The Effects Of Nourishing Spleen Yin Recipe On Endoplasmic Reticulum Stress In Different Brain Areas Of Spleen-Yin Deficiency Alzheimer's Disease Model Rats

Objective: Alzheimer's disease(AD), also called aged dementia, is a common disease of neurodegenerative disorders in the central nervous system, the clinical symptoms of which are the progressive decline of memory, congnition and the alteration of behavior. AD is characterized neuropathologically by the appearance of extracellular amyloid-βprotein(Aβ) forming senile plaques, the accumulation of intracellular neurofibrillary tangles(NFTs) consisting of tau protein. The pathogenesis of AD is not clear yet. Recent researches have showed the relationship between the aberrant functions of endoplasmic reticulum(ER) and AD. Endoplasmic reticulum stress(ERS) can be induced by some conditions, such as the accumulation of unfolded or misfolded proteins, and the disruption of calcium in ER. Normal cells respond to ERS by activating the unfolded protein response(UPR), to correct these abnormal changes. However, excessive or aberrant ERS results in cell injury or death. The research of ERS will provide novel insights into the mechanisms of AD pathology, and lead to new therapeutic targets for AD. Nourishing spleen yin recipe (Zibu Piyin recipe, ZBPYR), created by Professor Libin Zhan, can reinforce spleen and stomach and nourish spleen yin. It is established to aim directly at spleen-yin deficiency. Our previous studies showed that ZBPYR had notable effects on protecting nerve and anti-aging of brain, furthermore the neuroprotective effects of ZBPYR was associated with ERS. This experiment is going to investigate the funcion of ER and the effects of ZBPYR on ERS in spleen-yin deficiency Alzheimer's Disease model rats, further and it will be significant for preventing AD.Methods:1. Totally 35 healthy adult male SD rats were divided randomly into control group, AD group, spleen-yin deficiency group, spleen-yin deficiency AD group, spleen-yin deficiency AD +ZBPYR group, 7 rats every group.2. Firstly, We used the classical method to construct the spleen-yin deficiency rats model, then the incubated A_β1-40(5μg/μl)was injected into bilateral hippocampus of each rat to construct AD models. We administrated ZBPYR to spleen-yin deficiency AD group and ZBPYR treatment group intragastrically.3. Using the RT-PCR method to detect the mRNA expression of GRP78, CHOP and ATF4 in different brain areas.4. Using the immunochemistry method to detect the protein expressions of GRP78, CHOP in different brain areas.Results:1. The mRNA expression of GRP78 of AD group and spleen-yin deficiency AD group decreased significantly(P<0.05), and the mRNA expression of CHOP, ATF4 increased significantly(P<0.05) compared with the control group. The mRNA expression of GRP78 of ZBPYR treatment group increased significantly(P<0.05), and the mRNA expression of CHOP, ATF4 decreased significantly(P<0.05) compared with spleen-yin deficiency AD group.2. The protein expression of GRP78 of AD group and spleen-yin deficiency AD group decreased significantly(P<0.05), and the protein expression of CHOP increased significantly(P<0.05) compared with the control group. The protein expression of GRP78 of ZBPYR treatment group increased significantly(P<0.05), and the protein expression of CHOP decreased significantly(P<0.05) compared with spleen-yin deficiency AD group.Conclusions:1. The impaired learning and memory ability of spleen yin deficiency AD group may relate to affect the ERS signal pathway.2. ATF4 which can promote the synthesis of new protein and Aβ, was involved in spleen yin deficiency AD.3. ZBPYR may improve the learning and memory ability of spleen-yin deficiency AD rats by impacting the ERS signal pathway.4. The expression of ATF4 inhibited by ZBPYR may be the cause of the decrease of new protein and Aβ.