1.Studies on fermentation conditions and purification of mutant human interleukin-2 expressed in Pichia pastoris.
Yan LIU ; Chang SU ; Ying-He HU ; Ke-Qing OUYANG ; Shao-Xi CAI
Chinese Journal of Biotechnology 2005;21(3):430-434
Interleukin-2 (IL-2) was initially isolated as a T cell growth factor and had been shown to direct the expansion and differentiation of several hematopoietic cell types. Clinical studies using IL-2 in the treatment of AIDS have been encouraging, due to its critical role as a proliferative signal for activated T-lymphocytes. IL-2 has also undergone trials in the treatment of several types of cancer, based on its stimulation of cytotoxic, antitumor cells. Today, human IL-2 is produced completely by genetically engineered method, and it has been proved that genetically engineered recombinant human IL-2 has almost the same function and clinical effect as wild IL-2. In the former study, recombinant human IL-2 usually comes from E. coli, in this paper the mutant IL-2 was successfully expressed and purified in Pichia pastoris for the first time. As a eukaryote, Pichia pastoris has many of the advantages of higher eukaryotic expression systems such as protein processing, protein folding, and posttranslational modification, while being as easy to manipulate as E. coli or Saccharomyces cerevisiae. It is faster, easier, and less expensive to use than other eukaryotic expression systems such as baculovirus or mammalian tissue culture, and generally gives higher expression level. Expression conditions of human mutant interleukin-2(the codon for cysteine-125 of human IL-2 with alanine; the codon for leucine-18 with methionine; the codon for leucine-19 with serine) in the recombinant Pichia pastoris strain were optimized via test of some factors such as the rate of aeration, the inductive duration, the initial pH and the concentration of methanol. The results from tests showed that the most important parameter for efficient expression of interleukin-2 in recombinant Pichia pastoris strain is adequate aeration during methanol induction, and the optimum inductive condition for interleukin-2 expression was: more than 80% aeration, 2 days for induction, the initial pH of 6.0, the final methanol concentration of 1.0%. With this condition, the expressed IL-2 was secreted into fermentation broth and reached a yield of 30%, approximately 200 mg/L. Expressed interleutin-2 (MvIL-2) was isolated and purified by centrifugation, millipore filtration to concentration, Econo-PacS strongly acidic cation exchanger cartridge and molecular sieve chromatography and the yield of MvIL-2 was 27%. MvIL-2 was purified to electrophoretic purity by SDS-PAGE and only one peak being loaded on HPLC. Purified MvIL-2 protein had stimulating activity similar to the wild type of IL-2 as assayed by IL-2-dependent CTLL-2 cells. However, the stability of MvIL-2 was superior than that of IL-2 at different temperatures. The activity of obtained MvIL-2 was 4 - 5 times of the wild type of IL-2, So MvIL-2 had an advantage over wild type of rhIL-2 in storage stability and activity.
Fermentation
;
Humans
;
Interleukin-2
;
biosynthesis
;
genetics
;
Mutant Proteins
;
biosynthesis
;
Mutation
;
Pichia
;
genetics
;
metabolism
;
Protein Engineering
;
methods
;
Recombinant Proteins
;
biosynthesis
;
genetics
;
isolation & purification
2.Study on the production condition of extraction in combination hydrolysis in situ for isolating diosgenin.
Jun WANG ; Jun CHEN ; Ke-di YANG ; Liu-qing YANG ; Zhen OUYANG
China Journal of Chinese Materia Medica 2003;28(10):934-937
OBJECTIVETo study the production technology of extraction in combination hydrolysis in situ for isolating diosgenin from Dioscorea nipponica by orthogonal design.
METHODThe optimum production conditions were investigated with the recovery of diosgenin as an index by extraction in combination hydrolysis in situ, and were compared with the traditional method.
RESULTExtraction in combination hydrolysis in situ conducted in 1.5 mol x L(-1) sulfuric acid of water containing 75% isopropanol at 100 degrees C for 4.5 h could get higher recovery of diosgenin than traditional methods.
CONCLUSIONThis production technology can get higher recovery of diosgenin, and it is simple, time and money saving.
Dioscorea ; chemistry ; Diosgenin ; isolation & purification ; Hydrolysis ; Pressure ; Sulfuric Acids ; Technology, Pharmaceutical ; methods ; Temperature ; Time Factors
3.Reduction of plasma obestatin levels in patients with impaired glucose regulation and type 2 diabetes
Xiao-Ya QI ; Gang-Yi YANG ; Ling LI ; Ke LI ; Jian-Lei LIU ; Shao-Chuan SHI ; Ling-Yun OUYANG ; Qing SUN ; Yi TANG ; Gunther Boden
Chinese Journal of Endocrinology and Metabolism 2000;0(06):-
Plasma obestatin level was determined in patients with impaired glucose regulation and type 2 diabetes mellitus.The plasma obestatin levels in patients of both groups were significantly decreased as compared with that in controls.Plasma obestatin level was negatively correlated with body mass index,HbA_(1C),waist-to-hip ratio,plasma insulin and HOMA-IR.Obestatin level seems to be related with metabolic disorder.
4.Correlation between macrophage chemotaxis and disease severity in patients with knee osteoarthritis.
Zhi-Bo XIE ; Ke-Ming CHEN ; Cong-Wu HUANG ; Lin-Qing CHEN ; Kai OUYANG ; Qing-Xing PENG
China Journal of Orthopaedics and Traumatology 2023;36(6):514-518
OBJECTIVE:
To investigate the enhancement of macrophage chemotaxis in patients with knee osteoarthritis (KOA) and its correlation with the disease severity.
METHODS:
Eighty patients with KOA admitted from July 2019 to June 2022 were enrolled as the observation group and divided into 29 cases of moderate group, 30 cases of severe group and 21 cases of extremely severe group. At the same time, 30 healthy subjects were included as the control group. The gene expressions of NF-κB, CXC chemokine receptor 7 (CXCR7) and CXC chemokine ligand 12 (CXCL12) in macrophages of each group were analyzed. Visual analogue scale(VAS) was used to evaluate the degree of joint pain. Joint function was evaluated by knee Joint Society Scoring system(KSS). Finally, data analysis was carried out.
RESULTS:
The expression levels of NF-κB, CXCR7 and CXCL12 in moderate group, severe group and extreme recombination group were higher than those in control group. The VAS, the expression of NF-κB, CXCR7 and CXCL12 in the severe group and the extreme recombination group were higher than those in the moderate group, whereas KSS was lower than that in the moderate group. The VAS, expression levels of NF-κB, CXCR7 and CXCL12 in the extremely severe group were higher than those in the severe group, and KSS was lower than that in the severe group (all P<0.01). The expression levels of NF-κB, CXCR7 and CXCL12 in macrophages were positively correlated with VAS score, but negatively correlated with KSS(all P<0.01). The expression levels of NF-κB, CXCR7 and CXCL12 in macrophages were positively correlated with the severity of disease. After excluding the influence of traditional factors (gender, age and disease duration), multiple linear regression analysis further showed that the expression levels of NF-κB, CXCR7 and CXCL12 were still positively correlated with the severity of disease(all P<0.01).
CONCLUSION
The chemotaxis of macrophages in patients with KOA increased with the aggravation of the disease, and was related to the degree of pain and function impairment.
Humans
;
Osteoarthritis, Knee/genetics*
;
Chemotaxis/genetics*
;
NF-kappa B/metabolism*
;
Macrophages/metabolism*
;
Receptors, CXCR/metabolism*
;
Patient Acuity
5.Dynein axonemal heavy chain 10 deficiency causes primary ciliary dyskinesia in humans and mice.
Rongchun WANG ; Danhui YANG ; Chaofeng TU ; Cheng LEI ; Shuizi DING ; Ting GUO ; Lin WANG ; Ying LIU ; Chenyang LU ; Binyi YANG ; Shi OUYANG ; Ke GONG ; Zhiping TAN ; Yun DENG ; Yueqiu TAN ; Jie QING ; Hong LUO
Frontiers of Medicine 2023;17(5):957-971
Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.
Humans
;
Male
;
Animals
;
Mice
;
Semen/metabolism*
;
Dyneins/metabolism*
;
Cilia/metabolism*
;
Mutation
;
Ciliary Motility Disorders/genetics*