Targeting the Canonical Nuclear Factor-κB Pathway with a High-Potency IKK2 Inhibitor Improves Outcomes in a Mouse Model of Idiopathic Pneumonia Syndrome

Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation

Diffuse alveolar hemorrhage (DAH) is a morbid syndrome that occurs after autologous and allogeneic hematopoietic cell transplantation in children and adults. DAH manifests most often in the first few weeks following transplantation. It presents with pneumonia-like symptoms and acute respiratory failure, often requiring high levels of oxygen supplementation or mechanical ventilatory support. Hemoptysis is variably present. Chest radiographs typically feature widespread alveolar filling, sometimes with peripheral sparing and pleural effusions. The diagnosis is suspected when serial bronchoalveolar lavages return increasingly bloody fluid. DAH is differentiated from infectious causes of alveolar hemorrhage when extensive microbiological testing reveals no pulmonary pathogens. The cause is poorly understood, though preclinical and clinical studies implicate pretransplant conditioning regimens, particularly those using high doses of total-body-irradiation, acute graft-versus-host disease (GVHD), medications used to prevent GVHD, and other factors. Treatment consists of supportive care, systemic corticosteroids, platelet transfusions, and sometimes includes antifibrinolytic drugs and topical procoagulant factors. Therapeutic blockade of tumor necrosis factor-α showed promise in observational studies, but its benefit for DAH remains uncertain after small clinical trials. Even with these treatments, mortality from progression and relapse is high. Future investigational therapies could target the vascular endothelial cell biology theorized to contribute to alveolar bleeding and pathways that contribute to susceptibility, inflammation, cellular resilience, and tissue repair. This review will help clinicians navigate through the limited evidence to diagnose and treat DAH, counsel patients and families, and plan for future research.

Prevention of non-infectious pulmonary complications after intra-bone marrow stem cell transplantation in mice

Non-infectious pulmonary complications including idiopathic pneumonia syndrome (IPS) and bronchiolitis obliterans syndrome (BOS), which are clinical and diagnostic manifestations of lung chronic graft-versus-host disease (GVHD), cause significant mortality after allogeneic stem cell transplantation (SCT). Increasing evidence suggests that alloantigen reactions in lung tissue play a central role in the pathogenesis of IPS and BOS; however, the mechanism is not fully understood. Several clinical and experimental studies have reported that intra-bone marrow (IBM)-SCT provides high rates of engraftment and is associated with a low incidence of acute GVHD. In the present study, allogeneic SCT was conducted in mouse models of IPS and BOS, to compare intravenous (IV)-SCT with IBM-SCT. Allogeneic IBM-SCT improved the clinical and pathological outcomes of pulmonary complications compared to those of IV-SCT. The mechanisms underlying the reductions in pulmonary complications in IBM-SCT mice were explored. The infiltrating lung cells were mainly CD11b+ myeloid and CD3+ T cells, in the same proportions as in transplanted donor cells. In an in vivo bioluminescence imaging, a higher proportion of injected donor cells was detected in the lung during the early phase (1 h after IV-SCT) than after IBM-SCT (16.7 ± 1.1 vs. 3.1 ± 0.7 × 10⁵ photons/s/animal, IV-SCT vs. IBM-SCT, P = 1.90 × 10⁻¹⁰). In the late phase (5 days) after SCT, there were also significantly more donor cells in the lung after IV-SCT than after IBM-SCT or allogeneic-SCT (508.5 ± 66.1 vs. 160.1 ± 61.9 × 10⁶ photons/s/animal, IV-SCT vs. IBM-SCT, P = 0.001), suggesting that the allogeneic reaction induces sustained donor cell infiltration in the lung during the late phase. These results demonstrated that IBM-SCT is capable of reducing injected donor cells in the lung; IBM-SCT decreases donor cell infiltration. IBM-SCT therefore represents a promising transplantation strategy for reducing pulmonary complications, by suppressing the first step in the pathophysiology of chronic GVHD.

Ginsenoside Rb1 Alleviates Lipopolysaccharide-Induced Inflammatory Injury by Downregulating miR-222 in WI-38 Cells

Pneumonia is a serious respiratory tract infection disease in children, which threatens to the health or life of children patients. Ginsenoside Rb1 (Rb1) is a principle active ingredient extracted from the root of Panax notoginseng (Burk.) F.H. Chen with anti-inflammatory effect. Our study aimed to determine the effects and molecular mechanisms of Rb1 on lipopolysaccharide (LPS)-induced inflammatory injury of lung fibroblasts WI-38 cells. Cell viability and apoptosis were evaluated by CCK-8 and flow cytometry, respectively. The production of inflammatory cytokines were measured by ELISA and RT-qPCR. miR-222 expression was examined by RT-qPCR. The expression levels of the nuclear factor-kappa B (NF-κB) p65 and phosphorylated p65 were detected by western blot. We found that LPS stimulation induced WI-38 cell inflammatory injury by inhibiting cell viability, and inducing apoptosis and inflammatory cytokine production, while treatment with Rb1 significantly attenuated LPS-induced inflammatory injury in WI-38 cells. Additionally, Rb1 decreased LPS-induced upregulation of miR-222 and activation of the NF-κB pathway in WI-38 cells. Overexpression of miR-222 abolished the inhibitory effects of Rb1 on LPS-induced viability reduction, apoptosis, inflammatory cytokine production and activation of the NF-κB pathway. In conclusion, Rb1 alleviated LPS-induced inflammatory injury in WI-38 cells via downregulating miR-222 and inactivation of the NF-kB pathway.

Late Noninfectious Pulmonary Complications in Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic modality for a number of malignant and nonmalignant conditions. Pulmonary complications following HSCT are associated with increased mortality and morbidity. These complications may be classified into infectious versus noninfectious, and early versus late based on the time of occurrence post-transplant. Thus, exclusion of infectious etiologies is the first step in the diagnoses of pulmonary complications. Late onset noninfectious pulmonary complications typically occur 3 months post-transplant. Bronchiolitis obliterans is the major contributor to late-onset pulmonary complications, and its clinical presentation, pathogenesis, and current therapeutic approaches are discussed. Idiopathic pneumonia syndrome is another important complication which usually occurs early, although its onset may be delayed. Organizing pneumonia is important to recognize due to its responsiveness to corticosteroids. Other late onset noninfectious pulmonary complications discussed here include pulmonary venoocclusive disease, pulmonary cytolytic thrombi, pleuroparenchymal fibroelastosis, thoracic air leak syndrome, and posttransplant lymphoproliferative disorders.

Notoginsenoside R1 up-regulates microRNA-132 to protect human lung fibroblast MRC-5 cells from lipopolysaccharide-caused injury

BACKGROUND

Pneumonia is a common lung disease in children with high fatality rate. Notoginsenoside R1 (NGR1) is the main active component extracted from the roots of Panax notoginseng (Burk.) F.H. Chen (Araliaceae). Here, we carefully explored the potential anti-inflammatory and protective effects of NGR1 on lipopolysaccharide (LPS)-induced lung fibroblast MRC-5 cell injury.

METHODS

Viability and apoptosis of MRC-5 cells after different treatment or transfection were respectively assessed using CCK-8 assay and Annexin V-FITC/PI staining. The expression levels of microRNA-132 (miR-132), IL-1β, IL-6 and TNF-α in MRC-5 cells were measured using qRT-PCR. MicroRNA transfection was conducted to reduce the expression level of miR-132. Western blotting was used to analyze the protein expression levels of key factors involving in cell proliferation, apoptosis, NF-κB pathway and JNK pathway.

RESULTS

LPS treatment caused MRC-5 cell proliferation inhibition, apoptosis and over-production of inflammatory cytokines. NGR1 treatment had no significant effects on MRC-5 cell proliferation, apoptosis and production of inflammatory cytokines, but protected MRC-5 cells from LPS-caused cell proliferation inhibition, apoptosis and over-production of inflammatory cytokines. In addition, NGR1 increased the expression level of miR-132 in MRC-5 cells. Knockdown of miR-132 reversed the protective effects of NGR1 on LPS-treated MRC-5 cells. Furthermore, NGR1 attenuated LPS-activated NF-κB and JNK pathways in MRC-5 cells via up-regulation of miR-132.

CONCLUSION

This research confirmed the protective roles of NGR1 in lung fibroblast cell inflammatory injury. NGR1 protected MRC-5 cells from LPS-caused inflammatory injury through up-regulating miR-132 and then inactivating NF-κB and JNK pathways.

Impaired bone marrow B-cell development in mice with a bronchiolitis obliterans model of cGVHD

Chronic graft-versus-host disease (cGVHD) causes significant morbidity and mortality in patients after allogeneic bone marrow (BM) or stem cell transplantation (allo-SCT). Recent work has indicated that both T and B lymphocytes play an important role in the pathophysiology of cGVHD. Previously, our group showed a critical role for the germinal center response in the function of B cells using a bronchiolitis obliterans (BO) model of cGVHD. Here, we demonstrated for the first time that cGVHD is associated with severe defects in the generation of BM B lymphoid and uncommitted common lymphoid progenitor cells. We found an increase in the number of donor CD4⁺ T cells in the BM of mice with cGVHD that was negatively correlated with B-cell development and the frequency of osteoblasts and Prrx-1-expressing perivascular stromal cells, which are present in the B-cell niche. Use of anti-DR3 monoclonal antibodies to enhance the number of donor regulatory T cells (T_regs) in the donor T-cell inoculum ameliorated the pathology associated with BO in this model. This correlated with an increased number of endosteal osteoblastic cells and significantly improved the generation of B-cell precursors in the BM after allo-SCT. Our work indicates that donor T_regs play a critical role in preserving the generation of B-cell precursors in the BM after allo-SCT. Approaches to enhance the number and/or function of donor T_regs that do not enhance conventional T-cell activity may be important to decrease the incidence and severity of cGVHD in part through normal B-cell lymphopoiesis.

ETS1 is associated with cisplatin resistance through IKKα/NF-κB pathway in cell line MDA-MB-231

Background

Platinum-based drugs are used extensively in neoadjuvant chemotherapy for triple-negative breast cancer (TNBC), but their use can be limited by resistance. In this study, we established cisplatin (DDP) resistant TNBC cells to investigate the potential relationship among ETS1, IKKα/NF-κB and resistance.

Methods

The sensitivity was evaluated by MTT, apoptosis analysis. The intracellular DDP concentration difference was tested by inductively coupled plasma mass spectrometry (ICP-MS) method. Molecular pathological mechanism of DDP resistance was explored by microarray analysis and PPI network analysis. The ETS1, NF-κB signaling change were assessed by western blot and q-PCR in vitro and vivo. The existing binds between ETS1 and the core IKKα promoter were found by luciferase assay and chromatin immunoprecipitation technique (ChIP).

Results

MDA-MB-231/DDP (231/DDP) cell had a higher IC₅₀ value of cisplatin, lower intracellular DDP concentration, and lower apoptosis ratio than MDA-MB-231 (231/wt) cell line treated with DDP. Increased ABC transporters were induced by the activation of NF-κB pathway in 231/DDP cells. ETS1, RPL6, RBBP8, BIRC2, PIK3A and RARS were six important genes for DDP-resistance based on PPI network and expression validation. Protein expression of ETS1 and IKKα were significantly up-regulated in 231/DDP cells. However, inhibition of ETS1 expression enhances chemo-sensitivity to DDP and reversed the activation of NF-κB pathway in 231/DDP cells and subcutaneous transplantation tumor in vivo. Moreover, there is existing binds between ETS1 and the core IKKα promoter though luciferase assay and ChIP.

Conclusion

This study enables us to understand the functions of ETS1 in TNBC chemotherapy and suggests that ETS1 could be used as a novel marker of poor response to DDP and a potential therapeutic target for TNBC chemotherapy.