Fast and safe clinical response to sonidegib in a 98-year old woman affected by locally advanced basal cell carcinoma.

A 98-year-old woman presented with histologically confirmed locally advanced basal cell carcinoma of the face. A multidisciplinary approach excluded surgery because of the site near sensitive organs, extension, age, and comorbidities. Patient and caregivers declined radiotherapy considering the necessity of multiple hospital appointments. The patient was then placed on therapy with sonidegib, an oral inhibitor of the Hedgehog signaling pathway. There was a very rapid clinical response after only 28 days of treatment. The basal cell carcinoma improved progressively, with no adverse events reported. This case illustrates the efficacy and safety of this treatment in an advanced age patient. This treatment had a remarkably positive impact on quality of life, including that of the caregivers.

Therapeutic potential of hedgehog signaling in advanced cancer types.

In this chapter, we have made an attempt to elucidate the relevance of hedgehog signaling pathway in tumorigenesis. Here, we have described different types of hedgehog signaling (canonical and non-canonical) with emphasis on the different mechanisms (mutation-driven, autocrine, paracrine and reverse paracrine) it adopts during tumorigenesis. We have discussed the role of hedgehog signaling in regulating cell proliferation, invasion and epithelial-to-mesenchymal transition in both local and advanced cancer types, as reported in different studies based on preclinical and clinical models. We have specifically addressed the role of hedgehog signaling in aggressive neuroendocrine tumors as well. We have also elaborated on the studies showing therapeutic relevance of the inhibitors of hedgehog signaling in cancer. Evidence of the crosstalk of hedgehog signaling components with other signaling pathways and treatment resistance due to tumor heterogeneity have also been briefly discussed. Together, we have tried to put forward a compilation of the studies on therapeutic potential of hedgehog signaling in various cancers, specifically aggressive tumor types with a perspective into what is lacking and demands further investigation.

RSG1 is required for cilia-dependent neural tube closure.

Cilia play a key role in the regulation of signaling pathways required for embryonic development, including the proper formation of the neural tube, the precursor to the brain and spinal cord. Forward genetic screens were used to generate mouse lines that display neural tube defects (NTD) and secondary phenotypes useful in interrogating function. We describe here the L3P mutant line that displays phenotypes of disrupted Sonic hedgehog signaling and affects the initiation of cilia formation. A point mutation was mapped in the L3P line to the gene Rsg1, which encodes a GTPase-like protein. The mutation lies within the GTP-binding pocket and disrupts the highly conserved G1 domain. The mutant protein and other centrosomal and IFT proteins still localize appropriately to the basal body of cilia, suggesting that RSG1 GTPase activity is not required for basal body maturation but is needed for a downstream step in axonemal elongation.

A Pilot Immunohistochemical Study Identifies Hedgehog Pathway Expression in Sinonasal Adenocarcinoma.

Tumors of the head and neck, more specifically the squamous cell carcinoma, often show upregulation of the Hedgehog signaling pathway. However, almost nothing is known about its role in the sinonasal adenocarcinoma, either in intestinal or non-intestinal subtypes. In this work, we have analyzed immunohistochemical staining of six Hedgehog pathway proteins, sonic Hedgehog (SHH), Indian Hedgehog (IHH), Patched1 (PTCH1), Gli family zinc finger 1 (GLI1), Gli family zinc finger 2 (GLI2), and Gli family zinc finger 3 (GLI3), on 21 samples of sinonasal adenocarcinoma and compared them with six colon adenocarcinoma and three salivary gland tumors, as well as with matching healthy tissue, where available. We have detected GLI2 and PTCH1 in the majority of samples and also GLI1 in a subset of samples, while GLI3 and the ligands SHH and IHH were generally not detected. PTCH1 pattern of staining shows an interesting pattern, where healthy samples are mostly positive in the stromal compartment, while the signal shifts to the tumor compartment in tumors. This, taken together with a stronger signal of GLI2 in tumors compared to non-tumor tissues, suggests that the Hedgehog pathway is indeed activated in sinonasal adenocarcinoma. As Hedgehog pathway inhibitors are being tested in combination with other therapies for head and neck squamous cell carcinoma, this could provide a therapeutic option for patients with sinonasal adenocarcinoma as well.

A conserved molecular logic for neurogenesis to gliogenesis switch in the cerebral cortex.

During development, neural stem cells in the cerebral cortex, also known as radial glial cells (RGCs), generate excitatory neurons, followed by production of cortical macroglia and inhibitory neurons that migrate to the olfactory bulb (OB). Understanding the mechanisms for this lineage switch is fundamental for unraveling how proper numbers of diverse neuronal and glial cell types are controlled. We and others recently showed that Sonic Hedgehog (Shh) signaling promotes the cortical RGC lineage switch to generate cortical oligodendrocytes and OB interneurons. During this process, cortical RGCs generate intermediate progenitor cells that express critical gliogenesis genes Ascl1, Egfr, and Olig2. The increased Ascl1 expression and appearance of Egfr+ and Olig2+ cortical progenitors are concurrent with the switch from excitatory neurogenesis to gliogenesis and OB interneuron neurogenesis in the cortex. While Shh signaling promotes Olig2 expression in the developing spinal cord, the exact mechanism for this transcriptional regulation is not known. Furthermore, the transcriptional regulation of Olig2 and Egfr has not been explored. Here, we show that in cortical progenitor cells, multiple regulatory programs, including Pax6 and Gli3, prevent precocious expression of Olig2, a gene essential for production of cortical oligodendrocytes and astrocytes. We identify multiple enhancers that control Olig2 expression in cortical progenitors and show that the mechanisms for regulating Olig2 expression are conserved between the mouse and human. Our study reveals evolutionarily conserved regulatory logic controlling the lineage switch of cortical neural stem cells.

A novel combination therapy targets sonic hedgehog signaling by the dual inhibition of HMG-CoA reductase and HSP90 in rats with non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is characterized by liver inflammation, fat accumulation, and collagen deposition. Due to the limited availability of effective treatments, there is a pressing need to develop innovative strategies. Given the complex nature of the disease, employing combination approaches is essential. Hedgehog signaling has been recognized as potentially promoting NASH, and cholesterol can influence this signaling by modifying the conformation of PTCH1 and SMO activity. HSP90 plays a role in the stability of SMO and GLI proteins. We revealed significant positive correlations between Hedgehog signaling proteins (Shh, SMO, GLI1, and GLI2) and both cholesterol and HSP90 levels. Herein, we investigated the novel combination of the cholesterol-lowering agent lovastatin and the HSP90 inhibitor PU-H71 in vitro and in vivo. The combination demonstrated a synergy score of 15.09 and an MSA score of 22.85, as estimated by the ZIP synergy model based on growth inhibition rates in HepG2 cells. In a NASH rat model induced by thioacetamide and a high-fat diet, this combination therapy extended survival, improved liver function and histology, and enhanced antioxidant defense. Additionally, the combination exhibited anti-inflammatory and anti-fibrotic potential by influencing the levels of TNF-α, TGF-ß, TIMP-1, and PDGF-BB. This effect was evident in the suppression of the Col1a1 gene expression and the levels of hydroxyproline and α-SMA. These favorable outcomes may be attributed to the combination's potential to inhibit key Hedgehog signaling molecules. In conclusion, exploring the applicability of this combination contributes to a more comprehensive understanding and improved management of NASH and other fibrotic disorders.

Circular RNA Circ_0001322 inhibits gastric cancer progression by modulating the miR-1264/QKI axis and suppressing the Hedgehog pathway.

Circular RNA hsa_circ_0001322 (circ1322) was demonstrated to be significantly reduced in expression in gastric cancer patients in our previous study, and changes in its expression were significantly correlated with lymph node metastasis. However, the underlying workings of circ1322 in gastric cancer are still not fully understood. Therefore, to confirm the effect of circ1322 on gastric cancer, we examined the expression of circ1322 in gastric cancer cells and tissues. The results showed that circ1322 was lowly expressed in GC tissues and cells. Subsequently, we further performed cellular assays and animal experiments, which showed that Circ1322 upregulation inhibited GC cell proliferation, migration and invasion. while promoting GC cell apoptosis, and inhibited tumor growth in mice. The direct targeting of circ1322 to miR-1264 was confirmed by bioinformatics prediction and validation of luciferase reporter gene assay. Circ1322 can act as a miR-1264 sponge to alleviate the inhibitory effect of miR-1264 on its target gene, QKI. miR-1264 regulates the expression of QKI and the activity of the hedgehog pathway. That is, circ1322 may act as a competing endogenous RNA (ceRNA) to inhibit the hedgehog pathway by targeting the miR-1264/QKI axis, which in turn promotes GC progression.

[Alopecia due to chemotherapeutics, hedgehog inhibitors, targeted antibody therapies and immune checkpoint inhibitors : Pathogenesis, clinical picture, diagnostics and prophylaxis]. / Alopezie durch Chemotherapeutika, Hedgehog-Inhibitoren, zielgerichtete Antikörpertherapien und Immuncheckpointinhibitoren : Pathogenese, Klinik, Diagnostik und Prophylaxe.

BACKGROUND: The incidence and severity of alopecia vary mainly depending on the chemotherapeutic agent used or other drug groups. The pathogenetic characteristics of the different forms of alopecia are reflected in the clinical presentation and, in some cases, in the resulting recommendations for prophylaxis. OBJECTIVES: To provide an overview of the pathogenesis, clinical presentation, diagnosis and prophylaxis of alopecia with chemotherapeutic agents, hedgehog inhibitors, targeted therapies and immune checkpoint inhibitors. MATERIALS AND METHODS: Based on the current S3 guideline "Supportive therapy", an extensive literature search was carried out. RESULTS AND CONCLUSION: Chemotherapy-induced hair loss (CIA) occurs in up to 65% of cases. Anagen effluvium is observed as early as 1-3 weeks after the start of treatment and is reversible in most cases. Alopecia associated with inhibitors of the Sonic Hedgehog signaling pathway (HHIA) such as vismodegib or sonidegib are observed in up to 60% of cases. They are characterized by telogen effluvium. BRAF or immune checkpoint inhibitors lead significantly less frequently to alopecia (BRAFA, CPIA). According to taxane-based chemotherapy protocols, scalp cooling can help to prevent higher-grade CIA. If CIA or other forms of alopecia are expected, early contact with self-help organizations and early prescriptions for wigs should be offered.

Role of Hedgehog Signaling Pathways in Multipotent Mesenchymal Stem Cells Differentiation.

Multipotent mesenchymal stem cells (MSCs) have high self-renewal and multi-lineage differentiation potentials and low immunogenicity, so they have attracted much attention in the field of regenerative medicine and have a promising clinical application. MSCs originate from the mesoderm and can differentiate not only into osteoblasts, cartilage, adipocytes, and muscle cells but also into ectodermal and endodermal cell lineages across embryonic layers. To design cell therapy for replacement of damaged tissues, it is essential to understand the signaling pathways, which have a major impact on MSC differentiation, as this will help to integrate the signaling inputs to initiate a specific lineage. Hedgehog (Hh) signaling plays a vital role in the development of various tissues and organs in the embryo. As a morphogen, Hh not only regulates the survival and proliferation of tissue progenitor and stem populations but also is a critical moderator of MSC differentiation, involving tri-lineage and across embryonic layer differentiation of MSCs. This review summarizes the role of Hh signaling pathway in the differentiation of MSCs to mesodermal, endodermal, and ectodermal cells.

Diffuse infiltrating tumour with the molecular profile of an atypical teratoid rhabdoid tumour (AT/RT SHH-1B) in an adult patient.

We describe a 46-year-old patient with an IDH-wildtype diffusely infiltrating atypical teratoid/rhabdoid tumour (AT/RT), SHH-1B molecular subtype. The unusual histology and subsequent diagnosis in an adult patient will be discussed.

The importance of caregivers for patients with advanced basal cell carcinoma treated with hedgehog-pathway inhibitors: an observational prospective study.

Oral targeted therapy with hedgehog pathway inhibitors has revolutionized the standard of care for patients with advanced basal cell carcinoma (BCC). These patients are frail and elderly, have various comorbidities, and receive pharmacological polytherapy. Moreover, adverse events may have a significant impact on therapeutic adherence, which must be managed by the clinician. We evaluated the impact of caregivers on the treatment of patients with advanced BCC in terms of continuation of therapy over time. All patients included in this observational prospective study had histologically confirmed metastatic or locally advanced BCC (LaBCC) and were treated with hedgehog pathway inhibitors from January 2016 to December 2021 at the Department of Dermatology at the University of Florence, Italy. The collected patient data included: age, sex, BCC site and area of spread; number of cycles, dose, duration and tolerability of therapy; marital status (single, divorced, married/living with a partner, widow/widower); and information such as living with someone, and the presence of any caregivers. Of the 34 patients included, 33 had LaBCC and one metastatic BCC. There were 11 females (32.4%) and 23 males (67.6%). Patients who were married or living with a caregiver -tolerated therapy better than single patients who lived alone. Indeed, patients with married/live-in caregivers and/or those with an adequate caregiver experienced greater therapeutic adherence and tolerance of adverse events. Given the greater therapeutic adherence of patients with live-in caregivers as partners, it is essential to consider patients' marital status. It is advisable to involve the caregiver early on, and there should be a training discussion on the various possible adverse events and the best way to mitigate them. Therapeutic success is linked not only to patients being informed but also to training of caregivers.

Roles and interactions of tumor microenvironment components in medulloblastoma with implications for novel therapeutics.

Medulloblastomas, the most common malignant pediatric brain tumors, can be classified into the wingless, sonic hedgehog (SHH), group 3, and group 4 subgroups. Among them, the SHH subgroup with the TP53 mutation and group 3 generally present with the worst patient outcomes due to their high rates of recurrence and metastasis. A novel and effective treatment for refractory medulloblastomas is urgently needed. To date, the tumor microenvironment (TME) has been shown to influence tumor growth, recurrence, and metastasis through immunosuppression, angiogenesis, and chronic inflammation. Treatments targeting TME components have emerged as promising approaches to the treatment of solid tumors. In this review, we summarize progress in research on medulloblastoma microenvironment components and their interactions. We also discuss challenges and future research directions for TME-targeting medulloblastoma therapy.

The top 100 most cited articles in the treatment of basal cell carcinoma over the last decade: A bibliometric analysis and review.

Basal cell carcinoma (BCC) represents the most prevalent cancer globally. The past decade has witnessed significant advancements in BCC treatment, primarily through bibliometric studies. Aiming to perform a comprehensive bibliometric analysis of BCC treatments to comprehend the research landscape and identify trends within this domain, a dataset comprising 100 scientific publications from the Web of Science Core Collection was analyzed. Country co-operation, journal co-citation, theme bursts, keyword co-occurrence, author co-operation, literature co-citation, and field-specific references were examined using VOSviewer and CiteSpace visualization tools. These articles, published between 2013 and 2020, originated predominantly from 30 countries/regions and 159 institutions, with the USA and Germany at the forefront, involving a total of 1118 authors. The keyword analysis revealed significant emphasis on the hedgehog pathway, Mohs micrographic surgery, and photodynamic therapy. The research shows developed nations are at the forefront in advancing BCC therapies, with significant focus on drugs targeting the hedgehog pathway. This treatment avenue has emerged as a crucial area, meriting considerable attention in BCC therapeutic strategies.

Clinical determinants of clinical response to Sonidegib in advanced basal cell carcinoma: a monocenter experience.

OBJECTIVE: The purpose of this study is to evaluate the clinical determinants of complete response in locally advanced basal cell carcinoma (laBCC) patients receiving Sonidegib in a real-life, retrospective, observational study.  Hedgehog pathway inhibitors (Vismodegib and Sonidegib) are approved for the systemic treatment of locally advanced basal cell carcinoma (laBCC). The objective response rate was the primary endpoint of the trials for both drugs. PATIENTS AND METHODS: Adult patients with laBCC treated with Sonidegib at the Dermato-Oncology Unit of IFO San Gallicano between June 2020 and September 2022 were included in the study. Patient, tumor, and treatment characteristics were recorded. The complete response rate was the primary outcome. The median time to the best response and complete response were the secondary outcomes. Treatment-related adverse events (TRAEs) and dose adjustments were recorded. RESULTS: Of the 19 patients included in the study, eight (42.1%) achieved a complete response, seven (36.8%) had a partial response, and four experienced progressive disease (21%). The median time to the best response was 3 months in the group of patients with partial response (range 2.0-4.0, with three patients not evaluable) and 3.5 months in the group of patients with complete response (range 2-5). TRAEs occurred in 14 (73.6%) patients, with 8 (57.1%) reporting ≤2 TRAE categories and 6 (42.8%) >2. A total of 78.9% of patients received a modified treatment schedule; 12.5% of patients who achieved a complete response received full dosage from the beginning to the end of treatment, compared with 27.3% of those with a partial response. CONCLUSIONS: The associations between the clinical outcome of interest (objective response rate) and the clinicopathological and treatment characteristics were evaluated. No statistically significant association was observed. Our analysis confirms the observation that no statistically significant correlation exists between clinical response and Sonidegib alternate dose regimen.

Discovery of YS-1 as a cell line of gastric inflammatory cancer-associated fibroblasts.

BACKGROUND: Inflammatory cancer-associated fibroblasts (iCAFs) was first identified by co-culture of pancreatic stellate cells and tumor organoids. The key feature of iCAFs is IL-6high/αSMAlow. We examine this phenomenon in gastric cancer using two cell lines of gastric fibroblasts (HGF and YS-1). METHODS AND RESULTS: HGF or YS-1 were co-cultured with MKN7 (a gastric adenocarcinoma cell line) in Matrigel. IL-6 protein levels in the culture supernatant were measured by ELISA. The increased production of IL-6 was not observed in any of the combinations. Instead, the supernatant of YS-1 exhibited the higher levels of IL-6. YS-1 showed IL-6high/αSMA (ACTA2)low in real-time PCR, mRNA-seq and immunohistochemistry. In mRNA-seq, iCAFs-associated genes and signaling pathways were up-regulated in YS-1. No transition to myofibroblastic phenotype was observed by monolayer culture, or the exposure to sonic hedgehog (SHH) or TGF-ß. YS-1 conditioned medium induced changes of morphology and stem-ness/differentiation in NUGC-3 (a human gastric adenocarcinoma cell line) and UBE6T-15 (a human bone marrow-derived mesenchymal stem cell line). CONCLUSIONS: YS-1 is a stable cell line of gastric iCAFs. This discovery will promote further research on iCAFs for many researchers.

Human umbilical cord mesenchymal stem cell-derived exosomes ameliorate renal fibrosis in diabetic nephropathy by targeting Hedgehog/SMO signaling.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease globally. Currently, there are no effective drugs for the treatment of DN. Although several studies have reported the therapeutic potential of mesenchymal stem cells, the underlying mechanisms remain largely unknown. Here, we report that both human umbilical cord MSCs (UC-MSCs) and UC-MSC-derived exosomes (UC-MSC-exo) attenuate kidney damage, and inhibit epithelial-mesenchymal transition (EMT) and renal fibrosis in streptozotocin-induced DN rats. Strikingly, the Hedgehog receptor, smoothened (SMO), was significantly upregulated in the kidney tissues of DN patients and rats, and positively correlated with EMT and renal fibrosis. UC-MSC and UC-MSC-exo treatment resulted in decrease of SMO expression. In vitro co-culture experiments revealed that UC-MSC-exo reduced EMT of tubular epithelial cells through inhibiting Hedgehog/SMO pathway. Collectively, UC-MSCs inhibit EMT and renal fibrosis by delivering exosomes and targeting Hedgehog/SMO signaling, suggesting that UC-MSCs and their exosomes are novel anti-fibrotic therapeutics for treating DN.

Dual and opposing roles for the kinesin-2 motor, KIF17, in Hedgehog-dependent cerebellar development.

While the kinesin-2 motors KIF3A and KIF3B have essential roles in ciliogenesis and Hedgehog (HH) signal transduction, potential role(s) for another kinesin-2 motor, KIF17, in HH signaling have yet to be explored. Here, we investigated the contribution of KIF17 to HH-dependent cerebellar development, where Kif17 is expressed in both HH-producing Purkinje cells and HH-responding cerebellar granule neuron progenitors (CGNPs). Germline Kif17 deletion in mice results in cerebellar hypoplasia due to reduced CGNP proliferation, a consequence of decreased HH pathway activity mediated through decreased Sonic HH (SHH) protein. Notably, Purkinje cell-specific Kif17 deletion partially phenocopies Kif17 germline mutants. Unexpectedly, CGNP-specific Kif17 deletion results in the opposite phenotype-increased CGNP proliferation and HH target gene expression due to altered GLI transcription factor processing. Together, these data identify KIF17 as a key regulator of HH-dependent cerebellar development, with dual and opposing roles in HH-producing Purkinje cells and HH-responding CGNPs.

Epigenetic regulation by KDM5A mediates the effects of prenatal PM2.5 exposure on hippocampal development and synaptic integrity through the Shh signaling pathway.

Prenatal environmental exposure could be an essential health risk factor associated with neurodevelopmental disorders in offspring. However, the exact mechanisms underlying the impact of prenatal PM2.5 exposure on offspring cognition remain unclear. In our recent study using a PM2.5 exposed pregnant mouse model, we observed significant synaptic dysfunction in the hippocampi of the offspring. Concurrently, the epigenetic regulator of KDM5A and the Shh signaling pathway exhibited decreased activities. Significantly, changes in hippocampal KDM5A and Shh levels directly correlated with PM2.5 exposure intensity. Subsequent experiments revealed a marked reduction in the expression of Shh signaling and related synaptic proteins when KDM5A was silenced in cells. Notably, the effects of KDM5A deficiency were reversed significantly with the supplementation of a Shh activator. Furthermore, our findings indicate that Shh activation significantly attenuates PM2.5-induced synaptic impairments in hippocampal neurons. We further demonstrated that EGR1, a transcriptional inhibitor, plays a direct role in KDM5A's regulation of the Shh pathway under conditions of PM2.5 exposure. Our results suggest that the KDM5A's inhibitory regulation on the Shh pathway through the EGR1 gene is a crucial epigenetic mechanism underlying the synaptic dysfunction in hippocampal neurons caused by maternal PM2.5 exposure. This emphasizes the role of epigenetic regulations in neurodevelopmental disorders caused by environmental factors.

CBC-1 as a Cynanbungeigenin C derivative inhibits the growth of colorectal cancer through targeting Hedgehog pathway component GLI 1.

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers that results in death in worldwide. The Hedgehog (HH) signalling pathway regulates the initiation and progression of CRC. Inhibiting the HH pathway has been presented as a potential treatment strategy in recent years. Cynanbungeigenin C (CBC) is a new type of C21 steroid that has been previously reported for the treatment of medulloblastoma. However, its further investigation was limited by its poor water solubility. In this study, six new CBC derivatives were synthesized through the structural modification of CBC, and four of them showed better water solubility than CBC. Moreover, their antiproliferative activities on CRC were evaluated. It was found that CBC-1 presented the best inhibitory effect on three types of CRC cell lines, and this effect was superior to that of CBC. Mechanistically, CBC-1 inhibited the proliferation of CRC cells through regulation of mRNA and proteins of the HH pathway according to qRT-PCR and Western blotting analysis. Furthermore, Cellular Thermal Shift Assay results indicated that CBC-1 regulated this signalling pathway by targeting glioma­associated oncogene (GLI 1).In addition, cell apoptosis was induced increasingly by transfection with GLI 1 siRNA or treatment with CBC-1 to downregulate GLI 1. Last, the in vivo results demonstrated that CBC-1 significantly reduced tumour size and downregulated GLI 1 in CRC. Therefore, this study suggests that CBC-1, a new GLI 1 inhibitor derived from natural products, may be developed as a potential antitumour candidate for CRC treatment.

Hepatic progenitor cell-originated ductular reaction facilitates liver fibrosis through activation of hedgehog signaling.

Background: It is poorly understood what cellular types participate in ductular reaction (DR) and whether DR facilitates recovery from injury or accelerates hepatic fibrosis. The aim of this study is to gain insights into the role of hepatic progenitor cell (HPC)-originated DR during fibrotic progression. Methods: DR in liver specimens of PBC, chronic HBV infection (CHB) or NAFLD, and four rodent fibrotic models by different pathogenic processes was evaluated. Gli1 expression was inhibited in rodent models or cell culture and organoid models by AAV-shGli1 or treating with GANT61. Results: Severity of liver fibrosis was positively correlated with DR extent in patients with PBC, CHB or NAFLD. HPCs were activated, expanded, differentiated into reactive cholangiocytes and constituted "HPC-originated DR", accompanying with exacerbated fibrosis in rodent models of HPC activation & proliferation (CCl4/2-AAF-treated), Μdr2-/- spontaneous PSC, BDL-cholestatic fibrosis or WD-fed/CCl4-treated NASH-fibrosis. Gli1 expression was significantly increased in enriched pathways in vivo and in vitro. Enhanced Gli1 expression was identified in KRT19+-reactive cholangiocytes. Suppressing Gli1 expression by administration of AAV-shGli1 or GANT61 ameliorated HPC-originated DR and fibrotic extent. KRT19 expression was reduced after GANT61 treatment in sodium butyrate-stimulated WB-F344 cells or organoids or in cells transduced with Gli1 knockdown lentiviral vectors. In contrast, KRT19 expression was elevated after transducing Gli1 overexpression lentiviral vectors in these cells. Conclusions: During various modes of chronic injury, Gli1 acted as an important mediator of HPC activation, expansion, differentiation into reactive cholangiocytes that formed DR, and subsequently provoked hepatic fibrogenesis.