Hypoxic preconditioning improves the survival and pro-angiogenic capacity of transplanted human umbilical cord mesenchymal stem cells via HIF-1α signaling in a rat model of bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is a serious chronic respiratory disease that predominates in the neonatal period. Currently, efficacious and effective specific treatments are lacking. Mesenchymal stem cells (MSCs) transplantation has emerged as a promising option for treating BPD. However, the lower cell survival rate limits its therapeutic efficacy. Hypoxic preconditioning is a direct and effective strategy for promoting MSCs survival, proliferation, and paracrine secretion in the recipient after transplantation, which is greatly important to tissue engineering. We investigated whether hypoxia-pretreated MSCs (HPMSCs) confer superior benefit in an experimental BPD rat model. Neonatal Sprague-Dawley rats were exposed to 80-85% O2 for 14 days. Before tracheal transplantation, the MSCs were pretreated for 48 h with deferoxamine, a chemical hypoxia-mimicking agent. In vitro, the HPMSCs reduced the apoptosis rare, caspase-3 expression, and reactive oxygen species (ROS) generation and promoted proliferation, hypoxia inducible factor-1α (HIF-1α) expression, VEGF secretion, and human umbilical vein endothelial cell tube formation (p < 0.05). In vivo, the HPMSCs restored alveolar structure and lung function, ameliorated pulmonary hypertension, increased vessel density in the BPD rat model (p < 0.05). This work demonstrates for the first time that HPMSCs could have a markedly improved therapeutic effect in BPD, presenting a new potential strategy for the clinical implementation of stem cell biotechnology.

Human umbilical cord mesenchymal stem cells combined with pirfenidone upregulates the expression of RGS2 in the pulmonary fibrosis in mice.

OBJECTIVE: The therapeutic effect of umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in combination with pirfenidone (PFD) on pulmonary fibrosis in mice and its possible mechanism were investigated. METHODS: C57BL/6 mice were randomly divided into six groups: control group, model group, P10 group, P30 group, P100 group, and P300 group. Modeled by tracheal intubation with 3 mg/kg bleomycin drip, each dose of PFD was administered daily by gavage from day 7 onwards. The mice were observed continuously for 21 days and survival was recorded. Lung tissues were collected on day 21, and hematoxylin-eosin (HE) and Masson staining were performed to assess morphological changes and collagen deposition in the lungs. Collagen content was measured by the Sircol method, and fibrosis marker levels were detected by PCR and Western blot. Another batch of C57BL/6 mice was then randomly divided into five groups: hUC-MSC control group, model group, P100 group, hUC-MSC treatment group, and hUC-MSCs + P30 group. On day 7, 5 × 105 hUC-MSCs were injected into the tail vein, the mice were administered PFD gavage daily from day 7 onwards, and their survival was recorded. Lung tissues were collected on day 21 to detect pathological changes, the collagen content, and the expression of regulator of G protein signaling 2 (RGS2). Pulmonary myofibroblasts (MFBs) were divided into an MFB group and an MFB + hUC-MSCs group; different doses of PFD were administered to each group, and the levels of RGS2, intracellular Ca2+, and fibrosis markers were recorded for each group. RESULTS: Compared with other PFD group doses, the P100 group had significantly improved mouse survival and lung pathology and significantly reduced collagen and fibrosis marker levels (p < 0.05). The hUC-MSCs + P30 group had significantly improved mouse survival and lung pathology, significantly reduced collagen content and fibrosis marker levels (p < 0.05), and the efficacy was better than that of the P100 and hUC-MSCs groups (p < 0.05). RGS2 expression was significantly higher in the MSCs + P30 group compared with the P100 and hUC-MSCs groups (p < 0.05). PFD increased RGS2 expression in MFBs (p < 0.05) in a dose-dependent manner. Compared with PFD and hUC-MSCs treatment alone, combination of hUC-MSCs and PFD increased RGS2 protein levels, significantly decreased intracellular Ca2+ concentration, and significantly reduced fibrosis markers. CONCLUSION: The findings suggest that hUC-MSCs combined with low-dose PFD have a therapeutic effect better than that of the two treatments used separately. Its effect on attenuating bleomycin-induced pulmonary fibrosis in mice is related to the increase of RGS2.

Phase I trial of human umbilical cord-derived mesenchymal stem cells for treatment of severe bronchopulmonary dysplasia.

Severe bronchopulmonary dysplasia (BPD) is a chronic lung disorder that primarily affects premature babies with extremely low birth weight and involves in multiple organ system; no effective pharmacotherapy for this disease exists, and mortality remains high. Based on the evidence from previous preclinical studies and phase I clinical trials, this study aims to test the safety of intravenous application of a single dose of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in patients with severe BPD. The Mesenchymal Stem cells for Bronchopulmonary Dysplasia Treatment (MSBDT) trial is a single center, open-label, dose-escalation phase I clinical trial. Severe BPD patients were enrolled in Children Hospital of Chongqing Medical University, Chongqing, China. The first six patients were treated with low-dose hUC-MSCs (1 × 106 cells/kg) and the next seven patients were treated with high-dose hUC-MSCs (5 × 106 cells/kg). This study is registered with ClinicalTrials.gov, number NCT03558334. No prespecified infusion-associated adverse events, immediate complication, respiratory or cardiovascular compromise were observed during infusion and 24 h after infusion. No significant changes in safety laboratory values were observed. One death event occurred in the low-dose group on study day 10, and one death event occurred in the high-dose group on study day 24, while, after review in detail, the two cases are not believed to be infusion-associated events. In conclusion, intravenous application of a single dose of hUC-MSCs was tolerated in thirteen patients with severe BPD.

Microvesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Enhance Alveolar Type II Cell Proliferation and Attenuate Lung Inflammation in a Rat Model of Bronchopulmonary Dysplasia.

Although it is known that exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs) alleviate hyperoxic lung injury of bronchopulmonary dysplasia (BPD) in animal models, the role of microvesicles (MVs) derived from hUCMSCs in BPD is poorly defined. Furthermore, antenatal inflammation has been linked to high risk of BPD in preterm infants. The purpose of this study was to explore whether MVs derived from hUCMSCs can preserve lung structure and function in an antenatal lipopolysaccharide- (LPS-) induced BPD rat model and to clarify the underlying mechanism. We demonstrate that antenatal LPS induced alveolar simplification, altered lung function, and dysregulated pulmonary vasculature, which restored by hUCMSCs and MVs treatment. Furthermore, MVs were large vesicles with a diameter of 100-900 nanometers and mostly uptaken by alveolar epithelial type II cells (AT2) and macrophages. Compared with the LPS-exposed group, MVs restored the AT2 cell number and SP-C expression in vivo and promoted the proliferation of AT2 cells in vitro. MVs also restored the level of IL-6 and IL-10 in lung homogenate. Additionally, PTEN/AKT and MAPK pathways were associated with the protection of MVs. Taken together, this study suggests MVs derived from hUCMSCs improve lung architecture and function in an antenatal LPS-induced BPD rat model by promoting AT2 cell proliferation and attenuating lung inflammation; thus, MVs provide a promising therapeutic vehicle for BPD treatment.

Type 2 Alveolar Epithelial Cells Differentiated from Human Umbilical Cord Mesenchymal Stem Cells Alleviate Mouse Pulmonary Fibrosis Through ß-Catenin-Regulated Cell Apoptosis.

Pulmonary fibrosis (PF) is a chronic, progressive, and lethal disease with little response to available therapies. One of the major mechanisms of PF is the repeated injury and inadequate regeneration of the alveolar epithelium. In this study, we induced human umbilical cord mesenchymal stem cells (hUC-MSCs) to differentiate into type 2 alveolar epithelial cells (AEC2s), and we provided evidence that intratracheal transplantation of hUC-MSC-derived AEC2s (MSC-AEC2s) could improve mortality and alleviate fibrosis in bleomycin-induced PF mice. Transplantation of MSC-AEC2s could increase the AEC2 cell count in these mice, and the results of the cell tracing experiment exhibited that the increased AEC2s originated from the self-renewal of mouse alveolar epithelium. The AEC2 survival was controlled by the apoptosis of AEC2s via the expression of ß-catenin in PF mice. In in vitro experiments, MSC-AEC2s could alleviate the apoptosis of MLE-12 cells induced by transforming growth factor beta (TGF-ß1), which could be eliminated by using PRI-724, a ß-catenin inhibitor, suggesting ß-catenin signaling involved in the protection against apoptosis provided by MSC-AEC2s. Our study demonstrated that MSC-AEC2s could protect PF mice through regulating apoptosis mediated by ß-catenin, which provided a viable strategy for the treatment of PF.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Alleviate Lung Injury in Rat Model of Bronchopulmonary Dysplasia by Affecting Cell Survival and Angiogenesis.

Bronchopulmonary dysplasia (BPD) is a serious chronic lung disease in premature newborns, with high morbidity and mortality rates. Mesenchymal stem cell (MSC) transplantation has developed into a promising approach to alleviate BPD. Small extracellular vesicles, which are an important therapeutic component of MSCs, have been reported to be effective in a mouse model of BPD. However, the affected cell types and detailed underlying mechanisms are unclear. In this study, we found that human umbilical cord mesenchymal stem cell-derived small extracellular vesicles (hucMSC-sEVs) were successfully absorbed by lung tissue after intratracheal administration, and remained in the lungs for at least 72 h. The results showed that hucMSC-sEVs restored alveolar structure and lung function, and ameliorated pulmonary hypertension in a rat model of BPD. The number of Ki-67-positive lung cells were improved, while the number of TUNEL-positive lung cells were reduced in our hucMSC-sEV-treated BPD model. Additionally, SP-C staining (a marker of type II alveolar epithelial cells, TIIAECs) and CD31 staining (a marker of pulmonary vascular endothelial cells, PVECs) were both increased in a hyperoxia-induced BPD model treated with hucMSC-sEVs. In vitro, under hyperoxic conditions, the tube-like structure formation was improved in human umbilical vein endothelial cells, and the proliferation was increased and the apoptosis was attenuated in MLE-12 cells treated with hucMSC-sEVs. Furthermore, we observed downregulated expression of PTEN and cleaved-caspase3, and upregulated expression of p-Akt and vascular endothelial growth factor-A in our hucMSC-sEV-treated BPD model. In conclusion, hucMSC-sEVs improved alveolarization and angiogenesis in a rat BPD model by protecting TIIAECs and PVECs, which were associated with the PTEN/Akt signaling pathway.

Allogeneic human umbilical cord-derived mesenchymal stem cells for severe bronchopulmonary dysplasia in children: study protocol for a randomized controlled trial (MSC-BPD trial).

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a complex lung pathological lesion secondary to multiple factors and one of the most common chronic lung diseases. It has a poor prognosis, especially in preterm infants. However, effective therapies for this disease are lacking. Stem-cell therapy is a promising way to improve lung injury and abnormal alveolarization, and the human umbilical cord (hUC) is a good source of mesenchymal stem cells (MSCs), which have demonstrated efficacy in other diseases. We hypothesized that intravenously administered allogeneic hUC-MSCs are safe and effective for severe BPD. METHODS: The MSC-BPD trial is a randomized, single-center, open-label, dose-escalation, phase-II trial designed to investigate the safety and efficacy of hUC-MSCs in children with severe BPD. In this study, 72 patients will be enrolled and randomly divided into two intervention groups and one control group. Patients in the intervention groups will receive a low dose of hUC-MSCs (n = 24; 2.5 million cells/kg) or a high dose of hUC-MSCs (n = 24; 5 million cells/kg) in combination with traditional supportive treatments for BPD. The patients in the control group (n = 24) will be treated with traditional supportive treatments alone without hUC-MSCs. The primary outcome measures will be cumulative duration of oxygen therapy. Follow-up assessments will be performed at 1, 3, 6, 12, and 24 months post intervention, and the key outcome during follow-up will be changes on chest radiography. Statistical analyses will evaluate the efficacy of the hUC-MSC treatment. DISCUSSION: This will be the first randomized controlled trial to evaluate the safety and efficacy of intravenously administered hUC-MSCs in children with severe BPD. Its results should provide a new evidence-based therapy for severe BPD. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03601416. Registered on 26 July 2018.

Intravitreal injection of Conbercept combined with PPV in the treatment of proliferative diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe the value of intravitreal injection of Conbercept in the treatment of proliferative diabetic retinopathy(PDR).<p>METHODS: Totally 64 patients(75 eyes)with PDR admitted to the hospital between January 2016 and October 2019 were recruited and divided into observation group(32 cases, 38 eyes)and control group(32 cases, 37 eyes)by random number table method. The observation group received vitrectomy and intravitreal injection of Conbercept, while the control group received simple vitrectomy. The best corrected visual acuity(BCVA)was detected before treatment, at 1wk, 1mo, and 3mo after operation. Changes in central macular thickness(CMT)before treatment and at 3mo after operation were determined. Aqueous humor or vitreous humor samples were collected before and after treatment to measure concentrations of vascular endothelial growth factor(VEGF), placental growth factor(PIGF)and basic fibroblast growth factor(bFGF)by enzyme-linked immunosorbent assay. The operation time, intraoperative blood loss and improvement time of symptoms(retinal edema, fundus hemorrhage, exudation)of the 2 groups were statistically analyzed. Incidences of complications in the 2 groups were recorded.<p>RESULTS: The observation group had better BCVA than the control group at 1wk, 1mo and 3mo after operation(<i>P</i><0.05), and had smaller CMT than the control group at 3mo after operation(<i>P</i><0.001). The concentrations of VEGF, PIGF and bFGF in observation group during operation were lower than those in the control group(<i>P</i><0.001). The operation time, absorption time of retinal edema, fundus hemorrhage and exudation, intraoperative blood loss, and the total incidence of complications in the observation group were shorter and lower than those in the control group(<i>P</i><0.05).<p>CONCLUSION: Intravitreal injection of Conbercept before vitrectomy can degrade new blood vessels, and shorten the operation time. It can not only help improve vision and relieve macular edema but also reduce surgical complications and promote postoperative recovery.

Clinical efficacy of fecal microbiota transplantation in treatment of Parkinson′s disease with constipation / 中华神经科杂志

Objective@#To observe the safety and efficacy of fecal microbiota transplantation (FMT) in treatment of Parkinson′s disease (PD) with constipation.@*Methods@#From September 2017 to April 2019, 22 PD patients with serious constipation in the Department of Neurology, the Affiliated Huaian No. 1 People′s Hospital of Nanjing Medical University were treated with FMT and followed up for 12 weeks. Spontaneous bowel movement (SBM) per week and scores of Wexner Constipation Scale (Wexner), Constipation Quality of Life Scale (PAC-QOL) and Parkinson′s Disease Quality of Life Questionnaire (PDQ-39) were recorded before and after transplantation.@*Results@#Compared with the number of independent defecation and scores before treatment, the number of independent defecation per week (4.63±2.25, 5.38±1.23, 5.75±1.29, 5.54±1.30 vs 1.57±0.74), Wexner score (7.92±2.61, 5.67±1.78, 5.08±1.83, 4.92±1.78 vs 16.67±4.31), PAC-QOL score (62.3±3.2, 58.8±2.8, 57.1±3.9, 59.6±4.4 vs 110.3±14.7) and PDQ-39 score (44.8±14.8, 37.8±12.8, 32.8±12.3, 31.9±9.2 vs 58.7±16.7) were significantly improved by FMT treatment at two, four, eight and 12 weeks (P<0.01). After 12-week treatment, the effective rate was 100% (22/22), and the clinical cure rate was 86% (19/22). No serious adverse reactions occurred during treatment.@*Conclusion@#FMT is effective and safe in treating PD with constipation.