Combined intramuscular and intraspinal transplant of bone marrow cells improves neuromuscular function in the SOD1G93A mice

Schwann cell JUN expression worsens motor performance in an amyotrophic lateral sclerosis mouse model

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease characterized by motor neuron death and distal axonopathy. Despite its clinical severity and profound impact in the patients and their families, many questions about its pathogenesis remain still unclear, including the role of Schwann cells and axon-glial signaling in disease progression. Upon axonal injury, upregulation of JUN transcription factor promotes Schwann cell reprogramming into a repair phenotype that favors axon regrowth and neuronal survival. To study the potential role of repair Schwann cells on motoneuron survival in amyotrophic lateral sclerosis, we generated a mouse line that over-expresses JUN in the Schwann cells of the SOD1G93A mutant, a mouse model of this disease. Then, we explored disease progression by evaluating survival, motor performance and histology of peripheral nerves and spinal cord of these mice. We found that Schwann cell JUN overexpression does not prevent axon degeneration neither motor neuron death in the SOD1G93A mice. Instead, it induces a partial demyelination of medium and large size axons, worsening motor performance and resulting in more aggressive disease phenotype.

Adipose mesenchymal stem cells-derived extracellular vesicles exert their preferential action in damaged central sites of SOD1 mice rather than peripherally

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder involving motor neuron (MN) loss in the motor cortex, brainstem and spinal cord leading to progressive paralysis and death. Due to the pathogenetic complexity, there are no effective therapies available. In this context the use of mesenchymal stem cells and their vesicular counterpart is an emerging therapeutic strategy to counteract neurodegeneration. The extracellular vesicles derived from adipose stem cells (ASC-EVs) recapitulate and ameliorate the neuroprotective effect of stem cells and, thanks to their small dimensions, makes their use suitable to develop novel therapeutic approaches for neurodegenerative diseases as ALS. Here we investigate a therapeutic regimen of ASC-EVs injection in SOD1(G93A) mice, the most widely used murine model of ALS. Repeated intranasal administrations of high doses of ASC-EVs were able to ameliorate motor performance of injected SOD1(G93A) mice at the early stage of the disease and produce a significant improvement at the end-stage in the lumbar MNs rescue. Moreover, ASC-EVs preserve the structure of neuromuscular junction without counteracting the muscle atrophy. The results indicate that the intranasal ASC-EVs administration acts in central nervous system sites rather than at peripheral level in SOD1(G93A) mice. These considerations allow us to identify future applications of ASC-EVs that involve different targets simultaneously to maximize the clinical and neuropathological outcomes in ALS in vivo models.

A "messenger zone hypothesis" based on the visual three-dimensional spatial distribution of motoneurons innervating deep limb muscles

JOURNAL/nrgr/04.03/01300535-202407000-00036/figure1/v/2023-11-20T171125Z/r/image-tiff

Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneurons. However, current research on the spatial location of the spinal motoneurons innervating different muscles is limited. In this study, we investigated the spatial distribution and relative position of different motoneurons that control the deep muscles of the mouse hindlimbs, which were innervated by the obturator nerve, femoral nerve, inferior gluteal nerve, deep peroneal nerve, and tibial nerve. Locations were visualized by combining a multiplex retrograde tracking technique compatible with three-dimensional imaging of solvent-cleared organs (3DISCO) and 3-D imaging technology based on lightsheet fluorescence microscopy (LSFM). Additionally, we propose the hypothesis that “messenger zones” exist as interlaced areas between the motoneuron pools that dominate the synergistic or antagonist muscle groups. We hypothesize that these interlaced neurons may participate in muscle coordination as messenger neurons. Analysis revealed the precise mutual positional relationships among the many motoneurons that innervate different deep muscles of the mouse. Not only do these findings update and supplement our knowledge regarding the overall spatial layout of spinal motoneurons that control mouse limb muscles, but they also provide insights into the mechanisms through which muscle activity is coordinated and the architecture of motor circuits.

In situ Reprogramming as a Pro-Angiogenic Inducer to Rescue Ischemic Tissues

Background

Enhanced regenerative therapeutic strategies are required to treat intractable ischemic heart disease.

Summary

Since the discovery of putative endothelial progenitor cells (EPCs) in 1997, many studies have focused on their extraction, ex vivo processing, and autotransplantation under ischemic conditions. Nonetheless, numerous randomized clinical trials involving thousands of patients have yielded only marginal treatment effects, highlighting the need for advances regarding insufficient dosage and complex ex vivo processing. The prevailing paradigm of cellular differentiation highlights the potential of direct cellular reprogramming, which paves the way for in situ reprogramming. In situ reprogramming holds the promise of significantly enhancing current therapeutic strategies, yet its success hinges on the precise targeting of candidate cells for reprogramming. In this context, the spleen emerges as a pivotal "in situ reprogramming hub," owing to its dual function as both a principal site for nanoparticle distribution and a significant reservoir of putative EPCs. The in situ reprogramming of splenic EPCs offers a potential solution to overcome critical challenges, including the aforementioned insufficient dosage and complex ex vivo processing.

Key Messages

This review explores the latest advancements in EPC therapy and in situ reprogramming, spotlighting a pioneering study that integrates those two strategies with a specific focus on the spleen. Such an innovative approach will potentially herald a new era of regenerative therapy for ischemic heart disease.

Current Status of Mesenchymal Stem/Stromal Cells for Treatment of Neurological Diseases

Neurological disorders include a wide spectrum of clinical conditions affecting the central and peripheral nervous systems. For these conditions, which affect hundreds of millions of people worldwide, generally limited or no treatments are available, and cell-based therapies have been intensively investigated in preclinical and clinical studies. Among the available cell types, mesenchymal stem/stromal cells (MSCs) have been widely studied but as yet no cell-based treatment exists for neurological disease. We review current knowledge of the therapeutic potential of MSC-based therapies for neurological diseases, as well as possible mechanisms of action that may be explored to hasten the development of new and effective treatments. We also discuss the challenges for culture conditions, quality control, and the development of potency tests, aiming to generate more efficient cell therapy products for neurological disorders.

Rosuvastatin enhanced functional recovery after sciatic nerve injury in the rat

Posttraumatic nerve recovery remains a challenge in regenerative medicine. As such, there is a need for agents that limit nerve damage and enhance nerve regeneration. Here we investigate rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase inhibitor, with anti-inflammatory and antioxidant properties. We explore its neuroprotective properties on sciatic nerve crush injury in male Wistar Rats. Rats were subjected to crush injury to the left sciatic nerve using a vessel clamp for 30 s. Rosuvastatin or vehicle was prepared daily and administrated by oral gavage for seven days post-injury. In rosuvastatin treatment groups, rosuvastatin was administrated at the doses of (5 or 10 mg/kg) in the treatment group. The control group was given a vehicle in the same manner. Behavioral, electrophysiological, morphological and molecular parameters were examined during the recovery process. Chronic administration of rosuvastatin at all doses after sciatic nerve crush markedly promoted nerve regeneration and significantly accelerated motor function recovery (P < 0.05). Electrophysiological, morphological and molecular parameters also improved in the rosuvastatin treatment groups compared to the controls. These findings suggest that neuroprotective effects of rosuvastatin could be due to its antioxidant and anti-inflammatory activity. It is clear that more research is needed to confirm these findings.

ASC-Exosomes Ameliorate the Disease Progression in SOD1(G93A) Murine Model Underlining Their Potential Therapeutic Use in Human ALS

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motoneurons. To date, there is no effective treatment available. Exosomes are extracellular vesicles that play important roles in intercellular communication, recapitulating the effect of origin cells. In this study, we tested the potential neuroprotective effect of exosomes isolated from adipose-derived stem cells (ASC-exosomes) on the in vivo model most widely used to study ALS, the human SOD1 gene with a G93A mutation (SOD1(G93A)) mouse. Moreover, we compared the effect of two different routes of exosomes administration, intravenous and intranasal. The effect of exosomes administration on disease progression was monitored by motor tests and analysis of lumbar motoneurons and glial cells, neuromuscular junction, and muscle. Our results demonstrated that repeated administration of ASC-exosomes improved the motor performance; protected lumbar motoneurons, the neuromuscular junction, and muscle; and decreased the glial cells activation in treated SOD1(G93A) mice. Moreover, exosomes have the ability to home to lesioned ALS regions of the animal brain. These data contribute by providing additional knowledge for the promising use of ASC-exosomes as a therapy in human ALS.