Donor mesenchymal stem cell kinetics after transamniotic stem cell therapy (TRASCET) in a rodent model of gastroschisis

Bidirectional Feto-Maternal Traffic of Donor Mesenchymal Stem Cells Following Transamniotic Stem Cell Therapy (TRASCET)

PURPOSE

Transamniotic stem cell therapy (TRASCET) with mesenchymal stem cells (MSCs) has emerged experimentally as a potential treatment for different congenital diseases and maternal diseases of pregnancy. The broad applicability of TRASCET is predicated on hematogenous routing of donor MSCs via the placenta. We investigated whether donor MSC kinetics includes bidirectional traffic between the fetus and mother.

METHODS

Eight time-dated dams had their fetuses (n = 96) divided in 4 groups on gestational day 17 (E17, term = E21). Groups populating one uterine horn received intra-amniotic injections (50 μL) of either donor amniotic fluid-derived MSCs (2×106 cells/mL) labelled with a firefly luciferase reporter gene (MSC-injected, n = 32), or of acellular luciferase (luciferase-injected, n = 26). Contra-lateral (CL) horn fetuses received no injection (MSC-CL, n = 20 and luciferase-CL, n = 18). At term, samples from 11 fetal anatomical sites from CL fetuses, along with placentas from all fetuses and maternal blood were screened for luciferase activity via microplate luminometry.

RESULTS

Overall survival was 95 % (91/96). When controlled by the acellular injection, positive luciferase activity was observed in the placentas of all MSC-injected fetuses, confirming viability of the donor cells at term. When controlled by the acellular injection group, MSC-CL fetuses showed positive luciferase activity in the bone marrow, peripheral blood, brain and skin (p = <0.001-0.048). No luciferase activity was detected in any maternal blood sample.

CONCLUSION

Amniotic fluid-derived MSCs can traffic between the fetus and mother in both directions after simple intra-amniotic injection, in a healthy rat model. This phenomenon must be considered in TRASCET performed in twin/multiple pregnancies.

LEVEL OF EVIDENCE

N/A (animal and laboratory study).

Stem cell derived therapies to preserve and repair the developing intestine

Stem cell research and the use of stem cells in therapy have seen tremendous growth in the last two decades. Neonatal intestinal disorders such as necrotizing enterocolitis, Hirschsprung disease, and gastroschisis have high morbidity and mortality and limited treatment options with varying success rates. Stem cells have been used in several pre-clinical studies to address various neonatal disorders with promising results. Stem cell and patient population selection, timing of therapy, as well as safety and quality control are some of the challenges that must be addressed prior to the widespread clinical application of stem cells. Further research and technological advances such as the use of cell delivery technology can address these challenges and allow for continued progress towards clinical translation.

Fetal Surgery for Gastroschisis—A Review with Emphasis on Minimally Invasive Procedures

(1) Background: The morbidity of gastroschisis is defined by exposure of unprotected intestines to the amniotic fluid leading to inflammatory damage and consecutive intestinal dysmotility, the viscero-abdominal disproportion which results in an abdomen too small to incorporate the herniated and often swollen intestine, and by associated pathologies, such as in complex gastroschisis. To prevent intestinal damage and to provide for growth of the abdominal cavity, fetal interventions such as amnio exchange, gastroschisis repair or covering have been evaluated in several animal models and human trials. This review aims to evaluate the reported techniques for the fetal treatment of gastroschisis by focusing on minimally invasive procedures. (2) Methods: We conducted a systematic database search, quality assessment and analyzed relevant articles which evaluate or describe surgical techniques for the prenatal surgical management of gastroschisis in animal models or human application. (3) Results: Of 96 identified reports, 42 eligible studies were included. Fetal interventions for gastroschisis in humans are only reported for EXIT procedures and amnio exchange. In animal models, particularly in the fetal sheep model, several techniques of open or minimally invasive repair of gastroschisis or covering the intestine have been described, with fetoscopic covering being the most encouraging. (4) Discussion: Although some promising minimally invasive techniques have been demonstrated in human application and animal models, most of them are still associated with relevant fetal morbidity and mortality and barely appear to be currently applicable in humans. Further research on specific procedures, instruments and materials is needed before any human application.

Regenerative medicine for childhood gastrointestinal diseases

Several paediatric gastrointestinal diseases result in life-shortening organ failure. For many of these conditions, current therapeutic options are suboptimal and may not offer a cure. Regenerative medicine is an inter-disciplinary field involving biologists, engineers, and clinicians that aims to produce cell and tissue-based therapies to overcome organ failure. Exciting advances in stem cell biology, materials science, and bioengineering bring engineered gastrointestinal cell and tissue therapies to the verge of clinical trial. In this review, we summarise the requirements for bioengineered therapies, the possible sources of the various cellular and non-cellular components, and the progress towards clinical translation of oesophageal and intestinal tissue engineering to date.

Abdominal wall defects

Abdominal wall defects are common congenital anomalies with the most frequent being gastroschisis and omphalocele. Though both are the result of errors during embryologic development of the fetal abdominal wall, gastroschisis and omphalocele represent unique disorders that have different clinical sequelae. Gastroschisis is generally a solitary anomaly with postnatal outcomes related to the underlying integrity of the prolapsed bowel. In contrast, omphalocele is frequently associated with other structural anomalies or genetic syndromes that contribute more to postnatal outcomes than the omphalocele defect itself. Despite their embryological differences, both gastroschisis and omphalocele represent anomalies of fetal development that benefit from multidisciplinary and translational approaches to care, both pre- and postnatally. While definitive management of abdominal wall defects currently remains in the postnatal realm, advancements in prenatal diagnostics and therapies may one day change that. This review focuses on recent advancements, novel techniques, and current controversies related to the prenatal diagnosis and management of gastroschisis and omphalocele.

Is there a role for fetal interventions in gastroschisis management? - An updated comprehensive review

We conducted a comprehensive evidence-based review on the epidemiology and current standard of care of gastroschisis management as well as the pathophysiology, rationale and feasibility of fetal therapy as a viable alternative. Gastroschisis is a periumbilical abdominal wall defect characterized by abdominal viscera herniation in utero. It affects 4 in 10 000 live births, but the prevalence has steadily increased in recent years. Gastroschisis is typically diagnosed on routine second-trimester ultrasound. The overall prognosis is favorable, but complex gastroschisis, which accounts for about 10% to 15% of cases, is associated with a higher mortality, significant disease burden and higher healthcare costs due to long- and short-term complications. The current standard of care has yet to be established but generally involves continued fetal surveillance and multidisciplinary perinatal care. Postnatal surgical repair is achieved with primary closure, staged silo closure or sutureless repair. Experimental animal studies have demonstrated the feasibility of in utero closure, antiinflammatory therapy and prenatal regenerative therapy. However, reports of early preterm delivery and amnioinfusion trials have failed to show any benefit in humans. Further experimental studies and human trials are necessary to demonstrate the potential benefit of fetal therapy in gastroschisis.

Postnatal fate of donor mesenchymal stem cells after transamniotic stem cell therapy in a healthy model

PURPOSE

We sought to examine donor mesenchymal stem cell (MSC) fate after birth following transamniotic stem cell therapy (TRASCET) in a healthy model.

METHODS

Lewis rat fetuses (n = 91) were divided into two groups based on the content of volume-matched intraamniotic injections performed on gestational day 17 (term = 21-22 days): either a suspension of amniotic fluid-derived MSCs (afMSCs) labeled with luciferase (n = 38) or acellular luciferase only (n = 53). Infused afMSCs consisted of syngeneic Lewis rat cells phenotyped by flow cytometry. Samples from 14 anatomical sites (heart, lung, brain, liver, spleen, pancreas, bowel, kidney, thyroid, skin, skeletal muscle, thymus, peripheral blood and bone marrow) from survivors were screened for luciferase activity 16 days after birth. Statistical analysis was by logistic regression and the Wald test (p < 0.05).

RESULTS

Overall survival was 32% (29/91). When controlled by the acellular luciferase injections, donor afMSCs were not identified at any anatomical site in any neonate as measured by relative light units (all p > 0.05). Donor afMSC viability was confirmed in term placentas.

CONCLUSIONS

Donor mesenchymal stem cells are not detectable in the neonate after intraamniotic injection in a normal syngeneic rodent model. This finding suggests that clinical trials of transamniotic stem cell therapy may be amenable to regulatory approval.

LEVEL OF EVIDENCE

N/A (animal and laboratory study).