Fusion Expression and Fibrinolytic Activity of rPA/SP-B.

BACKGROUND: Pulmonary surfactant dysfunction is an important pathological factor in acute respiratory distress syndrome (ARDS) and pulmonary fibrosis (PF). OBJECTIVE: In this study, the characteristics of recombinant mature surfactant protein B (SP-B) and reteplase (rPA) fusion protein maintaining good pulmonary surface activity and rPA fibrinolytic activity in acute lung injury cell model were studied. METHODS: We studied the characteristics of SP-B fusion expression, cloned rPA gene and N-terminal rPA/C-terminal SP-B co-expression gene, and constructed them into eukaryotic expression vector pEZ-M03 to obtain recombinant plasmids pEZ-rPA and pEZ-rPA/SP-B. The recombinant plasmids was transfected into Chinese hamster ovary (CHO) K1 cells and the expression products were analyzed by Western Blot. Lipopolysaccharide (LPS) was used to induce CCL149 (an alveolar epithelial cell line) cell injury model. Fluorescence staining of rPA and rPA/SP-B was carried out with the enhanced green fluorescent protein (eGFP) that comes with pEZ-M03; the cell Raman spectroscopy technique was used to analyze the interaction between rPA/SP-B fusion protein and the phospholipid structure of cell membrane in CCL149 cells. The enzyme activity of rPA in the fusion protein was determined by fibrin-agarose plate method. RESULTS: The rPA/SP-B fusion protein was successfully expressed. In the CCL149 cell model of acute lung injury (ALI), the green fluorescence of rPA/SP-B is mainly distributed on the CCL149 cell membrane. The rPA/SP-B fusion protein can reduce the disorder of phospholipid molecules and reduce cell membrane damage. The enzyme activity of rPA/SP-B fusion protein was 3.42, and the fusion protein still had good enzyme activity. CONCLUSION: The recombinant eukaryotic plasmid pEZ-rPA/SP-B is constructed and can be expressed in the eukaryotic system. Studies have shown that rPA/SP-B fusion protein maintains good SP-B lung surface activity and rPA enzyme activity in acute lung injury cell model.

Recombinant expression of the precursor of rat lung surfactant protein B in Escherichia coli and its antibacterial mechanism.

While the discovery of antibiotics has made a huge contribution to medicine, bacteria that are resistant to many antibiotics pose new challenges to medicine. Antimicrobial peptides (AMPs), a new kind of antibiotics, have attracted people's attention because they are not prone to drug resistance. In this study, glutathione transferase (GST) was used as a fusion partner to recombinantly expressed rat lung surfactant protein B precursor (proSP-B) in E. coli pLySs. Cck-8 evaluated the cytotoxicity of the fusion protein and calculated its 50% inhibitory concentration (IC50). The purified peptides showed broad-spectrum antibacterial activity using filter paper method and MIC, and propidium iodide (PI) was used to explore the antibacterial mechanism against Staphylococcus aureus. In addition, the pEGFP-N2-proSP-B vector was constructed to explore the localization of proSP-B in CCL-149 cells. We found that proSP-B has obvious antibacterial activity against Gram-positive bacteria, Gram-negative bacteria and fungi, and has broad-spectrum antibacterial activity. Besides, proSP-B fusion protein has low toxicity and can change the permeability of Staphylococcus aureus cell membrane to realize its antibacterial. For these reasons, proSP-B can be used as a potential natural antibacterial drug.

[Toxicokinetics and tissue distribution study of arsenic in realgar].

OBJECTIVE: To study the toxicokinetics and tissue distribution of total arsenic after giving different doses realgar to rats. METHOD: The concentration of arsenic in blood, urine and main organs were determined after single oral administration of 3.738, 1.869, 0.935 g x kg(-1) realgar in rats. RESULT: The distribution half life (t(1/2 alpha)) and elimination half life (t(1/2 beta)) of total arsenic were 7.73 h and 17.21 h respectively in high dose group. The apparent distribution volume (Vd) were 10.8, 5.6, 3.9 L x kg(-1) respectively, the total clearance (Cltot) were 0.437, 0.16, 0.111 L x h(-1) x kg(-1) respectively in the three groups. The excretion of total urine arsenic got rid of 5.5%-13.0% of realgar which given to rats in 96 hours. Arsenic could be detected distributing into rat's main organs and tissues after administration of a single dose. Suprarenal gland, bladder and ovary accumulated most of the arsenic, while liver, spleen, lung and kidney accumulated less. Heart, brain, stomach and testis accumulated the least amount. CONCLUSION: It has nonlinear dynamics in the body of rats in toxic doses as the kinetics of realgar was changed according to the dosage.

Sustainable polymerizations in recoverable microemulsions.

Free radical and atom-transfer radical polymerizations were conducted in monomer/ionic liquid microemulsions. After the polymerization and isolation of the resultant polymers, the mixture of the catalyst and ionic liquids (surfactant and continuous phase) can be recovered and reused, thereby dramatically improving the environmental sustainability of such chemical processing. The addition of monomer to recovered ionic liquid mixtures regenerates transparent, stable microemulsions that are ready for the next polymerization cycle upon addition of initiator. The method combines the advantages of IL recycling and microemulsion polymerization and minimizes environmental disposable effects from surfactants and heavy metal ions.

[Effects of Realgar and prescription containing Realgar on stress response proteins, inflammatory mediators and complements in fever rat models].

OBJECTIVE: To explore the pharmacological mechanism of Realgar by the way of studying the effects of Realgar and the prescription containing Realgar named Niuhuang Jiedu Tablet on stress response proteins (heat shock protein 70, HSP70 and heme oxygenase-1, HO-1), inflammatory cytokines (IL-1beta, IL-6 and TNF-alpha), activities of nitric oxide synthetase (NOS) and its isoenzyme (inducible nitric oxide synthetase, iNOS), and complements C3, CA under pathologic status (fever model). METHODS: SD rats were randomly divided into four groups, 15 rats in each: untreated normal group, fever model group, Realgar (90 mg/kg) group and Niuhuang Jiedu Tablet (NJT, 1.404 g/kg) group. Each group was divided into three subgroups (5 rats/subgroup). Blood samples of the rats in subgroups were collected at 1 h, 2 h and 4 h after administration, respectively. ELISA method was used to determine HSP70, IL-1beta, IL-6, and TNF-alpha levels in serum. Dual wavelength spectrophotometry was used to determine activity of HO-1 in serum. Spectrophotometry was used to test activities of nitric oxide synthetase (NOS) and its isoenzyme (inducible nitric oxide synthetase, iNOS) in serum. Immunonephelometery method was used to test complements C3, C4 in serum. RESULTS: Realgar and NJT significantly increased the level of HSP70 in rat serum as compared with the fever model group. Realgar and NJT significantly enhanced the activity of HO-1 in rat serum as compared with the fever model group. The increase ranges of HO-1 activities at different time post administration changed with the arsenic concentration in rat serum. Realgar and NJT significantly decreased the level of IL-1beta in rat serum as compared with fever model group, and the level of IL-lbeta recovered normaly at 4 h after administration. NJT significantly inhibited activities of NOS and iNOS in rat serum as compared with the fever model group at 2 h after administration. CONCLUSION: Realgar as contained in certain prescriptions, at certain specific levels, assists in removal of internal toxins by inducing stress protein (HSP70, HO-1) to improve the positive stress level in the body and inhibiting some over-releasing inflammatory mediators (IL-1beta) to reduce the inflammatory reactions under pathologic status.

[Effects of Cinnabar and Realgar in Angong Niuhuang powder on heat shock protein, nitric oxide synthase and inflammatory cytokines in contusion cerebral edema].

OBJECTIVE: To explore the pharmacological mechanism of Cinnabar and Realgar in Angong Niuhuang powder (ANP). METHODS: SD rats were randomly divided into six groups (12 rats/group): normal controls group (NS group), contusion cerebral edema model group( CCE group) , cerebral edema rats administrated by cinnabar 0. 15 g/kg 1h (CA group), cerebral edema rats administrated by realgar 0.15 g/kg 1h (RG group), cerebral edema rats administrated by Angong Niuhuang powder 1.5 g/kg 1h (ANP I group), cerebral edema rats administrated by Angong Niuhuang powder substracted cinnabar and realgar 1.2 g/kg 1h (ANP II group). Each group was divided into two subgroups (6 rats/subgroup). The rats in subgroups were killed at 8h and 24h after modeling respectively. Expression of heat shock protein 70 ( HSP 70) mRNA in brain tissues was measured by RT-PCR. Activities of nitric oxide synthase (NOS) and its isoenzymes (iNOS, cNOS) in brain tissues were tested by colorimetry. Levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) in serum were determined by radioimmunoassay (RIA). RESULTS: Expression of HSP 70 mRNA in ANP I group and ANP II group significantly increased as compared with CCE group 8h after being modeled (P < 0.05), and increase range in ANP I group were singificantly higher than that in ANP II group (P < 0.05). Activities of iNOS in CA group, RG group, ANP I group and ANP II group were lower than that in CCE group 8h after being modeled (P < 0.05) , and the activities in ANP I group were the lowest in the four groups. Levels of TNF-alpha in RG group, ANP I group and ANP II group decreased obviously as compared with CCE group 8h after being modeled (P < 0.05) , so did levels of IL-1beta in ANP I group and ANP II group (P < 0.05). But no significant difference was shown between ANP I group and ANP 11 group. CONCLUSION: HSP 70, iNOS, TNF-alpha and IL-1beta are involved in contusion cerebral edema. ANP and CA, RG in ANP are protective against CCE in rats. It may be associated with the increase of HSP 70 mRNA expression, inhibition of iNOS activity, and the decreasae of inflammatory cytokines (TNF-alpha, IL-1beta) levels.

[Effects of cinnabar and realgar in angong niuhuang powder on lactate dehydrogenase and its isoenzymes in rats with infectious cerebral edema].

OBJECTIVE: To explore the pharmacologic mechanism of cinnabar (CA) and realgar (RG) in Angong Niuhuang powder (ANP) by way of studying the characteristics of their effects on organism under physiologic and pathologic states. METHODS: SD rats were randomly divided into six groups, 8-10 rats in each group. Group A: untreated normal rats; Group B: normal rats administered by ANP (drug I) 278 mg/kg; Group C: normal rats administered by ANP subtracted CA and RG (drug II) 222.7 mg/kg; Group D: brain edema model rats established by unilateral common carotid artery injection of Bacillus pertussis 250 million/kg; Group E: model rats administered by ANP 278 mg/kg 1 hr before modeling; Group F: model rats administered by drug II 222.7 mg 1 hr before modeling. Blood sample and brain tissue in Group D were obtained 4 hrs after modeling and those in other groups obtained 5 hrs after drug administration. The total activity of lactate dehydrogenase (LDH) in serum and brain tissue was determined by colorimetry and that of serum LDH isoenzymes (LDH(1-5)) were determined by gel electrophoresis. RESULTS: As compared with Group A, LDH, LDH1 and LDH2 activities increased in Group D (P < 0.01), and increased also in Group B and C (P < 0.05), while LDH4 and LDH5 decreased obviously in Group B and C. But except that of LDH5, no significant difference of LDH(1-4) in brain tissue and serum was shown in comparison of Group B and C. As compared with Group D, LDH was lower (P < 0.01) and LDH5 was higher (P < 0.01) in Group E and F without significant difference, LDH2, LDH3 were lower in Group E (P < 0.01) but unchanged in Group F, LDH1 and LDH4 were not changed in Group E but significantly lowered in Group F (P < 0.05 and P < 0.01). CONCLUSION: Administration of ANP in normal physiologic condition would cause damage on myocardium and kidney to certain extent, administration of ANP and drug II in pathologic (infectious brain edema) would suppress the hyper-activated LDH, with no significant difference between the effects of drug II and ANP. However, CA and RA in ANP are proven to have influence on the serum LDH isoenzymes, indicating that the two ingredients may have some potential pharmacological effects.