Effects of platelet-rich plasma on the memory impairment, apoptosis, and hippocampal synaptic plasticity in a rat model of hepatic encephalopathy

Combination Therapy with Platelet-Rich Plasma and Epidermal Neural Crest Stem Cells Increases Treatment Efficacy in Vascular Dementia

This study aimed to evaluate the efficacy and treatment mechanism of platelet-rich plasma (PRP) and neural crest-derived epidermal stem cells (ESCs) in their administration alone and combination in vascular dementia (VaD) model by two-vessel occlusion (2VO). Methods. Sixty-six rats were divided into six groups: the control, sham, 2VO + vehicle, 2VO + PRP, 2VO + ESC, and 2VO + ESC + PRP. The treated groups received 1 million cells on days 4, 14, and 21 with or without 500 µl PRP (twice a week) after 2VO. The memory performance and anxiety were evaluated by behavioral tests including open field, passive avoidance, and Morris water maze. The basal-synaptic transmission (BST) and long-term potentiation (LTP) were assessed through field-potential recordings of the CA1. The mRNA expression levels of IGF-1, TGF-β1, PSD-95, and GSk-3β were measured in the rat hippocampus by quantitative reverse transcription polymerase chain reaction. Results. The results demonstrated impaired learning, memory, and synaptic plasticity in the 2VO rats, along with a significant decrease in the expression of IGF-1, TGF-β1, PSD-95, and upregulation of GSK-3β. Treatment with ESC alone and ESC + PRP showed similar improvements in spatial memory and LTP induction, with associated upregulation of PSD-95 and downregulation of GSK-3β. However, only the ESC + PRP group showed recovery in BST. Furthermore, combination therapy was more effective than PRP monotherapy for LTP and memory. Conclusions. The transplantation of ESC showed better effects than PRP alone, and combination therapy increased the treatment efficacy with the recovery of BST. This finding may be a clue for the combination therapy of ESC and PRP for VaD.

Platelet-rich Plasma Improves Radiotherapy-induced Emotional Disorder and Cognitive Dysfunction, Neuroinflammation in Aged Rats by Inhibiting the Activation of NLRP3 Inflammasomes

Although radiotherapy (RT) is the preferred treatment for elderly patients with brain tumors, certain negative effects can't be ignored. Fortunately, platelet-rich plasma (PRP) presents with a promising potential for the treatment of neurological diseases. Therefore, this study aimed to explore the effect of PRP on neuroinflammation, emotional disorder and cognitive dysfunction induced by RT in aged rats. Firstly, whole brain RT (WBRT) model was established by whole brain irradiation with 10 Gy of 6-MeV electron beam in rats. Next, twenty 20-month-old female SD rats were divided into four groups (sham group, PRP group, WBRT group, and WBRT + PRP group) according different treatments. After that, the cognitive dysfunction and depression-like behavior of rats were examined by novel object recognition test (NORT), Morris water maze test (MWM), open field test (OFT) and elevated plus maze test (EPM). Besides, immunohistochemistry was used to detect the expression of microglial marker protein Iba-1 in rat hippocampus; enzyme linked immunosorbent assay (ELISA) to examine the levels of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 beta (IL-1β), IL-18, and monocyte chemoattractant protein 1 (MCP-1) in rat hippocampus; real-time quantitative reverse transcription PCR (qRT-PCR) and western blot to measure the levels of neurotrophic factors brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B receptor (TrkB), and nerve growth factor (NGF) in rat hippocampus; and western blot also to observe the protein expression levels of NOD-like receptor protein 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), and IL-1β in rat hippocampus. After experiments, some results obtained were shown as follows. PRP could significantly improve learning and memory ability and depression-like behavior, increase the level of neurotrophic factors, inhibit the activation of microglia and decrease the level of pro-inflammatory factors in WBRT rats. In addition, PRP significantly inhibited the activation of NLRP3 inflammasomes. To sum up, PRP can ameliorate neuroinflammation, emotional disorder and cognitive dysfunction induced by RT in aged rats, and the mechanism may be related to its inhibitory effect on NLRP3 inflammasome activation.

Overexpressing lnc240 Rescues Learning and Memory Dysfunction in Hepatic Encephalopathy Through miR-1264-5p/MEF2C Axis

Hepatic encephalopathy (HE) is a nervous system disease caused by severe liver diseases and different degrees of learning and memory dysfunction. Long non-coding RNA (lncRNA) is highly expressed in the brain and plays important roles in central nervous system diseases like Alzheimer's disease. In the present work, we found that the expression of lnc240 in the hippocampus of HE mice was significantly downregulated, but its pathogenesis in HE has not been clarified. This study aimed to explore the effects of lnc240 on the cognitive function of HE. The expression of lnc240, miR-1264-5p, and MEF2C was analyzed with RNA-seq and further determined by qRT-PCR in HE mouse. Double luciferase reporter gene testing confirmed the relationship between lnc240, MEF2C, and miR-1264-5p. The functional role of lnc240 and MEF2C in vitro and in vivo was evaluated by qRT-PCR, western blot analysis, immunofluorescence staining, Golgi staining, electrophysiology, and Morris water maze. The expression of lnc240 was decreased in HE mice. The overexpression of lnc240 could significantly downregulate miR-1264-5p and upregulate MEF2C, also increasing the amplitude and frequency of mEPSC in primary cultured hippocampal neurons. The overexpression of miR-1264-5p reversed the effect of lnc240 on MEF2C. Moreover, in vivo experiments have shown that the overexpression of lnc240 could improve HE mice's spatial learning and memory functions. Golgi staining suggested that overexpression of lnc240 could increase the density and maturity of dendritic spines in hippocampal neurons of HE mice. Lnc240 can regulate the expression of MEF2C through miR-1264-5p and regulate the synaptic plasticity of hippocampal neurons, thereby saving the learning and memory dysfunction in HE mice, suggesting that lnc240 might be a potential therapeutic target for the treatment of HE.

Enriched environment ameliorates learning and memory deficits in hepatic encephalopathy mice by restoration of the structure of dendrites and dendritic spines

Cognitive impairment is one of the most common symptoms of hepatic encephalopathy (HE). However, there is a lack of easily implementable rehabilitation strategies. As an easy-to-implement strategy, numerous studies suggest that enriched environment (EE) can be beneficial for cognitive function. However, the effects of EE on learning and memory, as well as dendritic spines plasticity in HE is still unclear. Accordingly, in the present study, we evaluated the effects of EE on the behavior and dendritic spine morphology in an animal model of HE. Our results showed that HE mice have no movement disorder and anxiety, but they exhibit spatial learning and memory dysfunction. Further analysis revealed that the complexity of the dendrites and the maturity of the dendritic spines are reduced in the hippocampus of HE mice. After 4 weeks of housekeeping in EE, dendritic complexity, and dendritic spine maturity, as well as the spatial learning and memory function of HE mice were restored. In conclusion, exposure to EE can positively influence dendritic spines plasticity in the hippocampus and thereby elicit its beneficial effects on cognitive functions in HE.