Therapeutic Efficacy and Migration of Mesenchymal Stem Cells after Intracerebral Transplantation in Rats with Experimental Ischemic Stroke.

We studied therapeutic efficacy and migration characteristics of mesenchymal stem cells isolated from the human placenta after their intracerebral (stereotactic) administration to rats with the experimental ischemic stroke. It was shown that cell therapy significantly improved animal survival rate and reduced the severity of neurological deficit. New data on the migration pathways of transplanted cells in the brain were obtained.

Dose-Dependent Effects of Intravenous Mesenchymal Stem Cell Transplantation in Rats with Acute Focal Cerebral Ischemia.

Intravenous transplantation of mesenchymal stem (stromal) cells (MSC) is a promising approach to the treatment of ischemic stroke. In the published reports of the already completed preclinical and clinical studies the dosages of transplanted MSC greatly vary. However, the optimal dosage has not been determined. The dose-dependent effect of intravenous MSC transplantation was studied, in rats with experimental cerebral infarction. To this end, 5×105 and 2×106 MSC were intravenously administered 24 h after modeling of acute focal ischemia followed by complex assessment of the therapeutic efficacy over 60 days. The rate and degree of the recovery of neurological functions in rats increased with increasing the dose of injected cells, which confirms the dose-dependent effect of intravenous MSC transplantation.

MRI-Based and Histologically Verified 3D Modeling of Spatial Distribution of Intra-Arterially Transplanted Cells in Rat Brain.

Visualization of transplanted stem cells in the brain is an important issue in the study of the mechanisms of their therapeutic action. MRI allowing visualization of single transplanted cells previously labeled with superparamagnetic iron oxide particles is among the most informative methods of non-invasive intravital imaging. Verification of MRI data using pathomorphological examination at the microscopic level helps to avoid errors in data interpretation. However, making serial sections of the whole brain and searching for transplanted cells under the microscope is laborious and time-consuming. We have developed a method for 3D modeling of the distribution of transplanted cells in the brain allowing navigating through various brain structures and identifying the areas of accumulation of transplanted cells, which significantly increases the efficiency and reduces the time of histological examination.

[The Peptide Drug ACTH(4-7)PGP (Semax) Suppresses mRNA Transcripts Encoding Proinflammatory Mediators Induced by Reversible Ischemia of the Rat Brain].

Due to its nootropic, neuroprotective, and immunomodulatory effects, the peptide Semax is utilized in the treatment of ischemic stroke. Our earlier RNA-Seq analysis of the transcriptome in an ischemic model of transient occlusion of the middle cerebral artery showed an increase in the mRNA levels of many proinflammatory genes, and the suppression of their induction by Semax. However, for many relevant genes, including Il1a, Il1b, Il6 and Tnfa, the levels of their expression were too low for detailed quantitative evaluation. Here we utilize qRT-PCR to analyze the effects of the Semax peptide on the expression of weakly expressed mRNAs encoding several proinflammatory mediators, and show that exposure to Semax leads to a statistically significant decrease in the Il1a, Il1b, Il6, Ccl3, and Cxcl2 mRNAs, which compensates for the increase in the transcription of these genes induced by ischemia-reperfusion. We conclude that the observed protective effect of Semax in the model of stroke may be due to its anti-inflammatory effects. We also discuss the limitations of the RNA-Seq when applied to quantifying less abundant transcripts as compared to the real-time RT-PCR method.

[Clinical polymorphism of amyotrophic lateral sclerosis]. / Klinicheskii polimorfizm bokovogo amiotroficheskogo skleroza.

AIM: To clarify clinical polymorphism of amyotrophic lateral sclerosis (ALS). MATERIAL AND METHODS: The study was based on records of a hospital personalized register. Ninety-four patients, aged from 25 to 81 years, diagnosed with ALS according to El Escorial criteria were included. Electromyography and, if necessary, transcranial magnetic stimulation and magnetic-resonance tomography were used to confirm the diagnosis. Disease progression was assessed with the ARSFRS. Age at disease onset, progression rate and duration of survival of patients, rare symptoms of ALS ('extramotor'), time for palliative care (gastrostomy, non-invasive and invasive lung ventilation) and provision of the care to the patient, family history were recorded in a specially designed questionnaire. RESULTS: Most of the patients had sporadic ALS, only two familial cases were identified. Spinal onset ALS was found in 66.0% of the patients, bulbar onset in 29.8%, diffuse onset (spinal and bulbar motor neurons were affected simultaneously) in 4.2%. Moderate ALS progression was observed in 42.6% of the patients, mean time till death was 3.0±1.2 years. A slow progression was found in patients with cervical, low back and bulbar onset. A rapid and even 'momentary' type of progression was in diffuse and breast onset. An extremely slow progression with the long-term hospital treatment and survival >5 years was found in 9.7%. Rare ALS symptoms were represented by specific cognitive and psychological impairments, a type of frontal/temporal dysfunction, but only 5 (5.3%) patients were diagnosed with ALS-dementia. Signs of pathological muscle fatigue (myasthenic syndrome) were identified in 18 (19.1%), extrapyramidal disorders in 5 (5.3%), coordination disorders in 4 (4.3%), pain in 12 (12.8%), sensory symptoms in 5 (5.3%) of the patients. CONCLUSION: ALS is a multisystemic neurodegeneration disease though the progressive motor neuron death determines the fatal outcome.

Intravenous xenotransplantation of human placental mesenchymal stem cells to rats: comparative analysis of homing in rat brain in two models of experimental ischemic stroke.

Mesenchymal stem cells from human placenta obtained after term natural delivery were cultured and labeled with vital dye Dil of magnetic fluorescing microparticles. The labeled cells were transplanted intravenously to rats with occlusion of the median cerebral artery. Penetration of cells through the brain-blood barrier and their distribution in the brain of experimental animals were studied on serial cryostat sections. Two models of cerebral artery occlusion associated with different traumatic consequences were used. The efficiency of crossing the blood-brain barrier by transplanted cells, the number of mesenchymal cells attaining the ischemic focus and neurogenic zones, and the time of death of transplanted cells largely depended on the degree and nature of injury to the central nervous system, which should be taken into account when planning the experiments for evaluation of the effects of cell therapy on the models of neurological diseases and in clinical studies in the field of regenerative neurology.

Mechanisms of positive effects of transplantation of human placental mesenchymal stem cells on recovery of rats after experimental ischemic stroke.

Mesenchymal stem cells isolated from human placenta and in vitro labeled with fluorescent magnetic microparticles were intravenously injected to rats 2 days after induction of focal cerebral ischemia (endovascular model). According to MRT findings, transplantation of mesenchymal stem cells led to an appreciable reduction of the volume of ischemic focus in the brain. Two or three weeks after transplantation, labeled cells accumulated near and inside the ischemic focus, in the hippocampus, and in the subventricular zone of both hemispheres. Only few human mesenchymal stem cells populating the zone adjacent to the ischemic focus started expressing astroglial and neuronal markers. On the other hand, transplantation of mesenchymal stem cells stimulated proliferation of stem and progenitor cells in the subventricular zone and migration of these cells into the ischemic zone. Positive effects of transplantation of these cells to rats with experimental ischemic stroke are presumably explained by stimulation of proliferation of resident stem and progenitor cells of animal brain and their migration into the ischemic tissue and adjacent areas. Replacement of damaged rat neurons and glial cells by transplanted human cells, if it does take place, is quite negligible.