Ultrashort peptides have higher stability, tissue penetrability, biocompatibility, and less immunogenicity, and are widely applied in biology and medicine. GHK (glycyl-l-histidyl-l-lysine) and GQPR (glycyl-l-glutamyl-l-prolyl-l-arginine) can stimulate collagen renewal and inhibit collagen degradation. GHK and GQPR have been used in cosmetic anti-wrinkle skincare and make-up products. The most common approach for ultrashort peptide production is the solid-phase synthesis, which is eco-unfriendly due to heavy usage of organic chemical reagents during the manufacturing process. Here we report a new approach to the production of ultrashort peptides. Recombinant expression of ultrashort peptides is usually unfeasible because of the short amino acid sequences. A vector pET28a-Trxm harboring the thioredoxin gene was first constructed for subsequent fusion expression. The tandem repeats of GHK and GQPR genes were used as the templates for rolling circle amplification (RCA). The RCA reaction was tuned to incorporate noncanonical nucleotides 5-methylcytosine to obtain long DNA fragments. Gene sequences with various lengths were generated through double digestion of Acc65 Ⅰ and Apa Ⅰ. The resulting digestion products were gel recovered by size (from 500 bp to 1 500 bp) and cloned into pET28a-Trxm to obtain the recombinant vector pET28a-Trxm-(TRSP)_n. The pET28a-Trxm-(TRSP)_n was introduced into E. coli BL21(DE3) to generate a library of Trxm-(TRSP)_n sequences with a controlled distribution of lengths. Through double digestion and sequencing, positive clones with tandem repeats n=1, 2, 3, 4, 6, 7, 8, 9 were obtained. Protein expression results showed protein bands with corresponding molecular weight, and the protein expression level decreased as the tandem repeats increased. The expression level of Trxm-(TRSP)₁ achieved 50% of the total protein, while the expression level of Trxm-(TRSP)₂ was 30% of the total protein. The crude extracts from cell pellets were further treated with enterokinase cleavage, and the supernatants containing (TRSP)₁ were collected after ultrafiltration and then subjected to trypsin cleavage. HPLC analysis indicated that the ultrashort peptides GHK and GQPR were successfully obtained through two-step cleavage. This study may facilitate the commercial production of ultrashort peptides.
Escherichia coli/metabolism* ; Peptides/chemistry* ; Amino Acid Sequence ; Gene Library ; Tandem Repeat Sequences

Myloid beta(Aβ) is produced by cleavage of amyloid precursor protein(APP), which is a main reason for Alzheimer's disease(AD) occurrence and development. This study preliminarily investigated the mechanism of Atractylodes macrocephala(AM) against AD based on LKB1-AMPK-TFEB pathway. The effect of AM on memory ability of AD transgenic Caenorhabditis elegans CL2241 was detected, and then the APP plasmid was transiently transferred to mouse neuroblastoma(N2 a) cells in vitro. The mice were divided into the blank control group, APP group(model group), positive control group(100 μmol·L~(-1) rapamycin), and AM low-, medium-and high-dose groups(100, 200 and 300 μg·mL~(-1)). The content of Aβ_(1-42) in cell medium, the protein level of APP, the fluorescence intensity of APP, the transcriptional activity of transcription factor EB(TFEB), the activity of lysosomes in autophagy, and autophagy flux were determined by enzyme-linked immunosorbent assay(ELISA), Western blot, fluorescence microscope, luciferase reporter gene assay, RLuc-LC3 wt/RLuc-LC3 G120 A, and mRFP-GFP-LC3, respectively. The protein expression of TFEB, LC3Ⅱ, LC3Ⅰ, LAMP2, Beclin1, LKB1, p-AMPK and p-ACC was detected by Western blot. Immunofluorescence and reverse transcription-polymerase chain reaction(RT-PCR) were used to detect the fluorescence intensity of TFEB and the mRNA expression of TFEB and downstream target genes, respectively. The results showed that AM reduced the chemotactic index of transgenic C. elegans CL2241, and decreased the content of Aβ in the supernatant of cell culture medium at different concentrations. In addition, AM lowered the protein level of APP and the fluorescence intensity of APP in a dose-dependent manner. Transcriptional activity of TFEB and fluorescence intensity of mRFP-GFP-LC3 plasmid were enhanced after AM treatment, and the value of RLuc-LC3 wt/RLuc-LC3 G120 A was reduced. AM promoted the protein levels of TFEB, LAMP2 and Beclin1 at different concentrations, and increased the protein expression ratio of LC3Ⅱ/LC3Ⅰ in a dose-dependent manner. Immunofluorescence results revealed that AM improved the fluorescence intensity and nuclear expression of TFEB, and RT-PCR results indicated that AM of various concentrations elevated the mRNA expression of TFEB in APP transfected N2 a cells and promoted the transcription level of LAMP2 in a dose-dependent manner, and high-concentration AM also increased the mRNA levels of LC3 and P62. The protein levels of LKB1, p-AMPK and p-ACC were elevated by AM of different concentrations. In summary, AM regulating lysophagy and degrading APP are related to the activation of LKB1-AMPK-TFEB pathway.
AMP-Activated Protein Kinases/metabolism* ; Alzheimer Disease/drug therapy* ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor/metabolism* ; Animals ; Atractylodes/chemistry* ; Autophagy/drug effects* ; Beclin-1/pharmacology* ; Caenorhabditis elegans/metabolism* ; Macroautophagy ; Mice ; RNA, Messenger ; Sirolimus/pharmacology*

To determine the inhibitory effect of endophytic fungi from Dysosma versipellis on HIV-1 IN-LEDGF/p75 interaction,the protein-protein interaction between human immunodeficiency virus type 1( HIV-1) integrase and lens epithelial growth factor p75 protein( LEDGF/p75) was used as a target. The homogeneous time-resolved fluorescence( HTRF) technique was used in the inhibitory activity assay. The results showed that eight endophytic fungi with anti-IN-LEDGF/p75 interaction activity were screened out from fifty-three strains with different morphological characteristic. Among them,106 strain showed strong inhibitory activity against HIV-1 IN-LEDGF/p75 interaction with IC50 value of 5. 23 mg·L-1,and was identified as a potential novel species of Magnaporthaceae family by the analyses of ITS-rDNA,LSU and RPB2 sequences data. This study demonstrated that potential natural active ingredients against the HIV-1 IN-LEDGF/p75 interaction exist in the endophytic fungi of D. versipellis. These results may provide available candidate strain resources for the research and development of new anti-acquired immunodeficiency syndrome drugs.
Berberidaceae ; microbiology ; Endophytes ; Fungi ; chemistry ; HIV Integrase ; metabolism ; HIV-1 ; drug effects ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Protein Binding

The aim of this paper was to discuss the protective effect and mechanism of Acanthopanax senticosus polysaccharides( ASPs) on immunological liver injury caused by conanavalin A( Con A). BALB/c mice were randomly divided into seven groups: control group,model group( Con A),low-,medium-,and high-dose( 36. 25,72. 5,145 mg·kg~(-1)) ASPs groups,bifendate( 200 mg·kg~(-1),positive drug) group and pyrrolidinedithiocarbamate( PDTC,NF-κB inhibitor,200 mg·kg~(-1)) group. ASPs groups and bifendate group were given with corresponding drugs by ig administration once daily for 7 d. Control group,model group and PDTC group were given with normal saline by ig administration once daily for 7 d. After the last ig administration,PDTC was given in DTC group by iv administration( 200 mg·kg~(-1)); 0. 5 h after that,Con A( 20 mg·kg~(-1)) was injected via the tail vein to induce immunological liver injury in all the mice except normal control group. The mice were killed 8 h later and their liver tissues were collected for histopathological examination. The contents of nitric oxide( NO),superoxide dismutase( SOD),malondialdehyde( MDA),reduced glutathione( GSHPX),interleukin( IL-1β) and tumor necrosis factor( TNF-α) in liver tissues were detected by kit assay. Western blot method was used to detect TNF-α,intercellular cell adhesion molecule-1( ICAM-1),inducible nitric oxide synthase( i NOS) and nuclear factor( NF-κB) protein expression in liver tissues. As compared with model group,ASPs not only could reduce the activity of MDA,NO,IL-1β and TNF-α,but also increase the content of GSH-PX and SOD; at the same time,the protein expression levels of TNF-α,ICAM-1,i NOS and NF-κB were reduced in liver tissues; in addition,inflammatory cell infiltration was alleviated,hepatocyte cytoplasm was loose and swollen,and nuclear condensation and staining were improved. ASPs has a protective effect on immunological liver injury,and the mechanism may be associated with regulating secretion of inflammatory cytokines and the expression of adhesion factor through NF-κB signaling pathway.
Animals ; Chemical and Drug Induced Liver Injury ; drug therapy ; Cytokines ; metabolism ; Eleutherococcus ; chemistry ; Liver ; drug effects ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; metabolism ; Peptides, Cyclic ; Polysaccharides ; pharmacology ; Random Allocation ; Signal Transduction

Romipeptides A and B (1 and 2), two new romidepsin derivatives, and three known compounds, chromopeptide A (3), romidepsin (4) and valine-leucine dipeptide (5) were isolated from the fermentation broth of Chromobacterium violaceum No. 968. Their structures were elucidated by interpretation of their UV, HR-ESI-MS and NMR spectra. The absolute configuration of compound 1 and 2 were established by single crystal X-ray diffraction analysis. Compounds 1-5 were evaluated for their anti-proliferative activities against three human cancer cell lines, SW620, HL60, and A549. The results showed most of these compounds exhibited antitumor activities in vitro, in which compound 2 displayed potent cytotoxicity to SW620, HL60 and A549 cell lines, with IC of 12.5, 6.7 and 5.7 nmol·L, respectively.
Antineoplastic Agents ; chemistry ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Chemistry Techniques, Analytical ; Chromobacterium ; metabolism ; Depsipeptides ; chemistry ; pharmacology ; Dipeptides ; chemistry ; Drug Screening Assays, Antitumor ; Fermentation ; Humans ; Molecular Structure ; Peptides, Cyclic ; chemistry

By using an RAD peptide display system derived from the ATPase domain of recombinase RadA of Pyrococcus furiosus, an anti-hCG antibody-like molecule was prepared by grafting an hCG-binding peptide to the RAD scaffold. After linking to sfGFP gene, a gene of hCG peptide-grafted RAD was synthesized and cloned into a bacterial expression vector (pET30a-RAD/hCGBP-sfGFP). The vector was transformed into Escherichia coli, and expression of the fusion protein was induced. After isolation and purification of the fusion protein, its binding affinity and specificity to hCG were determined by using a process of immunoabsorption followed by GFP fluorescence measurement. A comparison of hCG-binding activity with a similarly grafted single-domain antibody based on a universal scaffold was performed. The measurement of hCG-binding affinity and specificity revealed that the grafted RAD has an optimally high binding affinity and specificity to hCG, which are better than the grafted single-domain antibody. Moreover, the affinity and specificity of grafted RAD molecule are comparable to those of a commercial monoclonal antibody. In addition, the hCG-binding peptide-grafted RAD molecule has a relatively high biochemical stability, making it a good substitute for antibody with potential application.
Antibodies, Monoclonal ; chemistry ; isolation & purification ; metabolism ; Antibody Specificity ; DNA-Binding Proteins ; genetics ; metabolism ; Escherichia coli ; genetics ; Escherichia coli Proteins ; metabolism ; Humans ; Peptides ; Recombinant Fusion Proteins ; genetics ; metabolism

BACKGROUND: Bone marrow-derived mesenchymal stem cells (BM-MSCs) play an important role in cancer development and progression. However, the mechanism by which they enhance the chemoresistance of ovarian cancer is unknown. METHODS: Conditioned media of BM-MSCs (BM-MSC-CM) were analyzed using a technique based on microRNA arrays. The most highly expressed microRNAs were selected for testing their effects on glycolysis and chemoresistance in SKOV3 and COC1 ovarian cancer cells. The targeted gene and related signaling pathway were investigated using in silico analysis and in vitro cancer cell models. Kaplan-Merier survival analysis was performed on a population of 59 patients enrolled to analyze the clinical significance of microRNA findings in the prognosis of ovarian cancer. RESULTS: MiR-1180 was the most abundant microRNA detected in BM-MSC-CM, which simultaneously induces glycolysis and chemoresistance (against cisplatin) in ovarian cancer cells. The secreted frizzled-related protein 1 (SFRP1) gene was identified as a major target of miR-1180. The overexpression of miR-1180 led to the activation of Wnt signaling and its downstream components, namely Wnt5a, β-catenin, c-Myc, and CyclinD1, which are responsible for glycolysis-induced chemoresistance. The miR-1180 level was inversely correlated with SFRP1 mRNA expression in ovarian cancer tissue. The overexpressed miR-1180 was associated with a poor prognosis for the long-term (96-month) survival of ovarian cancer patients. CONCLUSIONS BM-MSCs enhance the chemoresistance of ovarian cancer by releasing miR-1180. The released miR-1180 activates the Wnt signaling pathway in cancer cells by targeting SFRP1. The enhanced Wnt signaling upregulates the glycolytic level (i.e. Warburg effect), which reinforces the chemoresistance property of ovarian cancer cells.
Adenosine Triphosphate/chemistry* ; Adult ; Aged ; Bone Marrow Cells/cytology* ; Cell Line, Tumor ; Cell Proliferation ; Cells, Cultured ; Drug Resistance, Neoplasm/genetics* ; Female ; Flow Cytometry ; Follow-Up Studies ; Glycolysis ; Humans ; Intercellular Signaling Peptides and Proteins/metabolism* ; Membrane Proteins/metabolism* ; Mesenchymal Stem Cells/cytology* ; MicroRNAs/genetics* ; Middle Aged ; Multivariate Analysis ; Ovarian Neoplasms/genetics* ; Up-Regulation ; Wnt Signaling Pathway

OBJECTIVETo research Angelica tenuissima Nakai (ATN) for use in novel Alzheimer's disease (AD) therapeutics.

METHODSThe effect of a 30% ethanol extract of ATN (KH032) on AD-like cognitive impairment and neuropathological and neuroinflammatory changes induced by bilateral intracerebroventricular injections of β-amyloid (Aβ) peptide (Aβ) was investigated. Male C57Bl/6 mice were randomly divided into 4 groups, 10 in each group. KH032-treated groups were administrated with a low or high dose of KH032 (50 and 200 mg/kg, respectively), intragastrically for 16 days; distilled water was applied in the sham and negative groups. Open fifield test, Y maze and Morris water maze test were used for behavior test and cognitive ability. In addition, the neuroprotective effects of KH032 in Aβ-infused mice on the histopathological markers [neuronspecific nuclear protein (NeuN), Aβ] of neurodegeneration were examined. The levels of glial fibrillary acidic protein (GFAP), NeuN, phosphorylation extracellular signal-regulated kinase (ERK)/ERK, brain-derived neurotrophic factor (BDNF), phosphorylation cAMP response element-binding (CREB)/CREB protein expression were measured by Western blot.

RESULTSKH032 treatment ameliorated cognitive impairments, reduced the overexpression of Aβ, and inhibited neuronal loss and neuroinflammatory response in the Aβ-infused mice. Moreover, KH032 treatment enhanced BDNF expression levels in the hippocampus. Finally, KH032 treatment increased phosphorylation of ERK1/2 and CREB, vital for ERK-CREB signaling.

CONCLUSIONSKH032 attenuated cognitive defificits in the Aβ-infused mice by increasing BDNF expression and ERK1/2 and CREB phosphorylation and inhibiting neuronal loss and neuroinflflammatory response, suggesting that KH032 has therapeutic potential in neurodegenerative disorders such as AD.

Alzheimer Disease ; drug therapy ; pathology ; physiopathology ; Amyloid beta-Peptides ; Angelica ; chemistry ; Animals ; Brain ; pathology ; Brain-Derived Neurotrophic Factor ; metabolism ; Cognitive Dysfunction ; complications ; drug therapy ; physiopathology ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Disease Models, Animal ; Male ; Maze Learning ; drug effects ; Memory, Short-Term ; drug effects ; Mice, Inbred C57BL ; Neurogenesis ; drug effects ; Neuroglia ; drug effects ; metabolism ; pathology ; Neurons ; drug effects ; metabolism ; pathology ; Neuroprotective Agents ; pharmacology ; therapeutic use ; Phosphorylation ; drug effects ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Plaque, Amyloid ; drug therapy ; pathology ; physiopathology ; Signal Transduction ; drug effects

OBJECTIVENew rationally designed i,i+7-hydrocarbon-stapled peptides that target both HIV-1 assembly and entry have been shown to have antiviral activity against HIV-1 subtypes circulating in Europe and North America. Here, we aimed to evaluate the antiviral activity of these peptides against HIV-1 subtypes predominantly circulating in China.

METHODSThe antiviral activity of three i,i+7-hydrocarbon-stapled peptides, NYAD-36, NYAD-67, and NYAD-66, against primary HIV-1 CRF07_BC and CRF01_AE isolates was evaluated in peripheral blood mononuclear cells (PBMCs). The activity against the CRF07_BC and CRF01_AE Env-pseudotyped viruses was analyzed in TZM-bl cells.

RESULTSWe found that all the stapled peptides were effective in inhibiting infection by all the primary HIV-1 isolates tested, with 50% inhibitory concentration toward viral replication (IC50) in the low micromolar range. NYAD-36 and NYAD-67 showed better antiviral activity than NYAD-66 did. We further evaluated the sensitivity of CRF01_AE and CRF07_BC Env-pseudotyped viruses to these stapled peptides in a single-cycle virus infectivity assay. As observed with the primary isolates, the IC50s were in the low micromolar range, and NYAD-66 was less effective than NYAD-36 and NYAD-67.

CONCLUSIONHydrocarbon-stapled peptides appear to have broad antiviral activity against the predominant HIV-1 viruses in China. This finding may provide the impetus to the rational design of peptides for future antiviral therapy.

Amino Acid Sequence ; Anti-HIV Agents ; chemistry ; pharmacology ; China ; epidemiology ; HIV Envelope Protein gp120 ; genetics ; metabolism ; HIV Infections ; epidemiology ; virology ; HIV-1 ; drug effects ; genetics ; Humans ; Peptides, Cyclic ; administration & dosage ; pharmacology ; Phylogeny

Nocathiacin I, a glycosylated thiopeptide antibiotic, displays excellent antibacterial activities against multidrug resistant bacterial pathogens. Previously, a novel nocathiacin I formulation for intravenous administration has been successfully developed and its aqueous solubility is greatly enhanced for clinical application. The purpose of the present study was to increase the fermentation titer of nocathiacin I and reduce or eliminate analogous impurities by screening the medium ingredients using response surface methodology. After a sysmatic optimization, a water-soluble medium containing quality-controllable components was developed and validated, resulting in an increase in the production of nocathiacin I from 150 to 405.8 mg·L at 150-L scale. Meanwhile, the analogous impurities existed in reported processes were greatly reduced or eliminated. Using optimized medium for fermentation, nocathiacin I with pharmaceutically acceptable quality was easily obtained with a recovery of 67%. In conclusion, the results from the present study offer a practical and efficient fermentation process for the production of nocathiacin I as a therapeutic agent.
Actinobacteria ; growth & development ; metabolism ; Anti-Bacterial Agents ; biosynthesis ; chemistry ; Bioreactors ; Culture Media ; Fermentation ; Intercellular Signaling Peptides and Proteins ; Peptides ; chemistry ; metabolism ; Quality Improvement