Role and limitation of cell therapy in treating neurological diseases

Abstract

The central role of the brain in governing systemic functions within human physiology underscores its paramount significance as the focal point of physiological regulation. The brain, a highly sophisticated organ, orchestrates a diverse array of physiological processes encompassing motor control, sensory perception, cognition, emotion, and the regulation of vital functions, such as heartbeat, respiration, and hormonal equilibrium. A notable attribute of neurological diseases manifests as the depletion of neurons and the occurrence of tissue necrosis subsequent to injury. The transplantation of neural stem cells (NSCs) into the brain exhibits the potential for the replacement of lost neurons and the reconstruction of neural circuits. Furthermore, the transplantation of other types of cells in alternative locations can secrete nutritional factors that indirectly contribute to the restoration of nervous system equilibrium and the mitigation of neural inflammation. This review summarized a comprehensive investigation into the role of NSCs, hematopoietic stem cells, mesenchymal stem cells, and support cells like astrocytes and microglia in alleviating neurological deficits after cell infusion. Moreover, a thorough assessment was undertaken to discuss extant constraints in cellular transplantation therapies, concurrently delineating indispensable model-based methodologies, specifically on organoids, which were essential for guiding prospective research initiatives in this specialized field.

Keywords: cell therapy; mechanism; neurological diseases; organoids.

Figure 1

NSCs differentiate into neurons to supplement the neurons lost in the brain due to diseases, oligodendrocytes to encapsulate neurons and prevent abnormal neuronal discharge, and astrocytes, providing both nutrition and structural support for neurons. NSC, neural stem cell. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 2

The mechanism involved in MSC transplantation for treating neurological diseases. MSCs release anti‐inflammatory factors to reduce abnormal activation of microglia and restore them to a resting state. They provide nutritional factors for astrocytes and neurons to reduce neuronal death. MSC, mesenchymal stem cell. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 3

The mechanism involved in astrocyte transplantation for treating neurological diseases. Astrocytes provide nutrients and structural support to neurons and rescue them from death. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 4

Mechanisms of transplanted microglia in addressing neurological diseases. The drug inhibits abnormal activation of microglia in the host's brain, while brain transplantation supplements healthy microglia. Microglia maintain brain homeostasis after self‐renewal. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 5

HSCs transplantation in neurological disease treatment. After HSCs transplantation, differentiation into microglia can migrate and colonize the brain to maintain neural homeostasis. HSC, hematopoietic stem cell. [Color figure can be viewed at wileyonlinelibrary.com]