3.Recent advances of studies on role of mTOR signaling in aging of hematopoietic and other organ systems-review.
Chun-Lan HUA ; Tao CHENG ; Wei-Ping YUAN
Journal of Experimental Hematology 2013;21(5):1313-1317
Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase, which plays an essential role in cell growth, proliferation and survival. mTOR regulates the transcription of mRNA, synthesis of ribosome and gene expression for metabolism. By forming mTOR complex, it regulates cellular activities by phosphorylating its downstream proteins, such as S6 protein kinase and 4E-BP1. In recent years, the role of mTORC1 in regulating aging is gradually recognized. Studies of physiological function and the regulatory mechanisms of mTOR signaling can not only help to better understand the aging mechanism for cells or organs, but also provide insights as to finding potential new drug targets for aging related diseases. This review focuses on recent advances of mTOR and aging related diseases in hematopoietic and other organ systems.
Aging
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Hematopoietic System
;
metabolism
;
Humans
;
Signal Transduction
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TOR Serine-Threonine Kinases
;
metabolism
4.ubtor Mutation Causes Motor Hyperactivity by Activating mTOR Signaling in Zebrafish.
Tiantian WANG ; Mingshan ZHOU ; Quan ZHANG ; Cuizhen ZHANG ; Gang PENG
Neuroscience Bulletin 2021;37(12):1658-1670
Mechanistic target of rapamycin (mTOR) signaling governs important physiological and pathological processes key to cellular life. Loss of mTOR negative regulators and subsequent over-activation of mTOR signaling are major causes underlying epileptic encephalopathy. Our previous studies showed that UBTOR/KIAA1024/MINAR1 acts as a negative regulator of mTOR signaling, but whether UBTOR plays a role in neurological diseases remains largely unknown. We therefore examined a zebrafish model and found that ubtor disruption caused increased spontaneous embryonic movement and neuronal activity in spinal interneurons, as well as the expected hyperactivation of mTOR signaling in early zebrafish embryos. In addition, mutant ubtor larvae showed increased sensitivity to the convulsant pentylenetetrazol, and both the motor activity and the neuronal activity were up-regulated. These phenotypic abnormalities in zebrafish embryos and larvae were rescued by treatment with the mTORC1 inhibitor rapamycin. Taken together, our findings show that ubtor regulates motor hyperactivity and epilepsy-like behaviors by elevating neuronal activity and activating mTOR signaling.
Animals
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Hyperkinesis/genetics*
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Mutation/genetics*
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Signal Transduction
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TOR Serine-Threonine Kinases/metabolism*
;
Zebrafish/metabolism*
5.Roles of Mammalian Target of Rapamycin Signaling and Autophagy Pathway in Alzheimer's Disease.
Acta Academiae Medicinae Sinicae 2019;41(2):248-255
The mammalian target of rapamycin(mTOR)is a serine/threonine protein kinase that regulates protein synthesis and degradation,cytoskeletal formation,and cell longevity.Autophagy,a catabolic process necessary for the maintenance of intracellular homeostasis,is essential for cell survival,whereas mTOR is the crucial regulator of autophagy.Alzheimer's disease(AD)is the most common cause of progressive dementia in the elderly.It has been shown that disorders of mTOR and autophagy signaling pathways are closely related to AD.In the present review,we describe the regulatory roles of mTOR signaling and autophagy pathway in AD brain and introduce drugs for AD acting via modulation of autophagy and mTOR.
Alzheimer Disease
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pathology
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Autophagy
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Humans
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Signal Transduction
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TOR Serine-Threonine Kinases
;
metabolism
7.Dihydromyricetin Alleviates H9C2 Cell Apoptosis and Autophagy by Regulating CircHIPK3 Expression and PI3K/AKT/mTOR Pathway.
Zhi-Ying ZHANG ; Chao LIU ; Peng-Xiang WANG ; Yi-Wei HAN ; Yi-Wen ZHANG ; Mei-Li HAO ; Zi-Xu SONG ; Xiao-Ying ZHANG
Chinese journal of integrative medicine 2023;29(5):434-440
OBJECTIVE:
To investigate the effect and potential mechanism of dihydromyricetin (Dmy) on H9C2 cell proliferation, apoptosis, and autophagy.
METHODS:
H9C2 cells were randomly divided into 7 groups, namely control, model, EV (empty pCDH-CMV-MCS-EF1-CopGFP-T2A-Puro vector), IV (circHIPK3 interference), Dmy (50 µ mol/L), Dmy+IV, and Dmy+EV groups. Cell proliferation and apoptosis were detected by cell counting kit-8 assay and flow cytometry, respectivley. Western blot was used to evaluate the levels of light chain 3 II/I (LC3II/I), phospho-phosphoinositide 3-kinase (p-PI3K), protein kinase B (p-AKT), and phospho-mammalian target of rapamycin (p-mTOR). The level of circHIPK3 was determined using reverse transcriptase polymerase chain reaction. Electron microscopy was used to observe autophagosomes in H9C2 cells.
RESULTS:
Compared to H9C2 cells, the expression of circHIPK in H9C2 hypoxia model cells increased significantly (P<0.05). Compared to the control group, the cell apoptosis and autophagosomes increased, cell proliferation rate decreased significantly, and the expression of LC3 II/I significantly increased (all P<0.05). Compared to the model group, the rate of apoptosis and autophagosomes in IV, Dmy, and Dmy+IV group decreased, the cell proliferation rate increased, and the expression of LC3 II/I decreased significantly (all P<0.05). Compared to the control group, the expressions of p-PI3K, p-AKT, and p-mTOR in the model group significantly reduced (P<0.05), whereas after treatment with Dmy and sh-circHIPK3, the above situation was reversed (P<0.05).
CONCLUSION
Dmy plays a protective role in H9C2 cells by inhibiting circHIPK expression and cell apoptosis and autophagy, and the mechanism may be related to PI3K/AKT/mTOR pathway.
Proto-Oncogene Proteins c-akt/metabolism*
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Signal Transduction
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Phosphatidylinositol 3-Kinases/metabolism*
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TOR Serine-Threonine Kinases/metabolism*
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Apoptosis
;
Autophagy
8.Ephedra Herb extract ameliorates adriamycin-induced nephrotic syndrome in rats via the CAMKK2/AMPK/mTOR signaling pathway.
Yuhan ZHANG ; Mengnan ZENG ; Benke LI ; Beibei ZHANG ; Bing CAO ; Yuanyuan WU ; Shan YE ; Ruiqi XU ; Xiaoke ZHENG ; Weisheng FENG
Chinese Journal of Natural Medicines (English Ed.) 2023;21(5):371-382
This study aimed to investigate the effect and mechanisms of Ephedra Herb (EH) extract on adriamycin-induced nephrotic syndrome (NS), providing an experimental basis for the clinical treatment of NS. Hematoxylin and eosin staining, creatinine, urea nitrogen, and kidn injury molecule-1 were used to evaluate the activities of EH extract on renal function. The levels of inflammatory factors and oxidative stress were detected by kits. The levels of reactive oxygen species, immune cells, and apoptosis were measured by flow cytometry. A network pharmacological approach was used to predict the potential targets and mechanisms of EH extract in the treatment of NS. The protein levels of apoptosis-related proteins and CAMKK2, p-CAMKK2, AMPK, p-AMPK, mTOR and p-mTOR in the kidneys were detected by Western blot. The effective material basis of EH extract was screened by MTT assay. The AMPK pathway inhibitor (compound C, CC) was added to investigate the effect of the potent material basis on adriamycin-induced cell injury. EH extract significantly improved renal injury and relieve inflammation, oxidative stress, and apoptosis in rats. Network pharmacology and Western blot results showed that the effect of EH extract on NS may be associated with the CAMKK2/AMPK/mTOR signaling pathway. Moreover, methylephedrine significantly ameliorated adriamycin-induced NRK-52e cell injury. Methylephedrine also significantly improved the phosphorylation of AMPK and mTOR, which were blocked by CC. In sum, EH extract may ameliorate renal injury via the CAMKK2/AMPK/mTOR signaling pathway. Moreover, methylephedrine may be one of the material bases of EH extract.
Rats
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Animals
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Doxorubicin/adverse effects*
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Nephrotic Syndrome
;
AMP-Activated Protein Kinases/metabolism*
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Signal Transduction
;
TOR Serine-Threonine Kinases/metabolism*
;
Apoptosis
10.Alternative Polyadenylation in Human Diseases.
Jae Woong CHANG ; Hsin Sung YEH ; Jeongsik YONG
Endocrinology and Metabolism 2017;32(4):413-421
Varying length of messenger RNA (mRNA) 3′-untranslated region is generated by alternating the usage of polyadenylation sites during pre-mRNA processing. It is prevalent through all eukaryotes and has emerged as a key mechanism for controlling gene expression. Alternative polyadenylation (APA) plays an important role for cell growth, proliferation, and differentiation. In this review, we discuss the functions of APA related with various physiological conditions including cellular metabolism, mRNA processing, and protein diversity in a variety of disease models. We also discuss the molecular mechanisms underlying APA regulation, such as variations in the concentration of mRNA processing factors and RNA-binding proteins, as well as global transcriptome changes under cellular signaling pathway.
Eukaryota
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Gene Expression
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Humans*
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Metabolism
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Polyadenylation*
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RNA Precursors
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RNA, Messenger
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RNA-Binding Proteins
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TOR Serine-Threonine Kinases
;
Transcriptome