ABSTRACT
Objective: To study the role of dopamine D2 receptor (D2R) on the regulation of prolactin (PRL) secretion by malt total alkaloids. Methods: MMQ and GH3 cells of pituitary adenoma were divided into control group, bromocriptine (5 μg/mL), malt total alkaloids (4.4, 8.8, 35.2, 70.4 μg/mL), haloperidol (10, 20, 40 μg/mL), and combined administration group of total malt alkaloids and haloperidol. Cell viability was detected by CCK-8; The expressions of PRL and D2R were detected by western blotting; The level of PRL was detected by ELISA; The level of PRL and D2R mRNA were detected by qRT-PCR. Results: Compared with control group, malt alkaloids (35.2, 70.4 μg/mL) significantly reduced the expression levels of PRL protein and mRNA, and the level of PRL in the supernatant of MMQ cells (P < 0.05). Malt alkaloids (35.2, 70.4 μg/mL) significantly increased the expression levels of D2R protein and mRNA in MMQ cells. Haloperidol significantly inhibited the downregulation of malt alkaloids on the expression levels of PRL protein and mRNA, and the expression level of PRL in supernatant of MMQ cells (P < 0.05). Haloperidol significantly inhibited the upregulation of malt alkaloids on the levels of D2R protein and mRNA (P < 0.05). The level of PRL in GH3 cells had no change by malt alkaloids. Conclusion: Malt alkaloids could inhibit the expression and secretion of PRL in MMQ cell by upregulating D2R.
ABSTRACT
Electrospray ionization is most commonly used in mass spectrometry for analysis of biological molecules such as peptides and proteins. However, peptides and proteins ions produced by electrospray ionization usually have multiple charges, and produce multiple spectrum peaks, making the mass spectrum complicated. Gas phase proton transfer ion/ion reaction can effectively regulate the charge states of peptides and proteins ions after electrospray ionization, simplifying the spectrogram, and thus is significant to the analysis of complex proteins and peptides samples. In this study, a dual-polarity linear ion trap ( LIT) mass spectrometer was used to control the charge state of peptide ions by proton transfer ion/ion reaction. The detection effect of the method was verified by using glutathione ( oxidation type) , oxytocin and dynorphin as typical samples. The results showed that this method could remove excess charges in the positive ions. When injecting enough negative ions for eaction, peptide ions with multiple charge valence state could be reduced to the minimum, therefore simplify the spectrogram effectively.
ABSTRACT
Heat shock protein 90 (HSP90) is a member of genetically conserved heat shock protein family. As an important molecular chaperone in eukaryotic cells, HSP90 plays a key regulatory role in maintaining cellular protein homeostasis. HSP90 clients encompass a wide range of proteins, thus HSP90 is involved in diverse biological process. With the deeper study, it is found that HSP90 takes an important part in the development and metastasis of cancer,and has become a promising target for the study of anticancer biology. We review the progress of HSP90 as molecular chaperone and its relationship with cancer.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influence of the materials commonly used in the assisted reproduction procedure on human germ cells and embryo development.</p><p><b>METHODS</b>We used human sperm survival assay to detect the influence of two brands of culture dishes, two brands of injection needles, washed and unwashed ovum aspiration needles, embryo transfer catheters and surgical gloves on sperm motility. All the data obtained went through variance analysis with SPSS 13.0.</p><p><b>RESULTS</b>Sperm motility differed significantly between Nunclons and Falcon's culture dishes (52.68 +/-16.21 vs 45.36 +/- 15.25, P < 0.01) but not between the BD and the Jie-rui injection needles (P > 0.05), nor among the washed and unwashed ovum aspiration needles, embryo transfer catheters and surgical gloves (P > 0.05).</p><p><b>CONCLUSION</b>Different brands of assisted reproduction materials of similar use had different or similar influences on germ cells and embryos, while no difference existed in the influences of the washed and unwashed ovum aspiration needles, embryo transfer catheters and surgical gloves.</p>
Subject(s)
Humans , Male , Culture Media, Conditioned , Embryonic Development , Reproductive Techniques, Assisted , Sperm MotilityABSTRACT
<p><b>OBJECTIVE</b>To observe the binding power of polymyxin B (PMB) and its simulation peptide to lipopolysaccharide (LPS) and lipoid A.</p><p><b>METHODS</b>LPS and lipoid A were separately coated on biosensor. 5 microl of PMB (0.01 microg/L) 5 microl of its simulating peptide 1 (PMBSP1 0.01 microg/L) and 5 microl of its simulating peptide 2 (PMBSP2, 0.01 microg/L) were respectively added into the hydrophobic sample pool. The combining power of PMB and its simulating peptides PMBSP1 and PMBSP2 to LPS and lipoid A was compared. RESULTS (1) PMBSP1 almost did not bind LPS and lipoid A, while PMB and PMBSP2 possessed high affinity with LPS and lipoid A. (2) The peak value (98.41 +/- 7.31) rad/s of PMBSP2 binding LPS was much higher than that (83.58 +/- 5.42) rad/s of PMB in binding LPS (P < 0.05). While the peak value of PMB in binding lipoid A was similar to that of PMBSP2. (3) The peak value of PMB binding LPS was significantly lower than that of PMB in binding lipoid A (P < 0.05). But there was no difference between the peak value of PMBSP2 in binding LPS and that of PMBSP2 in binding lipoid A. (4) PMBSP2 could bind to LPS and lipoid A in a shorter time to reach peak levels.</p><p><b>CONCLUSION</b>Compared with PMB, the PMBSP2 could bind to LPS and lipoid A in a shorter time. In addition, PMBSP2 exhibited similar affinity to LPS and lipoid A. This indicated that PMBSP might possess better anti-LPS activity due to its lack of space steric hindrance when PMBSP binding the lipoid A of LPS.</p>
Subject(s)
Cell Wall , Chemistry , Endotoxins , Gram-Negative Bacteria , Lipopolysaccharides , Chemistry , Toxicity , Peptides , Chemistry , Pharmacology , Polymyxin B , Chemistry , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To explore the application of biosensor technology in the determination of endotoxin-neutralizing materials.</p><p><b>METHODS</b>After mixing polymyxin B (PMB) with endotoxin in certain concentration, the neutralizing ratio of PMB to endotoxin was assessed by biosensor technique and limulus amebocyte lysate test respectively. The results from the two methods were compared.</p><p><b>RESULTS</b>The neutralizing ratio of PMB to endotoxin as assessed by biosensor technology was 0.35 microg to 1 ng, while that by dynamic turbidimetric and chromogenic limulus amebocyte lysate (LAL) technique was 0.5 mg to 1 ng and 1 mg to 1 ng, respectively. The results obtained by biotechnology were similar to that by biosensor technique.</p><p><b>CONCLUSION</b>Biosensor technology was an accurate, convenient and rapid method for the determination of potency of endotoxin-neutralizing materials.</p>