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Journal: Sheng li xue bao : [Acta physiologica Sinica]

112

The transcription factor Nrf2, nuclear factor erythroid-2-related factor 2, activates the transcription of over 500 genes in the human genome, most of which have cytoprotective functions. Nrf2 produces cytoprotection by detoxification mechanisms leading to increased detoxification and excretion of both organic xenobiotics and toxic metals; its action via over two dozen genes increases highly coordinated antioxidant activities; it produces major anti-inflammatory changes; it stimulates mitochondrial biogenesis and otherwise improves mitochondrial function; and it stimulates autophagy, removing toxic protein aggregates and dysfunctional organelles. Health-promoting nutrients and other factors act, at least in part by raising Nrf2 including: many phenolic antioxidants; gamma- and delta-tocopherols and tocotrienols; long chain omega-3 fatty acids DHA and EPA; many carotenoids of which lycopene may be the most active; isothiocyanates from cruciferous vegetables; sulfur compounds from allium vegetables; terpenoids. Other health promoting, Nrf2 raising factors include low level oxidative stress (hormesis), exercise and caloric restriction. Raising Nrf2 has been found to prevent and/or treat a large number of chronic inflammatory diseases in animal models and/or humans including various cardiovascular diseases, kidney diseases, lung diseases, diseases of toxic liver damage, cancer (prevention), diabetes/metabolic syndrome/obesity, sepsis, autoimmune diseases, inflammatory bowel disease, HIV/AIDS and epilepsy. Lesser evidence suggests that raising Nrf2 may lower 16 other diseases. Many of these diseases are probable NO/ONOO(-) cycle diseases and Nrf2 lowers effects of NO/ONOO(-) cycle elements. The most healthful diets known, traditional Mediterranean and Okinawan, are rich in Nrf2 raising nutrients as apparently was the Paleolithic diet that our ancestors ate. Modern diets are deficient in such nutrients. Nrf2 is argued to be both lifespan and healthspan extending. Possible downsides to too much Nrf2 are also discussed. Nrf2 is not a magic bullet but is likely to be of great importance in health promotion, particularly in those regularly exposed to toxic chemicals.

Concepts: Inflammation, DNA, Genetics, Nutrition, Fatty acid, Antioxidant, Omega-3 fatty acid, Inflammatory bowel disease

23

Under normal condition, there are a few lipid droplets in skeletal muscle. But in skeletal muscle acute injury, muscular dystrophy, muscle atrophy, obesity, diabetes and other pathological conditions, the fat deposition in skeletal muscle increases, which implicate that the fat deposition may play an important role in the pathogenesis of these diseases. However, the mechanisms of development and regulation of fat deposition in skeletal muscle are not clear. Clarifying the key signaling pathways and regulatory factors that affect fat deposition in skeletal muscle, and exploring new ways to improve the fat deposition in skeletal muscle will not only help to deepen our understanding of the pathogenesis of these diseases, but also provide new ideas for the treatment of these diseases. This paper reviews the research progresses and main mechanisms of fat deposition in skeletal muscle.

Concepts: Metabolism, Pathology, Muscle, Fat, Adipose tissue, Muscle atrophy, Muscular system, Atrophy

23

High altitude hypoxia is an important factor to affect fetal development during pregnancy. In the special environment, maternal physiological functions are regulated to maintain the maternal and fetal homeostasis, so that limited oxygen is to meet the needs of fetal growth and development. In this review, the literatures about the effects of hypoxic environment on fetal development during pregnancy in recent years were summarized, in which the fetal growth characteristics, maternal physiological regulation, genetic and placental influencing factors in high altitude areas were involved. This may be helpful for the reproductive healthcare of women in high altitude region, and also for the treatment and prevention of fetal growth retardation in the hypoxic environment.

Concepts: Pregnancy, Fertility, Embryology, Hypoxia, Implantation, Gestational age, Altitude sickness

1

Despite continued improvement in risk factor recognition and aggressive medical management, heart disease remains the number one killer in the world. Medications for primary or secondary prevention of heart disease can cause unpleasant side effects leading to non-compliance. Novel therapies are needed to serve as a complement to or alternative for current medical management. Acupuncture and more specifically electroacupuncture may serve as a safe and viable option in the cardiology clinic. This review article focuses on both mechanistic and clinical studies evaluating acupuncture’s effectiveness with symptomatic heart disease. Although continued research is needed, currently evidence warrants consideration of acupuncture’s use with myocardial ischemia, hypertension, arrhythmias, heart failure as well as autonomic dysfunction.

Concepts: Medicine, Myocardial infarction, Cardiology, Heart failure, Avicenna, Heart disease, Alternative medicine, Ischaemic heart disease

0

Drug addiction is a chronic psychiatric disorder characterized by compulsive drug taking, and involves neuronal plasticity changes in multiple brain regions. The prelimbic cortex (PrL) is a key region of the dorsomedial prefrontal cortex and contains majority of pyramidal neurons. The excitatory projections from PrL play a very important role in the drug seeking behaviors. PrL also contains a small amount of GABAergic interneurons, which regulate the information integration and transmission of the pyramidal neurons. However, the roles of the GABAergic interneurons in PrL in drug-induced behavior changes are not clear. In the PrL, parvalbumin (PV) and somatostatin (SST) interneurons are two major GABAergic interneurons, which have been reported to regulate the activity of glutamatergic input, and form inhibitory synaptic transmission to regulate the output of downstream signals. Here, we used PV-Cre and SST-Cre mice combined with chemical genetics to explore the role of PV and SST interneurons in PrL in morphine-induced behavior changes. Our data showed that specific inhibiting SST interneurons in PrL significantly increased the anxiety level and decreased morphine-induced locomotor activity and the conditioned place preference (CPP) score. Instead, specific inhibiting PV interneurons in PrL had no effect on the anxiety level, morphine induced-locomotor activity and CPP. Our findings provide a new insight into the cellular and neuronal specific mechanism for drug addiction.

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The mechanism for icaritin to improve postmenopausal osteoporosis (PMOP) has not been clarified. The aim of this study was to investigate the role of estrogen receptor α36 (ERα36) in the proliferation promotion and anti-apoptosis effects of icaritin on osteoblasts and the underlying mechanism of downstream signal transduction. The ERα36 knockdown human osteosarcoma MG63 cell model was constructed by transfection of shRNA vector. Cell proliferation was detected by CCK-8, the apoptosis was detected by flow cytometry, and the activation of ERK and AKT signaling pathways was detected by Western blot. The results showed that the effects of icaritin on the proliferation and apoptosis of MG63 cells were significantly decreased after ERα36 knockdown, and icaritin could up-regulate the levels of ERK and AKT phosphorylation in MG63 cells, which could be reduced by ERα36 knockdown. The effect of icaritin on the proliferation of MG63 cells was significantly decreased by pretreating the cells with U0126 (an ERK signaling pathway blocker) and LY294002 (an AKT signaling pathway blocker), respectively. Furthermore, anti-apoptotic effect of icaritin on MG63 cells was significantly decreased after the cells were pretreated with U0126, but not with LY294002. These results suggest that icaritin exerts proliferation promotion and anti-apoptosis effects on osteoblasts through ERα36 and its downstream ERK and AKT signaling pathways.

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Epithelial-mesenchymal transition (EMT) occurring in alveolar epithelial cells plays an important role in the development and progression of pulmonary fibrosis. Previous studies showed that antiflammin-1 (the active fragment of uteroglobin) effectively inhibited bleomycin-induced pulmonary fibrosis. However, its mechanism is still far from being clarified. In this study, we investigated the effects of antiflammin-1 on EMT in A549 cells induced by transforming growth factor-β1 (TGF-β1) and the underlying mechanism by using morphological observation and Western blot. The results showed that the expression of α-smooth muscle actin (α-SMA) increased significantly while the expression of E-cadherin decreased significantly in A549 cells following treatment with TGF-β1 concomitant with morphological change of A549 cells from pebble-like shape epithelial cells to spindle-like mesenchymal shape. This process of EMT in A549 cells induced by TGF-β1 was significantly inhibited when A549 cells were co-incubated with TGF-β1 and antiflammin-1. Furthermore, the anti-lipocalin interacting membrane receptor (LIMR) antibody and PD98059 (an ERK signaling pathway blocker) attenuated the inhibitory effect of antiflammin-1 on TGF-β1-induced EMT, respectively. Our findings indicate that antiflammin-1 can inhibit EMT in A549 cells induced by TGF-β1, which is related to LIMR and its downstream ERK signaling pathway.

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The purpose of the present study was to investigate the effects and underlying mechanism of gonadotropin-releasing hormone agonist (GnRHa) controlled ovarian hyperstimulation (COH) on embryo implantation in mice. Forty female Kunming mice aged 9 weeks were randomly divided into two groups (control and COH groups). The COH group received intraperitoneal (i.p.) injections of aminocyclin acetate (GnRHa), human menopausal gonadotropin (HMG) and human chorionic gonadotropin (hCG), while the control group was given equal amount of physiological saline by i.p. injection. One male mouse and two female mice were put into the same cage at 16:00 on the hCG injection day, and on the fourth day of pregnancy, 10 mice from each group were killed. The levels of serum estradiol (E2) and progesterone (P) were measured by radioimmunoassay; HE staining was used to observe the morphology of ovarian and endometrial tissues. The protein expression levels of endometrial leukemia inhibitory factor (LIF), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), heparin-binding epidermal growth factor-like growth factor (HB-EGF) and glycodelin A were detected by Western blot and immunohistochemistry. Ten mice from each group were sacrificed on the eighth day of pregnancy, and the status of the uterus and the average number of blastocysts were observed. The results showed that, compared with control group, the serum E2 level in COH group was significantly decreased (P < 0.05), while the P level was increased significantly (P < 0.05); the ovarian follicles at different developmental stages were rare, corpus lutea (CL) were visible and multiple, the endometrium was thinned, and the number of endometrial glands was reduced (P < 0.05); the contents of LIF, p-STAT3, HB-EGF and glycodelin A in the endometrium were decreased significantly (P < 0.05) on the fourth day of pregnancy; mouse blastocysts developed slowly and were decreased in number on the eighth day of pregnancy (P < 0.05). The above results suggest that GnRHa COH can affect embryo implantation in mice. The mechanism may be related to the imbalance of gonadal hormone, the changes in the structure of the endometrium and the expressions of LIF, p-STAT3, HB-EGF and glycodelin A in the implantation stage, which may lead to the decrease of endometrial receptivity and the abnormal dialogue between the embryo and the uterus.

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This work aimed to observe the effects of short hairpin RNA (shRNA)-silenced FBI-1 (factor that binds to the inducer of short transcripts of human immunodeficiency virus-1) on proliferation and apoptosis of triple-negative breast cancer cell line MDA-MB-231. qRT-PCR and Western blot analysis were applied to detect the mRNA and/or protein expression of FBI-1, Bcl-2, Bax, cleaved-Caspase 3 and Survivin. RNA interference method was used to silence FBI-1 expression in MDA-MB-231 cells. CCK-8 and colony formation assay were employed to detect the cell proliferation. Flow cytometry was employed for examining cell apoptosis. In vivo tumorigenicity of MDA-MB-231 cells was detected by tumor transplantation in nude mice. The results showed that the mRNA and protein expressions of FBI-1 were higher in MDA-MB-231 cells compared with those in normal human mammary epithelial cells MCF-10A. FBI-1 gene silencing inhibited proliferation and induced apoptosis of MDA-MB-231 cells in vitro, together with decreased Bcl-2 and Survivin protein expression, increased Bax protein expression and activated Caspase 3. Moreover, FBI-1 gene silencing inhibited the tumorigenesis of MDA-MB-231 cells in vivo. These results suggest that silencing of FBI-1 gene inhibits proliferation, induces apoptosis and suppresses the tumorigenesis of MDA-MB-231 cells.

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Integrin is a transmembrane receptor that mediates the connection between cells and their external environment, such as extracellular matrix (ECM). Integrin β4 (ITGβ4) plays a number of functions due to its special structures: forms α6β4 with ITGα6 subunit and participates in the formation of hemidesmosomes; mediates cell-to-cell matrix interaction and cell-to-cell interaction, cell proliferation and survival, as well as migration and invasion. Also, ITGβ4 participates in various disease processes by activating multiple signaling pathways. In this paper, the structure, physiological function and function of ITGβ4 in respiratory system, tumor, nervous system and other related diseases will be reviewed.