Effects of pcDNA3-beta-NGF gene-modified BMSC on the rat model of Parkinson's disease

Effects of mesenchymal stem cell on dopaminergic neurons, motor and memory functions in animal models of Parkinson's disease: a systematic review and meta-analysis

ABSTRACT

Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, and although restoring striatal dopamine levels may improve symptoms, no treatment can cure or reverse the disease itself. Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson's disease. Mesenchymal stem cells are considered a promising option due to fewer ethical concerns, a lower risk of immune rejection, and a lower risk of teratogenicity. We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function, memory, and preservation of dopaminergic neurons in a Parkinson's disease animal model. We searched bibliographic databases (PubMed/MEDLINE, Embase, CENTRAL, Scopus, and Web of Science) to identify articles and included only peer-reviewed in vivo interventional animal studies published in any language through June 28, 2023. The study utilized the random-effect model to estimate the 95% confidence intervals (CI) of the standard mean differences (SMD) between the treatment and control groups. We use the systematic review center for laboratory animal experimentation's risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment. A total of 33 studies with data from 840 Parkinson's disease model animals were included in the meta-analysis. Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test. Among the stem cell types, the bone marrow MSCs with neurotrophic factor group showed largest effect size (SMD [95% CI] = -6.21 [-9.50 to -2.93], P = 0.0001, I2 = 0.0 %). The stem cell treatment group had significantly more tyrosine hydroxylase positive dopaminergic neurons in the striatum ([95% CI] = 1.04 [0.59 to 1.49], P = 0.0001, I2 = 65.1 %) and substantia nigra (SMD [95% CI] = 1.38 [0.89 to 1.87], P = 0.0001, I2 = 75.3 %), indicating a protective effect on dopaminergic neurons. Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route (SMD [95% CI] = -2.59 [-3.25 to -1.94], P = 0.0001, I2 = 74.4 %). The memory test showed significant improvement only in the intravenous route (SMD [95% CI] = 4.80 [1.84 to 7.76], P = 0.027, I2 = 79.6 %). Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson's disease. Further research is required to determine the optimal stem cell types, modifications, transplanted cell numbers, and delivery methods for these protocols.

Proximity extension assay-based proteomics studies in neurodegenerative disorders and multiple sclerosis

Neurodegenerative diseases impact the structure and operation of the nervous system, causing progressive and irreparable harm. Efforts for distinguishing neurodegenerative diseases in their early stages are continuing. Despite several biomarkers being identified, there is always search for more accurate and abundant ones. Additionally, it can be difficult to pinpoint the precise neurodegenerative disorder affecting a patient as the symptoms of these conditions frequently overlap. Numerous studies have shown that pathological changes occur years before clinical signs appear. Therefore, it is crucial to discover blood-based biomarkers for neurodegenerative diseases for easier and earlier diagnosis. Proximity extension assay is a unique proteomics method that uses antibodies linked to oligonucleotides for quantifying proteins with real-time PCR. Proximity extension assay can identify even low-quantity proteins using a small volume of specimens with increased sensitivity compared to conventional methods. In this article, we reviewed the employment of proximity extension assay technology to detect biomarkers or protein profiles for several neurodegenerative diseases.

Blood Markers of Inflammation, Neurodegeneration, and Cardiovascular Risk in Early Parkinson's Disease

BACKGROUND

Recent studies point toward a significant impact of cardiovascular processes and inflammation on Parkinson's disease (PD) progression.

OBJECTIVE

The aim of this study was to assess established markers of neuronal function, inflammation, and cardiovascular risk by high-throughput sandwich immune multiplex panels in deeply phenotyped PD.

METHODS

Proximity Extension Assay technology on 273 markers was applied in plasma of 109 drug-naive at baseline (BL) patients with PD (BL, 2-, 4-, and 6-year follow-up [FU]) and 96 healthy control patients (HCs; 2- and 4-year FU) from the de novo Parkinson's cohort. BL plasma from 74 individuals (37 patients with PD, 37 healthy control patients) on the same platform from the Parkinson Progression Marker Initiative was used for independent validation. Correlation analysis of the identified markers and 6 years of clinical FU, including motor and cognitive progression, was evaluated.

RESULTS

At BL, 35 plasma markers were differentially expressed in PD, showing downregulation of atherosclerotic risk markers, eg, E-selectin and ß₂ -integrin. In contrast, we found a reduction of markers of the plasminogen activation system, eg, urokinase plasminogen activator. Neurospecific markers indicated increased levels of peripheral proteins of neurodegeneration and inflammation, such as fibroblast growth factor 21 and peptidase inhibitor 3. Several markers, including interleukin-6 and cystatin B, correlated with cognitive decline and progression of motor symptoms during FU. These findings were independently validated in the Parkinson Progression Marker Initiative.

CONCLUSIONS

We identified and validated possible PD plasma biomarker candidates for state, fate, and disease progression, elucidating new molecular processes with reduced endothelial/atherosclerotic processes, increased thromboembolic risk, and neuroinflammation. Further investigations and validation in independent and larger longitudinal cohorts are needed. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Effect of NTN and Lmx1α on the Notch Signaling Pathway during the Differentiation of Human Bone Marrow Mesenchymal Stem Cells into Dopaminergic Neuron-Like Cells

Human bone marrow mesenchymal stem cells (h-BMSCs) have the potential to differentiate into dopaminergic neuron-like cells to treat Parkinson's disease. The Notch signaling pathway has been implicated in the regulation of cell fate decisions such as differentiation of BMSCs. This study investigated changes in the expression of Notch-related genes in the differentiation of BMSCs in vitro into dopaminergic (DA) neuron-like cells. BMSCs transfected with empty lentiviral vectors served as the control group and those transfected with NTN and Lmx1α recombinant lentiviral vectors served as the experimental group. After induction and culture of NTN and Lmx1α-transfected h-BMSCs for 21 days, the cells exhibited features of dopaminergic neuron-like cells, which were observed by transmission and scanning electron microscopy and verified by immunofluorescence of tyrosine hydroxylase (TH) and dopamine transporter (DAT). These induced cells could secrete dopamine and had basic action potentials. Expression of the neural stem cell (NSC) markers, including octamer-binding protein (Oct4), paired box gene 6 (Pax6), and sex determining region Y-box 1 (SOX1), increased on day 14 of induction and decreased on day 21 of induction during differentiation. The human Notch signaling pathway PCR array showed a differential expression of Notch-related genes during the differentiation of h-BMSCs into DA neuron-like cells in vitro relative to that in the control group. In conclusion, h-BMSCs overexpressing NTN and Lmx1α can successfully be induced to differentiate into dopaminergic neuron-like cells with a neuronal phenotype exhibiting fundamental biological functions in vitro, and NTN and Lmx1α may affect the expression of Notch-related genes during differentiation.

Inflammation biomarker discovery in Parkinson's disease and atypical parkinsonisms

Background

Parkinson’s disease (PD) and atypical parkinsonisms (APD) have overlapping symptoms challenging an early diagnosis. Diagnostic accuracy is important because PD and APD have different prognosis and response to treatment. We aimed to identify diagnostic inflammatory biomarkers of PD and APD in cerebrospinal fluid (CSF) using the multiplex proximity extension assay (PEA) technology and to study possible correlations of biomarkers with disease progression.

Methods

CSF from a longitudinal cohort study consisting of PD and APD patients (PD, n = 44; multiple system atrophy (MSA), n = 14; vascular parkinsonism (VaP), n = 9; and PD with VaP, n = 7) and controls (n = 25) were analyzed.

Results

Concentrations of CCL28 were elevated in PD compared to controls (p = 0.0001). Five other biomarkers differentiated both MSA and PD from controls (p < 0.05) and 10 biomarkers differentiated MSA from controls, of which two proteins, i.e. beta nerve growth factor (β-NGF) and Delta and Notch like epidermal growth factor-related receptor (DNER), were also present at lower levels in MSA compared to PD (both p = 0.032). Two biomarkers (MCP-1 and MMP-10) positively correlated with PD progression (rho > 0.650; p < 0.01).

Conclusions

PEA technique identified potential new CSF biomarkers to help to predict the prognosis of PD. Also, we identified new candidate biomarkers to distinguish MSA from PD.

A Meta-Analysis of Mesenchymal Stem Cells in Animal Models of Parkinson's Disease

Multiple studies have been performed to evaluate the effects of mesenchymal stem cells (MSCs) in animal models of Parkinson's disease (PD). We performed a meta-analysis to estimate the treatment effect of unmodified MSCs on behavioral outcomes in preclinical studies of PD. We performed a systematic literature search to identify studies that used behavioral testing to evaluate the treatment effect of unmodified MSCs in PD models. Meta-analysis was used to determine pooled effect size for rotational behavior and limb function, and meta-regression was performed to explore sources of heterogeneity. Twenty-five studies, including three delivery routes, a wide range of doses, and multiple PD models, were examined. Significant improvement was seen in the pooled standardized mean difference (SMD) for both rotational behavior [SMD: 1.24, 95% confidence interval (95% CI): 0.84, 1.64] and limb function (SMD: 0.84, 95% CI: 0.01, 1.66). Using meta-regression, intravenous administration and higher dose had a larger effect on limb function. Treatment with MSCs improves behavioral outcomes in PD models. Our analyses suggest that MSCs could be considered for early-stage clinical trials in the treatment of PD.

Transplantation of mesenchymal stem cells: a future therapy for Parkinson’s disease?

ABSTRACT: 

Parkinson’s disease (PD) is a common, progressive neurodegenerative disorder associated with a loss of dopaminergic cells in the substantia nigra pars compacta and a lack of dopamine in the striatum. To halt or reverse this disease, neurorestorative approaches or neuroprotective treatments are urgently needed. Recently, the first clinical trials transplanting mesenchymal stem cells (MSCs) have been performed in PD. MSCs are adult stem cells abundant in several tissues, such as the umbilical cord, the bone marrow, the adipose tissue and other tissues. These cells are multipotent, and able to synthesize and secrete a wide spectrum of biologically active factors. MSCs of various origins have been explored as possible substrates for cell therapy in PD animal models. In this review, we summarize MSC-based experimental transplantation studies in PD, and discuss biological mechanisms that may explain the effects of MSC seen in PD models. Furthermore, we critically evaluate the recent clinical transplantation trials using MSCs in patients with PD.

Overexpression of β-NGF promotes differentiation of bone marrow mesenchymal stem cells into neurons through regulation of AKT and MAPK pathway

Bone marrow stromal stem cells (BMSCs) are fibroblastic in shape and capable of self-renewal and have the potential for multi-directional differentiation. Nerve growth factor (NGF), a homodimeric polypeptide, plays an important role in the nervous system by supporting the survival and growth of neural cells, regulating cell growth, promoting differentiation into neuron, and neuron migration. Adenoviral vectors are DNA viruses that contain 36 kb of double-stranded DNA allowing for transmission of the genes to the host nucleus but not inserting them into the host chromosome. The present study aimed to investigate the induction efficiency and differentiation of neural cells from BMSCs by β-NGF gene transfection with recombinant adenoviral vector (Ad-β-NGF) in vitro. The results of immunochemical assay confirmed the induced cells as neuron cells. Moreover, flow cytometric analysis, Annexin-V-FITC/PI, and BrdU assay revealed that chemical inducer β-mercaptoethanol (β-met) triggered apoptosis of BMSCs, as evidenced by inhibition of DNA fragmentation, nuclear condensation, translocation of phospholipid phosphatidylserine, and activation of caspase-3. Furthermore, the results of western blotting showed that β-met suppressed AKT signaling pathway and regulated the MAPKs during differentiation of BMSCs. In contrast, Ad-β-NGF effectively induced the differentiation of BMSCs without causing any cytopathic phenomenon and apoptotic cell death. Moreover, Ad-β-NGF recovered the expression level of phosphorylated AKT and MAPKs in cells exposed to chemical reagents. Taken together, these results suggest that β-NGF gene transfection promotes the differentiation of BMSCs into neurons through regulation of AKT and MAPKs signaling pathways.

The secretome of mesenchymal stem cells: potential implications for neuroregeneration

Mesenchymal stem cells have shown regenerative properties in many tissues. This feature had originally been ascribed to their multipotency and thus their ability to differentiate into tissue-specific cells. However, many researchers consider the secretome of mesenchymal stem cells the most important player in the observed reparative effects of these cells. In this review, we specifically focus on the potential neuroregenerative effect of mesenchymal stem cells, summarize several possible mechanisms of neuroregeneration and list key factors mediating this effect. We illustrate examples of mesenchymal stem cell treatment in central nervous system disorders including stroke, neurodegenerative disorders (such as Parkinson's disease, Huntington's disease, multiple system atrophy and cerebellar ataxia) and inflammatory disease (such as multiple sclerosis). We specifically highlight studies where mesenchymal stem cells have entered clinical trials.

Human umbilical vein-derived dopaminergic-like cell transplantation with nerve growth factor ameliorates motor dysfunction in a rat model of Parkinson's disease

Mesenchymal stem cells are capable of differentiating into dopaminergic-like cells, but currently no report has been available to describe the induction of human umbilical vein mesenchymal stem cells (HUVMSCs) into dopaminergic-like cells. In this study, we induced HUVMSCs in vitro into neurospheres constituted by neural stem-like cells, and further into cells bearing strong morphological, phenotypic and functional resemblances with dopaminergic-like cells. These HUVMSC-derived dopaminergic-like cells, after grafting into the brain of a rat model of Parkinson's disease (PD), showed a partial therapeutic effect in terms of the behavioral improvement. Nerve growth factor was reported to improve the local microenvironment of the grafted cells, and we therefore further tested the effect of dopaminergic-like cell grafting combined with nerve growth factor (NGF) administration at the site of cell transplantation. The results showed that NGF administration significantly promoted the survival of the grafted cells in the host brain and enhanced the content of dopaminergic in the local brain tissue. Behavioral test demonstrated a significant improvement of the motor function of the PD rats after dopaminergic-like cell grafting with NGF administration as compared with that of rats receiving the cell grafting only. These results suggest that transplantation of the dopaminergic-like cells combined with NGF administration may represent a new strategy of stem cell therapy for PD.

Effects of NT-4 gene modified fibroblasts transplanted into AD rats

It is well known that fibroblasts can act as a cell vector to express functional protein, like neurotrophin-4 (NT-4). The present study evaluated the effect of NT-4 gene modified fibroblasts grafted into the hippocampus of AD rat model. AD rats were reproduced by bilateral transection of the hippocampal fimbria-fornix. The transplanted fibroblasts steadily expressed NT-4 proteins at least 2 months after transplantation. This correlated with a significant rescue in the number of cholinergic neurons in the host hippocampus. Morris water maze tests demonstrated significant improvements in learning and memory, especially in rats receiving NT-4-modified fibroblasts. The present results showed that NT-4 gene modified fibroblasts could provide a long-term and steady expression of NT-4, and it significantly improved the behavior of AD rats. These findings should have important clinical applications in providing a long-term NT-4 Secretion for the treatment of AD.