11ß-HSD1 participates in epileptogenesis and the associated cognitive impairment by inhibiting apoptosis in mice.

BACKGROUND: Glucocorticoid signalling is closely related to both epilepsy and associated cognitive impairment, possibly through mechanisms involving neuronal apoptosis. As a critical enzyme for glucocorticoid action, the role of 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1) in epileptogenesis and associated cognitive impairment has not previously been studied. METHODS: We first investigated the expression of 11ß-HSD1 in the pentylenetetrazole (PTZ) kindling mouse model of epilepsy. We then observed the effect of overexpressing 11ß-HSD1 on the excitability of primary cultured neurons in vitro using whole-cell patch clamp recordings. Further, we assessed the effects of adeno-associated virus (AAV)-induced hippocampal 11ß-HSD1 knockdown in the PTZ model, conducting behavioural observations of seizures, assessment of spatial learning and memory using the Morris water maze, and biochemical and histopathological analyses. RESULTS: We found that 11ß-HSD1 was primarily expressed in neurons but not astrocytes, and its expression was significantly (p < 0.05) increased in the hippocampus of PTZ epilepsy mice compared to sham controls. Whole-cell patch clamp recordings showed that overexpression of 11ß-HSD1 significantly decreased the threshold voltage while increasing the frequency of action potential firing in cultured hippocampal neurons. Hippocampal knockdown of 11ß-HSD1 significantly reduced the severity score of PTZ seizures and increased the latent period required to reach the fully kindled state compared to control knockdown. Knockdown of 11ß-HSD1 also significantly mitigated the impairment of spatial learning and memory, attenuated hippocampal neuronal damage and increased the ratio of Bcl-2/Bax, while decreasing the expression of cleaved caspase-3. CONCLUSIONS: 11ß-HSD1 participates in the pathogenesis of both epilepsy and the associated cognitive impairment by elevating neuronal excitability and contributing to apoptosis and subsequent hippocampal neuronal damage. Inhibition of 11ß-HSD1, therefore, represents a promising strategy to treat epilepsy and cognitive comorbidity.

Research progress of fibroblast growth factor in nervous system diseases.

Fibroblast growth factors (FGF) are a group of structurally related polypeptides which constitute an elaborate signaling system with their receptors. Evidence accumulated in the years suggests that the FGF family plays a key role in the repair of central nervous system injury. The main protective mechanisms include activating the expression of PI3K-Akt, peroxisome proliferator-activated receptor (PPARγ) and other signals; inhibiting NF-κB-mediated inflammatory response, oxidative stress and apoptosis; regulating neuronal differentiation and neuronal excitability as well as participating in protection of neurovascular units and nerve function repair. This paper comprehensively summarizes the latest research progress in FGF signaling related to diseases of the central nervous system such as cerebral infarction, cerebral hemorrhage, traumatic brain injury, Alzheimer's disease, Parkinson's disease, epilepsy and depression, aiming to provide scientific basis and reference for the development of innovative FGF drugs for the prevention and treatment of neurological diseases.