Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018133 (graft-versus-host disease)
 18,032 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Accumulating evidence suggests that endothelial microparticles (EMPs), a marker of endothelial damage, are elevated in acute graft-versus-host disease (aGVHD), and that endothelial damage is implicated in the pathogenesis of aGVHD, but the mechanisms remain elusive. In this study, we detected the plasma EMP levels and endothelial damage in patients and mice with aGVHD in vivo and then examined the effects of EMPs derived from injured endothelial cells (ECs) on endothelial damage and the role of hedgehog-interacting protein (HHIP) carried by EMPs in these effects in vitro. Our results showed that EMPs were persistently increased in the early posttransplantation phase in patients and mice with aGVHD. Meanwhile, endothelial damage was continuous in aGVHD mice, but was temporary in non-aGVHD mice after transplantation. In vitro, EMPs induced endothelial damage, including increased EC apoptosis, enhanced reactive oxygen species, decreased nitric oxide production and impaired angiogenic activity. Enhanced expression of HHIP, an antagonist for the Sonic hedgehog (SHH) signaling pathway, was observed in patients and mice with aGVHD and EMPs from injured ECs. The endothelial damage induced by EMPs was reversed when the HHIP incorporated into EMPs was silenced with an HHIP small interfering RNA or inhibited with the SHH pathway agonist, Smoothened agonist. This work supports a feasible vicious cycle in which EMPs generated during endothelial injury, in turn, aggravate endothelial damage by carrying HHIP into target ECs, contributing to the continuously deteriorating endothelial damage in the development of aGVHD. EMPs harboring HHIP would represent a potential therapeutic target for aGVHD.
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PMID:Endothelial microparticles carrying hedgehog-interacting protein induce continuous endothelial damage in the pathogenesis of acute graft-versus-host disease. 2795 15

Hedgehog signaling plays a key role in tissue fibrosis, the pathological hallmark of chronic graft-versus-host disease (cGVHD). We conducted a phase 1 trial of sonidegib, a selective antagonist of the hedgehog coreceptor Smoothened, for the treatment of steroid-refractory cGVHD. After a 3+3 study design, sonidegib was administered for up to 12 cycles of 28 days each, using 3 doses: 200 mg/day (dose level 1), 400 mg/day (dose level 2), and 600 mg/day (dose level 3). Seventeen patients were enrolled. The median number of cycles completed was 6 (range, 0-12). There was only 1 dose-limiting toxicity (cohort 2, grade 3 creatine phosphokinase increase) observed. Immunohistochemical evaluation of skin biopsies revealed decreased protein expression of hedgehog signaling pathway molecules with sonidegib therapy. Clinically, 8 patients (47%) had a partial response in skin or sclerodermatous disease, 6 patients had no response, and 3 were not evaluable. Clinical responses were assessed by treating physicians and not by National Institutes of Health criteria. Overall, patients reported worsening of quality of life, which was more severe in clinical nonresponders. Accrual was terminated early as a result of the cumulative toxicity burden not attributed to sonidegib and patient decisions to stop taking sonidegib. We believe hedgehog signaling inhibition warrants further investigation in patients with cGVHD because of the association with clinical responses and immunohistochemical changes. This trial was registered at www.clinicaltrials.gov as #NCT02086513.
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PMID:Phase 1 study of the Hedgehog pathway inhibitor sonidegib for steroid-refractory chronic graft-versus-host disease. 2929 38

Steroid-refractory intestinal acute graft-versus-host disease (aGVHD) is a frequently fatal condition with little known about mechanisms driving failed steroid responses in gut mucosa. To uncover novel molecular insights in steroid-refractory aGVHD, we compared gene expression profiles of rectosigmoid biopsies from patients at diagnosis of clinical stage 3-4 lower intestinal aGVHD (N=22), to repeat biopsies when the patients became steroid refractory (N=22), and normal controls (N=10). We also performed single gene analyses of factors associated with tolerance (programmed death ligand-1 [PDL1], indoleamine 2,3 dioxygenase [IDO1], and T cell immunoreceptor with Ig and ITIM domains [TIGIT]) and found that significantly higher expression levels of these aGVHD inhibitory genes (PDL1, IDO1, TIGIT) at aGVHD onset became decreased in the steroid-refractory state. We examined genes triggered by microbial ligands to stimulate gut repair, amphiregulin (AREG) and the aryl hydrocarbon receptor (AhR), and found that both AREG and AhR gene expression levels were increased at aGVHD onset and remained elevated in steroid-refractory aGVHD. We also identified higher expression levels of metallothioneines, metal-binding enzymes induced in stress responses, and M2 macrophage genes in steroid-refractory aGVHD. We observed no differences in T-cell subsets between onset and steroid-refractory aGVHD. Patients with a rapidly fatal course showed greater DNA damage and a distinct microbial signature at aGVHD onset, whereas patients with more prolonged survival exhibited a gene expression profile consistent with activation of Smoothened. Our results extend the paradigm beyond T cell-centric therapies for steroid-refractory GI aGVHD and highlight new mechanisms for therapeutic exploration.
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PMID:Stress responses, M2 macrophages, and a distinct microbial signature in fatal intestinal acute graft-versus-host disease. 3139 54