Transplanted Neural Stem Cells: Playing a Neuroprotective Role by Ceruloplasmin in the Substantia Nigra of PD Model Rats?

Mechanisms and pharmacological applications of ferroptosis: a narrative review

Objective

We aimed at comprehensively analyzing ferroptosis regulation and its potential role in the treatment of associated diseases.

Background

Ferroptosis is a recently discovered form of cell death that involves small molecule-induced oxidative cell death. This process is usually accompanied by large amounts of iron accumulation and lipid peroxidation. Ferroptosis inducers directly or indirectly affect glutathione peroxidase (GPXs) through different pathways. Disturbances in GPXs result in suppressed cellular antioxidant capacities, accumulation of lipid reactive oxygen species (ROS) and oxidative cell death. It has been reported that ferroptosis is closely associated with the pathophysiological processes of many diseases, including tumors, nervous system diseases, ischemia-reperfusion injury, kidney injury and iron metabolism diseases among others.

Methods

First, we reviewed the mechanisms of ferroptosis, with emphasis on the characteristics and functions of ferroptosis in multiple pathways. Then, inducers and inhibitors of ferroptosis were reviewed, and their mechanisms of action elucidated. Finally, ferroptosis-associated pathophysiological processes of various diseases were reviewed.

Conclusions

Ferroptosis is associated with the occurrence and development of various diseases. Elucidation of the mechanisms involved in ferroptosis will inform new therapeutic targets and strategies for these diseases.

Role of Peripheral Immune Cells-Mediated Inflammation on the Process of Neurodegenerative Diseases

Neurodegenerative diseases are characterized by progressive loss of selectively vulnerable neuronal populations, which contrasts with selectively static loss of neurons due to toxic or metabolic disorders. The mechanisms underlying their progressive nature remain unknown. To date, a timely and well-controlled peripheral inflammatory reaction is verified to be essential for neurodegenerative diseases remission. The influence of peripheral inflammation on the central nervous system is closely related to immune cells activation in peripheral blood. The immune cells activation participated in the uncontrolled and prolonged inflammation that drives the chronic progression of neurodegenerative diseases. Thus, the dynamic modulation of this peripheral inflammatory reaction by interrupting the vicious cycle might become a disease-modifying therapeutic strategy for neurodegenerative diseases. This review focused on the role of peripheral immune cells on the pathological progression of neurodegenerative diseases.

Neural Stem Cell Transplantation Is Associated with Inhibition of Apoptosis, Bcl-xL Upregulation, and Recovery of Neurological Function in a Rat Model of Traumatic Brain Injury

Traumatic brain injury (TBI) is a common disease that usually causes severe neurological damage, and current treatment is far from satisfactory. The neuroprotective effects of neural stem cell (NSC) transplantation in the injured nervous system have largely been known, but the underlying mechanisms remain unclear, and their limited sources impede their clinical application. Here, we established a rat model of TBI by dropping a weight onto the cortical motor area of the brain and explored the effect of engrafted NSCs (passage 3, derived from the hippocampus of embryonic 12- to 14-d green fluorescent protein transgenic mice) on TBI rats. Moreover, RT-PCR and Western blotting were employed to investigate the possible mechanism associated with NSC grafts. We found rats with TBI exhibited a severe motor and equilibrium dysfunction, while NSC transplantation could partly improve the motor function and significantly reduce cell apoptosis and increase B-cell lymphoma–extra large (Bcl-xL) expression at 7 d postoperation. However, other genes including Bax, B-cell lymphoma 2, Fas ligand, and caspase3 did not exhibit significant differences in expression. Moreover, to test whether Bcl-xL could be used as a therapeutic target, herpes simplex virus (HSV) 1 carrying Bcl-xL recombinant was constructed and injected into the pericontusional cortices. Bcl-xL overexpression not only resulted in a significant improvement in neurological function but also inhibits cell apoptosis, as compared with the TBI rats, and exhibits the same effects as the administration of NSC. The present study therefore indicated that NSC transplantation could promote the recovery of TBI rats in a manner similar to that of Bcl-xL overexpression. Therefore, Bcl-xL overexpression, to some extent, could be considered as a useful strategy to replace NSC grafting in the treatment of TBI in future clinical practices.

[An improved method for stereotactic location of the supraoptic nucleus with oblique stereotactic puncture in rats]

OBJECTIVE

To establish an improved method for stereotactic location of the supraoptic nucleus in rats.

METHODS

Twenty-four SD rats were randomly divided into experimental group (12 rats) and control group (12 rats) for oblique (20° to the left) stereotactic puncture (OSP group) and vertical stereotactic puncture (VSP group), respectively, both targeting the supraoptic nucleus (SON). The surgical data and postoperative (within 24) mortality of the rats were compared between the two groups.

RESULTS

The nucleus locating time was longer in OSP group than in VSP group (59.55∓3.64s vs 27.44∓2.18 s, P=0.000), and the postoperative mortality rate of the rats did not differ significantly between the groups (0 vs 44.4%, P=0.082). In OSP group, compared with VSP group, the procedure was associated with a lowered rupture rate of the superior sagittal sinus (11.1% vs 88.9%, P=0.003), a shortened hemostatic time after craniotomy (52.89∓24.05 s vs 157.445 ime a s, P=0.000) and after puncture (24.33 reas 45 s vs 133.89∓28.81 s, P=0.000), and also a shortened operation time (178.89 on tims vs 362.44 timees, P=0.000).

CONCLUSION

The improved method for locating supraoptic nucleus in rats is convenient, stable and reproducible, and helps to avoid important blood vessels and specific nuclei according to the needs of different experiments and allows the operators to choose different surgical paths.

Fasudil Enhances Therapeutic Efficacy of Neural Stem Cells in the Mouse Model of MPTP-Induced Parkinson's Disease

Bone marrow-derived neural stem cells (NSCs) are ideal cells for cellular therapy because of their therapeutic potential for repairing and regenerating damaged neurons. However, the optimization of implanted cells and the improvement of microenvironment in the central nervous system (CNS) are still two critical elements for enhancing therapeutic effect. In the current study, we observed the combined therapeutic effect of NSCs with fasudil in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mouse model and explored the possible cellular and molecular mechanisms. The results clearly show that combined treatment of NSCs with fasudil further improves motor capacity of PD mice, thus exerting double effect in treating MPTP-PD. The combined intervention more effectively protected dopaminergic (DA) neurons from loss in the substantia nigra pars compacta (SNpc), which may be associated with the increased number and survival of transplanted NSCs in the brain. Compared with the treatment of fasudil or NSCs alone, the combined intervention more effectively inhibited the activation and aggregation of microglia and astrocytes, displayed stronger anti-inflammatory and antioxidant effects, induced more neurotrophic factor NT-3, and affected the dynamic homeostasis of NMDA and AMPA receptors in MPTP-PD mice. Our study demonstrates that intranasal administration of NSCs, followed by fasudil administration, is a promising cell-based therapy for neuronal lesions.

Oxidative damage of copper chloride overload to the cultured rat astrocytes

Disorders of copper metabolism are associated with neurological dysfunction including Wilson's disease (WD). WD is a autosomal recessive disorder caused by mutations in the ATP7B gene resulting in the inability of the hepatocytes to remove excess copper. Gradual copper accumulation causes damage to liver, brain and other organs manifesting in liver disease, neurological and psychiatric symptoms. Also scond copper-neurometaboic disorder: Menkes disease charaterized with mutated ATP7A gene, is ralated with abnormally neuroal transmission and synaptogenesis. Parkinson's disease and Alzheimer's disease both are refered to some degree of copper/iron metabolism changes. The precise mechanisms by which excess copper causes neurological damage remain to be elucidated. In this study, we aimed to investigate the influence of excessive amounts of Cu(2+) on the oxidative damage response and survival of primary astrocytes from newborn rats. Primary cultured rat astrocytes were divided into three groups: 30 μmol/L CuCl2, 100 μmol/L CuCl2 and control. At 12, 24, 48, 96 and 120 hours of CuCl2 intervention, cell viability, intracellular reduced glutathione level and glutathion reductase activity, and nitric oxide secretion were determined. It was found that 30 μmol/L CuCl2 might stimulate the exaltation and the compensatory proliferation of astrocytes. The survival rate of astrocytes in the 100 μmol/L CuCl2 group was significantly decreased relative to the 30 μmol/L CuCl2 group. At 24 hours of CuCl2 intervention, intracellular reduced glutathione level and glutathion reductase activity were significantly decreased in the 100 μmol/L CuCl2 group compared to the control group. At 120 hours of CuCl2 intervention, nitric oxide secretion in the 100 μmol/L CuCl2 group was significantly greater than in the control group. Under pathological conditions, excessive amounts of Cu(2+) greatly damaged the growth and proliferation of astrocytes, reduced the anti-oxidative capacity of astrocytes by reducing intracellular glutathione level and glutathion reductase activity, worsened oxidative stress, and activated inflammation pathway by increasing nitric oxide secretion. By the way, all these findings might provide potential molecular therapeutic targets for the neurodegenerative diseases related Cu(2+) Metabolic Disorders, e.g., Wilson's disease, Parkinson's disease and Alzheimer's disease.

Effects of electroacupuncture on cognitive function in rats with Parkinson's disease

This study was designed to illustrate the effects of electroacupuncture on cognitive function in rats with Parkinson's disease (PD). The PD model was established by injecting 6-OHDA into the rat brain. Rats with PD were then subjected to electroacupuncture and levodopa treatment for 2 weeks. The level of choline acetyltransferase (ChAT) activity in rat brain homogenates was assessed, for the cerebral cholinergic system is a major chemical pathway consisting of cognitive functions. Immunohistochemistry was applied to observe ChAT expression in the rat hippocampus and corpus striatum. The effects of electroacupuncture on cognitive function were comprehensively assessed in PD rats using Y-maze test. Compared with model control group, electroacupuncture group were apparently improved in learning & memory abilities, and ChAT activity was elevated, and apoptosis was reduced in the rat hippocampus and corpus striatum. No significant differences in learning & memory abilities and ChAT activity were detected between electroacupuncture and levodopa groups. Electroacupuncture remarkably improved cognition in PD rats, and its mechanisms are possibly associated with protecting cholinergic neurons in the central nervous system and elevating ChAT activity, and also might suitable dosage of levodopa protect physiologically the cognitive function in PD rats.