, SMARCA4, ATM, PTEN, MSH2, and PTCH1 were low frequency variants in both HCC and Non-HCC.ConclusionOur results are in accordance with previous studies in HCC regarding highly mutated genes, TCGA and specifically enriched pathways in HCC. Analysis for clinical interpretation of variants revealed the presence of Tier 1 and Tier 2 variants that represent potential clinically actionable targets. The use of sequencing techniques to detect structural variants and novel techniques as single cell sequencing together with multiomics transcriptomics, metagenomics will integrate the molecular pathogenesis of HCC in Egyptian patients.

Targeting ITGβ3 to Overcome Trastuzumab Resistance through Epithelial-Mesenchymal Transition Regulation in HER2-Positive Breast Cancer.

HER2-positive breast cancer, representing 15-20% of all breast cancer cases, often develops resistance to the HER2-targeted therapy trastuzumab. Unfortunately, effective treatments for advanced HER2-positive breast cancer remain scarce. This study aims to investigate the roles of ITGβ3, and Hedgehog signaling in trastuzumab resistance and explore the potential of combining trastuzumab with cilengitide as a therapeutic strategy. Quantitative gene expression analysis was performed to assess the transcription of EMT (epithelial-mesenchymal transition) markers Slug, Snail, Twist2, and Zeb1 in trastuzumab-resistant HER2-positive breast cancer cells. The effects of ITGβ3 and Hedgehog signaling were investigated. Additionally, the combination therapy of trastuzumab and cilengitide was evaluated. Acquired trastuzumab resistance induced the transcription of Slug, Snail, Twist2, and Zeb1, indicating increased EMT. This increased EMT was mediated by ITGB3 and Hedgehog signaling. ITGβ3 regulated both the Hedgehog pathway and EMT, with the latter being independent of the Hedgehog pathway. The combination of trastuzumab and cilengitide showed a synergistic effect, reducing both EMT and Hedgehog pathway activity. Targeting ITGβ3 with cilengitide, combined with trastuzumab, effectively suppresses the Hedgehog pathway and EMT, offering a potential strategy to overcome trastuzumab resistance and improve outcomes for HER2-positive breast cancer patients.

Study of the Immune Infiltration and Sonic Hedgehog Expression Mechanism in Synovial Tissue of Rheumatoid Arthritis-Related Interstitial Lung Disease under Machine Learning CIBERSORT Algorithm.

Rheumatoid arthritis-related interstitial lung disease (RA-ILD) is one of the common complications in patients with RA, which affects their quality of life. The CIBERSORT algorithm is widely employed to determine the proportion of immune cells (ICs) in diseased tissues, while the Sonic Hedgehog (Shh) signaling pathway, as an imperative regulatory factor, has also attracted attention in the pathology of RA-ILD. This work was to explore the mechanisms of RA-ILD immune infiltration and synovial tissue (ST) Shh expression based on the CIBERSORT algorithm. The differential genes of RA-ILD were subjected to pathway enrichment analysis using R language. The content and proportion of 22 types of ICs in RA-ILD lung tissues were analyzed using machine learning-based CIBERSORT algorithm. Meanwhile, immunoblotting was employed to detect and analyze the expression of Shh, Smoothened (Smo), and bone morphogenetic proteins (BMPs) proteins in ST samples from RA-ILD and Ctrl groups (RA patients without ILD). The hub target genes in the protein network associated with RA-ILD include BSG, CCL2, CTLA4, FGFBP1, GLI1, HHIP, HLA-DRB1, IFNAR1, IL17A, IL23A, IL-6, INPP4A, LILRB1, MUC5B, PADI4, PPM1A, PTCH1, PTPN22, RSPO4, Shh, SMO, STAT4, SUFU, TAOK2, TIMP2, and TWSG1, which are involved in multiple pathways, such as B cell regulation, transcription factors of the Shh pathway, and ST immune tolerance-related pathways. In the immunological analysis of RA-ILD using the CIBERSORT algorithm, HLA (r = -0.26), PTPN22 (r = -0.36), STAT4 (r = -0.18), IL-6 (r = -0.17), CTLA4 (r = -0.27), and PADI4 (r = -0.21) were all found to exhibit negative correlations with CD4+T cells (P < 0.05). Monocytes were found to be more abundant in RA-ILD patients' serum versus the Ctrl group. Shh, Smo, and BMP expressions were drastically lower in the RA-ILD group versus Ctrl group (P < 0.05). Significant immune cell infiltration was observed in the lung tissues of RA-ILD patients. Further analysis utilizing the CIBERSORT algorithm revealed alterations in the proportions of different IC subtypes, indicating their association with disease severity and prognosis. Moreover, there was a significant decrease in the expression levels of Shh, Smo, and BMP. These findings underscore the importance of immune cells in the pathophysiology of RA-ILD and suggest a potential involvement of the Shh signaling pathway in the pathogenesis of RA-ILD.

BCAA-producing Clostridium symbiosum promotes colorectal tumorigenesis through the modulation of host cholesterol metabolism

Identification of potential bacterial players in colorectal tumorigenesis has been a focus of intense research. Herein, we find that Clostridium symbiosum (C.symbiosum) is selectively enriched in tumor tissues of patients with colorectal cancer (CRC) and associated with higher colorectal adenoma recurrence after endoscopic polypectomy. The tumorigenic effect of C.symbiosum is observed in multiple murine models. Single-cell transcriptome profiling along with functional assays demonstrates that C.symbiosum promotes the proliferation of colonic stem cells and enhances cancer stemness. Mechanistically, C.symbiosum intensifies cellular cholesterol synthesis by producing branched-chain amino acids (BCAAs), which sequentially activates Sonic hedgehog signaling. Low dietary BCAA intake or blockade of cholesterol synthesis by statins could partially abrogate the C.symbiosum-induced cell proliferation invivo and invitro. Collectively, we reveal C.symbiosum as a bacterial driver of colorectal tumorigenesis, thus identifying a potential target in CRC prediction, prevention, and treatment.

Comparison of ovarian mRNA expression levels in wild and hatchery-produced greater amberjack Seriola dumerili

The greater amberjack Seriola dumerili is a promising candidate for aquaculture production. This study compares the ovary transcriptome of greater amberjack sampled in the wild (WILD) with hatchery-produced breeders reared in aquaculture sea cages in the Mediterranean Sea. Among the seven sampled cultured fish, three were classified as reproductively dysfunctional (DysF group), while four showed no signs of reproductive alteration (NormalF group). The DysF fish showed 1,166 differentially expressed genes (DEGs) compared to WILD females, and 755 DEGs compared to the NormalF. According to gene ontology (GO) analysis, DysF females exhibited enrichment of genes belonging to the biological categories classified as Secreted, ECM-receptor interaction, and Focal adhesion. Protein–protein interaction analysis revealed proteins involved in the biological categories of ECM-receptor interaction, Enzyme-linked receptor protein signaling, Wnt signal transduction pathways, and Ovulation cycle. KEGG pathway analysis showed DEGs involved in 111 pathways, including Neuroactive ligand-receptor interaction, Steroid hormone biosynthesis, Cell cycle, Oocyte meiosis, Necroptosis, Ferroptosis, Apoptosis, Autophagy, Progesterone-mediated oocyte maturation, Endocytosis and Phagosome, as well as Hedgehog, Apelin, PPAR, Notch, and GnRH signalling pathways. Additionally, DysF females exhibited factors encoded by upregulated genes associated with hypogonadism and polycystic ovary syndrome in mammals. This study -which is part of a broader research effort examining the transcriptome of the entire reproductive axis in greater amberjack of both sexes-, enhances our comprehension of the mechanisms underlying the appearance of reproductive dysfunctions when fish are reared under aquaculture conditions.

Abstract We080: Mapping the effect of Hedgehog signaling on cardiac differentiation and migration in space and time

Background: Organ morphogenesis requires precise control of organ-specific progenitor cell migration and differentiation. Hedgehog signaling is a major signaling pathway during animal development and is essential for proper cardiac development. Previous work demonstrated that Hedgehog signaling can regulate migration and the timing of differentiation of cardiac progenitors. However, how Hedgehog signaling integrates control of differentiation timing and migration in space to enable proper organ formation during development remains unclear. Hypothesis: We hypothesize that Hedgehog signaling explicitly controls cardiac morphogenesis by coordinating cellular migration and differentiation of cardiac progenitors to determining where and when they turn into cardiomyocytes. Methods: We combine mouse genetics, in-vivo lineage tracing, whole mouse embryo light-sheet imaging, and metanalysis of publicly available spatial transcriptomics datasets to address the hypothesis. Results: We identified the sites of active Hedgehog signaling by studying a reporter for Hedgehog signaling (GBS-GFP). Next, we determined the necessity of Hedgehog signaling for differentiation of cardiomyocytes at the right place and time by tracing the cardiac progenitors over developmental time in mutants in controls compared to Hedgehog signaling mutants. Conclusion and future directions: This work will establish the dual role of Hedgehog signaling in differentiation timing and migration control as a novel paradigm that may be generalizable to other organ systems dependent on Hedgehog signaling (e.g., neural cord and limb patterning).

Dysembryogenetic Pathogenesis of Basal Cell Carcinoma: The Evidence to Date.

The Basal Cell Carcinoma (BCC) is a sort of unique tumour due to its combined peculiar histological features and clinical behaviour, such as the constant binary involvement of the epithelium and the stroma, the virtual absence of metastases and the predilection of specific anatomical sites for both onset and spread. A potential correlation between the onset of BCC and a dysembryogenetic process has long been hypothesised. A selective investigation of PubMed-indexed publications supporting this theory retrieved 64 selected articles published between 1901 and 2024. From our analysis of the literature review, five main research domains on the dysembryogenetic pathogenesis of BCC were identified: (1) The correlation between the topographic distribution of BCC and the macroscopic embryology, (2) the correlation between BCC and the microscopic embryology, (3) the genetic BCC, (4) the correlation between BCC and the hair follicle and (5) the correlation between BCC and the molecular embryology with a specific focus on the Hedgehog signalling pathway. A large amount of data from microscopic and molecular research consistently supports the hypothesis of a dysembryogenetic pathogenesis of BCC. Such evidence is promoting advances in the clinical management of this disease, with innovative targeted molecular therapies on an immune modulating basis being developed.

Abstract We043: MYCN is a regulator of cardiomyocyte proliferation and regeneration in the mammalian heart

The identification of new factors and mechanisms that can promote the repair and regeneration of the adult injured mammalian heart are necessary as the adult heart has limited ability to repair itself. We identified MYCN as a downstream effector of the sonic hedgehog (SHH) signaling cascade during cardiomyocyte proliferation in the neonatal heart. Although the protooncogene, MYCN, has been shown to be an essential factor during embryonic heart development, its role in regenerating the adult heart has not been established. Here, we define MYCN as a critical regulator of cardiomyocyte (CM) proliferation and regeneration using genetic mouse models and in vivo modified RNA (modRNA) delivery. In these studies, we conditionally deleted Mycn in the neonatal heart (P0). Immunohistochemical (IHC) analysis of P3 neonatal hearts demonstrated significantly (p &lt; 0.05) decreased expression of Ki67 and pH3 in the absence of Mycn compared to control (no 4-OHT) hearts. This observation was further validated in isolated CMs and neonatal P7 hearts pulsed with EdU which demonstrated a significant decrease in EdU+ CMs in the absence of Mycn compared to control. Single-nucleus RNA-sequencing results from control and Mycn CKO P4 ventricles revealed a severe depletion of the proliferative and regenerative cardiomyocyte population in the Mycn CKO hearts. We then ligated the left anterior descending coronary artery (LAD) to produce an ischemic cardiac injury in control and Mycn CKO P2 neonatal mice. Echocardiography one-month following the LAD surgeries demonstrated that the Mycn CKO failed to recover baseline cardiac function compared to their control counterparts who achieved complete recovery. RNAseq analysis of control and Mycn CKO hearts 1 month following LAD ligations demonstrated that muscle developmental pathways were significantly downregulated in the Mycn CKO group compared to the control. We then delivered either GFP (control) or Mycn modRNA intramuscularly into the border zone following LAD coronary artery ligation surgeries in adult (2-6 month old) mice. We observed that the Mycn modRNA treated mice had significantly improved cardiac function at one month and two months following injury/delivery compared to controls. These results identify MYCN as an important regulator of CM proliferation and heart regeneration.

Hedgehog/Gli2 signaling triggers cell proliferation and metastasis via EMT and wnt/β-catenin pathways in oral squamous cell carcinoma

BackgroundOral squamous cell carcinoma (OSCC) is the most lethal oral malignant tumor, however, clinical outcomes remain unsatisfactory. The Hedgehog/Gli2 pathway plays a pivotal role in tumor progression, yet the regulatory mechanism governing its involvement in the malignant evolution process of OSCC remains elusive. MethodsOSCC animal tissue samples were used to detect the activation of the Hedgehog/Gli2 pathway in OSCC. Based on the clinical information of oral cancer patients in TCGA database, the role of this pathway in patients was analyzed, and the activation status of this pathway was verified in human OSCC cells. After activating or inhibiting the Hedgehog pathway, the effects of this pathway on the biological function of OSCC cells and its regulatory mechanism were examined. Interfering the expression of Gli2, a key transcription factor in this pathway, revealed the role of Hedgehog/Gli2 pathway in the malignant evolution of OSCC cells. ResultsThe Hedgehog pathway exhibits abnormal activation in animal models of OSCC. Clinical data from TCGA demonstrate a significant enrichment of the Hedgehog pathway in patients with OSCC, and Gli2, a key downstream factor of this pathway, is closely associated with the occurrence and progression of OSCC. Cellular studies have revealed aberrant activation of this pathway in human OSCC cells, which exerts its function by modulating the activation of epithelial-mesenchymal transition (EMT) and Wnt/β-catenin pathways. Subsequent investigations further confirm the pivotal involvement of Gli2 in the Hedgehog pathway activation, underscoring its potential as a therapeutic target for inhibiting malignant proliferation and metastasis of OSCC cells through modulation of EMT and Wnt/β-catenin pathways. ConclusionThe Hedgehog/Gli2 pathway induces EMT and activates Wnt/β-catenin pathway to trigger the malignant proliferation and metastasis of OSCC cells, and Gli2 plays a key role in this process, which suggests that targeting Gli2 may be a promising therapeutic strategy for inhibiting the proliferation and metastasis of OSCC.

Identification of truncated variants in GLI family zinc finger 3 (GLI3) associated with polydactyly

BackgroundPolydactyly is a prevalent congenital anomaly with an incidence of 2.14 per 1000 live births in China. GLI family zinc finger 3 (GLI3) is a classical causative gene of polydactyly, and serves as a pivotal transcription factor in the hedgehog signaling pathway, regulating the development of the anterior-posterior axis in limbs.MethodsThree pedigrees of polydactyly patients were enrolled from Hunan Province, China. Pathogenic variants were identified by whole-exome sequencing (WES) and Sanger sequencing.ResultsThree variants in GLI3 were identified in three unrelated families, including a novel deletion variant (c.1372del, p.Thr458GlnfsTer44), a novel insertion-deletion (indel) variant (c.1967_1968delinsAA, p.Ser656Ter), and a nonsense variant (c.2374 C > T, p.Arg792Ter). These variants were present exclusively in patients but not in healthy individuals.ConclusionsWe identified three pathogenic GLI3 variants in polydactyly patients, broadening the genetic spectrum of GLI3 and contributing significantly to genetic counseling and diagnosis for polydactyly.