The development and benefits of metformin in various diseases / 医学前沿

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.

miR-660-5p promotes breast cancer progression through down-regulating TET2 and activating PI3K/AKT/mTOR signaling

Breast cancer (BC) is a commonly diagnosed cancer in females. MicroRNA-660-5p (miR-660-5p) has been reported to be involved in the occurrence and development of BC. However, the regulatory network of miR-660-5p in BC has not been fully addressed. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the enrichment of miR-660-5p and tet-eleven translocation 2 (TET2) in BC tissues and cells. Cell counting kit-8 (CCK8), flow cytometry, and transwell migration and invasion assays were used to measure cell proliferation, apoptosis, migration, and invasion. The target relationship between miR-660-5p and TET2 was confirmed by dual luciferase reporter assay. Protein expression was measured by western blot. The expression of miR-660-5p was elevated in BC, and high expression of miR-660-5p was closely related to lymph node metastasis, advanced TNM stage, and vascular invasion of BC tumors. miR-660-5p silencing inhibited cell proliferation and metastasis, but induced apoptosis of BC cells. TET2 was identified as a direct target of miR-660-5p, and the interference of TET2 partly reversed the suppressive effects of miR-660-5p silencing on the malignant potential of BC cells. miR-660-5p promoted BC progression partly through modulating TET2 and PI3K/AKT/mTOR signaling. miR-660-5p/TET2 axis might be a promising target for BC treatment.

Isolation, identification and cultivation of primary rat hepatic stellate cells / 局解手术学杂志

Objeetive To improve the method for the isolation and purification of rat hepatic stellate(HSC) cells and to provide a stable cell source for the research on liver-related diseases.Methods Rat liver was digested in situ by a two-step infusion assay under a strict control of the infusion temperature,flow rate and time with a combined utilization of Pronase E and Collagenase Ⅳ.And then,the HSC cells were separated by Percoll density gradient centrifugation.The cell growth curve and survival rate were measured by CCK-8 and trypan blue staining,respectively.The HSC cells were identified by flow cytometry and immunofluorescence cytochemistry.Results With the improved methods,there were (2.1 ± 0.2) × 107 HSC cells isolated from one rat and the survival rate was (96.2 ± 0.8) ％.The percentage of HSC cells with a spontaneous fluorescent characteristic from the isolated cells was 96.3％.The immunofluorescence cytochemistry was used to detect the expressions of the surface antigens α-SMA and Desmin in the isolated HSC cells.Conclusion By strict control of infusion temperature,flow rate and perfusion time as well as the combined application of Pronase E and Collagenase Ⅳ,there is an increased harvest of HSC cells with improved cell viability and purity,which is helpful for further research on HSC cells.

Agglutinin isolated from Arisema heterophyllum Blume induces apoptosis and autophagy in A549 cells through inhibiting PI3K/Akt pathway and inducing ER stress / 中国天然药物

Arisaema heterophyllum Blume is one of the three medicinal plants known as traditional Chinese medicine Rhizoma Arisaematis (RA). RA has been popularly used to treat patients with convulsions, inflammation, and cancer for a long time. However, the underlying mechanisms for RA effects are still unclear. The present study was designed to determine the cytotoxicity of agglutinin isolated from Arisema heterophyllum Blume (AHA) and explore the possible mechanisms in human non-small-cell lung cancer A549 cells. AHA with purity up to 95% was isolated and purified from Arisaema heterophyllum Blume using hydrophobic interaction chromatography. AHA dose-dependently inhibited the proliferation of A549 cells and induced G phase cell cycle arrest. AHA induced apoptosis by up-regulating pro-apoptotic Bax, decreasing anti-apoptotic Bcl-2, and activating caspase-9 and caspase-3. In A549 cells treated with AHA, the PI3K/Akt pathway was inhibited. Furthermore, AHA induced increase in the levels of ER stress markers such as phosphorylated eukaryotic initiation factor 2α (p-eIF2α), C/EBP-homologous protein (CHOP), inositol-requiring enzyme 1α (IRE1α), and phosphorylated c-Jun NH-terminal kinase (p-JNK). AHA also induced autophagy in A549 cells. Staining of acidic vesicular organelles (AVOs) and increase in the levels of LC3II and ATG7 were observed in AHA-treated cells. These findings suggested that AHA might be one of the active components with anti-cancer effects in Arisaema heterophyllum Blume. In conclusion, cytotoxicity of AHA on cancer cells might be related to its effects on apoptosis and autophagy through inhibition of PI3K/Akt pathway and induction of ER stress.

Effects of different dietary fatty acid on expression of nuclear receptor genes in breast cancer of rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effects of different dietary fatty acid on the expression of nuclear receptor genes in the breast cancer of rats.</p><p><b>METHODS</b>Fifty-day-old female Sprague-Dawley rats were fed on eight different diets containing following fatty acids: saturated fatty acid (SFA); monounsaturated fatty acid (MUFA); n-6 polyunsaturated fatty acid (PUFA); n-3 PUFA; 1:1 n-6/n-3; 5:1 n-6/n-3; 10:1 n-6/n-3; 1:2:1 S/M/P (n-6/n-3 at 1:1). The rats were given a single intraperitoneal injection of methyl-nitrosourea (MNU) at 50 mg/kg body weight to establish the rat model of mammary carcinogenesis, the ultrastructure changes of mammary gland cells in rats were observed by transmission electron microscope, the cell proliferation activity was detected by BrdU-labeled immunocytochemistry, and the expression of PPARbeta and PPARgamma mRNA were assayed by RT-PCR.</p><p><b>RESULTS</b>There was no breast cancer occurring in control groups and the MNU-treated n-3 PUFA group, and the ultrastructure and proliferation activity of mammary gland cells in these groups were normal. In contrast, there appeared obvious marker of adenocarcinomas in mammary gland cells of MNU-induced breast cancer, and a high cell proliferation activity was found in tumor growth-enhancing groups (SFA, MUFA, n-6 PUFA, 5:1 n-6/n-3, 10:1 n-6/n-3 and S/M/P, 21% - 22% of BrdU-labeled cells), while a low cell proliferation activity was detected in rats fed with 1:1 n-6/n-3 diet (13% of BrdU-labeled cells, P < 0.05). Moreover, peroxisome proliferator-activated receptors (PPARs), as important nuclear receptor genes of relating lipid metabolism, the expressions of PPARbeta and PPARgamma mRNA were significantly up-regulated in mammary adipose tissues of MNU-induced breast cancer as compared with the control groups, but the expression levels of peroxisome proliferator-activated receptors (PPARs) in rats fed with 1:1 n-6/n-3 group were lowest (P < 0.05).</p><p><b>CONCLUSION</b>The different dietary fatty acid compositions should diversely adjust the expression of PPARs gene in rats, which maybe have an important role in affecting incidence of breast cancer.</p>

Effect of lovastatin on the expression of IkappaBalpha and cell-cycle regulating protein in MCF-7 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effect of lovastatin on the expression of IkappaBalpha and cell-cycle regulating proteins in MCF-7 cells.</p><p><b>METHODS</b>MCF-7 cells were treated with 4, 8 and 16 micro mol/L lovastatin for 48 - 72 h. The distribution of cell cycles was assayed by flow cytometry (FCM). The protein expression of IkappaBalpha, CDK4, p16, pRb in cytoplasm and IkappaBalpha in the nucleus were detected by Western blot.</p><p><b>RESULTS</b>Lovastatin could arrest cellcycle in the G(0)/G(1) phase in a dose- and time-dependent manner, obviously lowering the expression of IkappaBalpha, CDK4 and pRb protein level in the cytoplasm and increasing IkappaBalpha in the nucleus, but not on p16 protein level.</p><p><b>CONCLUSION</b>Lovastatin can induce the arrest of cell cycle in G(0)/G(1) phase by affecting the expression of IkappaBalpha and cell-cycle regulating protein in MCF-7 cells.</p>

Synthesis and function analysis of a new thrombopoietin (TPO) mimic peptide / 中国实验血液学杂志

In order to find a new TPO-mimic peptide with similar activity to TPO while reducing the side effects, a TPO-mimic peptide (P1) screened from a random peptide library was restructured. The new structure of the TPO mimic peptide (P2) was synthesized. After coupling P2 with Dextran 10 and performing intermolecular oxidation, dextran-coupled and dimerized form of P2 were obtained, naming D-P2 and (P2)(2) respectively. The activities of the peptides in vitro were measured with MTT method. The results showed that the EC50 of P2 was 20 nmol/L, 700 times higher than P1. The EC50 of D-P2 and (P2)(2) were 0.35 nmol/L and 0.14 nmol/L, respectively. After administrating to the mouse, the peptides increased the number of platelets in the blood circulation obviously without influence on other blood cells. In conclusion, the TPO-mimic peptides have prospects in treating diseases related with thrombocytopenia.

Effects of nutritional intervention on the micronutrients metabolis m of radar operators / 第三军医大学学报

Objective　To explore the metabolism of micronutri ents related to dark adaptation of radar operators through nutritional intervent ion. Methods　A total of 34 male radar operators aged between 18 ～29 years old were randomly divided into control and experimental groups. The c ontrol group were on normal diet, and the experimental group received the supple ment of VA, Zn and Se in additional to normal diet. The experiment lasted 4 week s. The levels of serum VA, Zn and Se were measured before and after the experime nt. Results　The levels of serum VA, Zn and Se in the experime ntal group were significantly higher than that in the control group after the experiment (P<0.01). Conclusion　The supplement of VA, Zn an d Se for 4 weeks may elevate, the levels of serum VA, Zn and Se significantly (reached or surpassed normal levels) and suggests that VA, Zn and Se su pplementation may effectively enhance the dark adaptation of radar operators.

Antiproliferative effect of soybean isoflavone on Bcap-37 cells and its relation with transforming growth factor β / 第三军医大学学报

Objective　To investigate the expression of TGF-β and TGF-β receptor in human breast cancer cell Bcap-37 inhibited by soybean isoflavones. Methods　mRNA and protein of TGF-β1、TGF-βRⅠ in Bcap-37 cells were examined with reverse transcription ploymerase chain reaction(RT-PCR) and immunohistochemistry after cells were treated with daidein or genistein for 1-4 d.The expression of TGF-β1 and TGF-β2 was determined with TGF-β resistance test. Results　The TGF-β1, TGF-β2 and TGF-β recepor increased in Bcap-37 cells at a concentration of 3×10-5 mol/L of genistein. No changes was found when treated with daidzein. Conclusion　Genistein may inhibit the proliferation of Bcap-37 cells and accompany with increasing expression of TGF-β1, TGF-β2 and TGF-β receptor.

Effects of nutritional intervention on the micronutrients metabolis m of radar operators / 第三军医大学学报

Objective　To explore the metabolism of micronutri ents related to dark adaptation of radar operators through nutritional intervent ion. Methods　A total of 34 male radar operators aged between 18 ～29 years old were randomly divided into control and experimental groups. The c ontrol group were on normal diet, and the experimental group received the supple ment of VA, Zn and Se in additional to normal diet. The experiment lasted 4 week s. The levels of serum VA, Zn and Se were measured before and after the experime nt. Results　The levels of serum VA, Zn and Se in the experime ntal group were significantly higher than that in the control group after the experiment (P<0.01). Conclusion　The supplement of VA, Zn an d Se for 4 weeks may elevate, the levels of serum VA, Zn and Se significantly (reached or surpassed normal levels) and suggests that VA, Zn and Se su pplementation may effectively enhance the dark adaptation of radar operators.

Antiproliferative effect of soybean isoflavone on Bcap-37 cells and its relation with transforming growth factor β / 第三军医大学学报

Objective　To investigate the expression of TGF-β and TGF-β receptor in human breast cancer cell Bcap-37 inhibited by soybean isoflavones. Methods　mRNA and protein of TGF-β1、TGF-βRⅠ in Bcap-37 cells were examined with reverse transcription ploymerase chain reaction(RT-PCR) and immunohistochemistry after cells were treated with daidein or genistein for 1-4 d.The expression of TGF-β1 and TGF-β2 was determined with TGF-β resistance test. Results　The TGF-β1, TGF-β2 and TGF-β recepor increased in Bcap-37 cells at a concentration of 3×10-5 mol/L of genistein. No changes was found when treated with daidzein. Conclusion　Genistein may inhibit the proliferation of Bcap-37 cells and accompany with increasing expression of TGF-β1, TGF-β2 and TGF-β receptor.