Spastic paresis after perinatal brain damage in rats is reduced by human cord blood mononuclear cells

Human umbilical cord blood mononuclear cells and chorionic plate-derived mesenchymal stem cells promote axon survival in a rat model of optic nerve crush injury

The use of mesenchymal stem cells (MSCs) in cell therapy in regenerative medicine has great potential, particularly in the treatment of nerve injury. Umbilical cord blood (UCB) reportedly contains stem cells, which have been widely used as a hematopoietic source and may have therapeutic potential for neurological impairment. Although ongoing research is dedicated to the management of traumatic optic nerve injury using various measures, novel therapeutic strategies based on the complex underlying mechanisms responsible for optic nerve injury, such as inflammation and/or ischemia, are required. In the present study, a rat model of optic nerve crush (ONC) injury was established in order to examine the effects of transplanting human chorionic plate-derived MSCs (CP‑MSCs) isolated from the placenta, as well as human UCB mononuclear cells (CB-MNCs) on compressed rat optic nerves. Expression markers for inflammation, apoptosis, and optic nerve regeneration were analyzed, as well as the axon survival rate by direct counting. Increased axon survival rates were observed following the injection of CB‑MNCs at at 1 week post-transplantation compared with the controls. The levels of growth-associated protein-43 (GAP‑43) were increased after the injection of CB‑MNCs or CP‑MSCs compared with the controls, and the expression levels of hypoxia-inducible factor-1α (HIF-1α) were also significantly increased following the injection of CB-MNCs or CP-MSCs. ERM-like protein (ERMN) and SLIT-ROBO Rho GTPase activating protein 2 (SRGAP2) were found to be expressed in the optic nerves of the CP‑MSC-injected rats with ONC injury. The findings of our study suggest that the administration of CB‑MNCs or CP‑MSCs may promote axon survival through systemic concomitant mechanisms involving GAP‑43 and HIF‑1α. Taken together, these findings provide further understanding of the mechanisms repsonsible for optic nerve injury and may aid in the development of novel cell-based therapeutic strategies with future applications in regenerative medicine, particularly in the management of optic nerve disorders.

Effects of Placental Transfusion on Neonatal and 18 Month Outcomes in Preterm Infants: A Randomized Controlled Trial

OBJECTIVE

To assess the effect of delayed cord clamping (DCC) vs immediate cord clamping (ICC) on intraventricular hemorrhage (IVH), late onset sepsis (LOS), and 18-month motor outcomes in preterm infants.

STUDY DESIGN

Women (n = 208) in labor with singleton fetuses (<32 weeks gestation) were randomized to either DCC (30-45 seconds) or ICC (<10 seconds). The primary outcomes were IVH, LOS, and motor outcomes at 18-22 months corrected age. Intention-to-treat was used for primary analyses.

RESULTS

Cord clamping time was 32 ± 16 (DCC) vs 6.6 ± 6 (ICC) seconds. Infants in the DCC and ICC groups weighed 1203 ± 352 and 1136 ± 350 g and mean gestational age was 28.3 ± 2 and 28.4 ± 2 weeks, respectively. There were no differences in rates of IVH or LOS between groups. At 18-22 months, DCC was protective against motor scores below 85 on the Bayley Scales of Infant Development, Third Edition (OR 0.32, 95% CI 0.10-0.90, P = .03). There were more women with preeclampsia in the ICC group (37% vs 22%, P = .02) and more women in the DCC group with premature rupture of membranes/preterm labor (54% vs 75%, P = .002). Preeclampsia halved the risk of IVH (OR 0.50, 95% CI 0.2-1.0) and premature rupture of membranes/preterm labor doubled the risk of IVH (OR 2.0, 95% CI 1.2-4.3).

CONCLUSIONS

Although DCC did not alter the incidence of IVH or LOS in preterm infants, it improved motor function at 18-22 months corrected age.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT00818220 and NCT01426698.

Cord blood mononuclear cells prevent neuronal apoptosis in response to perinatal asphyxia in the newborn lamb

Perinatal asphyxia is a significant cause of death or long-term neurodevelopmental impairment. Hypothermia, currently the only effective treatment, leads to modest improvements, but new therapeutic strategies are required. Umbilical cord blood (UCB) mononuclear cells have potent anti-inflammatory properties and may reduce neuropathology. This study examined whether autologous UCB mononuclear cells were neuroprotective when administered to newborn lambs at 12 h after birth asphyxia. At caesarean section, birth asphyxia was induced by clamping the umbilical cord until mean arterial blood pressure decreased to 18-20 mmHg. Asphyxia (n = 20) or control (n = 11) lambs were resuscitated and maintained, with magnetic resonance spectroscropy (MRS) performed at 12 and 72 h, and were then killed at 72 h. Cord blood was collected once the cord was clamped, and mononuclear cells were isolated and labelled fluorescently and administered to control (n = 3) or asphyxia (n = 8) lambs. Asphyxia induced a significant increase in cellular apoptosis (caspase-3 immunopositive) within all brain regions examined, including cortex, hippocampus, thalamus, striatum and subcortical white matter (P < 0.01 vs. control). Additionally, asphyxia induced significant and widespread astrogliosis and increased inflammatory cells (activated microglia and macrophages). The administration of UCB mononuclear cells (asphyxia+UCB) significantly decreased neuronal apoptosis, astrogliosis and inflammation (P < 0.05 vs. asphyxia alone). Asphyxia+UCB lambs also demonstrated decreased brain metabolites lactate:choline (P = 0.01) and lactate:N-acetylaspartate (P < 0.01) from 12 to 72 h, detected using MRS. Autologous UCB mononuclear cell treatment restores normal brain metabolism following perinatal asphyxia, and reduces brain inflammation, astrogliosis and neuronal apoptosis, supporting its use as a neuroprotective therapy following asphyxia.

Repeated autologous umbilical cord blood infusions are feasible and had no acute safety issues in young babies with congenital hydrocephalus

BACKGROUND

Babies with congenital hydrocephalus often experience developmental disabilities due to brain injury associated with prolonged increased pressure on the developing brain parenchyma. Umbilical cord blood (CB) infusion has favorable effects in animal models of brain hypoxia and stroke and is being investigated in clinical trials of brain injury in both children and adults. We sought to establish the safety and feasibility of repeated intravenous infusions of autologous CB in young babies with congenital hydrocephalus.

METHODS

Infants with severe congenital hydrocephalus and an available qualified autologous CB unit traveled to Duke for evaluation and CB infusion. When possible, the CB unit was utilized for multiple infusions. Patient and CB data were obtained at the time of infusion and analyzed retrospectively.

RESULTS

From October 2006 to August 2014, 76 patients with congenital hydrocephalus received 143 autologous CB infusions. Most babies received repeated doses, for a total of two (n = 45), three (n = 18), or four (n = 4) infusions. There were no infusion-related adverse events. As expected, all babies experienced developmental delays.

CONCLUSION

Cryopreserved CB products may be effectively manipulated to provide multiple CB doses. Repeated intravenous infusion of autologous CB is safe and feasible in young babies with congenital hydrocephalus.

Neuronal cell reconstruction with umbilical cord blood cells in the brain hypoxia-ischemia

Background: Brain hypoxia-ischemia is a human neonatal injury that is considered a candidate for stem cell therapy. Methods: The possible therapeutic potential of human umbilical cord blood (HUCB) stem cells was evaluated in 14-day-old rats subjected to the right common carotid occlusion, a model of neonatal brain hypoxia-ischemia. Seven days after hypoxia-ischemia, rats received either saline solution or 4 × 10⁵ HUCB cells i.v. Rats in control group did not receive any injection. After two weeks, rats were assessed using two motor tests. Subsequently, rats were scarified for histological and immunohistochemical analyses. Results: Our immunohistochemical findings demonstrated selective migration of the injected HUCB cells to the ischemic area as well as reduction in infarct volume. Seven days after surgery, we found significant recovery in the behavioral performance in the test group (12.7 +/- 0.3) compared to the sham group (10.0 +/-0.05), a trend which continued to day 14 (15.3 ± 0.3 vs. 11.9 ± 0.5, P<0.05). Postural and motor asymmetries at days 7 and 14 in the test group showed a significant decrease in the percentage of right turns in comparison to the sham group (75% and 59% vs. 97% and 96%, P<0.05). Conclusion: The results show the potential of HUCB stem cells in reduction of neurologic deficits associated with neonatal hypoxia-ischemia.

Systemic injection of CD34(+)-enriched human cord blood cells modulates poststroke neural and glial response in a sex-dependent manner in CD1 mice

Stroke in the developing brain is an important cause of neurological morbidity. We determined the impact of human cord blood-derived CD34(+)-enriched mononuclear cells (CBSC) intraperitoneally injected 48 h after an ischemic stroke at postnatal day 12 by evaluating poststroke neurogenic niche proliferation, glial response, and recovery in CD1 mice. Percent brain atrophy was quantified from Nissl-stained sections. Density of BrdU, Iba-1, and GFAP staining were quantified in the dentate gyrus and the subventricular zone (SVZ). Immunohistochemistry for human nuclear antibody, human mitochondrial antibody, and human CD34(+) cells was done on injured and uninjured brains from CBSC- and vehicle-treated mice. Developmental neurobehavioral milestones were evaluated pre- and post-treatment. No significant differences in stroke severity were noted between CBSC and vehicle-treated injured animals. With a 1×10(5) CBSC dose, there was a significant increase in subgranular zone (SGZ) proliferation in the CBSC-versus vehicle-treated stroke-injured male mice. SVZ glial fibrillary acidic protein (GFAP) expression was increased contralaterally in injured females treated with CBSC but suppressed in injured males. Significant negative correlations between severity of the stroke-injury and spleen weights, and between spleen weights and SGZ proliferation, and a positive correlation between GFAP expression and severity of brain injury were noted in the vehicle-treated injured mice but not in the CBSC-treated mice. GFAP expression and SVZ proliferation were positively correlated. In conclusion, neurogenic niche proliferation and glial brain responses to CBSC after neonatal stroke may involve interactions with the spleen and are sex dependent.

Neuroprotective Strategies after Neonatal Hypoxic Ischemic Encephalopathy

Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating disease that primarily causes neuronal and white matter injury and is among the leading cause of death among infants. Currently there are no well-established treatments; thus, it is important to understand the pathophysiology of the disease and elucidate complications that are creating a gap between basic science and clinical translation. In the development of neuroprotective strategies and translation of experimental results in HIE, there are many limitations and challenges to master based on an appropriate study design, drug delivery properties, dosage, and use in neonates. We will identify understudied targets after HIE, as well as neuroprotective molecules that bring hope to future treatments such as melatonin, topiramate, xenon, interferon-beta, stem cell transplantation. This review will also discuss some of the most recent trials being conducted in the clinical setting and evaluate what directions are needed in the future.

Stem Cells: Potential Therapy for Neonatal Injury?

Stem cell transplantation (SCT) is an established first-line or adjunctive therapy for a variety of neonatal and adult diseases. New evidence in preclinical models as well as a few human studies show the potential utility of SCT in neuroprotection and in the modulation of inflammatory injury in at risk-neonates. This review briefly summarizes current understanding of human stem cell biology during ontogeny and present recent evidence supporting SCT as a viable approach for postinsult neonatal injury.

Involvement of Immune Responses in the Efficacy of Cord Blood Cell Therapy for Cerebral Palsy

This study evaluated the efficacy of umbilical cord blood (UCB) cell for patients with cerebral palsy (CP) in a randomized, placebo-controlled, double-blind trial and also assessed factors and mechanisms related to the efficacy. Thirty-six children (ages 6 months to 20 years old) with CP were enrolled and treated with UCB or a placebo. Muscle strength and gross motor function were evaluated at baseline and 1, 3, and 6 months after treatment. Along with function measurements, each subject underwent (18)F-fluorodeoxyglucose positron emission tomography at baseline and 2 weeks after treatment. Cytokine and receptor levels were quantitated in serial blood samples. The UCB group showed greater improvements in muscle strength than the controls at 1 (0.94 vs. -0.35, respectively) and 3 months (2.71 vs. 0.65) after treatment (Ps<0.05). The UCB group also showed greater improvements in gross motor performance than the control group at 6 months (8.54 vs. 2.60) after treatment (P<0.01). Additionally, positron emission tomography scans revealed decreased periventricular inflammation in patients administered UCB, compared with those treated with a placebo. Correlating with enhanced gross motor function, elevations in plasma pentraxin 3 and interleukin-8 levels were observed for up to 12 days after treatment in the UCB group. Meanwhile, increases in blood cells expressing Toll-like receptor 4 were noted at 1 day after treatment in the UCB group, and they were correlated with increased muscle strength at 3 months post-treatment. In this trial, treatment with UCB alone improved motor outcomes and induced systemic immune reactions and anti-inflammatory changes in the brain. Generally, motor outcomes were positively correlated with the number of UCB cells administered: a higher number of cells resulted in better outcomes. Nevertheless, future trials are needed to confirm the long-term efficacy of UCB therapy, as the follow-up duration of the present trial was short.

A possible new focus for stroke treatment - migrating stem cells

INTRODUCTION

Stroke is a leading cause of mortality in the US. More so, its infliction often leaves patients with lasting morbidity and deficits. Ischemic stroke comprises nearly 90% of incidents and the majority of medical treatment aims at reestablishing perfusion and preventing recurrence.

AREAS COVERED

Long-term options for neurorestoration are limited by the infancy of their innovative approach. Accumulating evidence suggests the therapeutic potential of stem cells in neurorestoration, however, proper stem cell migration remains a challenge in translating stem cell therapy from the laboratory to the clinic. In this paper, we propose the role that exogenous stem cell transplantation may serve in facilitating the migration of endogenous stem cells to the site of injury, an idea termed 'biobridge'.

EXPERT OPINION

Recent research in the field of traumatic brain injury has provided a foundational understanding that, through the use of exogenous stem cells, native tissue architecture may be manipulated by proteinases to allow better communication between the endogenous sites of neural stem cells and the regions of injury. There is still much to be learned about these mechanisms, though it is the devastating nature of stroke that necessitates continued research into the prospective therapeutic potential of this novel approach.

Intraperitoneal and intravenous deliveries are not comparable in terms of drug efficacy and cell distribution in neonatal mice with hypoxia-ischemia

BACKGROUND AND PURPOSE

Most therapeutic agents are administered intravenously (IV) in clinical settings and intraperitoneally (IP) in preclinical studies with neonatal rodents; however, it remains unclear whether intraperitoneal (IP) injection is truly an acceptable alternative for intravenous (IV) injection in preclinical studies. The objective of our study is to clarify the differences in the therapeutic effects of drugs and in the distribution of infused cells after an IP or IV injection in animals with brain injury.

METHODS

Dexamethasone or MK-801, an N-methyl-d-aspartate receptor antagonist was administered either IP or IV in a mouse model of neonatal hypoxic-ischemic encephalopathy. Green fluorescent protein-expressing mesenchymal stem cells (MSCs) or mononuclear cells (MNCs) were injected IP or IV in the mouse model. Two hours and 24h after the administration of the cells, we investigated the cell distributions by immunohistochemical staining. We also investigated distribution of IV administered MNCs labeled with 2-[18F]fluoro-2-deoxy-d-glucose in a juvenile primate, a macaque with stroke 1h after the administration.

RESULTS

IP and IV administration of dexamethasone attenuated the brain injury to a similar degree. IP administration of MK-801 attenuated brain injury, whereas IV administration of MK-801 did not. The IV group showed a significantly greater number of infused cells in the lungs and brains in the MSC cohort and in the spleen, liver, and lung in the MNC cohort compared to the IP group. In the macaque, MNCs were detected in the spleen and liver in large amounts, but not in the brain and lungs.

CONCLUSIONS

This study demonstrated that the administration route influences the effects of drugs and cell distribution. Therefore, a preclinical study may need to be performed using the optimal administration route used in a clinical setting.

Cord blood for brain injury

Recovery from neurological injuries is typically incomplete and often results in significant and permanent disabilities. Currently, most available therapies are limited to supportive or palliative measures, aimed at managing the symptoms of the condition. Because restorative therapies targeting the underlying cause of most neurological diseases do not exist, cell therapies targeting anti-inflammatory, neuroprotective and regenerative potential hold great promise. Cord blood (CB) cells can induce repair through mechanisms that involve trophic or cell-based paracrine effects or cellular integration and differentiation. Both may be operative in emerging CB therapies for neurologic conditions, and there are numerous potential applications of CB-based regenerative therapies in neurological diseases, including genetic diseases of childhood, ischemic events such as stroke and neurodegenerative diseases of adulthood. CB appears to hold promise as an effective therapy for patients with brain injuries. In this Review, we describe the state of science and clinical applications of CB therapy for brain injury.

Human Umbilical Cord Blood Cells Ameliorate Motor Deficits in Rabbits in a Cerebral Palsy Model

Cerebral palsy (CP) has a significant impact on both patients and society, but therapy is limited. Human umbilical cord blood cells (HUCBC), containing various stem and progenitor cells, have been used to treat various brain genetic conditions. In small animal experiments, HUCBC have improved outcomes after hypoxic-ischemic (HI) injury. Clinical trials using HUCBC are underway, testing feasibility, safety and efficacy for neonatal injury as well as CP. We tested HUCBC therapy in a validated rabbit model of CP after acute changes secondary to HI injury had subsided. Following uterine ischemia at 70% gestation, we infused HUCBC into newborn rabbit kits with either mild or severe neurobehavioral changes. Infusion of high-dose HUCBC (5 × 10(6) cells) dramatically altered the natural history of the injury, alleviating the abnormal phenotype including posture, righting reflex, locomotion, tone, and dystonia. Half the high dose showed lesser but still significant improvement. The swimming test, however, showed that joint function did not restore to naïve control function in either group. Tracing HUCBC with either MRI biomarkers or PCR for human DNA found little penetration of HUCBC in the newborn brain in the immediate newborn period, suggesting that the beneficial effects were not due to cellular integration or direct proliferative effects but rather to paracrine signaling. This is the first study to show that HUCBC improve motor performance in a dose-dependent manner, perhaps by improving compensatory repair processes.

Administration of umbilical cord blood cells transiently decreased hypoxic-ischemic brain injury in neonatal rats

This study aimed to investigate whether the administration of mononuclear cells derived from human umbilical cord blood cells (UCBCs) could ameliorate hypoxic-ischemic brain injury in a neonatal rat model. The left carotid arteries of 7-day-old rats were ligated, and the rats were then exposed to 8% oxygen for 60 min. Mononuclear cells derived from UCBCs using the Ficoll-Hypaque technique were injected intraperitoneally 6 h after the insult (1.0 × 10(7) cells). Twenty-four hours after the insult, the number of cells positive for the oxidative stress markers 4-hydroxy-2-nonenal and nitrotyrosine, in the dentate gyrus of the hippocampus in the UCBC-treated group, decreased by 36 and 42%, respectively, compared with those in the control group. In addition, the number of cells positive for the apoptosis markers active caspase-3 and apoptosis-inducing factor decreased by 53 and 58%, respectively. The number of activated microglia (ED1-positive cells) was 51% lower in the UCBC group compared with the control group. In a gait analysis performed 2 weeks after the insult, there were no significant differences among the sham-operated, control and UCBC groups. An active avoidance test using a shuttle box the following week also revealed no significant differences among the groups. Neither the volumes of the hippocampi, corpus callosum and cortices nor the numbers of neurons in the hippocampus were different between the UCBC and control groups. In summary, a single intraperitoneal injection of UCBC-derived mononuclear cells 6 h after an ischemic insult was associated with a transient reduction in numbers of apoptosis and oxidative stress marker-positive cells, but it did not induce long-term morphological or functional protection. Repeated administration or a combination treatment may be required to achieve sustained protection.

Internal ribosomal entry site (IRES) activity generates endogenous carboxyl-terminal domains of Cx43 and is responsive to hypoxic conditions

Connexin43 (Cx43) is the most abundant gap junction protein in higher vertebrate organisms and has been shown to be involved in junctional and non-junctional functions. In addition to the expression of full-length Cx43, endogenously produced carboxyl-terminal segments of Cx43 have been described and have been suggested to be involved in manifold biological functions, such as hypoxic preconditioning and neuronal migration. Molecular aspects, however, behind the separate generation of carboxyl-terminal segments of Cx43 have remained elusive. Here we report on a mechanism that may play a key role in the separate production of these domains. First, stringent evidence derived from siRNA treatment and specific knockouts revealed significant loss of the low molecular weight fragments of Cx43. By applying a dicistronic vector strategy on transfected cell lines, we were able to identify putative IRES activity (nucleotides 442–637) in the coding region of Cx43, which resides upstream from the nucleotide sequence encoding the carboxyl terminus (nucleotides 637–1149). Functional responsiveness of the endogenous expression of Cx43 fragments to hypoxic/ischemic treatment was evaluated in in vitro and in vivo models, which led to a significant increase of the fastest migrating form (20 kDa) under conditions of metabolic deprivation. By nano-MS spectrometry, we achieved stringent evidence of the identity of the 20-kDa segment as part of the carboxyl-terminal domain of full-length Cx43. Our data prove the existence of endogenously expressed carboxyl-terminal domains, which may serve as valuable tools for further translational application in ischemic disorders.

Current proceedings of cerebral palsy

Cerebral palsy (CP) is a complicated disease with varying causes and outcomes. It has created significant burden to both affected families and societies, not to mention the quality of life of the patients themselves. There is no cure for the disease; therefore, development of effective therapeutic strategies is in great demand. Recent advances in regenerative medicine suggest that the transplantation of stem cells, including embryonic stem cells, neural stem cells, bone marrow mesenchymal stem cells, induced pluripotent stem cells, umbilical cord blood cells, and human embryonic germ cells, focusing on the root of the problem, may provide the possibility of developing a complete cure in treating CP. However, safety is the first factor to be considered because some stem cells may cause tumorigenesis. Additionally, more preclinical and clinical studies are needed to determine the type of cells, route of delivery, cell dose, timing of transplantation, and combinatorial strategies to achieve an optimal outcome.

Neuroprotection in preterm infants

Preterm infants born before the 30th week of pregnancy are especially at risk of perinatal brain damage which is usually a result of cerebral ischemia or an ascending intrauterine infection. Prevention of preterm birth and early intervention given signs of imminent intrauterine infection can reduce the incidence of perinatal cerebral injury. It has been shown that administering magnesium intravenously to women at imminent risk of a preterm birth leads to a significant reduction in the likelihood of the infant developing cerebral palsy and motor skill dysfunction. It has also been demonstrated that delayed clamping of the umbilical cord after birth reduces the rate of brain hemorrhage among preterm infants by up to 50%. In addition, mesenchymal stem cells seem to have significant neuroprotective potential in animal experiments, as they increase the rate of regeneration of the damaged cerebral area. Clinical tests of these types of therapeutic intervention measures appear to be imminent. In the last trimester of pregnancy, the serum concentrations of estradiol and progesterone increase significantly. Preterm infants are removed abruptly from this estradiol and progesterone rich environment. It has been demonstrated in animal experiments that estradiol and progesterone protect the immature brain from hypoxic-ischemic lesions. However, this neuroprotective strategy has unfortunately not yet been subject to sufficient clinical investigation.

What are the Best Animal Models for Testing Early Intervention in Cerebral Palsy?

Interventions to treat cerebral palsy should be initiated as soon as possible in order to restore the nervous system to the correct developmental trajectory. One drawback to this approach is that interventions have to undergo exceptionally rigorous assessment for both safety and efficacy prior to use in infants. Part of this process should involve research using animals but how good are our animal models? Part of the problem is that cerebral palsy is an umbrella term that covers a number of conditions. There are also many causal pathways to cerebral palsy, such as periventricular white matter injury in premature babies, perinatal infarcts of the middle cerebral artery, or generalized anoxia at the time of birth, indeed multiple causes, including intra-uterine infection or a genetic predisposition to infarction, may need to interact to produce a clinically significant injury. In this review, we consider which animal models best reproduce certain aspects of the condition, and the extent to which the multifactorial nature of cerebral palsy has been modeled. The degree to which the corticospinal system of various animal models human corticospinal system function and development is also explored. Where attempts have already been made to test early intervention in animal models, the outcomes are evaluated in light of the suitability of the model.

Is it time to rethink cord management when resuscitation is needed?

A newborn who receives a placental transfusion at birth, either from cord milking or delayed cord clamping, obtains about 30% more blood volume than the newborn whose cord is cut immediately. Receiving an adequate blood volume from placental transfusion at birth may be protective for the distressed neonate as it prevents hypovolemia and can support optimal perfusion to all organs. New research shows that ventilating before clamping the umbilical cord can reduce large swings in cardiovascular function and help to stabilize the newborn. Hypovolemia, often associated with nuchal cord or shoulder dystocia, may lead to an inflammatory cascade and subsequent ischemic injury. A sudden unexpected neonatal asystole at birth may occur from severe hypovolemia. The restoration of blood volume is an important action to protect the hearts and brains of these neonates. Current protocols for resuscitation imply immediate cord clamping and the care of the newborn away from the mother's bedside. We suggest that an intrapartum care provider can achieve placental transfusion for the distressed neonate by milking the cord several times or resuscitating the neonate at the perineum with an intact cord. Milking the cord can be done quickly within the current Neonatal Resuscitation Program guidelines. Cord blood gases can be collected with delayed cord clamping. Bringing the resuscitation to the mother's bedside is a novel concept and supports an intact cord. Adopting a policy for resuscitation with an intact cord in a hospital setting will take concentrated effort and team work by obstetrics, pediatrics, midwifery, and nursing.

Could cord blood cell therapy reduce preterm brain injury?

Major advances in neonatal care have led to significant improvements in survival rates for preterm infants, but this occurs at a cost, with a strong causal link between preterm birth and neurological deficits, including cerebral palsy (CP). Indeed, in high-income countries, up to 50% of children with CP were born preterm. The pathways that link preterm birth and brain injury are complex and multifactorial, but it is clear that preterm birth is strongly associated with damage to the white matter of the developing brain. Nearly 90% of preterm infants who later develop spastic CP have evidence of periventricular white matter injury. There are currently no treatments targeted at protecting the immature preterm brain. Umbilical cord blood (UCB) contains a diverse mix of stem and progenitor cells, and is a particularly promising source of cells for clinical applications, due to ethical and practical advantages over other potential therapeutic cell types. Recent studies have documented the potential benefits of UCB cells in reducing brain injury, particularly in rodent models of term neonatal hypoxia–ischemia. These studies indicate that UCB cells act via anti-inflammatory and immuno-modulatory effects, and release neurotrophic growth factors to support the damaged and surrounding brain tissue. The etiology of brain injury in preterm-born infants is less well understood than in term infants, but likely results from episodes of hypoperfusion, hypoxia–ischemia, and/or inflammation over a developmental period of white matter vulnerability. This review will explore current knowledge about the neuroprotective actions of UCB cells and their potential to ameliorate preterm brain injury through neonatal cell administration. We will also discuss the characteristics of UCB-derived from preterm and term infants for use in clinical applications.

The potential for cell-based therapy in perinatal brain injuries

Perinatal brain injuries are a leading cause of cerebral palsy worldwide. The potential of stem cell therapy to prevent or reduce these impairments has been widely discussed within the medical and scientific communities and an increasing amount of research is being conducted in this field. Animal studies support the idea that a number of stem cells types, including cord blood and mesenchymal stem cells have a neuroprotective effect in neonatal hypoxia-ischemia. Both these cell types are readily available in a clinical setting. The mechanisms of action appear to be diverse, including immunomodulation, activation of endogenous stem cells, release of growth factors, and anti-apoptotic effects. Here, we review the different types of stem cells and progenitor cells that are potential candidates for therapeutic strategies in perinatal brain injuries, and summarize recent preclinical and clinical studies.

Bone marrow transplant for a girl with bone marrow failure and cerebral palsy

Bone marrow transplantation (BMT) has been used with increasing frequency to treat congenital bone marrow failure syndrome (CBMFs) successfully. Decision to perform BMT, however, is difficult in the case of comorbidity because of regimen-related toxicities. We describe here a child with CBMFs, severe cerebral palsy (CP) at Gross Motor Function Classification System level V and mental retardation (MR) who was transfusion dependent despite various medications. She underwent BMT from an HLA-1 locus-mismatched unrelated donor. Although engraftment was successful, no neurological improvement was seen 5 years after BMT. While CBMFs patients who have CP and MR could undergo transplantation safely, they may not benefit neurologically from BMT.

Implication of cord blood for cell-based therapy in refractory childhood diseases

Since cord blood (CB) contains hematopoietic stem cells as well as a mixture of multipotent stem cells, CB has the ability to give rise to hematopoietic, epithelial, endothelial and neural tissues. Recently, the application of cell-based therapy using CB has expanded its clinical utility, particularly, by using autologous CB in children with refractory diseases. This review focuses clinical and pre-clinical application of CB cell-based therapy for inherited metabolic diseases as well as tissue regenerations in neonatal hypoxic-ischemic encephalopathy, cerebral palsy, and juvenile diabetes.

Feasibility of autologous cord blood cells for infants with hypoxic-ischemic encephalopathy

OBJECTIVE

To assess feasibility and safety of providing autologous umbilical cord blood (UCB) cells to neonates with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We enrolled infants in the intensive care nursery who were cooled for HIE and had available UCB in an open-label study of non-cyropreserved autologous volume- and red blood cell-reduced UCB cells (up to 4 doses adjusted for volume and red blood cell content, 1-5 × 10(7) cells/dose). We recorded UCB collection and cell infusion characteristics, and pre- and post-infusion vital signs. As exploratory analyses, we compared cell recipients' hospital outcomes (mortality, oral feeds at discharge) and 1-year survival with Bayley Scales of Infant and Toddler Development, 3rd edition scores ≥85 in 3 domains (cognitive, language, and motor development) with cooled infants who did not have available cells.

RESULTS

Twenty-three infants were cooled and received cells. Median collection and infusion volumes were 36 and 4.3 mL. Vital signs including oxygen saturation were similar before and after infusions in the first 48 postnatal hours. Cell recipients and concurrent cooled infants had similar hospital outcomes. Thirteen of 18 (74%) cell recipients and 19 of 46 (41%) concurrent cooled infants with known 1-year outcomes survived with scores >85.

CONCLUSIONS

Collection, preparation, and infusion of fresh autologous UCB cells for use in infants with HIE is feasible. A randomized double-blind study is needed.

Unmyelinated axon loss with postnatal hypertonia after fetal hypoxia

OBJECTIVE

White matter (WM) injury due to myelination defects is believed to be responsible for the motor deficits seen in cerebral palsy. We tested the hypothesis that the predominant injury is to functional electrical connectivity in unmyelinated WM fibers by conducting a longitudinal study of central WM tracts in newborn rabbit kits with hypertonia in our model of cerebral palsy.

METHODS

Pregnant rabbits at 70% gestation underwent 40-minute uterine ischemia. Motor deficits in newborn kits, including muscle hypertonia, were assessed by neurobehavioral testing. Major central WM tracts, including internal capsule, corpus callosum, anterior commissure, and fimbria hippocampi, were investigated for structural and functional injury using diffusion tensor magnetic resonance imaging (MRI), electrophysiological recordings of fiber conductivity in perfused brain slices, electron microscopy, and immunohistochemistry of oligodendrocyte lineage.

RESULTS

Motor deficits were observed on postnatal day 1 (P1) when WM tracts were unmyelinated. Myelination occurred later and was obvious by P18. Hypertonia was associated with microstructural WM injury and unmyelinated axon loss at P1, diagnosed by diffusion tensor MRI and electron microscopy. Axonal conductivity from electrophysiological recordings in hypertonic P18 kits decreased only in unmyelinated fibers, despite a loss in both myelinated and unmyelinated axons.

INTERPRETATION

Motor deficits in cerebral palsy were associated with loss of unmyelinated WM tracts. The contribution of injury to myelinated fibers that was observed at P18 is probably a secondary etiological factor in the motor and sensory deficits in the rabbit model of cerebral palsy.

Stem cell therapy for neonatal brain injury

This article introduces the basic concepts of modeling neonatal brain injury and provides background information regarding each of the commonly used types of stem cells. It summarizes the findings of preclinical research testing the therapeutic potential of stem cells in animal models of neonatal brain injury, reports briefly on the status of clinical trials, and discusses the important ongoing issues that need to be addressed before stem cell therapy is used to repair the injured brain.

Stem Cell Banking for Regenerative and Personalized Medicine

Regenerative medicine, tissue engineering and gene therapy offer the opportunity to treat and cure many of today’s intractable afflictions. These approaches to personalized medicine often utilize stem cells to accomplish these goals. However, stem cells can be negatively affected by donor variables such as age and health status at the time of collection, compromising their efficacy. Stem cell banking offers the opportunity to cryogenically preserve stem cells at their most potent state for later use in these applications. Practical stem cell sources include bone marrow, umbilical cord blood and tissue, and adipose tissue. Each of these sources contains stem cells that can be obtained from most individuals, without too much difficulty and in an economical fashion. This review will discuss the advantages and disadvantages of each stem cell source, factors to be considered when contemplating banking each stem cell source, the methodology required to bank each stem cell source, and finally, current and future clinical uses of each stem cell source.

Autologous cord blood therapy for infantile cerebral palsy: from bench to bedside

About 17 million people worldwide live with cerebral palsy, the most common disability in childhood, with hypoxic-ischemic encephalopathy, preterm birth, and low birth weight being the most important risk factors. This review will focus on recent developments in cell therapy for infantile cerebral palsy by transplantation of autologous umbilical cord blood. There are only 4 publications available at present; however, the observations made along with experimental data in vivo and in vitro may be of utmost importance clinically, so that a review at an early developmental stage of this new therapeutic concept seems justified. Particularly, since the first published double-blind randomized placebo-controlled trial in a paradigm using allogeneic cord blood and erythropoietin to treat cerebral palsy under immunosuppression showed beneficial therapeutic effects in infantile cerebral palsy, long-held doubts about the efficacy of this new cell therapy are dispelled and a revision of therapeutic views upon an ailment, for which there is no cure at present, is warranted. Hence, this review will summarize the available information on autologous cord blood therapy for cerebral palsy and that on the relevant experimental work as far as potential mechanisms and modes of action are concerned.

Restoration of tissue damage, and never activity after hypoxia-ischemia by implantation of peripheral blood mononuclear cells

Hypoxia-ischemia (HI) encephalopathy is a frequent cause of disability and mortality with limited therapeutic options. Here, we collected peripheral blood mononuclear cells (PB-MNCs) from healthy donors and labeled them with CM-DiI before implanting these cells by tail-vein injection into rats at day 3 after hypoxia-ischemia (HI). For immune-suppression the animals received daily injections of cyclosporine throughout the experiment, commencing 24h before cell transplantation. Then we observed the PB-MNCs by fluorescent microscopy, examined motor function of rats by rotarod and cylinder tests, measured the lesion volume using image-pro plus software, and analyzed the apoptosis of neural cells in HI rats by tunnel assay. The results showed PB-MNCs could survive in the brain of hosts, migrate to the damage area and express neural marker. In addition, The HI rats that received PB-MNCs showed a reduction in motor function impairment, lesion volume and neural cell apoptosis. To better understand the mechanism of cell migration, PB-MNCs were also injected into normal rats via tail-vein. The expression of stromal cell-derived factor-1 (SDF-1) in the brain of normal and HI rats was measured by RT- PCR and western-blot, while the response of PB-MNCs in vitro to HI or normal brain extracts were measured by cell migration assay. Collectively these data suggest that the migration of PB-MNCs is directed to the damaged brain through an SDF-1-dependent pathway. Our results suggest that intravenous transplantation of PB-MNCs may be a feasible candidate for HI therapy.

Use of umbilical cord and cord blood-derived stem cells for tissue repair and regeneration

INTRODUCTION

Potential use of umbilical cord (UC) is one of the most exciting frontiers in medicine for repairing damaged tissues. UC and cord blood-derived stem cells are the world's largest potential sources of stem cells. UC contains a mixture of stem and progenitor cells at different lineage commitment stages and UC has been verified as a candidate for cell-based therapies and tissue engineering applications due to the capability of these cells for extensive self-renewal and multi-lineage character in differentiation potential.

AREAS COVERED

UC-based repair or regeneration of organs (i.e., heart, nerve, skin, etc.) is a high-priority research worldwide.

EXPERT OPINION

The aim of this review is to summarize the knowledge about UC with main focus on its applications for tissue repair and regeneration.

Effects of intravenous administration of umbilical cord blood CD34(+) cells in a mouse model of neonatal stroke

Neonatal stroke occurs in approximately 1/4000 live births and results in life-long neurological impairments: e.g., cerebral palsy. Currently, there is no evidence-based specific treatment for neonates with stroke. Several studies have reported the benefits of umbilical cord blood (UCB) cell treatment in rodent models of neonatal brain injury. However, all of the studies examined the effects of administering either the UCB mononuclear cell fraction or UCB-derived mesenchymal stem cells in neonatal rat models. The objective of this study was to examine the effects of human UCB CD34(+) cells (hematopoietic stem cell/endothelial progenitor cells) in a mouse model of neonatal stroke, which we recently developed. On postnatal day 12, immunocompromized (SCID) mice underwent permanent occlusion of the left middle cerebral artery (MCAO). Forty-eight hours after MCAO, human UCB CD34(+) cells (1×10(5)cells) were injected intravenously into the mice. The area in which cerebral blood flow (CBF) was maintained was temporarily larger in the cell-treated group than in the phosphate-buffered saline (PBS)-treated group at 24h after treatment. With cell treatment, the percent loss of ipsilateral hemispheric volume was significantly ameliorated (21.5±1.9%) compared with the PBS group (25.6±5.1%) when assessed at 7weeks after MCAO. The cell-treated group did not exhibit significant differences from the PBS group in either rotarod (238±46s in the sham-surgery group, 175±49s in the PBS group, 203±54s in the cell-treated group) or open-field tests. The intravenous administration of human UCB CD34(+) cells modestly reduced histological ischemic brain damage after neonatal stroke in mice, with a transient augmentation of CBF in the peri-infarct area.

Hypothermia for hypoxic-ischemic encephalopathy

Moderate to severe hypoxic-ischemic injury in newborn infants, manifested as encephalopathy immediately or within hours after birth, is associated with a high risk of either death or a lifetime with disability. In recent multicenter clinical trials, hypothermia initiated within the first 6 postnatal hours has emerged as a therapy that reduces the risk of death or impairment among infants with hypoxic-ischemic encephalopathy. Prior to hypothermia, no therapies directly targeting neonatal encephalopathy secondary to hypoxic-ischemic injury had convincing evidence of efficacy. Hypothermia therapy is now becoming increasingly available at tertiary centers. Despite the deserved enthusiasm for hypothermia, obstetric and neonatology caregivers, as well as society at large, must be reminded that in the clinical trials more than 40% of cooled infants died or survived with impairment. Although hypothermia is an evidence-based therapy, additional discoveries are needed to further improve outcome after HIE. In this article, we briefly present the epidemiology of neonatal encephalopathy due to hypoxic-ischemic injury, describe the rationale for the use of hypothermia therapy for hypoxic-ischemic encephalopathy, and present results of the clinical trials that have demonstrated the efficacy of hypothermia. We also present findings noted during and after these trials that will guide care and direct research for this devastating problem.

Umbilical cord blood therapy potentiated with erythropoietin for children with cerebral palsy: a double-blind, randomized, placebo-controlled trial

Allogeneic umbilical cord blood (UCB) has therapeutic potential for cerebral palsy (CP). Concomitant administration of recombinant human erythropoietin (rhEPO) may boost the efficacy of UCB, as it has neurotrophic effects. The objectives of this study were to assess the safety and efficacy of allogeneic UCB potentiated with rhEPO in children with CP. Children with CP were randomly assigned to one of three parallel groups: the pUCB group, which received allogeneic UCB potentiated with rhEPO; the EPO group, which received rhEPO and placebo UCB; and the Control group, which received placebo UCB and placebo rhEPO. All participants received rehabilitation therapy. The main outcomes were changes in scores on the following measures during the 6 months treatment period: the gross motor performance measure (GMPM), gross motor function measure, and Bayley scales of infant development-II (BSID-II) Mental and Motor scales (18). F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET/CT) and diffusion tensor images (DTI) were acquired at baseline and followed up to detect changes in the brain. In total, 96 subjects completed the study. Compared with the EPO (n = 33) and Control (n = 32) groups, the pUCB (n = 31) group had significantly higher scores on the GMPM and BSID-II Mental and Motor scales at 6 months. DTI revealed significant correlations between the GMPM increment and changes in fractional anisotropy in the pUCB group. ¹⁸F-FDG-PET/CT showed differential activation and deactivation patterns between the three groups. The incidence of serious adverse events did not differ between groups. In conclusion, UCB treatment ameliorated motor and cognitive dysfunction in children with CP undergoing active rehabilitation, accompanied by structural and metabolic changes in the brain. Stem Cells2013;31:581–591

Perinatal neuroprotection

Fetal or neonatal brain injury can result in lifelong neurologic disability. The most significant risk factor for perinatal brain injury is prematurity; however, in absolute numbers, full-term infants represent the majority of affected children. Research on strategies to prevent or mitigate the impact of perinatal brain injury ("perinatal neuroprotection") has established the mitigating roles of magnesium sulfate administration for preterm infants and therapeutic hypothermia for term infants with suspected perinatal brain injury. Banked umbilical cord blood, erythropoietin, and a number of other agents that may improve neuronal repair show promise for improving outcomes following perinatal brain injury in animal models. Other preventative strategies include delayed umbilical cord clamping in preterm infants and progesterone in women with prior preterm birth or short cervix and avoidance of infections. Despite these advances, we have not successfully decreased the rate of preterm birth, nor are we able to predict term infants at risk of hypoxic brain injury in order to intervene prior to the hypoxic event. Further, we lack the ability to modulate the sequelae of neuronal cell insults or the ability to repair brain injury after it has been sustained. As a consequence, despite exciting advances in the field of perinatal neuroprotection, perinatal brain injury still impacts thousands of newborns each year with significant long-term morbidity and mortality.

Application of Umbilical Cord Blood Derived Stem Cells in Diseases of the Nervous System

Umbilical cord blood (UCB) derived multipotent stem cells are capable of giving rise hematopoietic, epithelial, endothelial and neural progenitor cells. Thus suggested to significantly improve graft-versus-host disease and represent the distinctive therapeutic option for several malignant and non-malignant diseases. Recent advances in strategies to isolate, expand and shorten the timing of UCB stem cells engraftment have tremendously improved the efficacy of transplantations. Nervous system has limited regenerative potential in disease conditions such as cancer, neurodegeneration, stroke, and several neural injuries. This review focuses on application of UCB derived stem/progenitor cells in aforementioned pathological conditions. We have discussed the possible attempts to make use of UCB therapies to generate neural cells and tissues with developmental and functional similarities to neuronal cells. In addition, emerging applications of UCB derived AC133+ (CD133+) endothelial progenitor cells (EPCs) as imaging probe, regenerative agent, and gene delivery vehicle are mentioned that will further improve the understanding of use of UCB cells in therapeutic modalities. However, safe and effective protocols for cell transplantations are still required for therapeutic efficacy.

The olfactory bulb in newborn piglet is a reservoir of neural stem and progenitor cells

The olfactory bulb (OB) periventricular zone is an extension of the forebrain subventricular zone (SVZ) and thus is a source of neuroprogenitor cells and neural stem cells. While considerable information is available on the SVZ-OB neural stem cell (NSC)/neuroprogenitor cell (NPC) niche in rodents, less work has been done on this system in large animals. The newborn piglet is used as a preclinical translational model of neonatal hypoxic-ischemic brain damage, but information about the endogenous sources of NSCs/NPCs in piglet is needed to implement endogenous or autologous cell-based therapies in this model. We characterized NSC/NPC niches in piglet forebrain and OB-SVZ using western blotting, histological, and cell culture methods. Immunoblotting revealed nestin, a NSC/NPC marker, in forebrain-SVZ and OB-SVZ in newborn piglet. Several progenitor or newborn neuron markers, including Dlx2, musashi, doublecortin, and polysialated neural cell adhesion molecule were also detected in OB-SVZ by immunoblotting. Immunohistochemistry confirmed the presence of nestin, musashi, and doublecortin in forebrain-SVZ and OB-SVZ. Bromodeoxyuridine (BrdU) labeling showed that the forebrain-SVZ and OB-SVZ accumulate newly replicated cells. BrdU-positive cells were immunolabeled for astroglial, oligodendroglial, and neuronal markers. A lateral migratory pathway for newly born neuron migration to primary olfactory cortex was revealed by BrdU labeling and co-labeling for doublecortin and class III β tubulin. Isolated and cultured forebrain-SVZ and OB-SVZ cells from newborn piglet had the capacity to generate numerous neurospheres. Single cell clonal analysis of neurospheres revealed the capacity for self-renewal and multipotency. Neurosphere-derived cells differentiated into neurons, astrocytes, and oligodendrocytes and were amenable to permanent genetic tagging with lentivirus encoding green fluorescent protein. We conclude that the piglet OB-SVZ is a reservoir of NSCs and NPCs suitable to use in autologous cell therapy in preclinical models of neonatal/pediatric brain injury.

Environmental Enrichment Synergistically Improves Functional Recovery by Transplanted Adipose Stem Cells in Chronic Hypoxic-Ischemic Brain Injury

We investigated the effects of environmental enrichment (EE) on the function of transplanted adipose stem cells (ASCs) and the combined effect of EE and ASC transplantation on neurobehavioral function in an animal model of chronic hypoxic-ischemic (HI) brain injury. HI brain damage was induced in 7-day-old mice by unilateral carotid artery ligation and exposure to hypoxia (8% O2 for 90 min). At 6 weeks of age, the mice were randomly injected with either ASCs or PBS into the striatum and were randomly assigned to either EE or standard cages (SC), comprising ASC-EE ( n = 18), ASC-SC ( n = 19), PBS-EE ( n = 12), PBS-SC ( n = 17), and untreated controls ( n = 23). Rotarod, forelimb-use asymmetry, and grip strength tests were performed to evaluate neurobehavioral function. The fate of transplanted cells and the levels of endogenous neurogenesis, astrocyte activation, and paracrine factors were also measured. As a result, EE and ASC transplantation synergistically improved rotarod latency, forelimb-use asymmetry, and grip strength compared to those of the other groups. The number of engrafted ASCs and βIII-tubulin+ neurons derived from the transplanted ASCs was significantly higher in mice in EE than those in SC. EE and ASC transplantation also synergistically increased BrdU+βIII-tubulin+ neurons, GFAP+ astrocytic density, and fibroblast growth factor 2 (FGF2) level but not the level of CS-56+ glial scarring in the striatum. In conclusion, EE and ASC transplantation synergistically improved neurobehavioral functions. The underlying mechanisms of this synergism included enhanced repair processes such as higher engraftment of the transplanted ASCs, increased endogenous neurogenesis and astrocytic activation coupled with upregulation of FGF2.

The potential for stem cell therapies to have an impact on cerebral palsy: opportunities and limitations

Cerebral palsy (CP) is a chronic childhood disorder described by a group of motor and cognitive impairments and results in a substantial socio-economic burden to the individual, family, and healthcare system. With no effective biological interventions, therapies for CP are currently restricted to supportive and management strategies. Cellular transplantation has been suggested as a putative intervention for neural pathology, as mesenchymal and neural stem cells, as well as olfactory ensheathing glia and Schwann cells, have shown some regenerative and functional efficacy in experimental central nervous system disorders. This review describes the most common cell types investigated and delineates their purported mechanisms in vivo. Furthermore, it provides a cogent summary of both current early-phase clinical trials using neural precursor cells (NPCs) and the state of stem cell therapies for neurodegenerative conditions. Although NPCs are perhaps the most promising candidates for cell replacement therapy in the context of CP, much still remains to be understood regarding safety, efficacy, timing, dose, and route of transplantation, as well as the capacity for combinatorial strategies.

First autologous cell therapy of cerebral palsy caused by hypoxic-ischemic brain damage in a child after cardiac arrest-individual treatment with cord blood

Each year, thousands of children incur brain damage that results in lifelong sequelae. Therefore, based on experimental evidence, we explored the therapeutic potential of human cord blood, known to contain stem cells, to examine the functional neuroregeneration in a child with cerebral palsy after cardiac arrest. The boy, whose cord blood was stored at birth, was 2.5 years old and normally developed when global ischemic brain damage occurred resulting in a persistent vegetative state. Nine weeks later, he received autologous cord blood (91.7 mL, cryopreserved, 5.75 × 10e8 mononuclear cells) intravenously. Active rehabilitation (physio- and ergotherapy) was provided daily, follow-up at 2, 5, 12, 24, 30, and 40 months. At 2-months follow-up the boy's motor control improved, spastic paresis was largely reduced, and eyesight was recovered, as did the electroencephalogram. He smiled when played with, was able to sit and to speak simple words. At 40 months, independent eating, walking in gait trainer, crawling, and moving from prone position to free sitting were possible, and there was significantly improved receptive and expressive speech competence (four-word sentences, 200 words). This remarkable functional neuroregeneration is difficult to explain by intense active rehabilitation alone and suggests that autologous cord blood transplantation may be an additional and causative treatment of pediatric cerebral palsy after brain damage.

Hypoxic–ischemic brain injury and neuroprotection in the newborn infant

Recent clinical trials have confirmed that in term infants with moderate-to-severe hypoxic–ischemic encephalopathy, death and severe developmental disability can be reduced by early treatment with hypothermia. However, meta-analysis of these trials has confirmed that two-thirds of the survivors remain seriously impaired. The search for new neuroprotective interventions has therefore continued. Extensive research has identified the important biochemical pathways that result in neuronal loss, and the subsequent repair and regeneration processes. The most promising neuroprotective agents that limit the former, and promote the latter, are being tested in animal models of hypoxic–ischemic brain injury and are awaiting clinical trials. It is likely that a ‘cocktail’ of agents, affecting a number of pathways, will ultimately prove to be the most effective intervention. The latest additions to a long list of proposed substances are various stem cells that promote neurogenesis by releasing trophic substances into the injured brain. Future clinical trials are likely to employ early biomarkers, of which MRI and proton spectroscopy are probably the most predictive of long-term neurodevelopmental outcome. In conclusion, the exponential increase in knowledge in this field can be expected to provide many more neuroprotective agents within the next decade.

Pluripotent possibilities: human umbilical cord blood cell treatment after neonatal brain injury

Perinatal hypoxic-ischemic brain injury and stroke in the developing brain remain important causes of chronic neurologic morbidity. Emerging data suggest that transplantation of umbilical cord blood-derived stem cells may have therapeutic potential for neuroregeneration and improved functional outcome. The pluripotent capacity of stem cells from the human umbilical cord blood provides simultaneous targeting of multiple neuropathologic events initiated by a hypoxic-ischemic insult. Their high regenerative potential and naïve immunologic phenotype makes them a preferable choice for transplantation. A multiplicity of transplantation protocols have been studied with a variety of brain injury models; however, only a few have been conducted on immature animals. Biological recipient characteristics, such as age and sex, appear to differentially modulate responses of the animals to the transplanted cord blood stem cells. Survival, migration, and function of the transplanted cells have also been studied and reveal insights into the mechanisms of cord blood stem cell effects. Data from preclinical studies have informed current clinical safety trials of human cord blood in neonates, and further work is needed to continue progress in this field.

Bronchopulmonary dysplasia in a double-hit mouse model induced by intrauterine hypoxia and postnatal hyperoxia: closer to clinical features?

Despite increased survival of very preterm newborns, bronchopulmonary dysplasia (BPD) remains a major threat, as it affects long-term pulmonary function and neurodevelopmental outcome. Recent research focused on mechanisms of lung repair. Animal models of BPD in term rodents use postnatal hyperoxia in order to mimic features observed in very preterm human neonates: reduced alveolarization and impaired septal architecture without profound inflammatory changes. In contrast, BPD in very preterm human neonates involves prenatal hits e.g. infections and growth restriction plus postnatal ventilation. BPD induced in rodents by postnatal hyperoxia also exhibits reduced alveolarization however without septal pathology but with marked inflammation. We therefore aimed to establish an animal model combining prenatal growth restriction (FiO₂ 0.1 for 4 days) with postnatal hyperoxia (FiO₂ 0.7 for 2 weeks). In double-hit mice the development was retarded: body weight and length, lung and brain weight were significantly reduced by day P14 compared with normoxic controls. Histomorphometric analysis revealed reduced alveolarization and increased septal thickness without pronounced inflammatory lesions. A down-regulation of SftpB and SftpC genes was observed in double-hit animals compared with controls. Thus, we established a new model of BPD using pre- and postnatal hits.

Human umbilical vein endothelial cells protect against hypoxic-ischemic damage in neonatal brain via stromal cell-derived factor 1/C-X-C chemokine receptor type 4

BACKGROUND AND PURPOSE

Agents that protect against neurovascular damage provide a powerful neuroprotective strategy. Human umbilical vein endothelial cells (HUVECs) may be used to treat neonates with hypoxic-ischemia (HI) because of its autologous capability. We hypothesized that peripherally injected HUVECs entered the brain after HI, protected against neurovascular damage, and provided protection via stromal cell-derived factor 1/C-X-C chemokine receptor type 4 pathway in neonatal brain.

METHODS

Postpartum day 7 rat pups received intraperitoneal injections of low-passage HUVEC-P4, high-passage HUVEC-P8, or conditioned medium before and immediately after HI. HUVECs were transfected with adenovirus-green fluorescent protein for cell tracing. Oxygen-glucose deprivation was established by coculturing HUVEC-P4 with mouse neuroblastoma neuronal cells (Neuro-2a) and with mouse immortalized cerebral vascular endothelial cells (b.End3).

RESULTS

HUVEC-P4-treated group had more blood levels of green fluorescent protein-positive cells than HUVEC-P8-treated group 3 hours postinjection. Intraperitoneally injected HUVEC-P4, but not HUVEC-P8, entered the cortex after HI and positioned closed to the neurons and microvessels. Compared with the condition medium-treated group, the HUVEC-P4-treated but not the HUVEC-P8-treated group showed significantly less neuronal apoptosis and blood-brain barrier damage and more preservation of microvessels in the cortex 24 hours after HI. On postpartum day 14, the HUVEC-P4-treated group showed significant neuroprotection compared with the condition medium-treated group. Stromal cell-derived factor 1 was upregulated in the ipsilateral cortex 3 hours after HI, and inhibiting the stromal cell-derived factor 1/C-X-C chemokine receptor type 4 reduced the protective effect of HUVEC-P4. In vitro transwell coculturing of HUVEC-P4 also significantly protected against oxygen-glucose deprivation cell death in neurons and endothelial cells.

CONCLUSIONS

Cell therapy using HUVECs may provide a powerful therapeutic strategy in treating neonates with HI.

Intravenous administration of human umbilical cord blood-mononuclear cells dose-dependently relieve neurologic deficits in rat intracerebral hemorrhage model

Human umbilical cord blood (HUCB) is now considered as a valuable source for stem cell-based therapies. Previous studies showed that intravascular injection of the HUCB significantly improves neurological functional recovery in a model of intracerebral hemorrhage (ICH). To extend these findings, we examined the behavioral recovery and injured volume in the presence of increasing doses of human umbilical cord blood derived mononuclear cells (HUC-MCs) after intracerebral hemorrhage in rats. The experimental ICH was induced by intrastriatal administration of bacterial collagenase IV in adult rats. One day after the surgery, the rats were randomly divided into 4 groups to receive intravenously either BrdU positive human UC-MCs (4 × 10(6), 8 × 10(6) and 16 × 10(6) cells in 1 ml saline, n=10, respectively) as treated groups or the same amount of saline as lesion group (n=10). There was also one group (control n=10) that received only the vehicle solution of collagenase. The animals were evaluated for 14 days with modified limb placing and corner turn tests. The transplanted human UC-MCs were also detected by immunohistochemistry with labeling of BrdU. Two weeks after infusion, there was a significant recovery in the behavioral performance when 4 × 10(6) or more UC-MCs were delivered (P<0.05-0.001). Injured volume measurements disclosed an inverse relationship between UC-MCs dose and damage reaching significance at the higher UC-MCs doses. Moreover, human UC-MCs were localized by immunohistochemistry only in the injured area. Intravenously transplanted UC-MCs can accelerate the neurological function recovery of ICH rat and diminish the striatum lesion size by demonstrating a dose relationship between them.

Proteomic analysis of alterations induced by perinatal hypoxic-ischemic brain injury

Perinatal hypoxic-ischemic brain injury is an important cause of neurological deficits still causing mortality and morbidity in the early period of life. As efficient clinical or pharmaceutical strategies to prevent or reduce the outcome of perinatal hypoxic-ischemic brain damage are limited, the development of new therapies is of utmost importance. To evolve innovative therapeutic concepts, elucidation of the mechanisms contributing to the neurological impairments upon hypoxic-ischemic brain injury is necessary. Therefore, we aimed for the identification of proteins that are affected by hypoxic-ischemic brain injury in neonatal rats. To assess changes in protein expression two days after induction of brain damage, a 2D-DIGE based proteome analysis was performed. Among the proteins altered after hypoxic-ischemic brain injury, Calcineurin A, Coronin-1A, as well as GFAP were identified, showing higher expression in lesioned hemispheres. Validation of the changes in Calcineurin A expression by Western Blot analysis demonstrated several truncated forms of this protein generated by limited proteolysis after hypoxia-ischemia. Further analysis revealed activation of calpain, which is involved in the limited proteolysis of Calcineurin. Active forms of Calcineurin are associated with the dephosphorylation of Darpp-32, an effect that was also demonstrated in lesioned hemispheres after perinatal brain injury.

Changes in Interleukin-1 alpha serum levels after transplantation of umbilical cord blood cells in a model of perinatal hypoxic-ischemic brain damage

Transplantation of human umbilical cord blood (hUCB) cells is a potential approach for the treatment of perinatal hypoxic-ischemic brain injury. Neurological and motor deficits resulting from the brain lesion are ameliorated upon transplantation. The molecular mechanisms underlying these improvements are currently being unravelled. One parameter identified as part of the beneficial effects of hUCB cells is the reduction of brain inflammation. It is, however, unclear whether the modulation of brain inflammation is due to local or systemic effects of hUCB cells. In this study, the effects of hUCB cell transplantation in a model of perinatal hypoxic-ischemic brain injury were investigated at the systemic level by measurement of serum levels of pro-inflammatory cytokines by multiplex bead arrays. Two days after induction of the brain damage, levels of the pro-inflammatory cytokines Interleukin-1α (IL-1α), Interleukin-1β (IL-1β), and Tumor necrosis factor α (TNFα) were increased in the serum of rats. Application of hUCB cells, in turn, correlated with a reduced elevation of serum levels of these pro-inflammatory cytokines. This decrease was accompanied by a reduced expression of CD68, a marker protein of activated microglia/macrophages in the brain. Therefore, systemic modulation of the immune response by hUCB cells could represent one possible mechanism of how these cells might mediate their beneficial effects. Creation of a regenerative environment with reduced inflammation might account for the functional regeneration observed upon hUCB cell treatment in lesioned animals.