Monocytes are essential for the neuroprotective effect of human cord blood cells following middle cerebral artery occlusion in rat.

Systemic administration of human umbilical cord blood (HUCB) mononuclear cells (MNC) following middle cerebral artery occlusion (MCAO) in the rat reduces infarct size and, more importantly, restores motor function. The HUCB cell preparation is composed of immature T-cells, B-cells, monocytes and stem cells. In this study we examined whether the beneficial effects of HUCB injection were attributable to one of these cell types. Male Sprague Dawley rats underwent permanent MCAO followed 48 h later by intravenous administration of HUCB MNC preparations depleted of either CD14(+) monocytes, CD133(+) stem cells, CD2(+) T-cells or CD19(+) B cells. Motor function was measured prior to MCAO and 30 days post-stroke. When CD14(+) monocytes were depleted from the HUCB MNC, activity and motor asymmetry were similar to the MCAO only treated animals. Monocyte depletion prevented HUCB cell treatment from reducing infarct size while monocyte enrichment was sufficient to reduce infarct size. Administration of monocyte-depleted HUCB cells did not suppress Iba1 labeling of microglia in the infarcted area relative to treatment with the whole HUCB preparation. These data demonstrate that the HUCB monocytes provide the majority of the efficacy in reducing infarct volume and promoting functional recovery.

Stem cells and G-CSF for treating neuroinflammation in traumatic brain injury: aging as a comorbidity factor.

Traumatic brain injury (TBI), often called the signature wound of Iraq and Afghanistan wars, is characterized by a progressive histopathology and long-lasting behavioral deficits. Treatment options for TBI are limited and patients are usually relegated to rehabilitation therapy and a handful of experimental treatments. Stem cell-based therapies offer alternative treatment regimens for TBI, and have been intended to target the delayed therapeutic window post-TBI, in order to promote "neuroregeneration," in lieu of "neuroprotection" which can be accomplished during acute TBI phase. However, these interventions may require adjunctive pharmacological treatments especially when aging is considered as a comorbidity factor for post-TBI health outcomes. Here, we put forward the concept that a combination therapy of human umbilical cord blood cell (hUCB) and granulocyte-colony stimulating factor (G-CSF) attenuates neuroinflammation in TBI, in view of the safety and efficacy profiles of hUCB and G-CSF, their respective mechanisms of action, and efficacy of hUCB+G-CSF combination therapy in TBI animal models. Further investigations on the neuroinflammatory pathway as a key pathological hallmark in acute and chronic TBI and also as a major therapeutic target of hUCB+G-CSF are warranted in order to optimize the translation of this combination therapy in the clinic.

Neural transplants in patients with Huntington's disease undergo disease-like neuronal degeneration.

The clinical evaluation of neural transplantation as a potential treatment for Huntington's disease (HD) was initiated in an attempt to replace lost neurons and improve patient outcomes. Two of 3 patients with HD reported here, who underwent neural transplantation containing striatal anlagen in the striatum a decade earlier, have demonstrated marginal and transient clinical benefits. Their brains were evaluated immunohistochemically and with electron microscopy for markers of projection neurons and interneurons, inflammatory cells, abnormal huntingtin protein, and host-derived connectivity. Surviving grafts were identified bilaterally in 2 of the subjects and displayed classic striatal projection neurons and interneurons. Genetic markers of HD were not expressed within the graft. Here we report in patients with HD that (i) graft survival is attenuated long-term; (ii) grafts undergo disease-like neuronal degeneration with a preferential loss of projection neurons in comparison to interneurons; (iii) immunologically unrelated cells degenerate more rapidly than the patient's neurons, particularly the projection neuron subtype; (iv) graft survival is attenuated in the caudate in comparison to the putamen in HD; (v) glutamatergic cortical neurons project to transplanted striatal neurons; and (vi) microglial inflammatory changes in the grafts specifically target the neuronal components of the grafts. These results, when combined, raise uncertainty about this potential therapeutic approach for the treatment of HD. However, these observations provide new opportunities to investigate the underlying mechanisms involved in HD, as well as to explore additional therapeutic paradigms.

The boundlessness of behavioral neuroscience: A look across 30 years.

It has been more than thirty years since the two inaugural IBNS presidents sat down at a larger neuroscience conference and decided that there should be more to behavioral neuroscience than a single theme at a meeting. The progeny of these conversations is the International Behavioral Neuroscience Society (IBNS) and this year will be its thirty year anniversary. We reflect back on the last thirty years of the research career of the society's second president, Paul R. Sanberg, as an example of how behavioral neuroscience research has changed these last few decades.

Testis-derived Sertoli cells have a trophic effect on dopamine neurons and alleviate hemiparkinsonism in rats.

Neural tissue transplantation has become an alternative treatment for Parkinson's disease (PD) and other neurodegenerative disorders. The clinical use of neural grafts as a source of dopamine for Parkinson's disease patients, although beneficial, is associated with logistical and ethical issues. Thus, alternative graft sources have been explored including polymer-encapsulated cells and nonneural cells (that is, adrenal chromaffin cells) or genetically modified cells that secrete dopamine and/or trophic factors. Although progress has been made, no current alternative graft source has ideal characteristics for transplantation. Emerging evidence suggests the importance of trophic factors in enhancing survival and regeneration of intrinsic dopaminergic neurons. It would be desirable to transplant cells that are readily available, immunologically accepted by the central nervous system and capable of producing dopamine and/or trophic factors. Sertoli cells have been shown to secrete CD-95 ligand and regulatory proteins, as well as trophic, tropic, and immunosuppressive factors that provide the testis, in part, with its "immunoprivileged" status. The present study demonstrated that transplantation of rat testis-derived Sertoli cells into adult rat brains ameliorated behavioral deficits in rats with 6-hydroxydopamine-induced hemiparkinsonism. This was associated with enhanced tyrosine hydroxylase (TH) immunoreactivity in the striatum in the area around the transplanted Sertoli cells. Furthermore, in vitro experiments demonstrated enhanced dopaminergic neuronal survival and outgrowth when embryonic neurons were cultured with medium in which rat Sertoli cells had been grown. Transplantation of Sertoli cells may provide a useful alternative treatment for PD and other neurodegenerative disorders.

Mannitol facilitates neurotrophic factor up-regulation and behavioural recovery in neonatal hypoxic-ischaemic rats with human umbilical cord blood grafts.

We recently demonstrated that blood-brain barrier permeabilization using mannitol enhances the therapeutic efficacy of systemically administered human umbilical cord blood (HUCB) by facilitating the entry of neurotrophic factors from the periphery into the adult stroke brain. Here, we examined whether the same blood-brain barrier manipulation approach increases the therapeutic effects of intravenously delivered HUCB in a neonatal hypoxic-ischaemic (HI) injury model. Seven-day-old Sprague-Dawley rats were subjected to unilateral HI injury and then at day 7 after the insult, animals intravenously received vehicle alone, mannitol alone, HUCB cells (15k mononuclear fraction) alone or a combination of mannitol and HUCB cells. Behavioural tests at post-transplantation days 7 and 14 showed that HI animals that received HUCB cells alone or when combined with mannitol were significantly less impaired in motor asymmetry and motor coordination compared with those that received vehicle alone or mannitol alone. Brain tissues from a separate animal cohort from the four treatment conditions were processed for enzyme-linked immunosorbent assay at day 3 post-transplantation, and revealed elevated levels of GDNF, NGF and BDNF in those that received HUCB cells alone or when combined with mannitol compared with those that received vehicle or mannitol alone, with the combined HUCB cells and mannitol exhibiting the most robust neurotropic factor up-regulation. Histological assays revealed only sporadic detection of HUCB cells, suggesting that the trophic factor-mediated mechanism, rather than cell replacement per se, principally contributed to the behavioural improvement. These findings extend the utility of blood-brain barrier permeabilization in facilitating cell therapy for treating neonatal HI injury.

Kainic acid lesions of the striatum dissociate amphetamine and apomorphine stereotypy: similarities to Huntingdon's chorea.

Kainic acid lesion of cell bodies in the dorsal striatum enhanced the stereotypy-producing effects of d-amphetamine without affecting the sterotypy produced by the direct receptor agonist apomorphine. This pattern of results parallels that found in patients suffering from Hungtington's chorea, thus strengthening the parallels between the kainic acid animal model and the human disease state initially suggested on biochemical gounds. The present results further suggest a dissociation of the mechanisms involved in the production of stereotypy by these two drugs, perhaps in terms of differential involvement of the striato-nigral negative feedback loop.

Effects of Sertoli cell-conditioned medium on ventral midbrain neural stem cells: a preliminary report.

The 796RMB cell line is a multipotent stem cell line isolated from human fetal midbrain tissues, a region from which dopamine neurons of the substantia nigra develop. It would be useful to increase the dopaminergic characteristics of this cell line to enhance its usefulness as a cell therapy for Parkinson's disease utilizing transplantation protocols. Sertoli cells and its conditioned media isolated from the testis have been previously shown to enhance tyrosine hydroxylase expression in ventral mesencephalon neurons both in vitro and in vivo. Therefore, the present preliminary study investigated the ability of Sertoli cell pre-conditioned medium to enhance differentiation of the 796MB cell line toward the domaminergic phenotype. Results showed that secretory products derived from Sertoli cell conditioned medium increased cell proliferation and enhanced dopaminergic neuronal differentiation of the 796RMB cell line. These findings may lead to alternative therapeutic cell transplantation protocols for the treatment of Parkinson's disease.

A comparison of dopaminergic cells from the human NTera2/D1 cell line transplanted into the hemiparkinsonian rat.

Human NT cells derived from the NTera2/D1 cell line express a dopaminergic phenotype making them an attractive vehicle to supply dopamine to the depleted striatum of the Parkinsonian patient. In vitro, hNT neurons express tyrosine hydroxylase (TH), depending on the length of time they are exposed to retinoic acid. This study compared two populations of hNT neurons that exhibit a high yield of TH+ cells, MI-hNT and DA-hNT. The MI-hNT and DA-hNT neurons were intrastriatally transplanted into the 6-OHDA hemiparkinsonian rat. Amelioration in rotational behavior was measured and immunohistochemistry was performed to identify surviving hNT and TH+ hNT neurons. Results indicated that both MI-hNT and DA-hNT neurons can survive in the striatum, however, neither maintained their dopaminergic phenotype in vivo. Other strategies used in conjunction with hNT cell replacement are likely needed to enhance and maintain the dopamine expression in the grafted cells.

Testis-derived Sertoli cells survive and provide localized immunoprotection for xenografts in rat brain.

Transplantation of neural tissue into the mammalian central nervous system has become an alternative treatment for neurodegenerative disorders such as Parkinson's disease. Logistical and ethical problems in the clinical use of human fetal neural grafts as a source of dopamine for Parkinson's disease patients has hastened a search for successful ways to use animal dopaminergic cells for human transplantation. The present study demonstrates that transplanted testis-derived Sertoli cells into adult rat brains survive. Furthermore, when cotransplanted with bovine adrenal chromaffin cells (xenograft), Sertoli cells produce localized immunoprotection, suppress microglial response and allow the bovine cells to survive in the rat brain without continuous systemic immunosuppressive drugs. These novel features support Sertoli cells as a viable graft source for facilitating the use of xenotransplantation for Parkinson's disease and suggest their use as facilitators, (i.e., localized immunosuppression) for cell transplantation in general.

Sertoli cells induce systemic donor-specific tolerance in xenogenic transplantation model.

Cell therapy is a potentially powerful tool in the treatment of many grave disorders including leukemia, immune deficiencies, autoimmune diseases, and diabetes. However, finding matched donors is challenging and recipients may suffer from the severe complications of systemic immune suppression. Sertoli cells, when cotransplanted with both allo- and xenograft tissues, promote graft acceptance in the absence of systemic immunosuppression. How Sertoli cells do this is not, as yet, clearly defined. We have examined the ability of Sertoli cells to produce systemic immune tolerance. For this purpose, Sertoli cells were injected into an otherwise normal C57/BL6 mouse host via the lateral tail vein. No other immunosuppressive protocols were applied. Six to 8 weeks posttransplantation, blood was collected for analysis of cytokine levels. Tolerance to donor cells was determined by mixed lymphocytic culture, and production of T-cell-dependent antibody was determined by an in vitro anti-sheep red blood cell plaque-forming assay. Results showed a marked modulation of immune cytokines in the transplanted mouse host and donor-specific transplantation tolerance was achieved. Tolerant mouse lymphocytes maintained a competent humoral antibody response. Additionally, C57/BL6 mice transplanted with rat Sertoli cells tolerated rat skin grafts significantly longer than control non-Sertoli cell transplanted mice. We conclude that systemic administration of rat Sertoli cells across xenogenic barrier induces transplantation tolerance without altering systemic immune competence. These data suggest that Sertoli cells may be used as a novel and potentially powerful tool in cell transplantation therapy.

Nicotine for the treatment of Tourette's syndrome.

Recent evidence has demonstrated that nicotine may obtund the symptoms of Tourette's syndrome (TS). TS is a neuropsychiatric disorder characterized by motor and vocal tics, obsessions and compulsions, and frequently with impulsivity, distractibility, and visual-motor deficits. While neuroleptics, such as haloperidol, are most effective for treatment of the motor and vocal tics of TS, these medications have many side effects. In this article, we review the evidence, consistent with findings in animals, that administration of nicotine (either 2 mg nicotine gum or 7 mg transdermal nicotine patch) potentiates the therapeutic properties of neuroleptics in treating TS patients and that a single patch may be effective for a variable number of days. These findings suggest that transdermal nicotine could serve as an effective adjunct to neuroleptic therapy for TS.

Survival of rat or mouse ventral mesencephalon neurons after cotransplantation with rat sertoli cells in the mouse striatum.

Transplanting cells across species (xenotransplantation) for the treatment of Parkinson's disease has been considered an option to alleviate ethical concerns and shortage of tissues. However, using this approach leads to decreased cell survival; the xenografted cells are often rejected. Sertoli cells (SCs) are testis-derived cells that provide immunological protection to developing germ cells and can enhance survival of both allografted and xenografted cells. It is not clear whether these cells will maintain their immunosuppressive support of cografted cells if they are transplanted across species. In this study, we investigated the immune modulatory capacity of SCs and the feasibility of xenografting these cells alone or with allografted and xenografted neural tissue. Transplanting xenografts of rat SCs into the mouse striatum with either rat or mouse ventral mesencephalon prevented astrocytic infiltration of the graft site, although all transplants showed activated microglia within the core of the graft. Surviving tyrosine hydroxylase-positive neurons were observed in all conditions, but the size of the grafts was small at best. SCs were found at 1 and 2 weeks posttransplant. However, few SCs were found at 2 months posttransplant. Further investigation is under way to characterize the immune capabilities of SCs in a xenogeneic environment.

Behavioral alterations in Lewis rats following two-day continuous 3-nitropropionic acid administration.

The mitochondrial toxin, 3-nitropropionic acid (3-NP), produces motor dysfunction and striatal atrophy in rats. However, rat strain and method of administration may contribute to variability in the deficits caused by 3-NP toxicity. To evaluate this, changes in nocturnal spontaneous locomotor activity from chronic administration of 3-NP using an osmotic mini pump, were examined in the Lewis rats. Lewis rats were treated with 3-NP or saline for 2 days and behavior was tested daily for a 15 day period. Animals receiving 3-NP displayed significantly less spontaneous activity than animals in the saline group. 3-NP treated animals also weighed significantly less when compared to saline treated animals. These results demonstrate that even though there were no significant alterations in overt anatomical pathology, even short-term exposure to 3-NP produced significant effects. This short-term administration may present a potential paradigm for examination of sub-threshold neurotoxicity.

3-Nitropropionic acid animal model and Huntington's disease.

Huntington's disease (HD) is a progressive neurodegenerative disorder associated with severe degeneration of basal ganglia neurons, especially the intrinsic neurons of the striatum, and characterized by progressive dementia and involuntary abnormal choreiform movements. Despite our increasing knowledge of the pathophysiology of HD, culminating with the discovery of the gene underlying HD, there has been no cure available to completely cease or reverse the progressive neurodegeneration and behavioral consequences of the disease. Animal models that closely mimic the neurobiological and clinical symptoms of the disease continue to offer alternative approaches for studying HD. Recently, we have reported that systemic administration of 3-nitropropionic acid (3-NP), an inhibitor of the mitochondrial citric acid cycle, results in a progressive locomotor deterioration resembling that of HD. Furthermore, we observed congruent with other reports, that 3-NP produces a very selective striatal degeneration. It differs mechanistically from excitotoxic lesions in that 3-NP irreversibly inhibits the mitochondrial citric acid cycle and leads to depressed ATP levels and elevated lactate concentrations. Recent neurochemical studies have implicated lowered glutamate levels and impaired oxidative energy metabolism as underlying mechanisms for many neurodegenerative disorders, including HD. Because of the mechanistic and pathologic similarities between 3-NP lesions and HD, 3-NP has been proposed as an alternative HD model. We further demonstrated that manipulating the time course of 3-NP injections leads to sustained hyperactivity (early HD) or hypoactivity (late HD). The present review will primarily discuss this progressive behavioral pathology induced by 3-NP that closely resembles that of HD. This body of evidence suggests that the 3-NP model is an improved HD model and may offer a unique system wherein testing of experimental treatments for HD can be carried out across different stages of the disease. This future application of the 3-NP model will be very useful especially in assessing the efficacy of treatment modalities, e.g. neural transplantation, during the progression of the disease.

A novel approach to neural transplantation in Parkinson's disease: use of polymer-encapsulated cell therapy.

Transplantation of dopaminergic neurons derived from fetal or adrenal tissue into the striatum is a potentially useful treatment for Parkinson's disease (PD). Although initially promising, recent clinical studies using adrenal autografts have demonstrated limited efficacy. The use of human fetal cells, despite promising preliminary results, is complicated by tissue availability and ethical concerns. An attractive alternative is based on encapsulating dopamine-producing cells into polymer capsules prior to transplantation. Polymer capsules can be fabricated to surround the cells with a semi-permeable and immunoprotective barrier. The semi-permeable membrane allows nutrients to enter the capsule, so the encapsulated cells will survive and function, and dopamine and other low molecular weight constituents to diffuse out into the host tissue. Thus, the technique allows use of unmatched human tissue (allografts), or even animal tissue (xenografts) without immunosuppression of the recipient. Cell-loaded polymer capsules can also be retrieved if necessary or desired. The demonstration that striatal implants of encapsulated dopamine-producing cells promote behavioral recovery in rodent and primate models of PD further suggests that cellular encapsulation may be a useful strategy for ameliorating the behavioral consequences of PD.

Neural transplantation as an experimental treatment modality for cerebral ischemia.

Cerebrovascular disease exemplifies the poor regenerative capacity of the CNS. While there are methods to prevent cerebral infarction, there is no effective therapy available to ameliorate the anatomical, neurochemical and behavioral deficits which follow cerebral ischemia. Focal and transient occlusion of the middle cerebral artery (MCA) in rodents has been reported to result in neuropathology similar to that seen in clinical cerebral ischemia. Using specific techniques, this MCA occlusion can result in a well-localized infarct of the striatum. This review article will provide data accumulated from animal studies using the MCA occlusion technique in rodents to examine whether neural transplantation can ameliorate behavioral and morphological deficits associated with cerebral infarction. Recent advances in neural transplantation as a treatment modality for neurodegenerative disorders such as Parkinson's disease, have revealed that fetal tissue transplantation may produce neurobehavioral recovery. Accordingly, fetal tissue transplantation may provide a potential therapy for cerebral infarction. Preliminary findings in rodents subjected to unilateral MCA occlusion, and subsequently transplanted with fetal striatal tissue into the infarcted striatum have produced encouraging results. Transplanted fetal tissue, assessed immunohistochemically, has been demonstrated to survive and integrate with the host tissue, and, more importantly, ameliorate the ischemia-related behavioral deficits, at least in the short term. Although, this review will focus primarily on cerebral ischemia, characterized by a localized CNS lesion within the striatum, it is envisioned that this baseline data may be extrapolated and applied to cerebral infarction in other brain areas.

Intravenous administration of human umbilical cord blood reduces behavioral deficits after stroke in rats.

BACKGROUND AND PURPOSE: Human umbilical cord blood cells (HUCBC) are rich in stem and progenitor cells. In this study we tested whether intravenously infused HUCBC enter brain, survive, differentiate, and improve neurological functional recovery after stroke in rats. In addition, we tested whether ischemic brain tissue extract selectively induces chemotaxis of HUCBC in vitro. METHODS: Adult male Wistar rats were subjected to transient (2-hour) middle cerebral artery occlusion (MCAO). Experimental groups were as follows: group 1, MCAO alone (n=5); group 2, 3x10(6) HUCBC injected into tail vein at 24 hours after MCAO (n=6) (animals of groups 1 and 2 were killed at 14 days after MCAO); group 3, MCAO alone (n=5); group 4, MCAO injected with PBS at 1 day after stroke (n=8); and group 5, 3x10(6) HUCBC injected into tail vein at 7 days after MCAO (n=5). Rats of groups 3, 4, and 5 were killed at 35 days after MCAO. Behavioral tests (rotarod and Modified Neurological Severity Score [mNSS]) were performed. Immunohistochemical staining was used to identify cells derived from HUCBC. Chemotactic activity of ischemia brain tissue extracts toward HUCBC at different time points was evaluated in vitro. RESULTS: Treatment at 24 hours after MCAO with HUCBC significantly improved functional recovery, as evidenced by the rotarod test and mNSS (P<0.05). Treatment at 7 days after MCAO with HUCBC significantly improved function only on the mNSS (P<0.05). Some HUCBC were reactive for the astrocyte marker glial fibrillary acidic protein and the neuronal markers NeuN and microtubule-associated protein 2. In vitro, significant HUCBC migration activity was present at 24 hours after MCAO (P<0.01) compared with normal brain tissue. CONCLUSIONS: Intravenously administered HUCBC enter brain, survive, migrate, and improve functional recovery after stroke. HUCBC transplantation may provide a cell source to treat stroke.

Comorbid bipolar disorder in Tourette's syndrome responds to the nicotinic receptor antagonist mecamylamine (Inversine).

BACKGROUND: We have previously proposed that the therapeutic effect of transdermal nicotine in Tourette's syndrome may involve nicotinic receptor inactivation resulting from a prolonged continuous exposure to nicotine. In vitro studies with nicotine and preliminary positive experience with mecamylamine (Inversine), a nicotinic receptor antagonist, in the clinical treatment of Tourette's syndrome patients, further supports the receptor inactivation hypothesis. METHODS: We retrospectively documented an unexpected therapeutic response to mecamylamine (2.5-7.5 mg/day) in two Tourette's syndrome patients who were subsequently found to have comorbid bipolar disorder as defined by DSM-IV criteria. RESULTS: In patient 1, the mood-stabilizing effect of mecamylamine was noticed by the patient during the course of mecamylamine treatment and brought to our attention, whereas for patient 2, manic symptoms were only apparent clinically following cessation of mecamylamine treatment. CONCLUSIONS: The clinical observations presented here suggest that nicotinic antagonists might be potential therapeutic agents for the treatment of bipolar disorder. Double-blind, placebo-controlled studies are now necessary to investigate these observations under more rigorous conditions.

The effects of nicotine plus haloperidol compared to nicotine only and placebo nicotine only in reducing tic severity and frequency in Tourette's disorder.

We studied the effects of chewing nicotine gum on tic frequency and severity in 10 patients with Tourette's disorder (TD) on haloperidol, versus 9 untreated TD patients; placebo gum was administered to 5 of these untreated patients. Videotapes of patients during a 2-hr period of 30 min baseline, 30 min gum chewing, and two 30-min postgum-chewing periods were utilized. For those TD patients on haloperidol, significant reductions occurred in tic frequency and severity during the gum-chewing and the two postgum-chewing periods. Nicotine gum alone caused a decrease in tic frequency only during gum-chewing and one postgum-chewing period, while placebo gum showed no effect. In this study, nicotine markedly potentiated haloperidol effects in treating TD, and showed lesser effects on TD when used alone.