Effects of human umbilical cord blood mononuclear cells on ovalbumin-induced asthma in mice.

Background: Umbilical cord blood mononuclear cells (UCMNCs) show broad immune-modulation effects, which may be helpful for treating asthma. Effects of UCMNCs on asthma were investigated with mouse model in present study. Methods: Asthma was induced in BALB/c mice by ovalbumin (OVA) immunization and challenge. Asthmatic mice were then treated on days 7 and 20 with intravenous injections of UCMNCs in doses of 4×105, 2×106, and 107 cells per mouse for the low-dose UCMNC (UCMNCL), medium-dose UCMNC (UCMNCM), and high-dose UCMNC (UCMNCH) groups, respectively. Fetal mouse blood mononuclear cells (FMMNCs) were administered to FMMNC group at a dose of 2×106 cells per mouse as approximate allograft control. Airway hyperresponsiveness (AHR), airway inflammation indexes, and CD4/CD8 T cell subsets were measured at day 25. Results: Compared with the model group, AHR in the UCMNCL group, inflammation score of lung tissue in the UCMNCM group, interleukin (IL)-5 in bronchoalveolar lavage fluid (BALF) in UCMNCL group, IL-5 and IL-13 in BALF in UCMNCM group, and IL-17 in serum in UCMNCH group were significantly inhibited. Compared with the model group, CD4+CD8+ T cells were reduced in the UCMNCL group, while decrease of CD4-CD8- T cells and increase of CD4+CD8- T cells were further strengthened in UCMNCM group. FMMNC treatment significantly reduced the IL-13 and IL-17 in serum, decreased CD4-CD8- and CD4+CD8- T cells, and increased the CD4+CD8+ and CD4-CD8+ T cells in BALF. Conclusions: UCMNCs can modulate AHR, T-helper (Th)2 inflammation, and airway injury in experimental asthma at appropriate dose.

Autologous Airway Basal Cell Transplantation Alleviates Airway Epithelium Defect in Recurrent Benign Tracheal Stenosis.

BACKGROUND: Airway epithelium defects are a hallmark of recurrent benign tracheal stenosis (RBTS). Reconstructing an intact airway epithelium is of great importance in airway homeostasis and epithelial wound healing and has great potential for treating tracheal stenosis. METHODS: An experimental study was conducted in canines to explore the therapeutic effect of autologous basal cell transplantation in restoring airway homeostasis. First, airway mucosae from human patients with recurrent tracheal stenosis were analyzed by single-cell RNA sequencing. Canines were then randomly divided into tracheal stenosis, Stent, Stent + Cells, and Stent + Cells + Biogel groups. Autologous airway basal cells of canines in the Stent + Cells and Stent + Cells + Biogel groups were transplanted onto the stenotic airway after modeling. A biogel was coated on the airway prior to basal cell transplantation in the Stent + Cells + Biogel group. After bronchoscopic treatments, canines were followed up for 16 weeks. RESULTS: Single-cell RNA sequencing demonstrated packed airway basal cells and an absence of normal airway epithelial cells in patients with RBTS. Autologous airway basal cell transplantation, together with biogel coating, was successfully performed in the canine model. Follow-up observation indicated that survival time in the Stent + Cells + Biogel group was significantly prolonged, with a higher (100%) survival rate compared with the other groups. In terms of pathological and bronchoscopic findings, canines that received autologous basal cell transplantation showed a reduction in granulation hyperplasia as well as airway re-epithelialization with functionally mature epithelial cells. CONCLUSIONS: Autologous airway basal cell transplantation might serve as a novel regenerative therapy for airway re-epithelialization and inhibit recurrent granulation hyperplasia in benign tracheal stenosis.

Mechanical stretch promotes apoptosis and impedes ciliogenesis of primary human airway basal stem cells.

BACKGROUND: Airway basal stem cells (ABSCs) have self-renewal and differentiation abilities. Although an abnormal mechanical environment related to chronic airway disease (CAD) can cause ABSC dysfunction, it remains unclear how mechanical stretch regulates the behavior and structure of ABSCs. Here, we explored the effect of mechanical stretch on primary human ABSCs. METHODS: Primary human ABSCs were isolated from healthy volunteers. A Flexcell FX-5000 Tension system was used to mimic the pathological airway mechanical stretch conditions of patients with CAD. ABSCs were stretched for 12, 24, or 48 h with 20% elongation. We first performed bulk RNA sequencing to identify the most predominantly changed genes and pathways. Next, apoptosis of stretched ABSCs was detected with Annexin V-FITC/PI staining and a caspase 3 activity assay. Proliferation of stretched ABSCs was assessed by measuring MKI67 mRNA expression and cell cycle dynamics. Immunofluorescence and hematoxylin-eosin staining were used to demonstrate the differentiation state of ABSCs at the air-liquid interface. RESULTS: Compared with unstretched control cells, apoptosis and caspase 3 activation of ABSCs stretched for 48 h were significantly increased (p < 0.0001; p < 0.0001, respectively), and MKI67 mRNA levels were decreased (p < 0.0001). In addition, a significant increase in the G0/G1 population (20.2%, p < 0.001) and a significant decrease in S-phase cells (21.1%, p < 0.0001) were observed. The ratio of Krt5+ ABSCs was significantly higher (32.38% vs. 48.71%, p = 0.0037) following stretching, while the ratio of Ac-tub+ cells was significantly lower (37.64% vs. 21.29%, p < 0.001). Moreover, compared with the control, the expression of NKX2-1 was upregulated significantly after stretching (14.06% vs. 39.51%, p < 0.0001). RNA sequencing showed 285 differentially expressed genes, among which 140 were upregulated and 145 were downregulated, revealing that DDIAS, BIRC5, TGFBI, and NKX2-1 may be involved in the function of primary human ABSCs during mechanical stretch. There was no apparent difference between stretching ABSCs for 24 and 48 h compared with the control. CONCLUSIONS: Pathological stretching induces apoptosis of ABSCs, inhibits their proliferation, and disrupts cilia cell differentiation. These features may be related to abnormal regeneration and repair observed after airway epithelium injury in patients with CAD.

Long-term efficacy and safety of the Dumon stent for treatment of benign airway stenosis.

BACKGROUND: The long-term efficacy of the Dumon stent in the treatment of benign airway stenosis is unclear. OBJECTIVE: The objective of this study was to evaluate the long-term efficacy and safety of the Dumon stent in patients with benign airway stenosis. METHODS: We retrospectively reviewed patients with benign airway stenosis who were treated with a Dumon stent at the First Affiliated Hospital of Guangzhou Medical University between March 2014 and October 2021. We included patients with successful removal of silicone stents after implantation. The clinical data and information on bronchoscopic interventional procedures and related complications were collected and analyzed. RESULTS: Ninety-nine patients with benign airway stenosis were included. The stent was placed mainly in the trachea (44.4%) and left main bronchus (43.4%). The main type of stenosis was post-tuberculosis bronchial stenosis (57.6%). The overall cure rate was 60.6%. Stent-related complications included retention of secretions (70.7%), granuloma formation (67.7%), stent angulation (21.2%), and stent migration (12.1%). The stent was less effective for left main bronchus stenosis (p = 0.012). Multivariate logistic regression analysis identified that stent placement for more than 13 months, a stent-intervention number of ⩽ 1 predicted a favorable outcome. CONCLUSION: The efficacy and safety of the Dumon stent for benign airway stenosis need improvement. The stent is less effective for left main bronchus stenosis; regular follow-up is required in such cases. Stent placement for > 13 months and no more than once stent intervention within a 6-month period were associated with a favorable outcome.

A clinical and canine experimental study in small-airway response to bronchial thermoplasty: Role of the neuronal effect.

BACKGROUND: The effects of bronchial thermoplasty (BT) on smooth muscle (SM) and nerves in small airways are unclear. METHODS: We recruited 15 patients with severe refractory asthma, who received BT treatment. Endobronchial optical-coherence tomography (EB-OCT) was performed at baseline, 3 weeks' follow-up and 2 years' follow-up to evaluate the effect of BT on airway structure. In addition, we divided 12 healthy beagles into a sham group and a BT group, the latter receiving BT on large airways (inner diameter >3 mm) of the lower lobe. The dogs' lung lobes were resected to evaluate histological and neuronal changes of the treated large airways and untreated small airways 12 weeks after BT. RESULTS: Patients receiving BT treatment had significant improvement in Asthma Control Questionnaire (ACQ) scores and significant reduction in asthma exacerbations. EB-OCT results demonstrated a notable increase in inner-airway area (Ai) and decrease in airway wall area percentage (Aw%) in both large (3rd-to 6th-generation) and small (7th-to 9th-generation) airways. Furthermore, the animal study showed a significant reduction in the amount of SM in BT-treated large airways but not in untreated small airways. Protein gene product 9.5 (PGP9.5)-positive nerves and muscarinic receptor 3 (M3 receptor) expression in large and small airways were both markedly decreased throughout the airway wall 12 weeks after BT treatment. CONCLUSIONS: BT significantly reduced nerves, but not SM, in small airways, which might shed light on the mechanism of lung denervation by BT.

Long-term efficacy and safety of the Dumon stent for benign tracheal stenosis: a meta-analysis.

BACKGROUND: The short-term efficacy of Dumon stent has been well demonstrated. Across years, however, due to insufficient sample size and absent of the randomized controlled trial, no reliable conclusion could be reach for Dumon stent's long-term efficacy. So, we conducted the first meta-analysis to evaluate the long-term efficacy and safety of the Dumon stent for benign tracheal stenosis. METHODS: Data on related trials were obtained by doing a literature search in PubMed, Web of Science and Cochrane Library. Random-effect and fixed-effect models were used to calculate the efficacy and incidence of complication of Dumon stent placement. RESULTS: A total of 395 patients from 8 studies were included in this study, revealing that the stability rate was 41.12% (95% CI, 34.85-48.52%) of Dumon stenting. Further, a curative rate of 40.74% (95% CI, 34.92-47.53%), and efficacy of 75.49% (95% CI, 70.89-80.39%) were obtained from this study. Analysis of the incidence of complications indicated 25.04% of migration (95% CI, 17.52-35.79%), 15.66% granulation (95% CI, 9.39-26.11%) and 23.82% of mucus retention 23.82% (95% CI, 13.77-41.20%). CONCLUSIONS: Dumon stent has a moderate efficacy for treating benign tracheal stenosis with approximately 20% incidence of complication, regular bronchoscopy follow-up should be conducted. Thus, further research is required to modified Dumon stenting.

Incidence and risk of thromboembolism associated with bevacizumab in patients with non-small cell lung carcinoma.

BACKGROUND: Bevacizumab, a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF), is effective for the treatment of advanced non-small cell lung cancer (NSCLC). However, severe adverse events (AEs) have been reported in NSCLC patients treated with bevacizumab. Currently, the contribution of Bevacizumab to thromboembolism is still controversial. We conducted a study to determine the overall risk and incidence of thromboembolism with bevacizumab in NSCLC patients. METHODS: Electronic databases such as the PubMed, Web of Science and Cochrane Library were searched for related trials. Statistical analyses were conducted to calculate the overall incidence rates, odds ratios (ORs), and 95% confidence intervals (CIs) by using either random-effect or fixed-effect models depending on the heterogeneity. We also used trial sequence analysis (TSA) to verify the pooled result. RESULTS: A total of 3,555 subjects from nine studies were included. The overall incidence of thromboembolism events in NSCLC patients treated with bevacizumab was 4.8% (95% CI: 1.9-7.7%). Without bevacizumab, this incidence was 2.9% (95% CI: 0.6-5.1%). Bevacizumab use was associated with a significantly increased risk in thromboembolism events (OR =1.74; 95% CI: 1.15-2.62; P=0.008). Subgroup analysis based on the doses showed that bevacizumab administered at 15 mg/kg (OR =1.81; 95% CI: 1.14-2.86; P=0.012), but not 7.5 mg/kg (OR =1.32; 95% CI: 0.78-2.24; P=0.296), increased the risk of thromboembolism. CONCLUSIONS: Bevacizumab is associated with a significantly increased risk of thromboembolism development in NSCLC patients. It may have dose-toxicity relationship and low dose of bevacizumab may be a better choice for NSCLC patients, with equal efficacy and low hazard of thromboembolism events.

Dual effects of cycloheximide on U937 apoptosis induced by its combination with VP-16.

In this study, cycloheximide (CHX) and VP-16 alone and in combination (C&V) have been used to strongly trigger apoptosis in U937 cells. The presence of CHX markedly prevented VP-16-induced apoptosis, suggesting that in this process de novo protein synthesis is required. But interestingly, C&V had shown more similarities with CHX but not VP-16 alone, including the effects on cell cycle distribution and induction of apoptosis, which occurred more quickly and was steadily enhanced by increasing concentrations of CHX or by N-alpha-tosyl-L-lysyl-chloromethyl ketone (TLCK), a serine protease inhibitor. These results indicate that CHX, not VP-16, is indeed the dominant inducer of U937 apoptosis, when they are coadministered. In particular, VP-16 even promoted CHX-induced apoptosis, but did not alter its selection of cell types. In T-cells resistant to CHX (Molt-4), we have detected no apoptotic response to their combination. These findings may well explain why the inhibitory effects of CHX on apoptosis induced by the same stimuli are usually different according to the cell type used, and also suggest that CHX may have the potential to lower side effects and drug resistance of cancer therapy.