1.Serum metabolomics study of Psoraleae Fructus in improving learning and memory ability of APP/PS1 mice.
Jia-Ming GU ; Hui XUE ; Ao XUE ; Jing JIANG ; Fang GENG ; Ji-Hui ZHAO ; Bo YANG ; Ning ZHANG
China Journal of Chinese Materia Medica 2023;48(15):4039-4045
This study aimed to investigate the mechanism of Psoraleae Fructus in improving the learning and memory ability of APP/PS1 mice by serum metabolomics, screen the differential metabolites of Psoraleae Fructus on APP/PS1 mice, and reveal its influence on the metabolic pathway of APP/PS1 mice. Thirty 3-month-old APP/PS1 mice were randomly divided into a model group and a Psoraleae Fructus extract group, and another 15 C57BL/6 mice of the same age were assigned to the blank group. The learning and memory ability of mice was evaluated by the Morris water maze and novel object recognition tests, and metabolomics was used to analyze the metabolites in mouse serum. The results of the Morris water maze test showed that Psoraleae Fructus shortened the escape latency of APP/PS1 mice(P<0.01), and increased the number of platform crossing and residence time in the target quadrant(P<0.01). The results of the novel object recognition test showed that Psoraleae Fructus could improve the novel object recognition index of APP/PS1 mice(P<0.01). Eighteen differential metabolites in serum were screened out by metabolomics, among which the levels of arachidonic acid, tryptophan, and glycerophospholipid decreased after drug administration, while the levels of glutamyltyrosine increased after drug administration. The metabolic pathways involved included arachidonic acid metabolism, glycerophospholipid metabolism, tryptophan metabolism, linoleic acid metabolism, α-linolenic acid metabolism, and glycerolipid metabolism. Therefore, Psoraleae Fructus can improve the learning and memory ability of APP/PS1 mice, and its mechanism may be related to the effects in promoting energy metabolism, reducing oxidative damage, protecting central nervous system, reducing neuroinflammation, and reducing Aβ deposition. This study is expected to provide references for Psoraleae Fructus in the treatment of Alzheimer's disease(AD) and further explain the mechanism of Psoraleae Fructus in the treatment of AD.
Mice
;
Animals
;
Amyloid beta-Protein Precursor/genetics*
;
Mice, Transgenic
;
Arachidonic Acid
;
Tryptophan
;
Mice, Inbred C57BL
;
Alzheimer Disease/genetics*
;
Maze Learning
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Glycerophospholipids
;
Disease Models, Animal
;
Amyloid beta-Peptides/metabolism*
2.Knock-down of ROCK2 gene improves cognitive function and reduces neuronal apoptosis in AD mice by promoting mitochondrial fusion and inhibiting its division.
Minfang GUO ; Huiyu ZHANG ; Peijun ZHANG ; Jingwen YU ; Tao MENG ; Suyao LI ; Lijuan SONG ; Zhi CHAI ; Jiezhong YU ; Cungen MA
Chinese Journal of Cellular and Molecular Immunology 2023;39(8):701-707
Objective To explore the effect of knocking down Rho-associated coiled-coil kinase (ROCK2) gene on the cognitive function of amyloid precursor protein/presenilin-1 (APP/PS1) double transgenic mice and its mechanism. Methods APP/PS1 double transgenic mice were randomly divided into AD model group (AD group), ROCK2 gene knock-down group (shROCK2 group), ROCK2 gene knock-down control group (shNCgroup), and wild-type C57BL/6 mice of the same age served as the wild-type control (WT group). Morris water maze and Y maze were employed to test the cognitive function of mice. Neuron morphology was detected by Nissl staining. Immunofluorescence histochemical staining was used to detect the expression of phosphorylated dynamin-related protein 1 (p-Drp1) and mitochondrial fusion 1 (Mfn1). Western blot analysis was used to detect the expression ROCK2, cleaved-caspase-3 (c-caspase-3), B-cell lymphoma 2 (Bcl2), Bcl2-related protein X (BAX), p-Drp1, mitochondrial fission 1 (Fis1), optic atrophy 1 (OPA1), Mfn1 and Mfn2. Results Compared with AD group mice, the expression of ROCK2 in shROCK2 group mice was significantly reduced; the cognitive function was significantly improved with the number of neurons in the hippocampal CA3 and DG areas increasing, and nissl bodies were deeply stained; the expression of c-caspase-3 and BAX was decreased, while the expression of Bcl2 was increased; the expression of mitochondrial division related proteins p-Drp1 and Fis1 were decreased, while the expression of mitochondrial fusion-related proteins OPA1, Mfn1 and Mfn2 were increased. Conclusion Knock-down of ROCK2 gene can significantly improve the cognitive function and inhibit the apoptosis of nerve cells of APP/PS1 mice. The mechanism may be related to promoting mitochondrial fusion and inhibiting its division.
Animals
;
Mice
;
Alzheimer Disease/pathology*
;
Amyloid beta-Peptides/metabolism*
;
Amyloid beta-Protein Precursor
;
Apoptosis/genetics*
;
bcl-2-Associated X Protein
;
Caspase 3
;
Cognition
;
Disease Models, Animal
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
Mitochondrial Dynamics/genetics*
3.Clinical Significance of SFRP1 Gene Methylation in Patients with Childhood Acute Lymphoblastic Leukemia.
Jing YAN ; Wen-Peng WANG ; Xuan LI ; Wei HAN ; Feng-Qi QI ; Ji-Zhao GAO
Journal of Experimental Hematology 2023;31(2):377-382
OBJECTIVE:
To investigate the clinical significance of SFRP1 gene and its methylation in childhood acute lymphoblastic leukemia (ALL) .
METHODS:
Methylation-specific PCR (MSP) was used to detect the methylation status of SFRP1 gene in bone marrow mononuclear cells of 43 children with newly diagnosed ALL before chemotherapy (primary group) and when the bone marrow reached complete remission d 46 after induction of remission chemotherapy (remission group), the expression of SFRP1 mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR), the expression of SFRP1 protein was detected by Western blot, and clinical data of children were collected, the clinical significance of SFRP1 gene methylation in children with ALL was analyze.
RESULTS:
The positive rate of SFRP1 gene promoter methylation in the primary group (44.19%) was significantly higher than that in the remission group (11.63%) (χ2=11.328, P<0.05). The relative expression levels of SFRP1 mRNA and protein in bone marrow mononuclear cells of children in the primary group were significantly lower than those in the remission group (P<0.05). Promoter methylation of SFRP1 gene was associated with risk level (χ2=15.613, P=0.000) and survival of children (χ2=6.561, P=0.010) in the primary group, children with SFRP1 hypermethylation had significantly increased risk and shortened event-free survival time, but no significant difference in other clinical data.
CONCLUSION
Hypermethylation of SFRP1 gene promoter may be involved in the development of childhood ALL, and its hypermethylation may be associated with poor prognosis.
Child
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Humans
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Clinical Relevance
;
DNA Methylation
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Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics*
;
Bone Marrow/metabolism*
;
RNA, Messenger/metabolism*
;
Membrane Proteins/genetics*
;
Intercellular Signaling Peptides and Proteins/metabolism*
4.Time dependent expression profiling of PTK2B and its relationship with Aβ, Tau and LRP-1 in hippocampus and blood of APPswe/PS1dE9 double-transgenic mouse.
Kai-Min HAO ; Zhen LIU ; Hao-Yu WANG ; Wen-Xiu QI
Chinese Journal of Applied Physiology 2022;38(1):17-24
Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P< 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P<0.05), but other indicators had no significant differences (P>0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.
Alzheimer Disease/metabolism*
;
Amyloid beta-Peptides
;
Amyloid beta-Protein Precursor/genetics*
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Animals
;
Focal Adhesion Kinase 2/metabolism*
;
Hippocampus/metabolism*
;
Low Density Lipoprotein Receptor-Related Protein-1
;
Maze Learning
;
Mice
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
RNA, Messenger
5.PRKCDBP Methylation is a Potential and Promising Candidate Biomarker for Non-small Cell Lung Cancer.
Jing LI ; Lin QI ; Mingfang ZHANG ; Caiyun YAO ; Jinan FENG ; Zhonghua ZHENG ; Chujia CHEN ; Shiwei DUAN ; Yuanlin QI
Chinese Journal of Lung Cancer 2022;25(2):78-85
BACKGROUND:
The occurrence and development of lung cancer are closely linked to epigenetic modification. Abnormal DNA methylation in the CpG island region of genes has been found in many cancers. Protein kinase C delta binding protein (PRKCDBP) is a potential tumor suppressor and its epigenetic changes are found in many human malignancies. This study investigated the possibility of PRKCDBP methylation as a potential biomarker for non-small cell lung cancer (NSCLC).
METHODS:
We measured the methylation levels of PRKCDBP in the three groups of NSCLC tissues. Promoter activity was measured by the dual luciferase assay, with 5'-aza-deoxycytidine to examine the effect of demethylation on the expression level of PRKCDBP.
RESULTS:
The methylation levels of PRKCDBP in tumor tissues and 3 cm para-tumor were higher than those of distant (>10 cm) non-tumor tissues. Receiver operating characteristic (ROC) curve analysis between tumor tissues and distant non-tumor tissues showed that the area under the line (AUC) was 0.717. Dual luciferase experiment confirmed that the promoter region was able to promote gene expression. Meanwhile, in vitro methylation of the fragment (PRKCDBP_Me) could significantly reduce the promoter activity of the fragment. Demethylation of 5'-aza-deoxycytidine in lung cancer cell lines A549 and H1299 showed a significant up-regulation of PRKCDBP mRNA levels.
CONCLUSIONS
PRKCDBP methylation is a potential and promising candidate biomarker for non-small cell lung cancer.
Biomarkers/metabolism*
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Carcinoma, Non-Small-Cell Lung/pathology*
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Cell Line, Tumor
;
DNA Methylation
;
Gene Expression Regulation, Neoplastic
;
Humans
;
Intracellular Signaling Peptides and Proteins/genetics*
;
Lung Neoplasms/pathology*
;
Promoter Regions, Genetic
6.Genetic research progress in branchio-oto syndrome/ branchio-oto-renal syndrome.
Anhai CHEN ; Jie LING ; Yong FENG
Journal of Central South University(Medical Sciences) 2022;47(1):129-138
Branchio-oto syndrome (BOS)/branchio-oto-renal syndrome (BORS) is a kind of autosomal dominant heterogeneous disorder. These diseases are mainly characterized by hearing impairment and abnormal phenotype of ears, accompanied by renal malformation and branchial cleft anomalies including cyst or fistula, with an incidence of 1/40 000 in human population. Otic anormalies are one of the most obvious clinical manifestations of BOS/BORS, including deformities of external, middle, inner ears and hearing loss with conductive, sensorineural or mix, ranging from mild to profound loss. Temporal bone imaging could assist in the diagnosis of middle ear and inner ear malformations for clinicians. Multiple methods including direct sequencing combined with next generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), or array-based comparative genomic hybridization (aCGH) can effectively screen and identify pathogenic genes and/or variation types of BOS/BORS. About 40% of patients with BOS/BORS carry aberrations of EYA1 gene which is the most important cause of BOS/BORS. A total of 240 kinds of pathogenic variations of EYA1 have been reported in different populations so far, including frameshift, nonsense, missense, aberrant splicing, deletion and complex rearrangements. Human Endogenous Retroviral sequences (HERVs) may play an important role in mediating EYA1 chromosomal fragment deletion mutations caused by non-allelic homologous recombination. EYA1 encodes a phosphatase-transactivator cooperated with transcription factors of SIX1, participates in cranial sensory neurogenesis and development of branchial arch-derived organs, then regulates the morphological and functional differentiation of the outer ear, middle ear and inner ear toward normal tissues. In addition, pathogenic mutations of SIX1 and SIX5 genes can also cause BOS/BORS. Variations of these genes mentioned above may cause disease by destroying the bindings between SIX1-EYA1, SIX5-EYA1 or SIX1-DNA. However, the role of SIX5 gene in the pathogenesis of BORS needs further verification.
Branchio-Oto-Renal Syndrome/pathology*
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Chromosome Deletion
;
Comparative Genomic Hybridization
;
Genetic Research
;
Homeodomain Proteins/genetics*
;
Humans
;
Intracellular Signaling Peptides and Proteins
;
Nuclear Proteins/metabolism*
;
Pedigree
;
Protein Tyrosine Phosphatases/metabolism*
7.circBIRC6 contributes to the development of non-small cell lung cancer via regulating microRNA-217/amyloid beta precursor protein binding protein 2 axis.
Da NI ; Jiping TENG ; Youshuang CHENG ; Zhijun ZHU ; Bufeng ZHUANG ; Zhiyin YANG
Chinese Medical Journal 2022;135(6):714-723
BACKGROUND:
Circular RNAs (circRNAs) are considered to be important regulators in cancer biology. In this study, we focused on the effect of circRNA baculoviral inhibitor of apoptosis protein (IAP) repeat containing 6 (circBIRC6) on non-small cell lung cancer (NSCLC) progression.
METHODS:
The NSCLC and adjacent non-tumor tissues were collected at Shanghai Ninth People's Hospital. Quantitative real-time polymerase chain reaction was conducted for assessing the levels of circBIRC6, amyloid beta precursor protein binding protein 2 (APPBP2) messenger RNA (mRNA), baculoviral IAP repeat containing 6 mRNA (BIRC6), and microRNA-217 (miR-217). Western blot assay was adopted for measuring the protein levels of APPBP2, E-cadherin, N-cadherin, and vimentin. Colony formation assay, transwell assay, and flow cytometry analysis were utilized for evaluating cell colony formation, metastasis, and apoptosis. Dualluciferase reporter assay and RNA immunoprecipitation assay were carried out to determine the interaction between miR-217 and circBIRC6 and APPBP2 in NSCLC tissues. The murine xenograft model assay was used to investigate the function of circBIRC6 in tumor formation in vivo. Differences were analyzed via Student's t test or one-way analysis of variance. Pearson's correlation coefficient analysis was used to analyze linear correlation.
RESULTS:
CircBIRC6 was overexpressed in NSCLC tissues and cells. Knockdown of circBIRC6 repressed the colony formation and metastasis and facilitated apoptosis of NSCLC cells in vitro and restrained tumorigenesis in vivo. Mechanically, circBIRC6 functioned as miR-217 sponge to promote APPBP2 expression in NSCLC cells. MiR-217 inhibition rescued circBIRC6 knockdown-mediated effects on NSCLC cell colony formation, metastasis, and apoptosis. Overexpression of miR-217 inhibited the malignant phenotypes of NSCLC cells, while the effects were abrogated by elevating APPBP2.
CONCLUSIONS
CircBIRC6 aggravated NSCLC cell progression by elevating APPBP2 via sponging miR-217, which might provide a fresh perspective on NSCLC therapy.
Amyloid beta-Peptides/metabolism*
;
Amyloid beta-Protein Precursor/metabolism*
;
Animals
;
Carcinoma, Non-Small-Cell Lung/pathology*
;
Cell Movement/genetics*
;
Cell Proliferation/genetics*
;
China
;
Gene Expression Regulation, Neoplastic/genetics*
;
Humans
;
Lung Neoplasms/pathology*
;
Mice
;
MicroRNAs/metabolism*
;
RNA, Circular/genetics*
;
RNA, Messenger
8.Effect of moxibustion with deqi on Aβ-receptor mediated transport and enzymatic degradation in hippocampus in rats with Alzheimer's disease.
Zhi-Mai LV ; Dan-Dan HUANG ; Ding-Yi XIE ; Rui-Zhen YUE ; Jin-Wei WANG ; Wei-Feng LUO ; Ri-Xin CHEN
Chinese Acupuncture & Moxibustion 2022;42(8):899-906
OBJECTIVE:
To observe the clinical effect of moxibustion with deqi on Alzheimer's disease (AD) rats, and evaluate its effect on β-amyloid (Aβ) transport and enzymatic degradation proteins, to explore its molecular mechanism for improving cognitive function.
METHODS:
Sixty SPF-grade male SD rats were randomly divided into a blank group (8 rats), a sham-operation group (8 rats) and a model establishment group (44 rats). The rats in the model establishment group were injected with Aβ1-42 at bilateral ventricles to establish AD model. Among the 38 rats with successful model establishment, 8 rats were randomly selected as the model group, and the remaining rats were treated with mild moxibustion at "Dazhui" (GV 14), once a day, 40 min each time, for 28 days. According to whether deqi appeared and the occurrence time of deqi, the rats were divided into a deqi group (12 rats), a delayed deqi group (10 rats) and a non-deqi group (8 rats). After the intervention, the Morris water maze test was applied to evaluate the cognitive function; the HE staining was applied to observe the brain morphology; the Western blot method was applied to measure the protein expression of Aβ and its receptor mediated transport [low-density lipoprotein receptor-related protein (LRP) 1, receptor for advanced glycation end products (RAGE), apolipoprotein E (ApoE)] and enzymatic degradation [neprilysin (NEP), insulin degrading enzyme (IDE), endothelin converting enzyme (ECE)-1 and angiotensin converting enzyme (ACE) 2].
RESULTS:
Compared with the sham-operation group, in the model group, the escape latency was prolonged (P<0.01), and the times of platform crossing and the ratio of platform quadrant to total time were reduced (P<0.01); the brain tissue was seriously damaged; the expression of hippocampal Aβ and RAGE was increased (P<0.01), and the expression of hippocampal LRP1, ApoE, NEP, IDE, ECE-1 and ACE2 was decreased (P<0.01). Compared with the model group, the escape latency was shortened in the deqi group (P<0.05, P<0.01), and the escape latency in the delayed deqi group and the non-deqi group was shortened from Day 2 to Day 5 (P<0.05, P<0.01), and the times of platform crossing and the ratio of platform quadrant to total time were increased in the deqi group and the delayed deqi group (P<0.01, P<0.05); the brain damage in each moxibustion group was reduced, which was smallest in the deqi group, followed by the delayed deqi group and the non-deqi group; the expression of Aβ and RAGE was decreased (P<0.01, P<0.05) and the expression of LRP1 and IDE was increased in each moxibustion group (P<0.01, P<0.05); the expression of ApoE was increased in the deqi group and the delayed deqi group (P<0.01, P<0.05); the expression of NEP was increased in deqi group (P<0.05), and the expression of ECE-1 and ACE2 was increased in the deqi group and the delayed deqi group (P<0.05). Compared with the delayed deqi group and the non-deqi group, the escape latency in the deqi group was shortened from Day 3 to Day 5 (P<0.05), and the times of platform crossing and the ratio of platform quadrant to total time were increased (P<0.05, P<0.01). Compared with the non-deqi group, the expression of Aβ was reduced (P<0.05), the expression of LRP1 and ApoE was increased in the deqi group (P<0.05). The expression of NEP in the deqi group was higher than that in the delayed deqi group and the non-deqi group (P<0.05).
CONCLUSION
Compared with non-deqi, moxibustion with deqi could promote Aβ transport and degradation, thereby reducing Aβ level in the brain and improving cognitive function for AD rats.
Alzheimer Disease/therapy*
;
Amyloid beta-Peptides/genetics*
;
Angiotensin-Converting Enzyme 2
;
Animals
;
Apolipoproteins E/metabolism*
;
Hippocampus/metabolism*
;
Male
;
Moxibustion
;
Rats
;
Rats, Sprague-Dawley
9.Effect of moxibustion on autophagy in mice with Alzheimer's disease based on mTOR/p70S6K signaling pathway.
Yang-Yang WU ; Xiao-Ge SONG ; Cai-Feng ZHU ; Sheng-Chao CAI ; Xia GE ; Ling WANG ; Yu-Mei JIA
Chinese Acupuncture & Moxibustion 2022;42(9):1011-1016
OBJECTIVE:
To investigate the effect of moxibustion on autophagy and amyloid β-peptide1-42 (Aβ1-42) protein expression in amyloid precursor protein/presenilin 1 (APP/PS1) double-transgenic mice with Alzheimer's disease (AD).
METHODS:
After 2-month adaptive feeding, fifty-six 6-month-old APP/PS1 double transgenic AD mice were randomly divided into a model group, a moxibustion group, a rapamycin group and an inhibitor group, 14 mice in each group. Another 14 C57BL/6J mice with the same age were used as a normal group. The mice in the moxibustion group were treated with monkshood cake-separated moxibustion at "Baihui"(GV 20), "Fengfu" (GV 16) and "Dazhui" (GV 14) for 20 min; the mice in the rapamycin group were intraperitoneally injected with rapamycin (2 mg/kg); the mice in the inhibitor group were treated with moxibustion and injection of 1.5 mg/kg 3-methyladenine (3-MA). All the treatments were given once a day for consecutive 2 weeks. The morphology of hippocampal tissue was observed by HE staining; the ultrastructure of hippocampal tissue was observed by transmission electron microscopy; the expression of Aβ1-42 protein in frontal cortex and hippocampal tissue was detected by immunohistochemistry; the expressions of mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), p70 ribosomal protein S6 kinase (p70S6K) and phosphorylated p70S6K (p-p70S6K) protein in hippocampus were detected by Western blot method.
RESULTS:
Compared with the normal group, the number of neuron cells was decreased, cells were necrotic and deformed, and autophagy vesicle and lysosome were decreased in the model group. Compared with the model group, the number of neuron cells was increased, cell necrosis was decreased, and autophagy vesicle and lysosome were increased in the moxibustion group and the rapamycin group. Compared with the normal group, the protein expressions of Aβ1-42, mTOR, p-mTOR, p70S6K and p-p70S6K in the model group were increased (P<0.05); compared with the model group, the protein expressions of Aβ1-42, mTOR, p-mTOR, p70S6K and p-p70S6K in the moxibustion group, rapamycin group and inhibitor group were decreased (P<0.05); compared with the inhibitor group, the protein expressions of Aβ1-42, mTOR, p-mTOR, p70S6K and p-p70S6K in the moxibustion group and rapamycin group were decreased (P<0.05); compared with the rapamycin group, the protein expressions of mTOR, p-mTOR, p70S6K and p-p70S6K in the moxibustion group were decreased (P<0.05).
CONCLUSION
Moxibustion could enhance autophagy in hippocampal tissue of APP/PS1 double transgenic AD mice and reduce abnormal Aβ aggregation in brain tissue, the mechanism may be related to the inhibition of mTOR/p70S6K signaling pathway.
Alzheimer Disease/therapy*
;
Amyloid beta-Peptides/genetics*
;
Animals
;
Autophagy
;
Disease Models, Animal
;
Hippocampus/metabolism*
;
Mammals/metabolism*
;
Mice
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
Moxibustion
;
Ribosomal Protein S6 Kinases, 70-kDa/pharmacology*
;
Signal Transduction
;
Sirolimus/pharmacology*
;
TOR Serine-Threonine Kinases/metabolism*
10.Expression, purification, and characterization of cell-permeable fusion antioxidant enzyme sensitive to matrix metalloproteinases-2/9.
Huocong HE ; Lixiang LIN ; Lingling LI ; Lunqiao WU ; Haiying LIN ; Jianru PAN
Chinese Journal of Biotechnology 2022;38(9):3515-3527
Antioxidant enzymes fused with cell-penetrating peptides could enter cells and protect cells from irradiation damage. However, the unselective transmembrane ability of cell-penetrating peptide may also bring antioxidant enzymes into tumor cells, thus protecting tumor cells and consequently reducing the efficacy of radiotherapy. There are active matrix metalloproteinase (MMP)-2 or MMP-9 in most tumor cellular microenvironments. Therefore, a fusion protein containing an MMP-2/9 cleavable substrate peptide X, a cell-penetrating peptide R9, a glutathione S-transferase (GST), and a human Cu, Zn superoxide dismutase (SOD1), was designed and named GST-SOD1-X-R9. In the tumor microenvironment, GST-SOD1-X-R9 would lose its cell-penetrating peptide and could not enter tumor cells due to the cleavage of substrate X by active MMP-2/9, thereby achieving selected entering normal cells. The complete nucleotide sequence of SOD1-X-R9 was synthesized and inserted into the prokaryotic expression vector pGEX-4T-1. The pGEX4T-1-SOD1-X-R9 recombinant plasmid was obtained, and soluble expression of the fusion protein was achieved. GST-SOD1-X-R9 was purified by ammonium sulfate precipitation and GST affinity chromatography. The molecular weight of the fusion protein was approximately 47 kDa, consistent with the theoretical value. The SOD and GST activities were 2 954 U/mg and 328 U/mg, respectively. Stability test suggested that almost no change in either SOD activity or GST activity of GST-SOD1-X-R9 was observed under physiological conditions. The fusion protein could be partially digested by collagenase Ⅳ in solution. Subsequently, the effect of MMP-2/9 activity on transmembrane ability of the fusion protein was tested using 2D and 3D cultured HepG2 cells. Little extracellular MMP-2 activity of HepG2 cells was observed under 2D culture condition. While under the 3D culture model, the size and the MMP-2 activity of the HepG2 tumor spheroid increased daily. GST-SOD1-R9 proteins showed the same transmembrane efficiency in 2D cultured HepG2 cells, but the transmembrane efficiency of GST-SOD1-X-R9 in 3D cultured HepG2 spheres was reduced remarkably. This study provided a basis for further investigating the selectively protective effect of GST-SOD1-X-R9 against oxidative damage in normal cells.
Ammonium Sulfate
;
Antioxidants
;
Cell-Penetrating Peptides/pharmacology*
;
Endopeptidases
;
Glutathione Transferase/metabolism*
;
Humans
;
Matrix Metalloproteinase 2/genetics*
;
Matrix Metalloproteinase 9/genetics*
;
Recombinant Fusion Proteins
;
Recombinant Proteins
;
Superoxide Dismutase/metabolism*
;
Superoxide Dismutase-1

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