PPAR Gamma Coactivator 1 Beta (PGC-1ß) Reduces Mammalian Target of Rapamycin (mTOR) Expression via a SIRT1-Dependent Mechanism in Neurons.

Mammalian target of rapamycin (mTOR) is a key regulator of metabolism, cell growth, and protein synthesis. Since decreased mTOR activity has been found to slow aging in many species, the aim of this study was to examine the activity of mTOR and its phosphorylated form in in vitro and in vivo models mimicking Alzheimer's disease (AD), and investigate the potential pathway of PGC-1ß in regulating mTOR expression. Primary neurons and N2a cells were treated with Aß25-35, while untreated cells served as controls. The expression of mTOR, p-mTOR (Ser2448), and PGC-1ß was determined with Western blotting and RT-PCR assay, and the translocation of mTOR was detected using confocal microscopy. Aß25-35 treatment stimulated the translocation of mTOR from cytoplasm to nucleus, and resulted in elevated expression of mTOR and p-mTOR (Ser2448) and reduced PGC-1ß expression. In addition, overexpression of PGC-1ß was found to decrease mTOR expression. The results of this study demonstrate that Aß increases the expression of mTOR and p-mTOR at the site of Ser2448, and the stimulation of Aß is likely to depend on sirtuin 1, PPARγ, and PGC-1ß pathway in regulating mTOR expression.

N-terminal and C-terminal heparin-binding domain polypeptides derived from fibronectin reduce adhesion and invasion of liver cancer cells.

BACKGROUND: Fibronectin (FN) is known to be a large multifunction glycoprotein with binding sites for many substances, including N-terminal and C-terminal heparin-binding domains. We investigated the effects of highly purified rhFNHN29 and rhFNHC36 polypeptides originally cloned from the two heparin-binding domains on the adhesion and invasion of highly metastatic human hepatocellular carcinoma cells (MHCC97H) and analyzed the underlying mechanism involved. METHODS: The MHCC97H cells that adhered to FN in the presence of various concentrations of rhFNHN29 and rhFNHC36 polypeptides were stained with crystal violet and measured, and the effects of rhFNHN29 and rhFNHC36 on the invasion of the MHCC97H cells were then detected using the Matrigel invasion assay as well as a lung-metastasis mouse model. The expression level of integrins and focal adhesion kinase (FAK) phosphotyrosyl protein was examined by Western blot, and the activity of matrix metalloproteinases (MMPs) and activator protein 1 (AP-1) was analyzed by gelatin zymography and the electrophoretic mobility band-shift assay (EMSA), respectively. RESULTS: Both of the polypeptides rhFNHN29 and rhFNHC36 inhibited adhesion and invasion of MHCC97H cells; however, rhFNHC36 exhibited inhibition at a lower dose than rhFNHN29. These inhibitory effects were mediated by integrin αvß3 and reversed by a protein tyrosine phosphatase inhibitor. Polypeptides rhFNHN29 and rhFNHC36 abrogated the tyrosine phosphorylation of focal adhesion kinase (p-FAK) and activation of activator protein 1 (AP-1), resulting in the decrease of integrin αv, ß3 and ß1 expression as well as the reduction of MMP-9 activity. CONCLUSIONS: Polypeptides rhFNHN29 and rhFNHC36 could potentially be applicable to human liver cancer as anti-adhesive and anti-invasive agents.

[Preparation of recombinant polypeptide of N-terminal heparin-binding domain of fibronectin and its effect on disseminated intravascular coagulation in rats].

This study was aimed to prepare the polypeptide of N-terminal heparin-binding domain of fibronectin(rhFNHN-29 polypeptide) with pichia expression system, to detect biological activity of recombinant polypeptide and investigate its effect on disseminated intravascular coagulation (DIC) in rats. The sequence of N-terminal heparin-binding domain of fibronectin was amplified from FNcDNA by PCR. The aim gene was cloned into T vector for selection. Then it was cloned into pAo815SM and pPIC9K vectors.Lined pPIC9K vectors were transformed into GS115 Pichia cells so as to express the aim polypeptide in Pichia expression system. The fermentation liquid were precipitated by 80% ammonium sulfate, and the further dissolved sediment were purified using S-100 column and SP column. Its activity of binding with heparin were detected by Western-blot. The established DIC rats (40 rats) were randomly divided into two groups. One group was treated with rhFNHN-29 polypeptide, and the other was treated with normal saline. The rats in the former group were injected with rhFNHN-29 polypeptide (10 mg/kg) through tail vein at 0.5 hour before, 2 hours and 4 hours after injection of LPS respectively. The rats in latter group were injected with equal volume saline. In addition, 20 normal rats injected with normal saline were as normal controls. 500 microl blood was taken from the rat vein, at 6 hours after the injection of LPS. White blood cell (WBC), hemoglobin (Hb) and platelets were tested from 50 microl blood. The rest 450 microl blood was used to isolate plasma for detecting TNFa level and coagulogram. The rats were killed at 24 hours after injection with LPS. Their livers, lungs, hearts, kidneys, and brain tissues were taken for histopathologic examination. The results showed that the aim polypeptide was successfully expressed in Pichia expression system. The expression level reached approximately 30 mg/L. The polypeptide had activity of binding with heparin antibody. In the experiment study of polypeptide effect on DIC in rats, the plasma TNFa level in polypeptide-treated group was lower than that in saline control group, the hemogram, coagulogram and histopathology were more obviously improved in polypeptide-treated group as compared with saline control group. It is concluded that the rhFNHN-29 polypeptide is successfully prepared, this polypeptide can antagonize DIC induced by endotoxin in rats.

[Recombinant polypeptide of N-terminal heparin-binding domain of fibronectin antagonizes hepatic failure induced by endotoxin in mice].

OBJECTIVE: To study the preventive effect of recombinant polypeptide of N-terminal heparin-binding domain of fibronectin on hepatic failure induced by endotoxin in mice. METHODS: The 40 hepatic failure Balb/C mice were established by intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). The mice were randomly divided into two groups, one for polypeptide treatment, the othe for saline treatment.Another 20 mice were used as normal control. Half hour prior to, 1, 2, and 3 hours after injection of LPS and GalN, the rhFNHN-29 polypeptide (10 mg/kg) was injected through the tail vein of mice. The same volume of saline was given to the saline treated group and the normal control group.Six hours after the injection of LPS and GalN, 250 microl blood was taken from the eye vein of each mouse for plasma TNFalpha testing, and 72 hours after the injection, mortality rates of the mice of different groups were observated. The liver, lung, heart, kidney, and brain tissues of the survival mice were examined for histopathology after 72 hours. The Liver tissue was also examined for electron micrograph and for mRNA expression of TNFalpha, IL-1beta, IL-6 by RT-PCR. RESULTS: The 72 hours mortality rates in saline-treated and polypeptide treated-mice were 70% and 15% respectively (P < 0.01). The histopathology showed that necrosis occurred less on the hepatocytes of polypeptide treated mice than on the saline treated ones. The ultrastructure of hepatocyte under the electron microscope showed that cell apparatus of saline treated mice were destroyed and cytoplasm become loose. The expression level of TNFalpha, IL-1beta, IL-6 mRNA on hepatocytes in polypeptide treated mice was significantly lower (1.26 +/- 0.37, 0.98 +/- 0.21, 0.43 +/- 0.17, 87.43 +/- 16.7 respectively) than that in the saline treated ones (1.98 +/- 0.56, 1.24 +/- 0.35, 0.64 +/- 0.25 and 236.11 +/- 32.7, respectively) (P < 0.01). Similarly, the plasm TNFalpha level (87.43 +/- 16.7) in polypeptide treated group was significantly lower than that (236.11 +/- 32.7) in the saline treated group (P < 0.01). CONCLUSION: The rhFNHN-29 polypeptide can prevent and treat hepatic failure induced by endotoxin. The mechanism by which the polypeptide takes the effect may involve its ability to down-regulate expression of those inflammation factors such as TNFalpha, IL-1beta, IL-6.

[Rapid diagnosis of Down's syndrome by multiplex real-time fluorescence relative quantitative PCR].

To establish a multiplex real-time fluorescence relative quantitative PCR method for diagnosis of Down's syndrome. The fragment from Down's syndrome critical region gene 3 (DSCR3) on chromosome 21 was used as the target gene, and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene on chromosome 12 was used as the control gene. The two genes were amplified in the same tube. The relative quantitative index-CT value was used to differentiate trisomy 21 patient from normal person. The peripheral blood sample from a Down's syndrome patient was collected and the B-lymphocytes were transformed by Epstein-Barr virus to establish the immortalized cell lines as standard material. The reaction conditions were optimized to obtain an equal amplification efficiency from both the target and the control genes. The slopes of both genes were almost -3.32, indicating that the efficiencies of the two amplifications were approximately equal. Among a certain range from 3-300 ng/PCR, the variation of detected DeltaCT value were less than 15%, and amplification showed the highest reproducibility when the concentration of DNA template was 30 ng/microL. Then, the variation of DeltaCT value with inter- and intra-assay were 9.8% and 13.3% at this DNA concentration of the templates. Clinical samples, including 20 blood samples from patients and 30 blood samples from normal persons, were detected using the established method. The DeltaCT value from Down's syndrome group were dramatically different from normal group (P < 0.001). The trisomy 21 immortalized cell lines were established and the genetic integrity of the cell lines was stable as evaluated by karyotype and DNA analysis. The relative quantitative PCR with DeltaCT value could be used to rapidly diagnose Down's syndrome.

[Y chromosome relative length analysis of 106 case of Fujian she ethnic].

It is found that the distribution of Human Y chromosome relative length (Y/F) is different obviously within different ethnic and population. There are disputations on the relationship of Y/F with height and reproduction. By measuring the Y/F and height of 106 case (53 pairs of fathers and sons) of Fujian she ethnic, we can find that the Y chromosome relative length of Fujian she ethnic has plumb inheritance within pedigree and the appearance rate of long Y is 11.1%, below the medium level.