Intra-Arterial Administration of Multipotent Mesenchymal Stromal Cells Promotes Functional Recovery of the Brain After Traumatic Brain Injury

Effects of bone marrow mesenchymal stromal cells-derived therapies for experimental traumatic brain injury： A meta-analysis

Background

Bone-marrow-derived mesenchymal stromal (stem) cells [also called MSC(M)] and their extracellular vesicles (EVs) are considered a potentially innovative form of therapy for traumatic brain injury (TBI). Nevertheless, their application to TBI particularly remains preclinical, and the effects of these cells remain unclear and controversial. Therefore, an updated meta-analysis of preclinical studies is necessary to assess the effectiveness of MSC(M) and MSC(M) derived EVs in clinical trials.

Methods

The following databases were searched (to December 2022): PubMed, Web of Science, and Embase. In this study, we measured functional outcomes based on the modified neurological severity score (mNSS), cognitive outcomes based on the Morris water maze (MWM), and histopathological outcomes based on lesion volume. A random effects meta-analysis was conducted to evaluate the effect of mNSS, MWM, and lesion volume.

Results

A total of 2163 unique records were identified from our search, with Fifty-five full-text articles satisfying inclusion criteria. A mean score of 5.75 was assigned to the studies' quality scores, ranging from 4 to 7. MSC(M) and MSC(M) derived EVs had an overall positive effect on the mNSS score and MWM with SMDs -2.57 (95 % CI -3.26; -1.88; p < 0.01) and - 2.98 (95 % CI -4.21; -1.70; p < 0.01), respectively. As well, MSC(M) derived EVs were effective in reducing lesion volume by an SMD of - 0.80 (95 % CI -1.20; -0.40; p < 0.01). It was observed that there was significant variation among the studies, but further analyses could not determine the cause of this heterogeneity.

Conclusions

MSC(M) and MSC(M) derived EVs are promising treatments for TBI in pre-clinical studies, and translation to the clinical domain appears warranted. Besides, large-scale trials in animals and humans are required to support further research due to the limited sample size of MSC(M) derived EVs.

Systematic review and meta-analysis of preclinical studies testing mesenchymal stromal cells for traumatic brain injury

Mesenchymal stromal cells (MSCs) are widely used in preclinical models of traumatic brain injury (TBI). Results are promising in terms of neurological improvement but are hampered by wide variability in treatment responses. We made a systematic review and meta-analysis: (1) to assess the quality of evidence for MSC treatment in TBI rodent models; (2) to determine the effect size of MSCs on sensorimotor function, cognitive function, and anatomical damage; (3) to identify MSC-related and protocol-related variables associated with greater efficacy; (4) to understand whether MSC manipulations boost therapeutic efficacy. The meta-analysis included 80 studies. After TBI, MSCs improved sensorimotor and cognitive deficits and reduced anatomical damage. Stratified meta-analysis on sensorimotor outcome showed similar efficacy for different MSC sources and for syngeneic or xenogenic transplants. Efficacy was greater when MSCs were delivered in the first-week post-injury, and when implanted directly into the lesion cavity. The greatest effect size was for cells embedded in matrices or for MSC-derivatives. MSC therapy is effective in preclinical TBI models, improving sensorimotor, cognitive, and anatomical outcomes, with large effect sizes. These findings support clinical studies in TBI.

Linking 7-Nitrobenzo-2-oxa-1,3-diazole (NBD) to Triphenylphosphonium Yields Mitochondria-Targeted Protonophore and Antibacterial Agent

Appending lipophilic cations to small molecules has been widely used to produce mitochondria-targeted compounds with specific activities. In this work, we obtained a series of derivatives of the well-known fluorescent dye 7-nitrobenzo-2-oxa-1,3-diazole (NBD). According to the previous data [Denisov et al. (2014) Bioelectrochemistry, 98, 30-38], alkyl derivatives of NBD can uncouple isolated mitochondria at concentration of tens of micromoles despite a high pK_a value (~11) of the dissociating group. Here, a number of triphenylphosphonium (TPP) derivatives linked to NBD via hydrocarbon spacers of varying length (C5, C8, C10, and C12) were synthesized (mitoNBD analogues), which accumulated in the mitochondria in an energy-dependent manner. NBD-C10-TPP (C10-mitoNBD) acted as a protonophore in artificial lipid membranes (liposomes) and uncoupled isolated mitochondria at micromolar concentrations, while the derivative with a shorter linker (NBD-C5-TPP, or C5-mitoNBD) exhibited no such activities. In accordance with this data, C10-mitoNBD was significantly more efficient than C5-mitoNBD in suppressing the growth of Bacillus subtilis. C10-mitoNBD and C12-mitoNBD demonstrated the highest antibacterial activity among the investigated analogues. C10-mitoNBD also exhibited the neuroprotective effect in the rat model of traumatic brain injury.

Locoregional delivery of stem cell-based therapies

Interventional regenerative medicine (IRM) uses image-guided, minimally invasive procedures for the targeted delivery of stem cell-based therapies to regenerate, replace, or repair damaged organs. Although many cellular therapies have shown promise in the preclinical setting, clinical results have been suboptimal. Most intravenously delivered cells become trapped in the lungs and reticuloendothelial system, resulting in little therapy reaching target tissues. IRM aims to increase the efficacy of cell-based therapies by locoregional stem cell delivery via endovascular, endoluminal, or direct injection into tissues. This review highlights routes of delivery, disease states, and mechanisms of action involved in the targeted delivery of stem cells.

Canine Model for Selective and Superselective Cerebral Intra-Arterial Therapy Testing

PURPOSE

With advancing endovascular technology and increasing interest in minimally invasive intra-arterial therapies such as stem cell and chemotherapy for cerebral disease, the establishment of a translational model with cerebral circulation accessible to microcatheters is needed. We report our experience catheterizing canine cerebral circulation with microcatheters, present high-resolution angiographic images of the canine vascular anatomy, describe arterial branch flow patterns and provide measurements of canine arterial conduits.

MATERIALS AND METHODS

Angiograms were performed on 10 intact purpose-bred hounds. Angiography, measurements of arterial conduits and catheterization information for intracranial arterial branches were obtained.

RESULTS

Selective and superselective cerebral angiography was successful in all subjects. Relevant arterial mean diameters include the femoral (4.64 mm), aorta (9.38 mm), external carotid (3.65 mm), internal carotid arteries (1.6 mm), vertebrobasilar system and Circle of Willis branches. Catheterization of the Circle of Willis was achieved via the posterior circulation in all subjects tested (n=3) and the use of flow directed microcatheters resulted in reduced arterial tree deformation and improved superselection of intracranial vessels. Catheterization of the intracranial circulation was attempted but not achieved via the internal carotid artery (n=7) due to its tortuosity and subsequent catheter related vasospasm.

CONCLUSION

The canine cerebral vasculature is posterior circulation dominant. Anterior circulation angiography is achievable via the internal carotid artery, but direct cerebral arterial access is best achieved via the posterior circulation using flow-directed microcatheters. It is feasible to deliver intra-arterial therapies to selective vascular territories within the canine cerebral circulation, thus making it a viable animal model for testing novel intra-arterial cerebral treatments.

The Influence of Proinflammatory Factors on the Neuroprotective Efficiency of Multipotent Mesenchymal Stromal Cells in Traumatic Brain Injury

We studied the neuroprotective potential of multipotent mesenchymal stromal cells in traumatic brain injury and the effect of inflammatory preconditioning on neuroprotective properties of stem cells under in vitro conditions. To this end, the effects of cell incubation with LPS or their co-culturing with leukocytes on production of cytokines IL-1α, IL-6, TNFα, and MMP-2 and MMP-9 by these cells were evaluated. Culturing under conditions simulating inflammation increased the production of all these factors by multipotent mesenchymal stromal cells. However, acquisition of the inflammatory phenotype by stromal cells did not reduce their therapeutic effectiveness in traumatic brain injury. Moreover, in some variants of inflammatory preconditioning, multipotent mesenchymal stromal cells exhibited more pronounced neuroprotective properties reducing the volume of brain lesion and promoting recovery of neurological functions after traumatic brain injury.

Diosmin improved cognitive deficit and amplified brain electrical activity in the rat model of traumatic brain injury

OBJECTIVE

Traumatic brain injury (TBI) is one of the main causes of intellectual and cognitive disabilities in humans. Clinically, it is essential to limit the progress of cognitive impairment after TBI. It is reported that diosmin has a neuroprotective effect that can limit the progress of the impairment. The aim of this study was to evaluate the effects of diosmin on neurological score, memory, tumor necrosis factor-α (TNF-α) level and long-term potentiation in hippocampal dentate gyrus after the injury.

METHODS

A total of ninety six adult male Wistar rats were used as test subjects in this study. The animals were randomly assigned into one of the following three groups (n=32/group): Sham, TBI and diosmin (100mg/kg, p.o for seven consecutive days before TBI induction). TBI was induced into the animals by Marmarou's method. Briefly, a 200g weight was dropped from a 1m height through a free-falling tube onto the head of the anesthetized rats.

RESULTS

The veterinary coma scale scores, memory and long-term potentiation in TBI group showed significant decrease at different times after the onset of TBI when compared with Sham (p<0.001). The TNF-α level in the hippocampus of the TBI group of animals was significantly higher than that found in the test subjects from the Sham group (p<0.001). The pre-treatment of the TBI group with diosmin significantly improved their neurological scores, memory and long-term potentiation (p<0.001) when compared with the TBI group. The TNF-α level in hippocampus of the diosmin group was significantly lower than the TBI group (p<0.001).

CONCLUSION

Based on the results of the present study, pre-treatment with diosmin has protective effects against TBI-induced memory and long-term potentiation impairment. The effects of diosmin may be mediated through a decrement in the TNF-α concentration of hippocampus as a pro-inflammatory cytokine.

Real-time MRI for precise and predictable intra-arterial stem cell delivery to the central nervous system

Stem cell therapy for neurological disorders reached a pivotal point when the efficacy of several cell types was demonstrated in small animal models. Translation of stem cell therapy is contingent upon overcoming the challenge of effective cell delivery to the human brain, which has a volume ∼1000 times larger than that of the mouse. Intra-arterial injection can achieve a broad, global, but also on-demand spatially targeted biodistribution; however, its utility has been limited by unpredictable cell destination and homing as dictated by the vascular territory, as well as by safety concerns. We show here that high-speed MRI can be used to visualize the intravascular distribution of a superparamagnetic iron oxide contrast agent and can thus be used to accurately predict the distribution of intra-arterial administered stem cells. Moreover, high-speed MRI enables the real-time visualization of cell homing, providing the opportunity for immediate intervention in the case of undesired biodistribution.

Preclinical progenitor cell therapy in traumatic brain injury: a meta-analysis

BACKGROUND

No treatment is available to reverse injury associated with traumatic brain injury (TBI). Progenitor cell therapies show promise in both preclinical and clinical studies. We conducted a meta-analysis of preclinical studies using progenitor cells to treat TBI.

METHODS

EMBASE, MEDLINE, Cochrane Review, Biosis, and Google Scholar were searched for articles using prespecified search strategies. Studies meeting inclusion criteria underwent data extraction. Analysis was performed using Review Manager 5.3 according to a fixed-effects model, and all studies underwent quality scoring.

RESULTS

Of 430 abstracts identified, 38 met inclusion criteria and underwent analysis. Average quality score was 4.32 of 8 possible points. No study achieved a perfect score. Lesion volume (LV) and neurologic severity score (NSS) outcomes favored cell treatment with standard mean difference (SMD) of 0.86 (95% CI: 0.64-1.09) and 1.36 (95% CI: 1.11-1.60), respectively. Rotarod and Morris water maze outcomes also favored treatment with improvements in SMD of 0.34 (95% CI: 0.02-0.65) and 0.46 (95% CI: 0.17-74), respectively. Although LV and NSS were robust to publication bias assessments, rotarod and Morris water maze tests were not. Heterogeneity (I²) ranged from 74%-85% among the analyses, indicating a high amount of heterogeneity among studies. Precision as a function of quality score showed a statistically significant increase in the size of the confidence interval as quality improved.

CONCLUSIONS

Our meta-analysis study reveals an overall positive effect of progenitor cell therapies on LV and NSS with a trend toward improved motor function and spatial learning in different TBI animal models.

The Use of Technetium-99m for Intravital Tracing of Transplanted Multipotent Stromal Cells

We studied the possibility of in vivo tracing of multipotent mesenchymal stromal cells labeled with a radiophermaceutic preparation based on metastable isotope Technetium-99m and injected to rats with modeled traumatic brain injury. Accumulation of labeled cells occurred primarily in the liver and lungs. The cells distribution in internal organs greatly varied depending on the administration route. Cell injection into the carotid artery led to their significant accumulation in the damaged brain hemisphere, while intravenous injection was followed by diffuse cell distribution in all brain structures. Scintigraphy data were confirmed by magnetic resonance imaging and histological staining of cells. Visualization of stem cells labeled with Technetium-99m-based preparation by scintigraphy is an objective and highly informative method allowing real-time in vivo cell tracing in the body.

Microcirculatory Response In Vivo on Local Intraarterial Infusion of Autogenic Adipose-derived Stem Cells or Stromal Vascular Fraction

Both adipose-derived stem cells (ASCs) and stromal vascular fraction (SVF) have been demonstrated to have regenerative properties with therapeutic potential for numerous diseases through local or topical applications. However, it is unclear whether ASC or SVF can be delivered systemically through an intra-arterial infusion. The purpose of this study was to examine the microcirculatory response in vivo on local intraarterial infusion of autogenic ASCs or SVF in a vascular pedicle isolated rat cremaster microcirculation model.

MATERIALS AND METHODS

Fat tissue was surgically harvested from the flanks of male Sprague-Dawley rats (n = 12) and processed for SVF isolation. Some SVF samples were cultured for 24 hours for ASC purification. The autogenic SVF (1 × 105) cells (n = 6) or purified ASC (1 × 105) cells (n = 6) cells were infused into the microcirculation of cremaster muscle at a speed of 0.05 mL/min through the cannulation of femoral artery. As this is a vascular pedicle isolated preparation, the infused SVF or ASC cells went nowhere but the cremaster muscle. The video image of the microcirculation was monitored in real time during infusion.

RESULTS

Arteriole diameter was measured as A1 (100-160 µm), A2 (40-80 µm), and A3/A4 (10-30 µm). Capillary perfusion was quantified in 18 capillary fields of each muscle. There was a significant increase in the diameter of terminal arterioles (P = 0.049) and the capillary density (P = 0.02) after ASC intraarterial infusion. However, a significant cell aggregation, embolisms, and arterial obstruction were observed in the microcirculation in every case during SVF infusion.

CONCLUSIONS

Intraarterial infusion is an appropriate route for the delivery of autogenic ASCs, but not of SVF. SVF-induced microembolisms were the reason for narrowing or blocking the lumen of terminal arterioles, resulting in no flow in the corresponding capillaries.