Prevention for moderate or severe BPD with intravenous infusion of autologous cord blood mononuclear cells in very preterm infants-a prospective non-randomized placebo-controlled trial and two-year follow up outcomes

The potential therapeutic effect of human umbilical cord mesenchymal stem cell-derived exosomes in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of preterm infants, with its incidence rising due to improved survival rates of these infants. BPD results from a combination of prenatal and postnatal factors, such as mechanical ventilation, oxygen toxicity, and infections, all of which significantly impact the prognosis and growth of affected infants. Current treatment options for BPD are largely supportive and do not address the underlying pathology. Exosomes are cell-derived bilayer-enclosed membrane structures enclosing proteins, lipids, RNAs, growth factors, cytokines and metabolites. They have become recognized as crucial regulators of intercellular communication in various physiological and pathological processes. Previous studies have revealed the therapeutic potential of human umbilical cord mesenchymal stem cells-derived exosomes (HUCMSCs-Exos) in promoting tissue repair and regeneration. Therefore, HUCMSCs-Exos maybe a promising and effective therapeutic modality for BPD. In this review, we firstly provide a comprehensive overview of BPD, including its etiology and the mechanisms of lung injury. Then we detail the isolation, characterization, and contents of HUCMSCs-Exos, and discuss their potential mechanisms of HUCMSCs-Exos in BPD treatment. Additionally, we summarize current clinical trials and discuss the challenges in translating these findings from bench to bedside. This review aims to lay the groundwork for future clinical applications of HUCMSCs-Exos in treating BPD.

Reinitiating lung development: a novel approach in the management of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the predominant chronic lung disease in preterm infants, linked with various adverse long-term outcomes. Multiple prenatal and postnatal risk factors can impede lung development, leading to BPD. Current management of BPD relies heavily on pharmacotherapies and alterations in ventilatory strategies. However, these interventions only mitigate BPD symptoms without addressing underlying alveolar, vascular, structural, and functional deficiencies. Given the retarded lung development in infants with BPD and the limitations of existing modalities, new therapeutic approaches are imperative. The induced differentiation of stem/progenitor cells and the spatiotemporal expression patterns of growth factors associated with lung developmental processes are critical for lung development reactivation in BPD, which focuses on stimulating pulmonary vasculogenesis and alveolarization. This review summarizes the process of lung development and offers a comprehensive overview of advancements in therapies designed to reinitiate lung development in BPD. Furthermore, we assessed the potential of these therapies for maintaining lung homeostasis and effectively restoring pulmonary structure and function through stem/progenitor cells and growth factors, which have been widely researched.

Umbilical cord blood-derived therapy for preterm lung injury: a systematic review and meta-analysis

INTRODUCTION

Lung injuries, such as bronchopulmonary dysplasia (BPD), remain a major complication of preterm birth, with limited therapeutic options. One potential emerging therapy is umbilical cord blood (UCB)-derived therapy.

OBJECTIVES

To systematically assess the safety and efficacy of UCB-derived therapy for preterm lung injury in preclinical and clinical studies.

METHODS

A systematic search of MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and WHO International Trials Registry Platform was performed. A meta-analysis was conducted with Review Manager (5.4.1) using a random effects model. Data was expressed as standardized mean difference (SMD) for preclinical data and pooled relative risk (RR) for clinical data, with 95% confidence intervals (CI). Potential effect modifiers were investigated via subgroup analysis. Certainty of evidence was assessed using the GRADE system.

RESULTS

Twenty-three preclinical studies and six clinical studies met eligibility criteria. Statistically significant improvements were seen across several preclinical outcomes, including alveolarization (SMD, 1.32, 95%CI [0.99, 1.65]), angiogenesis (SMD, 1.53, 95%CI [0.87, 2.18]), and anti-inflammatory cytokines (SMD, 1.68, 95%CI [1.03, 2.34]). In clinical studies, 103 preterm infants have received UCB-derived therapy for preterm lung injury and no significant difference was observed in the development of BPD (RR, 0.93, 95%CI [0.73, 1.18]). Across both preclinical and clinical studies, administration of UCB-derived therapy appeared safe. Certainty of evidence was assessed as "low."

CONCLUSIONS

Administration of UCB-derived therapy was associated with statistically significant improvements across several lung injury markers in preclinical studies. Early clinical studies demonstrated the administration of UCB-derived therapy as safe and feasible but lacked data regarding efficacy.

Human Muse cells isolated from preterm- and term-umbilical cord delivered therapeutic effects in rat bleomycin-induced lung injury model without immunosuppressant

BACKGROUND

Bleomycin (BLM)-induced lung injury is characterized by mixed histopathologic changes with inflammation and fibrosis, such as observed in human patients with bronchopulmonary dysplasia, idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease. Although no curative therapies for these lung diseases exist, stem cell therapy has emerged as a potential therapeutic option. Multilineage-differentiating stress-enduring (Muse) cells are endogenous pluripotent- and macrophage-like stem cells distributed in various adult and fetal tissues as stage-specific embryonic antigen-3-positive cells. They selectively home to damaged tissue by sensing sphingosine-1-phosphate and replace the damaged/apoptotic cells by in vivo differentiation. Clinical trials for some human diseases suggest the safety and therapeutic efficacy of intravenously injected human leukocyte antigen-mismatched allogenic Muse cells from adult bone marrow (BM) without immunosuppressant. Here, we evaluated the therapeutic effects of human Muse cells from preterm and term umbilical cord (UC), and adult BM in a rat BLM-induced lung injury model.

METHODS

Rats were endotracheally administered BLM to induce lung injury on day 0. On day 3, human preterm UC-Muse, term UC-Muse, or adult BM-Muse cells were administered intravenously without immunosuppressants, and rats were subjected to histopathologic analysis on day 21. Body weight, serum surfactant protein D (SP-D) levels, and oxygen saturation (SpO2) were monitored. Histopathologic lung injury scoring by the Ashcroft and modified American Thoracic Society document scales, quantitative characterization of engrafted Muse cells, RNA sequencing analysis, and in vitro migration assay of infused Muse cells were performed.

RESULTS

Rats administered preterm- and term-UC-Muse cells exhibited a significantly better recovery based on weight loss, serum SP-D levels, SpO2, and histopathologic lung injury scores, and a significantly higher rate of both Muse cell homing to the lung and alveolar marker expression (podoplanin and prosurfactant protein-C) than rats administered BM-Muse cells. Rats receiving preterm-UC-Muse cells showed statistically superior results to those receiving term-UC-Muse cells in many of the measures. These findings are thought to be due to higher expression of genes related to cell migration, lung differentiation, and cell adhesion.

CONCLUSION

Preterm UC-Muse cells deliver more efficient therapeutic effects than term UC- and BM-Muse cells for treating BLM-induced lung injury in a rat model.

Antimicrobial peptide LL37 and regulatory T cell associated with late-onset sepsis in very preterm infants

Stem cell therapy may prevent late-onset sepsis (LOS) via antimicrobial peptide LL37 secretion and regulatory T cell (Treg) regulation. The early prediction of LOS is still a challenge. This study evaluated whether immunological state of LL37 or Tregs precedes LOS. We firstly analyzed the LL37 level, Treg proportion, and LOS incidence in very preterm infants treated with autologous cord blood mononuclear cells (ACBMNCs) in our previous trial. Then, we constructed a prediction model and built validation cohort. We found ACBMNC intervention reduced the incidence of LOS from 27.3% to 6.9% (p = 0.021). LL37 and Treg abundances were higher in the ACBMNCs group. The nomogram demonstrated that early-life Treg and LL37 characteristics were closely associated with LOS (area under the curve, AUC 0.936), with implications for early prediction and timely clinical management. This composite model was also helpful to evaluate the beneficial effect of ACBMNCs intervention on LOS, thus promoting translational research.

Umbilical cord blood cell characteristics in very preterm neonates for autologous cell therapy of preterm-associated complications

BACKGROUND

There are emerging clinical evidence for umbilical cord blood mononuclear cells (UCBMNCs) intervention to improve preterm complications. The first critical step in cell therapy is to obtain high-quality cells. This retrospective study aimed to investigate the quantity and quality of UCBMNCs from very preterm infants (VPIs) for the purpose of autologous cell therapy in prevention and treatment of preterm complications.

METHODS

Very preterm infants (VPIs) born in Guangdong Women and Children Hospital from January 1, 2017, to December 8, 2022, from whom cord blood was successfully collected and separated for public or private banking, were enrolled. The UCBMNCs characters from route cord blood tests performed in cord blood bank, impact of perinatal factors on UCBMNCs, the relationship between UCBMNCs characteristics and preterm outcomes, and the correlation of UCBMNCs characteristics and peripheral blood cells in VPIs were analyzed.

RESULTS

Totally, 89 VPIs underwent UCB collection and processing successfully. The median cell number post processing was 2.6 × 108. To infuse a dose of 5 × 107 cells/kg, only 3.4% of infants required a volume of more than 20 mL/kg, which exceeded the maximum safe volume limit for VPIs. However, when infusing 10 × 107 cells/kg, 25.8% of infants required a volume of more than 20 ml/kg volume. Antenatal glucocorticoids use and preeclampsia was associated with lower original UCBMNCs concentration. Both CD34+ hematopoietic stem cells (HSC) frequency and colony forming unit - granulocyte and macrophage (CFU-GM) number correlated negatively with gestational age (GA). UCBMNCs characters had no significant effect on preterm outcomes, whereas a significant positive correlation was observed between UCBMNCs concentration and total white blood cell, neutrophil, lymphocyte and PLT counts in peripheral blood.

CONCLUSION

UCBMNCs collected from VPIs was feasible for autologous cell therapy in improving preterm complications. Setting the infusion dose of 5 × 107 cells/kg guaranteed a safe infusion volume in more than 95% of the targeted infants. UCBMNCs characters did not affect preterm complications; however, the effect of UCBMNCs concentration on peripheral blood classification count should be considered when evaluating the immunomodulation of UCBMNCs transfusion.

Pharmacotherapy of BPD: Current status & future perspectives

Bronchopulmonary dysplasia (BPD) is a disease exclusive to prematurity and has changed in its definition since Northway first described it in 1967. There have been countless clinical trials evaluating the efficacy of drugs in the treatment and prevention of BPD in human subjects, and an even larger number of animal studies. Despite these, only a handful of drugs are used at the bedside today, primarily due to the lack of consistent efficacy seen in clinical trials or due to reports of adverse effects. This review summarizes the list of the most commonly used drugs and emerging new therapies which target BPD and BPD-related pulmonary hypertension (BPD-PH), including those which have shown promise in human trials but are not yet used routinely.

Progress in Research on Stem Cells in Neonatal Refractory Diseases

With the development and progress of medical technology, the survival rate of premature and low-birth-weight infants has increased, as has the incidence of a variety of neonatal diseases, such as hypoxic-ischemic encephalopathy, intraventricular hemorrhage, bronchopulmonary dysplasia, necrotizing enterocolitis, and retinopathy of prematurity. These diseases cause severe health conditions with poor prognoses, and existing control methods are ineffective for such diseases. Stem cells are a special type of cells with self-renewal and differentiation potential, and their mechanisms mainly include anti-inflammatory and anti-apoptotic properties, reducing oxidative stress, and boosting regeneration. Their paracrine effects can affect the microenvironment in which they survive, thereby affecting the biological characteristics of other cells. Due to their unique abilities, stem cells have been used in treating various diseases. Therefore, stem cell therapy may open up the possibility of treating such neonatal diseases. This review summarizes the research progress on stem cells and exosomes derived from stem cells in neonatal refractory diseases to provide new insights for most researchers and clinicians regarding future treatments. In addition, the current challenges and perspectives in stem cell therapy are discussed.