Intracerebral Transplantation of BDNF-overexpressing Human Neural Stem Cells (HB1.F3.BDNF) Promotes Migration, Differentiation and Functional Recovery in a Rodent Model of Huntington's Disease

Levothyroxine attenuates behavioral impairment and improves oxidative stress and histological alteration 3-nitropropionic acid induced experimental Huntington's disease in rats

Huntington's disease (HD) is a neurodegenerative disorder characterized by degeneration of the striatum; it results in oxidative stress and motor deficits. Thyroid hormones regulate oxidative metabolism. In the present study, we evaluated the effect of administration of levothyroxine (LT-4) on neurobehavioral, oxidative stress, and histological changes in a rat model of HD. Forty-eight Wistar male rats were divided into the following six groups (n = 8): Group 1 (control) received physiological saline intraperitoneally (ip). Groups 2 and 3 received L-T4,30 and L-T4100 (μg/kg, ip, respectively) daily for 7 days. Group 4 (HD) received 3-nitropropionic acid (3-NP) (25 mg/kg, ip) daily for 7 days. Groups 5 and 6 received L-T4,30 and L-T4100 (μg/kg, ip, respectively) 30 min after 3-NP (25 mg/kg, ip) injection for the same duration. On the 8th day, behavioral parameters were evaluated with the Rotarod, Narrow beam walk, and Limb withdrawal tests. Oxidative markers such as Malondialdehyde (MDA) and Glutathione (GSH) levels and Superoxide dismutase (SOD) activity, in striatum tissue were measured. Moreover, striatum tissues were analyzed by Hematoxylin-eosin staining for histological alterations. We found that 3-NP administration caused motor incoordination and induced oxidative stress increased but reduced free radical scavenging. Also, increased amounts of lipid peroxides caused striatal damage as shown by histopathological evaluation. Administration of L-T4 led to increased falling time in the Rotarod, but reduced the time taken in Narrow beam walking and Limb withdrawal test. Furthermore, L-T4 increased antioxidant activity, decreased lipid peroxidation and ameliorated 3-NP-induced degeneration in neurons.

Nanotechnology and bioengineering approaches to improve the potency of mesenchymal stem cell as an off-the-shelf versatile tumor delivery vehicle

Targeting actionable mutations in oncogene-driven cancers and the evolution of immuno-oncology are the two prominent revolutions that have influenced cancer treatment paradigms and caused the emergence of precision oncology. However, intertumoral and intratumoral heterogeneity are the main challenges in both fields of precision cancer treatment. In other words, finding a universal marker or pathway in patients suffering from a particular type of cancer is challenging. Therefore, targeting a single hallmark or pathway with a single targeted therapeutic will not be efficient for fighting against tumor heterogeneity. Mesenchymal stem cells (MSCs) possess favorable characteristics for cellular therapy, including their hypoimmune nature, inherent tumor-tropism property, straightforward isolation, and multilineage differentiation potential. MSCs can be loaded with various chemotherapeutics and oncolytic viruses. The combination of these intrinsic features with the possibility of genetic manipulation makes them a versatile tumor delivery vehicle that can be used for in vivo selective tumor delivery of various chemotherapeutic and biological therapeutics. MSCs can be used as biofactory for the local production of chemical or biological anticancer agents at the tumor site. MSC-mediated immunotherapy could facilitate the sustained release of immunotherapeutic agents specifically at the tumor site, and allow for the achievement of therapeutic concentrations without the need for repetitive systemic administration of high therapeutic doses. Despite the enthusiasm evoked by preclinical studies that used MSC in various cancer therapy approaches, the translation of MSCs into clinical applications has faced serious challenges. This manuscript, with a critical viewpoint, reviewed the preclinical and clinical studies that have evaluated MSCs as a selective tumor delivery tool in various cancer therapy approaches, including gene therapy, immunotherapy, and chemotherapy. Then, the novel nanotechnology and bioengineering approaches that can improve the potency of MSC for tumor targeting and overcoming challenges related to their low localization at the tumor sites are discussed.

Genetically engineered neural stem cells (NSCs) therapy for neurological diseases; state-of-the-art

Neural stem cells (NSCs) are multipotent stem cells with remarkable self-renewal potential and also unique competencies to differentiate into neurons, astrocytes, and oligodendrocytes (ODCs) and improve the cellular microenvironment. In addition, NSCs secret diversity of mediators, including neurotrophic factors (e.g., BDNF, NGF, GDNF, CNTF, and NT-3), pro-angiogenic mediators (e.g., FGF-2 and VEGF), and anti-inflammatory biomolecules. Thereby, NSCs transplantation has become a reasonable and effective treatment for various neurodegenerative disorders by their capacity to induce neurogenesis and vasculogenesis and dampen neuroinflammation and oxidative stress. Nonetheless, various drawbacks such as lower migration and survival and less differential capacity to a particular cell lineage concerning the disease pathogenesis hinder their application. Thus, genetic engineering of NSCs before transplantation is recently regarded as an innovative strategy to bypass these hurdles. Indeed, genetically modified NSCs could bring about more favored therapeutic influences post-transplantation in vivo, making them an excellent option for neurological disease therapy. This review for the first time offers a comprehensive review of the therapeutic capability of genetically modified NSCs rather than naïve NSCs in neurological disease beyond brain tumors and sheds light on the recent progress and prospect in this context.

Brain-Derived Neurotrophic Factor Dysregulation as an Essential Pathological Feature in Huntington's Disease: Mechanisms and Potential Therapeutics

Brain-derived neurotrophic factor (BDNF) is a major neurotrophin whose loss or interruption is well established to have numerous intersections with the pathogenesis of progressive neurological disorders. There is perhaps no greater example of disease pathogenesis resulting from the dysregulation of BDNF signaling than Huntington's disease (HD)-an inherited neurodegenerative disorder characterized by motor, psychiatric, and cognitive impairments associated with basal ganglia dysfunction and the ultimate death of striatal projection neurons. Investigation of the collection of mechanisms leading to BDNF loss in HD highlights this neurotrophin's importance to neuronal viability and calls attention to opportunities for therapeutic interventions. Using electronic database searches of existing and forthcoming research, we constructed a literature review with the overarching goal of exploring the diverse set of molecular events that trigger BDNF dysregulation within HD. We highlighted research that investigated these major mechanisms in preclinical models of HD and connected these studies to those evaluating similar endpoints in human HD subjects. We also included a special focus on the growing body of literature detailing key transcriptomic and epigenetic alterations that affect BDNF abundance in HD. Finally, we offer critical evaluation of proposed neurotrophin-directed therapies and assessed clinical trials seeking to correct BDNF expression in HD individuals.

Practical Use of Immortalized Cells in Medicine: Current Advances and Future Perspectives

In modern science, immortalized cells are not only a convenient tool in fundamental research, but they are also increasingly used in practical medicine. This happens due to their advantages compared to the primary cells, such as the possibility to produce larger amounts of cells and to use them for longer periods of time, the convenience of genetic modification, the absence of donor-to-donor variability when comparing the results of different experiments, etc. On the other hand, immortalization comes with drawbacks: possibilities of malignant transformation and/or major phenotype change due to genetic modification itself or upon long-term cultivation appear. At first glance, such issues are huge hurdles in the way of immortalized cells translation into medicine. However, there are certain ways to overcome such barriers that we describe in this review. We determined four major areas of usage of immortalized cells for practical medicinal purposes, and each has its own means to negate the drawbacks associated with immortalization. Moreover, here we describe specific fields of application of immortalized cells in which these problems are of much lesser concern, for example, in some cases where the possibility of malignant growth is not there at all. In general, we can conclude that immortalized cells have their niches in certain areas of practical medicine where they can successfully compete with other therapeutic approaches, and more preclinical and clinical trials with them should be expected.

Ginsenoside Rg1 attenuation of neurogenesis disorder and neuronal apoptosis in the rat hippocampus after spinal cord injury may involve brain-derived neurotrophic factor/extracellular signal-regulated kinase signaling

OBJECTIVE

We previously demonstrated that spinal cord injury (SCI) induced hippocampus injury and depression in rodents. Ginsenoside Rg1 effectively prevents neurodegenerative disorders. Here, we investigated the effects of ginsenoside Rg1 on the hippocampus after SCI.

METHODS

We used a rat compression SCI model. Western blotting and morphologic assays were used to investigate the protective effects of ginsenoside Rg1 in the hippocampus.

RESULTS

Brain-derived neurotrophic factor/extracellular signal-regulated kinases (BDNF/ERK) signaling was altered in the hippocampus at 5 weeks after SCI. SCI attenuated neurogenesis and enhanced the expression of cleaved caspase-3 in the hippocampus; however, ginsenoside Rg1 attenuated cleaved caspase-3 expression and improved neurogenesis and BDNF/ERK signaling in the rat hippocampus. The results suggest that SCI affects BDNF/ERK signaling, and ginsenoside Rg1 can attenuate hippocampal damage after SCI.

CONCLUSION

We speculate that the protective effects of ginsenoside Rg1 in hippocampal pathophysiology after SCI may involve BDNF/ERK signaling. Ginsenoside Rg1 shows promise as a therapeutic pharmaceutical product when seeking to counter SCI-induced hippocampal damage.

The role of brain derived neurotrophic factor in central nervous system

Brain derived neurotrophic factor (BDNF) has multiple biological functions which are mediated by the activation of two receptors, tropomyosin receptor kinase B (TrkB) receptor and the p75 neurotrophin receptor, involving in physiological and pathological processes throughout life. The diverse presence and activity of BDNF indicate its potential role in the pathogenesis, progression and treatment of both neurological and psychiatric disorders. This review is to provide a comprehensive assessment of the current knowledge and future directions in BDNF-associated research in the central nervous system (CNS), with an emphasis on the physiological and pathological functions of BDNF as well as its potential treatment effects in CNS diseases, including depression, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, multiple sclerosis, and cerebral ischemic stroke.

Stem Cell Therapy in Treating Epilepsy

Epilepsy is a common disabling chronic neurological disorder characterized by an enduring propensity for the generation of seizures that result from abnormal hypersynchronous firing of neurons in the brain. Over 20–30% of epilepsy patients fail to achieve seizure control or soon become resistant to currently available therapies. Prolonged seizures or uncontrolled chronic seizures would give rise to neuronal damage or death, astrocyte activation, reactive oxygen species production, and mitochondrial dysfunction. Stem cell therapy is potentially a promising novel therapeutic strategy for epilepsy. The regenerative properties of stem cell-based treatment provide an attractive approach for long-term seizure control, particularly in drug-resistant epilepsy. Embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), neural stem cells (NSCs), induced pluripotent stem cells (iPSCs), and adipose-derived regenerative cells (ADRCs) are capable of differentiating into specialized cell types has been applied for epilepsy treatment in preclinical animal research and clinical trials. In this review, we focused on the advances in stem cell therapy for epilepsies. The goals of stem cell transplantation, its mechanisms underlying graft effects, the types of grafts, and their therapeutic effects were discussed. The cell and animal models used for investigating stem cell technology in epilepsy treatment were summarized.

Dietary Plant Polyphenols as the Potential Drugs in Neurodegenerative Diseases: Current Evidence, Advances, and Opportunities

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD), are characterized by the progressive degeneration of neurons. Although the etiology and pathogenesis of neurodegenerative diseases have been studied intensively, the mechanism is still in its infancy. In general, most neurodegenerative diseases share common molecular mechanisms, and multiple risks interact and promote the pathologic process of neurogenerative diseases. At present, most of the approved drugs only alleviate the clinical symptoms but fail to cure neurodegenerative diseases. Numerous studies indicate that dietary plant polyphenols are safe and exhibit potent neuroprotective effects in various neurodegenerative diseases. However, low bioavailability is the biggest obstacle for polyphenol that largely limits its adoption from evidence into clinical practice. In this review, we summarized the widely recognized mechanisms associated with neurodegenerative diseases, such as misfolded proteins, mitochondrial dysfunction, oxidative damage, and neuroinflammatory responses. In addition, we summarized the research advances about the neuroprotective effect of the most widely reported dietary plant polyphenols. Moreover, we discussed the current clinical study and application of polyphenols and the factors that result in low bioavailability, such as poor stability and low permeability across the blood-brain barrier (BBB). In the future, the improvement of absorption and stability, modification of structure and formulation, and the combination therapy will provide more opportunities from the laboratory into the clinic for polyphenols. Lastly, we hope that the present review will encourage further researches on natural dietary polyphenols in the treatment of neurodegenerative diseases.

Cell Therapy for Neurological Disorders: The Perspective of Promising Cells

Neurological disorders are big public health challenges that are afflicting hundreds of millions of people around the world. Although many conventional pharmacological therapies have been tested in patients, their therapeutic efficacies to alleviate their symptoms and slow down the course of the diseases are usually limited. Cell therapy has attracted the interest of many researchers in the last several decades and has brought new hope for treating neurological disorders. Moreover, numerous studies have shown promising results. However, none of the studies has led to a promising therapy for patients with neurological disorders, despite the ongoing and completed clinical trials. There are many factors that may affect the outcome of cell therapy for neurological disorders due to the complexity of the nervous system, especially cell types for transplantation and the specific disease for treatment. This paper provides a review of the various cell types from humans that may be clinically used for neurological disorders, based on their characteristics and current progress in related studies.

Recent advances in stem cell therapy for neurodegenerative disease: Three dimensional tracing and its emerging use

Neurodegenerative disease is a brain disorder caused by the loss of structure and function of neurons that lowers the quality of human life. Apart from the limited potential for endogenous regeneration, stem cell-based therapies hold considerable promise for maintaining homeostatic tissue regeneration and enhancing plasticity. Despite many studies, there remains insufficient evidence for stem cell tracing and its correlation with endogenous neural cells in brain tissue with three-dimensional structures. Recent advancements in tissue optical clearing techniques have been developed to overcome the existing shortcomings of cross-sectional tissue analysis in thick and complex tissues. This review focuses on recent progress of stem cell treatments to improve neurodegenerative disease, and introduces tissue optical clearing techniques that can implement a three-dimensional image as a proof of concept. This review provides a more comprehensive understanding of stem cell tracing that will play an important role in evaluating therapeutic efficacy and cellular interrelationship for regeneration in neurodegenerative diseases.

A novel Huntington's disease mouse model to assess the role of neuroinflammation on disease progression and to develop human cell therapies

Huntington's disease (HD) is a fatal autosomal-dominant neurodegenerative disease caused by a trinucleotide CAG repeat expansion of the huntingtin gene (HTT) that affects 1 in every 10 000 individuals in the United States. Our lab developed a novel immune deficient HD mouse strain, the YACNSG, from a commonly used line, the YAC128 mouse, to enable transplantation studies using engineered human cells in addition to studying the impact of the immune system on disease progression. The primary goal of this project was to characterize this novel immune deQficient HD mouse model, using behavioral assays and histology to compare this new model to the immune competent YAC128 and immune deficient mice that had engraftment of a human immune system. Flow cytometry was used to confirm that the YACNSG strain lacked immune cells, and in vivo imaging was used to assess human mesenchymal stem/stromal cell (MSC) retention compared with a commonly used immune deficient line, the NSG mouse. We found that YACNSG were able to retain human MSCs longer than the immune competent YAC128 mice. We performed behavioral assessments starting at 4 months of age and continued testing monthly until 12 months on the accelerod and in the open field. At 12 months, brains were isolated and evaluated using immunohistochemistry for striatal volume. Results from these studies suggest that the novel immune deficient YACNSG strain of mice could provide a good model for human stem-cell based therapies and that the immune system appears to play an important role in the pathology of HD.

Multipronged Attack of Stem Cell Therapy in Treating the Neurological and Neuropsychiatric Symptoms of Epilepsy

Epilepsy stands as a life-threatening disease that is characterized by unprovoked seizures. However, an important characteristic of epilepsy that needs to be examined is the neuropsychiatric aspect. Epileptic patients endure aggression, depression, and other psychiatric illnesses. Therapies for epilepsy can be divided into two categories: antiepileptic medications and surgical resection. Antiepileptic drugs are used to attenuate heightened neuronal firing and to lessen seizure frequency. Alternatively, surgery can also be conducted to physically cut out the area of the brain that is assumed to be the root cause for the anomalous firing that triggers seizures. While both treatments serve as viable approaches that aim to regulate seizures and ameliorate the neurological detriments spurred by epilepsy, they do not serve to directly counteract epilepsy's neuropsychiatric traits. To address this concern, a potential new treatment involves the use of stem cells. Stem cell therapy has been employed in experimental models of neurological maladies, such as Parkinson's disease, and neuropsychiatric illnesses like depression. Cell-based treatments for epilepsy utilizing stem cells such as neural stem cells (NSCs), mesenchymal stem cells (MSCs), and interneuron grafts have been explored in preclinical and clinical settings, highlighting both the acute and chronic stages of epilepsy. However, it is difficult to create an animal model to capitalize on all the components of epilepsy due to the challenges in delineating the neuropsychiatric aspect. Therefore, further preclinical investigation into the safety and efficacy of stem cell therapy in addressing both the neurological and the neuropsychiatric components of epilepsy is warranted in order to optimize cell dosage, delivery, and timing of cell transplantation.

Cell therapy in Huntington's disease: Taking stock of past studies to move the field forward

Huntington's disease (HD) is a rare inherited neurodegenerative disease that manifests mostly in adulthood with progressive cognitive, behavioral, and motor dysfunction. Neuronal loss occurs predominantly in the striatum but also extends to other brain regions, notably the cortex. Most patients die around 20 years after motor onset, although there is variability in the rate of progression and some phenotypic heterogeneity. The most advanced experimental therapies currently are huntingtin-lowering strategies, some of which are in stage 3 clinical trials. However, even if these approaches are successful, it is unlikely that they will be applicable to all patients or will completely halt continued loss of neural cells in all cases. On the other hand, cellular therapies have the potential to restore atrophied tissues and may therefore provide an important complementary therapeutic avenue. Pilot studies of fetal cell grafts in the 2000s reported the most dramatic clinical improvements yet achieved for this disease, but subsequent studies have so far failed to identify methodology to reliably reproduce these results. Moving forward, a major challenge will be to generate suitable donor cells from (nonfetal) cell sources, but in parallel there are a host of procedural and trial design issues that will be important for improving reliability of transplants and so urgently need attention. Here, we consider findings that have emerged from clinical transplant studies in HD to date, in particular new findings emerging from the recent multicenter intracerebral transplant HD study, and consider how these data may be used to inform future cell therapy trials.