Stem Cell Therapy in Pediatric Neurological Disabilities

Pediatric neurological disorders represent a major part of the disabilities worldwide. In over 10 decades of research to find a cure for these disorders, medical science has not been able to repair the underlying brain injury. This chapter focuses on recent advances in the application of stem cells as a therapeutic tool for some of the common neurodevelopmental disorders (cerebral palsy, autism, intellectual disability and muscular dystrophy). The mechanism of action of stem cells in each disorder has been explained. A review of clinical data has been described giving a clear understanding of current status of stem cell therapy in these disorders. Various factors influencing the outcome of stem cell therapy such as different types of cells, different routes of administration and dosage and frequency of transplantation have also been discussed. Our experience of treating these disorders is exhibited in the form of our published data. Use of novel monitoring tools such as MRI MSK and PET‐CT scan brain to track the changes occurring at cellular level after stem cell therapy are described. We also highlight the importance of a multidisciplinary approach of combining rehabilitation with stem cell therapy

Intercellular calcium communication regulates platelet aggregation and thrombus growth

The ability of platelets to form stable adhesion contacts with other activated platelets (platelet cohesion or aggregation) at sites of vascular injury is essential for hemostasis and thrombosis. In this study, we have examined the mechanisms regulating cytosolic calcium flux during the development of platelet–platelet adhesion contacts under the influence of flow. An examination of platelet calcium flux during platelet aggregate formation in vitro demonstrated a key role for intercellular calcium communication (ICC) in regulating the recruitment of translocating platelets into developing aggregates. We demonstrate that ICC is primarily mediated by a signaling mechanism operating between integrin αIIbβ3 and the recently cloned ADP purinergic receptor P2Y12. Furthermore, we demonstrate that the efficiency by which calcium signals are propagated within platelet aggregates plays an important role in dictating the rate and extent of thrombus growth

The Phosphoinositide 3-Kinase Isoform PI3Kβ Regulates Osteoclast-Mediated Bone Resorption in Humans and Mice

OBJECTIVE: While phosphoinositide 3-kinases (PI3Ks) are involved in various intracellular signal transduction processes, the specific functions of the different PI3K isoforms are poorly understood. We have previously shown that the PI3Kβ isoform is required for arthritis development in the K/BxN serum–transfer model. Since osteoclasts play a critical role in pathologic bone loss during inflammatory arthritis and other diseases, we undertook this study to test the role of PI3Kβ in osteoclast development and function using a combined genetic and pharmacologic approach. METHODS: The role of PI3Kβ in primary human and murine osteoclast cultures was tested with the PI3Kβ-selective inhibitor TGX221 and by using PI3Kβ(−/−) mice. The trabecular bone architecture of PI3Kβ(−/−) mice was evaluated using micro–computed tomography and histomorphometric analyses. RESULTS: The expression of PI3Kβ was strongly and specifically up-regulated during in vitro osteoclast differentiation. In vitro development of large multinucleated osteoclasts from human or murine progenitors and their resorption capacity were strongly reduced by the PI3Kβ inhibitor TGX221 or by the genetic deficiency of PI3Kβ. This was likely due to defective cytoskeletal reorganization and vesicular trafficking, since PI3Kβ(−/−) mouse multinucleated cells failed to form actin rings and retained intracellular acidic vesicles and cathepsin K. In contrast, osteoclast-specific gene expression and the survival and apoptosis of osteoclasts were not affected. PI3Kβ(−/−) mice had significantly increased trabecular bone volume and showed abnormal osteoclast morphology with defective resorption pit formation. CONCLUSION: PI3Kβ plays an important role in osteoclast development and function and is required for in vivo bone homeostasis

Functional Redundancy of Class I Phosphoinositide 3-Kinase (PI3K) Isoforms in Signaling Growth Factor-Mediated Human Neutrophil Survival

We have investigated the contribution of individual phosphoinositide 3-kinase (PI3K) Class I isoforms to the regulation of neutrophil survival using (i) a panel of commercially available small molecule isoform-selective PI3K Class I inhibitors, (ii) novel inhibitors, which target single or multiple Class I isoforms (PI3Kα, PI3Kβ, PI3Kδ, and PI3Kγ), and (iii) transgenic mice lacking functional PI3K isoforms (p110δKOγKO or p110γKO). Our data suggest that there is considerable functional redundancy amongst Class I PI3Ks (both Class IA and Class IB) with regard to GM-CSF-mediated suppression of neutrophil apoptosis. Hence pharmacological inhibition of any 3 or more PI3K isoforms was required to block the GM-CSF survival response in human neutrophils, with inhibition of individual or any two isoforms having little or no effect. Likewise, isolated blood neutrophils derived from double knockout PI3K p110δKOγKO mice underwent normal time-dependent constitutive apoptosis and displayed identical GM-CSF mediated survival to wild type cells, but were sensitized to pharmacological inhibition of the remaining PI3K isoforms. Surprisingly, the pro-survival neutrophil phenotype observed in patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD) was resilient to inactivation of the PI3K pathway

SCFAs Induce Mouse Neutrophil Chemotaxis through the GPR43 Receptor

Short chain fatty acids (SCFAs) have recently attracted attention as potential mediators of the effects of gut microbiota on intestinal inflammation. Some of these effects have been suggested to occur through the direct actions of SCFAs on the GPR43 receptor in neutrophils, though the precise role of this receptor in neutrophil activation is still unclear. We show that mouse bone marrow derived neutrophils (BMNs) can chemotax effectively through polycarbonate filters towards a source of acetate, propionate or butyrate. Moreover, we show that BMNs move with good speed and directionality towards a source of propionate in an EZ-Taxiscan chamber coated with fibrinogen. These effects of SCFAs were mimicked by low concentrations of the synthetic GPR43 agonist phenylacetamide-1 and were abolished in GPR43−/− BMNs. SCFAs and phenylacetamide-1 also elicited GPR43-dependent activation of PKB, p38 and ERK and these responses were sensitive to pertussis toxin, indicating a role for Gi proteins. Phenylacetamide-1 also elicited rapid and transient activation of Rac1/2 GTPases and phosphorylation of ribosomal protein S6. Genetic and pharmacological intervention identified important roles for PI3Kγ, Rac2, p38 and ERK, but not mTOR, in GPR43-dependent chemotaxis. These results identify GPR43 as a bona fide chemotactic receptor for neutrophils in vitro and start to define important elements in its signal transduction pathways

Cellular Therapy for Chronic Traumatic Brachial Plexus Injury

Cellular therapy is being actively pursued as a therapeutic modality in many of the neurological diseases. A variety of stem cells from diverse sources have been studied in detail and have been shown to exhibit angiogenetic and immunomodulatory properties in addition to other neuroprotective effects. Published clinical data have shown bone marrow mononuclear cell (BMMNC) injection in neurological disorders is safe and possesses regenerative potential. We illustrate a case of 27-year-old male with traumatic brachial plexus injury, administered with autologous BMMNCs intrathecally and intramuscularly, followed by multidisciplinary rehabilitation. At the follow-up assessment of 3 and 7 months after first cell transplantation, improvements were recorded in muscle strength and movements. Electromyography (EMG) performed after the intervention showed a response in biceps and deltoid muscles suggesting the process of reinnervation at the site of injury. In view of the improvements observed after the treatment, the patient underwent second cell transplantation 8 months after the first transplantation. Muscle wasting had completely stopped with an increase in the muscle girth. No adverse effects were noted. Improvements were maintained for 4 years. A comprehensive randomized study for this type of injury is needed to establish the therapeutic benefits of cellular therapy

Functional improvements monitored by Positron Emission Tomography imaging after cell transplantations in severe chronic Traumatic Brain Injury

Introduction: Positron Emission Tomography (PET) imaging provides exquisite sensitivity information regarding changes in brain metabolism after traumatic brain injury (TBI). TBI is major cause of morbidity and mortality resulting in permanent neurobiological damage and lifelong deficits. Cell transplantation in combination with neurorehabilitation has a potential to cease the degeneration and replace the damaged neurons, which current standard intervention may not tackle. Methods: Herein, we present a case of a 7-year-old female who suffered from TBI 15 months before she underwent first cell transplantation. She underwent two cell transplantations at an interval of 4 months with intrathecal autologous bone marrow derived mononuclear cells. Results: Over the span of 9 months, improvements in posture, balance, bed mobility, voluntary control of the upper extremity, overhead activities, cognition, speech, understanding and attention was observed. Percutaneous endoscopic gastrostomy (PEG) tube was removed as her swallowing capacity improved. The Functional independence measure (FIM) score improved from 22 to 35 and Disability rating scale (DRS) improved from 15 to 12. There was an improvement in the Glasgow coma scale from 8 to 15. A repeat PET CT scan of the brain at 4 months' post first cellular transplantation revealed improved metabolism in the cerebellum, cingulate regions, vermis and parietal gyrus. These changes corresponded to the clinical improvements seen in the patient. No adverse events related to the procedure was observed. Conclusion: Cell transplantation is a safe and efficacious treatment for chronic TBI. However, we recommend future controlled clinical trials with objective imaging like PET CT to further establish cell transplantation as a therapeutic modality in severe chronic TBI

An open-label proof-of-concept study of intrathecal autologous bone marrow mononuclear cell transplantation in intellectual disability

Abstract Background The underlying pathophysiology in intellectual disability (ID) involves abnormalities in dendritic branching and connectivity of the neuronal network. This limits the ability of the brain to process information. Conceptually, cellular therapy through its neurorestorative and neuroregenerative properties can counteract these pathogenetic mechanisms and improve neuronal connectivity. This improved networking should exhibit as clinical efficacy in patients with ID. Methods To assess the safety and efficacy of cellular therapy in patients with ID, we conducted an open-label proof-of-concept study from October 2011 to December 2015. Patients were divided into two groups: intervention group (n = 29) and rehabilitation group (n = 29). The intervention group underwent cellular transplantation consisting of intrathecal administration of autologous bone marrow mononuclear cells and standard neurorehabilitation. The rehabilitation group underwent only standard neurorehabilitation. The results of the symptomatic outcomes were compared between the two groups. In the intervention group analysis, the outcome measures used were the intelligence quotient (IQ) and the Wee Functional Independence Measure (Wee-FIM). To compare the pre-intervention and post-intervention results, statistical analysis was done using Wilcoxon’s matched-pairs test for Wee-FIM scores and McNemar’s test for symptomatic improvements and IQ. The effect of age and severity of the disorder were assessed for their impact on the outcome of intervention. Positron emission tomography-computed tomography (PET-CT) brain scan was used as a monitoring tool to study effects of the intervention. Adverse events were monitored for the safety of cellular therapy. Results On symptomatic analysis, greater improvements were seen in the intervention group as compared to the rehabilitation group. In the intervention group, the symptomatic improvements, IQ and Wee-FIM were statistically significant. A significantly better outcome of the intervention was found in the paediatric age group (<18 years) and patients with milder severity of ID. Repeat PET-CT scan in three patients of the intervention group showed improved metabolism in the frontal, parietal cortex, thalamus, mesial temporal structures and cerebellum. No major adverse events were witnessed. Conclusions Cellular transplantation with neurorehabilitation is safe and effective for the treatment of underlying brain deficits in ID. Trial registration ClinicalTrials.gov NCT02245724. Registered 12 September 2014