Enhancing peptaibols production in the biocontrol fungus Trichoderma longibrachiatum SMF2 by elimination of a putative glucose sensor.

Trichoderma spp. are main producers of peptide antibiotics known as peptaibols. While peptaibols have been shown to possess a range of biological activities, molecular understanding of the regulation of their production is largely unclear, which hampers the production improvement through genetic engineering. Here, we demonstrated that the orthologue of glucose sensors in the outstanding biocontrol fungus Trichoderma longibrachiatum SMF2, TlSTP1, participates in the regulation of peptaibols production. Deletion of Tlstp1 markedly impaired hyphal growth and conidiation, but significantly increased peptaibols yield by 5-fold for Trichokonins A and 2.6-fold for Trichokonins B. Quantitative real-time polymerase chain reaction analyses showed that the increased peptaibols production occurs at the transcriptional levels of the two nonribosomal peptide synthetase encoding genes, tlx1 and tlx2. Transcriptome analyses of the wild type and the Tlstp1 mutant strains indicated that TlSTP1 exerts a regulatory effect on a set of genes that are involved in a number of metabolic and cellular processes, including synthesis of several other secondary metabolites. These results suggest an important role of TlSTP1 in the regulation of vegetative growth and peptaibols production in T. longibrachiatum SMF2 and provide insights into construction of peptaibol-hyperproducing strains through genetic engineering.

Characterization of Gut Microbiota Compositions along the Intestinal Tract in CD163/pAPN Double Knockout Piglets and Their Potential Roles in Iron Absorption.

The gut microbiota is known to play a role in regulating host metabolism, yet the mechanisms underlying this regulation are not well elucidated. Our study aimed to characterize the differences in gut microbiota compositions and their roles in iron absorption between wild-type (WT) and CD163/pAPN double-gene-knockout (DKO) weaned piglets. A total of 58 samples along the entire digestive tract were analyzed for microbial community using 16S rRNA gene sequencing. The colonic microbiota and their metabolites were determined by metagenomic sequencing and untargeted liquid chromatography-mass spectrometry (LC-MS), respectively. Our results showed that no alterations in microbial community structure and composition were observed between DKO and WT weaned piglets, with the exception of colonic microbiota. Interestingly, the DKO piglets had selectively increased the relative abundance of the Leeia genus belonging to the Neisseriaceae family and decreased the Ruminococcaceae_UCG_014 genus abundance. Functional capacity analysis showed that organic acid metabolism was enriched in the colon in DKO piglets. In addition, the DKO piglets showed increased iron levels in important tissues compared with WT piglets without any pathological changes. Pearson's correlation coefficient indicated that the specific bacteria such as Leeia and Ruminococcaceae_UCG_014 genus played a key role in host iron absorption. Moreover, the iron levels had significantly (P < 0.05) positive correlation with microbial metabolites, particularly carboxylic acids and their derivatives, which might increase iron absorption by preventing iron precipitation. Overall, this study reveals an interaction between colonic microbiota and host metabolism and has potential significance for alleviating piglet iron deficiency. IMPORTANCE Iron deficiency is a major risk factor for iron deficiency anemia, which is among the most common nutritional disorders in piglets. However, it remains unclear how the gut microbiota interacts with host iron absorption. The current report provides the first insight into iron absorption-microbiome connection in CD163/pAPN double knockout piglets. The present results showed that carboxylic acids and their derivatives contributed to the absorption of nonheme iron by preventing ferric iron precipitation.

Risk Factors and Clinical Characteristics of Neonatal Acute Respiratory Distress Syndrome Caused by Early Onset Sepsis.

Purpose: To identify risk factors associated with the development of acute respiratory distress syndrome (ARDS) in infants with early onset sepsis (EOS) and to describe the clinical features. Methods: A retrospective study was conducted at the Children's Hospital of Chongqing Medical University between January 2000 and October 2020. The infants were divided into ARDS and non-ARDS groups. Clinical characteristics and risk factors were compared between the two groups. Results: Two hundred fifty infants (58 with ARDS) were included. Smaller gestational age, lower birth weight (LBW), lower serum albumin level, a higher rate of preterm birth, premature rupture of membranes, antenatal steroid exposure, and lower Apgar score were associated with an increased development of ARDS by univariate analysis (P < 0.05). LBW (ß = -0.001, P = 0.000, OR: 0.999, 95% CI: 0.998-0.999) and low serum albumin levels (ß = -0.063, P = 0.022, OR: 0.939, 95% CI: 0.889-0.991) were identified as independent risk factors for the development of ARDS by logistic regression analysis. A higher frequency of complications, including persistent pulmonary hypertension, intraventricular hemorrhage, pulmonary hemorrhage, septic shock, and bronchopulmonary dysplasia, was found in the ARDS group (P < 0.05). The rate of mortality was higher for those in the ARDS group than for those in the non-ARDS group (46.6% vs. 15.6%, χ2 = 24.205, P = 0.000). Conclusion: Acute respiratory distress syndrome (ARDS) in EOS could lead to a higher frequency of complications and mortality. The risk factors for the development of ARDS were LBW and low serum albumin levels.

Malignant transformation of 293 cells induced by ectopic expression of human Nanog.

Tumor development has long been known to resemble abnormal embryogenesis. The ESC self-renewal gene NANOG is purportedly expressed in some epithelial cancer cells and solid tumors, but a casual role in tumor development has remained unclear. In order to more comprehensively elucidate the relationship between human Nanog and tumorigenesis, the hNanog was ectopically expressed in the 293 cell line to investigate its potential for malignant transformation of cells both in vitro and in vivo. Here we provide compelling evidence that the overexpression of hNanog resulted in increased cell proliferation, anchor-independent growth in soft agar, and formation of tumors after subcutaneous injection of athymic nude mice. Pathologic analysis revealed that these tumors were poorly differentiated. In analysis of the underlying molecular mechanism, two proteins, FAK and Ezrin, were identified to be upregulated in the hNanog expressing 293 cells. Our results demonstrate that hNanog is a potent human oncogene and has the ability to induce cellular transformation of human cells.

The Putative Methyltransferase TlLAE1 Is Involved in the Regulation of Peptaibols Production in the Biocontrol Fungus Trichoderma longibrachiatum SMF2.

The biocontrol fungus Trichoderma longibrachiatum SMF2 secretes a large quantity of peptaibols that have been shown to have a range of biological activities and therefore great application values. However, the mechanism of the regulatory expression of peptaibols is still unclear. The putative methyltransferase LaeA/LAE1 is a global regulator involved in the biosynthesis of some secondary metabolites in filamentous fungi. In this study, we demonstrated that the ortholog of LaeA/LAE1 in the biocontrol fungus T. longibrachiatum SMF2, TlLAE1, plays an important role in the regulation of peptaibols production. Deletion of Tllae1 resulted in a slight negative impact on mycelial growth, and a significant defect in conidial production. Deletion of Tllae1 also compromised the production of peptaibols to a large degree. Further analyses indicated that this defect occurred at the transcriptional level of the two synthetases-encoding genes, tlx1 and tlx2, which are responsible for peptaibols production. By contrast, constitutive expression of Tllae1 in T. longibrachiatum SMF2 led to 2-fold increased peptaibols production, suggesting that this is a strategy to improve peptaibols production in Trichoderma fungi. These results demonstrate the important role of LAE1 in the regulation of peptaibols production in T. longibrachiatum SMF2.

[Effect of polycythemia on hypoxia induced pulmonary hypertension and pulmonary vascular remodeling in rats].

OBJECTIVE: To investigate the effect of polycythemia on hypoxia induced pulmonary hypertension and pulmonary vascular remodeling in rats. METHODS: The healthy female Sprague-Dawley rats were randomly divided into 3 groups: normoxia control group (C group), hypoxia group (H group), hypoxia + different doses of human recombine hemopoietin (rEPO) group. All rats in hyoxia groups were exposed to hypoxia, 8 hours every day, for 21 days. The rEPO groups were injected sc with different doses of rEPO (300 U/kg, 600 U/kg, 900 U/kg, 1200 U/kg) thrice weekly. Blood samples were taken for the measurement of RBC, Hb, Hct, plasma EPO concentration, whole blood/plasma viscosities, the animals were then catheterized to record mean pulmonary arterial pressure (mPAP) and demised to calculate the ratio [RV/(LV+S)]. Percentage of vascular wall thickness and muscularization of non-muscular pulmonary arteriole were examined microscopically. RESULTS: (1) As the dosage of exogenous rEPO increased, blood concentration of EPO increased correspondingly, as RBC, Hb, Hct and whole blood/plasma viscosities increased in various degrees. (2) There was positive correlation between whole blood viscosity and Hct at both high and low shears and linear correlation between mPAP and whole blood viscosity at high shear. (3) The degree of pulmonary hypertension, reflected by mPAP increased in accordance to rEPO dosage increment. However, the extent of pulmonary vascular remodeling alleviated somehow as the rEPO dose increased and so did right ventricular hypertrophy. CONCLUSION: Polycythemia induced by exogenous EPO increases the blood viscosity and the pulmonary vascular resistance, which contributes to the formation of hypoxia induced pulmonary hypertension.

Up-regulated GGA3 promotes non-small cell lung cancer proliferation by regulating TrkA receptor.

BACKGROUND: GGA3 has been reported to be related to cellular events such as cell survival, cell migration and cell apoptosis through different molecular mechanisms, which imply the potential role in tumorigenesis. However, the function of GGA3 in non-small cell lung cancer (NSCLC) is not clear. This research aims to reveal the effect of GGA3 on NSCLC proliferation and its underlying mechanisms. METHODS: The mRNA expression of GGA3 and TrkA, and association between GGA3 and TrkA in NSCLC tissues were analyzed based on data from TCGA database. And the mRNA expression level of GGA3 in NSCLC cell lines was determined by qRT-PCR. Expression level of GGA3 in A549 cell was detected by qRT-PCR and western blot after transfected with pcDNA3.1-GGA3. Cell counting kit 8, transwell, and flow cytometry assays were performed to detect A549 cell proliferation, aggressiveness, and apoptosis. Western blot was applied to assess the protein expression during apoptosis and TrkA-AKT/ERK signaling pathway. RESULTS: High expression of GGA3 was presented in NSCLC tissues and cell lines. In addition, overexpression of GGA3 could promote proliferation, invasion, and migration of A549 cell, but inhibit the apoptosis of A549 cell. After depletion of GGA3, the expression of anti-apoptotic protein Bcl-2 was increased, and the expression of pro-apoptotic protein Bax and Active Caspase 3 were reduced. Moreover, we found the expression of TrkA, p-AKT and p-ERK in pcDNA3.1-GGA3 group were obviously up-regulated in contrast with the sham group, which suggested that the induced effect of GGA3 on NSCLC cells might be performed via the TrkA-AKT/ERK signaling pathway. CONCLUSIONS: Taken together, overexpressed GGA3 in NSCLC could promote the A549 cells tumorigenesis partly through TrkA-AKT/ERK signaling pathway, supplying a theoretical basis for revealing the mechanism for NSCLC.

[Boldness of the alpine musk deer in captivity during non-mating season and its relationships with the musk secretion and reproduction succes]. / åœˆå »é©¬éºéžç¹æ®–å­£èŠ‚èƒ†é‡æ°´å¹³åŠä¸Žéºé¦™åˆ†æ³Œå’Œç¹æ®–æˆæ•ˆçš„å ³ç³».

This study was conducted in 2017 from July 1st to August 31st at Xinglongshan musk deer farm in the Xinglongshan National Nature Reserve of Gansu Province, where we recorded behaviors and locations of 29 captive musk deer using the integrated methods of focal sampling and all occurrence recording. Based on the location selection patterns under artificial stress, we defined the animal's stress level and quantified individuals' boldness by combination with the occupation time ratio at each level. Then, the effects of gender, age-class, and other factors on boldness were analyzed along with musk secretion and reproduction success. The results showed that musk deer in better health (1.731±0.347) were significantly bolder than those in ill health (0.915±0.789). Female musk deer (1.901±0.391) were significantly bolder than the males (1.035±0.120). The boldness of sub-adults (1.450±0.463) was higher than those of the adults (1.093±0.321) and the old (1.430±0.189). No significant difference in boldness was observed among three age-classes under the same gender. Deer living in groups (1.397±0.179) were not significantly bolder than those living alone (0.853±0.326). More individuals in groups, less boldness. Furthermore, there was negative correlation between male's boldness and musk secretion. The litter size had positive relationship with boldness. The non-pregnant percentage was strongly correlated to the boldness, namely the bolder females had lower non-pregnant ratio. Our results provide reference for forecasting the musk secretion and reproduction success of captive musk deer, and provide new ideas for the study of boldness in captive animals.

The prevalence of dementia in the People's Republic of China: a systematic analysis of 1980-2004 studies.

BACKGROUND: Dementia has been a major public health problem. However, there has not yet been a nationwide investigation or systematic analysis of the prevalence of dementia in China from 1980 to 2004. OBJECTIVES: The aim of this study was to analyse the prevalence of dementia and its major subtypes [Alzheimer disease (AD), vascular dementia (VD)] among the population aged 60 years and older in China from 1980 to 2004. METHODS: Epidemiological investigations on dementia in China published in journals and covering the period from 1980 to 2004 were identified manually and on-line by using CBMDISK, Chongqing VIP database and CNKI database. Those reported in English journals were identified using MEDLINE. Selected studies had to describe an original study defined by strict screening and diagnostic criteria. The fixed effects model or random effects model was employed according to statistical test for homogeneity. RESULTS: Twenty-five studies were selected, the statistical information of which was collected for systematic analysis. Our results showed that AD and VD were the two major subtypes of dementia in China, and the pooled prevalence of AD and VD for the population aged 60 years and older was 1.6 and 0.8%, respectively. There was a higher prevalence of AD in the illiterate elderly population (3.2%) than in those who received years of education. The chronological prevalence of AD increased significantly from 1980 to 2004. In southern and northern China, the prevalence of AD was 2.0 and 1.2%, respectively, while VD was 0.6 and 1.1%, respectively. CONCLUSIONS: In the last 24 years, AD and VD were the two major subtypes of dementia in China. The prevalence of AD may be affected by sex, education, occupation or age. The prevalence of VD, which was higher in northern than in southern China, seems not to be affected by age, sex or education.

[Characteristics and Influencing factors of Sperm Interaction with Exogenous DNA].

Exogenous DNA localization and the frequency of spermatozoa carrying exogenous DNA after sperm/DNA co-culture are key to a successful sperm mediated-gene transfer (SMGT). In the study, the characteristics and influencing factors of exogenous DNA uptake by spermatozoa were tested using digoxigenin (DIG) labeled DNA as trace. Results showed that goat spermatozoa could spontaneously take up exogenous DNA. The exogenous DNA was initially bound to the outer sperm membrane at postacrosomal region; subsequently party of the bound DNA was internalized into nucleus. There were considerable differences in the capability of spermatozoa from different donors to bind and internalize exogenous DNA. In 35 samples, binding rates (before DNase I digestion) and internalization rates (the positive rate after DNase I digestion) varied between 4.6%-62.4% and 2.1%-53.8%, respectively. For the spermatozoa from the same goat, the binding and internalization capacities were mostly inhibited by the seminal fluid. Compared to ejaculate sperm, the binding rate and internalization rate were increased three and five times in washed sperm cells, respectively. At the same time, capacitated spermatozoa also had lower exogenous DNA uptake (P<0.01). Dead spermatozoa did not complete the internalization process. The highest positive rate (before DNase I digestion) was found in membrane-broken spermatozoa as a result of freeze-thawing and this was independent of the sperm donors. These results suggest that selection of appropriate sperm donors and optimization of sperm processing procedures are the key steps for successful SMGT.

[Accelerated somatic cell senescence and changes in p16INK4a expression after exogenous DNA transfection].

During the transfection of mouse embryonic fibroblasts (MEF), we found these cells became senescent, appearing enlarged with hollow cytoplasm and multinucleated. The telomere lengths of these senescent MEFs were significantly shorter than primary untransfected MEFs. In senescent MEF cells, DNA methylation of p16INK4a 5'-regulatory region showed gradual reduction as cells aged. RT-PCR and Northern blot demonstrated that the expression of p16INK4a in transfected senescent cells was 12-16 times more than primary cells. The senescent transfected MEF cells as donors of nuclei could support the early development of cloned embryos after nuclear transfer.

[Synthesis of total sFat-1 gene by PCR-restrict enzyme ligation method].

Gene synthesis is very important in life science research, and it becomes a technique in common use. It is difficult for long gene synthesis, because the mismatches and mutations of DNA sequence in nucleotide fragments assembling. This study established a new method for long gene synthesis, which was referred to as PCR-restrict enzyme ligation method. With this method, a omega-3 fatty acid desaturase gene, sFat-1, from Caenorhabditis briggssae, was successfully assembled from 27 synthesized nucleotide fragments (60 ~ 68 bp for each fragment ) following 3 rounds of PCR (7 reactions) and 2 rounds of restrict enzyme ligation (3 reactions). This shows that the PCR-restrict enzyme ligation method is an effective method for long gene synthesis.

[High-efficient gene targeting of goat mammary epithelium cell by the multi-selection mechanism].

Gene targeting is a more powerful method to produce mammary gland bioreactor and nuclear transfer from cultured somatic cells provides an wonderful means of cell-mediated transgensis. Here we describe an efficient and reproducible gene targeting in goat mammary epithelium cell to place the GFP and neo at the beta-casein locus. The transgenic goat would be produced by nuclear transfer. To construct the gene targeting vector pGBC-GFP-neo, the milk goat beta-casein genomic DNA sequence for homologous arms was cloned first. The left arm was 2.1 kb fragment including goat beta-casein gene exon1 and part of exon 2, and the right arm was 5.1 kb fragment including beta-casein gene from exon 7 to 3'-flanking sequence. The bacterial neomycin (neo) gene as positive selection marker gene, with the promoter-trap GFP, was placed between two loxPs. The thymidine kinase (tk) as negative selection marker gene was just outside the right or left arms. Goat mammary epithelium cells were cultured to sub-confluence about 90% and transfected with linear pGBC-GFP-neo using Lipefectamin-2000. These transfected cells were cultured in collagen-coated 96-wellplate for 24 h without selection, then added the drug G418(600 microg/mL) and GANC(2 micromol/L). After nine days of selection, well separated G418r/GANCr clones were isolated and expanded in 24-wellplate; 51 clones were selected; 17 clones were tested by GFP expression using promoter-trap strategy; only four clones grow well. After PCR confirmation the four targeting cell clones homologous recombination were used as the donor cell for nuclear transfer. 59.5% cloned embryos could develop up. Some could develop to morula or blastocyst in vitro.

[The targeting study of human serum albumin gene].

To generate transgenic porcine which expresses human serum albumin (HSA), the HSA gene targeting vector was constructed with HSA cDNA as the gene of interestand partial porcine serum albumin (PSA) gene as homologous arms which respectively were 7.2 kb 5' regulation sequence and 2.8 kb genomic sequence from the first intron to the fourth intron. The resistant gene neo was inserted into intron 1 and tk was ligated to the 3' end of the construct. Linearized targeting construct DNA was introduced into the fibroblast cells obtained from porcine fetus by electroporation. The positive-negative selection was performed and survival clones were screened by PCR and Southern blot. Three colonies with correct homologous recombination were obtained. Our results set a good basis for the establishment of transgenic porcine by gene target and nuclear transfer methods.

[The synthesis and function analysis of omega-3 fatty acid desaturase gene from Caenorhabditis briggssae].

Omega-3 polyunsaturated fatty acids (PUFAs) have been broadly investigated and shown to exert many preventive and therapeutic actions besides their important role in maintenances human health and normal development. In mammals, the level of omega-3 PUFAs is relatively too low compared with omega-6 PUFAs, which metabolically and functionally distinct from omega-3 PUFAs and often have important opposing physiological functions. Either the inefficiency of omega-3 PUFAs or the excess of omega-6 PUFAs will cause many healthy problems. So methods have been sought to increase the amount of omega-3 PUFAs and to improve the omega-6/omega-3 ratio in body. In this study, the sFat-1 gene, which putatively encodes a omega-3 fatty acid desaturase, was chemically synthesized according to the sequence from Caenorhabditis briggssae (with codon usage modified), and constructed into a mammal expression vector pcDNA3. 1-sFat1-EGFP. This vector was introduced into CHO cells by lipid-mediated transfection, and it's expression quickly and effectively elevated the cellular omega-3 PUFAs (from 18-carbon to 22-carbon) contents and dramatically improved the ratio of omega-6/omega-3 PUFAs. Cellular lipids extracts from stably selected cells were analyzed with GC-MS and the results showed that amount of total omega-6 PUFAs dropped from 48.97% (in GFP cells)to 35.29% (in sFat-1 cells), whereas the amount of total omega-3 PUFAs increased from 7.86% to 24.02%, respectively. The omega-6/omega-3 ratio also dropped from 6.23 to 1.47. These data demonstrates the Caenorhabditis briggssae omega-3 Fatty Acid Desaturase gene, sFat-1, was synthesized successfully and can produce omega-3 PUFAs by using the corresponding omega-6 PUFAs as substrates, which shows its potential for use in the production of omega-3 PUFAs in transgenic animals.

[The construction and characterization of human pro-urokinase mutant].

It is very easy for the pro-UK to lose it's biological activity because of the digestion of pro-UK by the thrombin or the inhibition of pro-UK by the PAI-I. So three pro-UK mutant (pro-UK) genes were constructed in this experiment with the PCR point-mutant method. The thrombin cleavage site Arg156 in pro-UK was mutated into His156, and named as pro-UKM1; PAI binding sites Arg178, Arg179, Arg181 were mutated into Lys178, Lys179, His181, named as pro-UKM2; The mutant containing His156, Lys178, Lys179, His181 as pro-UKM3. Three mutants were expressed in CHO cells respectively and analyzed with SDS-PAGE fibrin plate assay and western blot. The results showed that the three mutants and the native pro-UK have the same single electrophoresis band indicating most of the pro-UK was single chain. In vitro plasma clot lysis assays indicated that the pro-UKM1 have the ability to resistant against thrombin digestion; pro-UK2 could resist against PAI inhibition; while pro-UK3 improved resistances against both thrombin and PAI. It looks very promising that the pro-UK3 can be a new medicine of dissolving thrombus.

[Exact logistic regression and its performance to SAS system].

OBJECTIVE: To explore the feasibility of exact logistic regression, used as a complemental method for the maximum liklihood estimation, and to analyse with data small sample, unbalanced structure and highly stratal nature under the situations of questionable results or inexistence of the maximum likelihood estimation. METHODS: Data from 37 postoperative breast cancer cases were analyzed in 1997 by exact logistic regression under SAS system. RESULTS: Data calculated by SAS software showed that Quasi-complete separation of data points was detected but the results of maximum likelihood estimation did not exist, SAS outputs conflicted the results of the last maximum likelihood iteration (likelihood Chi-square and score Chi-square have similar P, less than 0.05, but the Wald chi-square had a larger P, more than 0.05). Under conditional exact parameter estimation, it appeared that: (1) the joint effect of conditional score statistics was 21.12 with P = 0.000 3; (2) for individual parameters, the effect conditional score statistics of histological classification (grades) was 5.80 with P = 0.020 8; axillary node metastasis (diversion) was 5.74 with P = 0.019 5; tumor size (size) was 0.79, with P = 0.647 6. The effects of tumor histological classification and axillary node metastasis were statistically significant on breast cancer tumour. CONCLUSION: Exact logistic regression seemed to be a very useful method in analyzing data from small sample when the maximum likelihood estimation was either with no effect or did not exist.

[Screening of TNF-alpha antagonist peptides from a random peptide library displayed with Escherichia coli flagellar].

Tumor necrosis factor(TNF-alpha) plays an improtant role in the process of anti-infection and anti-cancer. It can both protect and make damage to the host. In order to find new way of inhibiting its host-damaging activity, An E. coli flagella displayed random peptide library was constructed and TNF-alpha antagonist peptides were screened using the peptide library. After 5 rounds of panning and DNA sequencing, six peptide sequences were obtained. Two of them(TBP2, TBP3) have the same sequence frame of V--N-WG. After primary comparation of TNF-alpha binding ability, four peptides were synthesised and purified with RP-HPLC. The activity of inhibiting TNF-alpha was detected with L929 cell and MTT method. The data show that TBP2 and TBP3 can inhibit 90% of TNF-alpha activity when TNF-alpha gives about 30% cell toxicity on L929. The two sequences have not been reported.

[Synthesis and function analysis of a new thrombopoietin (TPO) mimic peptide].

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.