Pulmonary and Neurologic Effects of Mesenchymal Stromal Cell Extracellular Vesicles in a Multifactorial Lung Injury Model.

Rationale: Bronchopulmonary dysplasia, a chronic respiratory condition originating from preterm birth, is associated with abnormal neurodevelopment. Currently, there is an absence of effective therapies for bronchopulmonary dysplasia and its associated brain injury. In preclinical trials, mesenchymal stromal cell therapies demonstrate promise as a therapeutic alternative for bronchopulmonary dysplasia. Objectives: To investigate whether a multifactorial neonatal mouse model of lung injury perturbs neural progenitor cell function and to assess the ability of human umbilical cord-derived mesenchymal stromal cell extracellular vesicles to mitigate pulmonary and neurologic injury. Methods: Mice at Postnatal Day 7 or 8 were injected intraperitoneally with LPS and ventilated with 40% oxygen at Postnatal Day 9 or 10 for 8 hours. Treated animals received umbilical cord-mesenchymal stromal cell-derived extracellular vesicles intratracheally preceding ventilation. Lung morphology, vascularity, and inflammation were quantified. Neural progenitor cells were isolated from the subventricular zone and hippocampus and assessed for self-renewal, in vitro differentiation ability, and transcriptional profiles. Measurements and Main Results: The multifactorial lung injury model produced alveolar and vascular rarefaction mimicking bronchopulmonary dysplasia. Neural progenitor cells from lung injury mice showed reduced neurosphere and oligodendrocyte formation, as well as inflammatory transcriptional signatures. Mice treated with mesenchymal stromal cell extracellular vesicles showed significant improvement in lung architecture, vessel formation, and inflammatory modulation. In addition, we observed significantly increased in vitro neurosphere formation and altered neural progenitor cell transcriptional signatures. Conclusions: Our multifactorial lung injury model impairs neural progenitor cell function. Observed pulmonary and neurologic alterations are mitigated by intratracheal treatment with mesenchymal stromal cell-derived extracellular vesicles.

Existence, functional impairment, and lung repair potential of endothelial colony-forming cells in oxygen-induced arrested alveolar growth.

BACKGROUND: Bronchopulmonary dysplasia and emphysema are life-threatening diseases resulting from impaired alveolar development or alveolar destruction. Both conditions lack effective therapies. Angiogenic growth factors promote alveolar growth and contribute to alveolar maintenance. Endothelial colony-forming cells (ECFCs) represent a subset of circulating and resident endothelial cells capable of self-renewal and de novo vessel formation. We hypothesized that resident ECFCs exist in the developing lung, that they are impaired during arrested alveolar growth in experimental bronchopulmonary dysplasia, and that exogenous ECFCs restore disrupted alveolar growth. METHODS AND RESULTS: Human fetal and neonatal rat lungs contain ECFCs with robust proliferative potential, secondary colony formation on replating, and de novo blood vessel formation in vivo when transplanted into immunodeficient mice. In contrast, human fetal lung ECFCs exposed to hyperoxia in vitro and neonatal rat ECFCs isolated from hyperoxic alveolar growth-arrested rat lungs mimicking bronchopulmonary dysplasia proliferated less, showed decreased clonogenic capacity, and formed fewer capillary-like networks. Intrajugular administration of human cord blood-derived ECFCs after established arrested alveolar growth restored lung function, alveolar and lung vascular growth, and attenuated pulmonary hypertension. Lung ECFC colony- and capillary-like network-forming capabilities were also restored. Low ECFC engraftment and the protective effect of cell-free ECFC-derived conditioned media suggest a paracrine effect. Long-term (10 months) assessment of ECFC therapy showed no adverse effects with persistent improvement in lung structure, exercise capacity, and pulmonary hypertension. CONCLUSIONS: Impaired ECFC function may contribute to arrested alveolar growth. Cord blood-derived ECFC therapy may offer new therapeutic options for lung diseases characterized by alveolar damage.

Stem cell-based therapy for neonatal lung disease: it is in the juice.

Bronchopulmonary dysplasia, the chronic lung disease of prematurity, is the most common complication in extremely premature infants (born before 28 wk gestation). Despite advances in perinatal care, modern clinical management remains devoid of therapies specifically promoting lung repair and lung growth. Recent progress in stem cell biology has uncovered the promise of stem/progenitor cells to repair damaged organs. Contrary to the original theory that stem cells engraft and repopulate the damaged organ, evidence suggests that stem cells act via a paracrine mechanism. This review highlights the preclinical evidence for the therapeutic potential of cell-based therapies in animal models of neonatal chronic lung injury and the multiple therapeutic avenues offered by soluble stem cell-derived factors.

Does combined medical and surgical treatment improve perianal fistula outcomes in patients with Crohn's disease? A systematic review and meta-analysis.

BACKGROUND: The optimal treatment of perianal fistulizing Crohn's disease (PFCD) is unknown. We performed a systematic review with meta-analysis to compare combined surgical intervention and anti-TNF therapy (combined therapy) vs. either therapy alone. METHODS: MEDLINE, EMBASE, and Cochrane databases were searched systematically through December 2023. Surgical intervention was defined as an exam under anesthesia ± setons. We calculated weighted risk ratios (RR) with 95% confidence intervals (CI) for our co-primary outcomes: fistula response and healing, defined clinically as a reduction in fistula drainage or number of draining fistulas and fistula closure respectively. RESULTS: Thirteen studies were analysed: 515 patients treated with combined therapy, 330 patients with surgical intervention and 406 patients with anti-TNF therapy with follow-up between 10 weeks and 3 years. Fistula response (RR 1.10; 95% CI, 0.93-1.30, p=0.28) and healing (RR 1.06; 95% CI, 0.86-1.31, p=0.58) was not significantly different when comparing combined therapy with anti-TNF therapy alone. In contrast, combined therapy was associated with significantly higher rates of fistula response (1.25; 95% CI, 1.10-1.41, p<0.001) and healing (RR 1.17; 95% CI, 1.00-1.36, p=0.05) compared with surgical intervention alone. Our results remained stable when limiting to studies that assessed outcomes within 1 year and studies where <10% of patients underwent fistula closure procedures. CONCLUSION: Combined surgery and anti-TNF therapy was not associated with improved PFCD outcomes compared with anti-TNF therapy alone. Due to an inability to control for confounding and small study sizes, future, controlled trials are warranted to confirm these findings.

Examination Under Anesthesia May Not Be Universally Required Prior to Anti-TNF Therapy in Perianal Crohn's Disease: A Comparative Cohort Study.

BACKGROUND: Multidisciplinary care involving exam under anesthesia (EUA) and tumor necrosis factor (TNF) inhibitors is recommended for perianal Crohn's disease. However, the impact of this combined approach is not well established. METHODS: We performed a comparative cohort study between 2009 and 2019. Patients with perianal Crohn's disease treated with EUA before anti-TNF therapy (combined modality therapy) were compared with anti-TNF alone. The primary outcome was fistula closure assessed clinically. Secondary outcomes included subsequent local surgery and fecal diversion. Multivariable analysis adjusted for abscesses, concomitant immunomodulators, and time to anti-TNF initiation was performed. RESULTS: Anti-TNF treatment was initiated 188 times in 155 distinct patients: 66 (35%) after EUA. Abscesses (50% vs 15%; P < .001) and concomitant immunomodulators (64% vs 50%; P = .07) were more common in the combined modality group, while age, smoking status, disease duration, and intestinal disease location were not significantly different. Combined modality therapy was not associated with higher rates of fistula closure at 3 (adjusted odds ratio [aOR], 0.7; 95% confidence interval [CI], 0.3-1.8), 6 (aOR, 0.8; 95% CI, 0.4-2.0) and 12 (aOR, 1.0; 95% CI, 0.4-2.2) months. After a median follow-up of 4.6 (interquartile range, 5.95; 2.23-8.18) years, combined therapy was associated with subsequent local surgical intervention (adjusted hazard ratio, 2.2; 95% CI, 1.3-3.6) but not with fecal diversion (adjusted hazard ratio, 1.3; 95% CI, 0.45-3.9). Results remained consistent when excluding patients with abscesses and prior biologic failure. CONCLUSIONS: EUA before anti-TNF therapy was not associated with improved clinical outcomes compared with anti-TNF therapy alone, suggesting that EUA may not be universally required. Future prospective studies controlling for fistula severity are warranted.

This comparative cohort study found that an exam under anesthesia before initiation of anti-tumor necrosis factor therapy in perianal Crohn's disease was not associated with higher rates of fistula closure, suggesting that an exam under anesthesia may not be universally required in patients with perianal Crohn's disease.

Late Rescue Therapy with Cord-Derived Mesenchymal Stromal Cells for Established Lung Injury in Experimental Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD), the main complication of extreme prematurity, has lifelong consequences for lung health. Mesenchymal stromal cells (MSCs) prevent lung injury in experimental BPD in newborn rodents when given in the immediate neonatal period. Whether MSC therapy can restore normal lung growth after established lung injury in adulthood is clinically relevant, but currently unknown. Experimental BPD was achieved by exposing newborn rats to 95% O2 from postnatal days 4-14. Human umbilical cord-derived MSCs were intratracheally administered to rats (1 × 106cells/kg body weight) as a single dose at 3 or 6 months of age followed by assessment at 5 or 8 months of age, respectively. Lung alveolar structure and vessel density were histologically analyzed. O2-exposed rats exhibited persistent lung injury characterized by arrested alveolar growth with airspace enlargement and a lower vessel density at both 5 and 8 months of age compared with controls. Single-dose MSC treatment at 3 months partially attenuated O2-induced alveolar injury and restored vessel density at 5 months. Treatment with a single dose at 6 months did not attenuate alveolar injury or vessel density at 8 months. However, treatment with multiple MSC doses at 6, 6.5, 7, and 7.5 months significantly attenuated alveolar injury and improved vessel density at 8 months of age. Treatment of the adult BPD lung with MSCs has the potential to improve lung injury if administered in multiple doses or at an early stage of adulthood.

Responsible Translation of Stem Cell Research: An Assessment of Clinical Trial Registration and Publications.

We assessed the extent to which the publication of clinical trial results of innovative cell-based interventions reflects International Society for Stem Cell Research best practice guidelines. We assessed: (1) characteristics and time to publication of completed trials; (2) quality of reported trials; and (3) results of published trials. We identified and analyzed publications from 1,052 novel stem cell clinical trials: 179 (45.4%) of 393 completed trials had published results; 48 trials were registered by known stem cell tourism clinics, none of which reported results. Completed non-industry-sponsored trials initially published more rapidly, but differences with industry-sponsored trials decreased over time. Most publications reported safety, and 67.3% (mainly early-stage trials) reported positive outcomes. A higher proportion of industry trials reported positive efficacy. Heightened patient expectations for stem cell therapies give rise to ethical obligations for the transparent conduct of clinical trials. Reporting guidelines need to be developed that are specific to early-phase clinical trials.