Effects of rehabilitation training on apoptosis of nerve cells and the recovery of neural and motor functions in rats with ischemic stroke through the PI3K/Akt and Nrf2/ARE signaling pathways

Better rehabilitation using these methods, but nothing will occur for stroke survivors since we have NO stroke strategy to update and NO stroke leadership to drive that strategy.
http://www.sciencedirect.com/science/article/pii/S0361923017302381

• Xiao-Fei Jin^{a, 1},
• Shan Wang^{b, 1},
• Min Shen^{b, 1},
• Xin Wen^b,
• Xin-Rui Han^b,
• Jun-Chang Wu^c,
• Gao-Zhuo Tang^c,
• Dong-Mei Wu^{b, ,} ,
• Jun Lu^{b, ,} ,
• Yuan-Lin Zheng^{b, ,}

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https://doi.org/10.1016/j.brainresbull.2017.08.011

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Highlights

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Rehabilitation training reduced apoptosis of hippocampal neurons.

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Rehabilitation training activated PI3K/Akt and Nrf2/ARE signaling pathways.

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Activated PI3K/Akt and Nrf2/ARE pathways improved neural and motor functions.

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Activated PI3K/Akt and Nrf2/ARE pathways reduced apoptosis of hippocampal neurons.

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Rehabilitation training is an effective treatment for neural deficits.

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Abstract

This study was designed in order to investigate the effects between rehabilitation training on the apoptosis of nerve cells and the recovery of neural and motor functions of rats with ischemic stroke by way of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and nuclear factor E2-related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathways. In total, 110 healthy adult male Sprague-Dawley (SD) rats were selected in order to take part in this study. Ninety SD rats were used in order to establish the middle cerebral artery occlusion (MCAO), among which 80 rats were randomly assigned as part of the natural recovery, natural recovery + Rp-PI3K (the rats injected with PI3K/Akt inhibitor LY294002), rehabilitation training, and rehabilitation training + Rp-PI3K groups. Meanwhile, 20 rats were selected as part of the sham operation group. The neural and motor functions of these rats were evaluated using a balance beam test and the Bederson score. The mRNA expressions of PI3K, Akt, Nrf2 and HO-1 were measured using an RT-qPCR. The protein expressions of PI3K, p-PI3K, Akt, p-Akt, Nrf2 and HO-1 were also detected by using western blotting and the immunohistochemistry process. The cell cycle and cell apoptosis were detected by using a flow cytometry and TUNEL assay. The sham operation group exhibited lower neural and motor function scores than other groups. At the 7, 14, and 21 d marks of this study, the neural and motor function scores were increased in the natural recovery, natural recovery + Rp-PI3K, and rehabilitation training + Rp-PI3K groups in comparison with the rehabilitation training group but found to be decreased in the natural recovery group in comparison with the natural recovery + Rp-PI3K group. In comparison with the sham operation group, expressions of PI3K, Nrf2 and HO-1, and proportions of p-PI3 K/PI3 K and p-Akt/Akt were all higher in the natural recovery, rehabilitation training, and rehabilitation training + Rp-PI3K groups. Same trends were found in the rehabilitation training group in comparison with the natural recovery and rehabilitation training + Rp-PI3K groups, as well as in the natural recovery group in comparison with the natural recovery + Rp-PI3K group. In comparison with the sham operation and rehabilitation training groups, hippocampal nerve cells at G1 phase and the cells apoptosis were both elevated in the other three groups which were found to be decreased in the natural recovery group in comparison with the natural recovery + Rp-PI3K group. Our results indicated that the rehabilitation training can inhibit the apoptosis of nerve cells as well as promote the recovery of both neural and motor functions in rats with ischemic stroke by activation of the PI3K/Akt and Nrf2/ARE signaling pathways.

Direct Stimulation of Adult Neural Stem/Progenitor Cells In Vitro and Neurogenesis In Vivo by Salvianolic Acid B

Some actual TCM research. 

Direct Stimulation of Adult Neural Stem/Progenitor Cells In Vitro and Neurogenesis In Vivo by Salvianolic Acid B

Introduction Top

Ischemic brain damage is one of the most dangerous ailments that lead to learning and memory disability, physical dysfunction and even death. Up to now, no effective treatment has been reported [1]. Neurons as terminally differentiated cells cannot regenerate after injury in traditional view. However, appropriate exercise training can facilitate some neurological function recovery after stroke in clinical practice [2], [3], with the evidence that neurogenesis occurs in the adult brain. Neural stem/precursor cells (NSPCs) had been found and confirmed in adult brain in past decades that it can differentiate into neurons or glial cells as a result of neurogenesis [4]–[7], NSPCs can be stimulated in several pathological conditions, such as neurological diseases, cerebral ischemic in adult brain, and many reports showed that they are an excellent candidate for developing therapeutic strategies to repair the injured CNS [8], [9]. Although the NSPCs would be stimulated to proliferation and differentiation during the brain injury, often this response is not sufficient to overcome the damage. It is essential to study the signalling mechanisms that are activated by small molecular materials in the NSPCs to enhance their response pharmacologically. NSPCs proliferation and neurogensis involves a series of intracellular signaling pathways [10], [11]. Among these pathways, the activation of Notch, mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase (PI3K)/Akt pathways are known to play major roles in cell growth and survival responses [12]–[14]. Numerous studies have shown that small molecular materials such as growth factors [15], retinoic acid [16] and Traditional Chinese Medicine (TCM) active constituent [17], [18] can regulate the biological characteristics of neural stem cell and promote neurogenesis. Therefore, regulation of neurogenesis by NSPCs is anticipated as a noble therapeutic strategy for brain damage.
Herbs have been used for treating diseases for centuries, and a lot of natural compounds that with neural beneficial from medicinal plants had been discovered [19]. Treatment of stroke by TCM has a wealth of clinical experience and theoretical basis, and a large number of effective clinical prescriptions have been accumulated. In recent years a large number of studies have shown that TCM prescription and its active ingredient can improve cerebral ischemic injury in experimental animal [20], [21]. Ginsenoside Rb1 and Rg1, for example, improved spatial learning and increase hippocampal synaptophysin level in mice [22]. Curcumin had been demonstrated to stimulate developmental and adult hippocampal neurogenesis, and a biological activity that may enhance neural plasticity and repair [23]. A recent report has shown that NeuroAid (MLC601 and MLC901), a Traditional Chinese Medicine is used in China for patients after stroke, reduced the increase in escape latency and in swim distance induced by ischemia [24]. With an extensive clinical experience, there are ample opportunities to discover natural compounds that effectively promote the proliferation of NSPCs and neurogenesis from TCM.

Results Top

Salvianolic acid B induced the proliferation of cultured NSPCs in vitro

Forty-five herbal compounds, which are extensively used clinically for treating stroke in China, were screened in an in vitro proliferation assay to identify compounds that could induce proliferation of NSPCs. As shown in Fig. 1, among these natural compounds screened, berberine and Sal B displayed marked activity promoting NSPCs proliferation. In the following study, the proliferative effect of berberine and Sal B were systematically investigated but the action of berberine was proved to be an illusion by BrdU incorporation assay (See Figure S1 in the Supporting Information).
To study the proliferation-inducing effect of Sal B in detail, we investigated effects of Sal B on the viability of NSPCs in vitro using the MTS assay, NSPCs were treated with Sal B at different concentrations and for different durations. We investigated Sal B at 5, 10, 20, 30, 40, 50 µM dose exposure for 24 hours, and at 20 µM dose incubated for 24, 48, 72 hours on promoting NSPCs proliferation. The results showed that the viability of NSPCs significantly increased as the dose (P<0.01, F_{(6, 35)} = 103.06) and time increases (P<0.01, Fig. 2A–B). The number and size of neurospheres were increased by addition of 20 µM of Sal B (Figure 2C–D). These results suggested that Sal B significantly increased the viability of NSPCs in dose- and time- dependent manners.