Effect of Static Magnetic Field on Extracellular Proteins Synthesis in Escherichia coli

Escherichia coli type 1 was used as a model system to determine whether static magnetic fields are a general stress factor. The bacterial broth culture were exposed to different magnetic force （400, 800, 1200 and 1600 Gauss） with incubation at 37 ℃ for different times （24, 48 and 72 hrs） under aerobic conditions. The response of the cells to the magnetic fields was estimated from the change in total protein synthesis by using spectrophotometer at 550 nm and by using of SDS-PAGE （Sodium dodecyl sulfate- polyacrylamide gel electrophoresis）. Results concluded that was approximately no reproducible changes qualitatively in extracellular proteins were observed in the SDS-PAGE electrophoresis and did not act as a general stress factor. While, increases in the level of extra-cellular synthesis were observed using different magnetic field exposed samples when compared with the control.

Screening of Extracellular Binding Proteins of Rice Receptor-like Kinase CR4 by the Yeast Two-hybrid

[Objective] The research aimed to find the extracellular binding proteins of CR4.[Method] The extracellular domain of OsCR4 was as the bait protein,and the yeast two-hybrid was used to screen cDNA library of seedling which was cultivated 14 d.[Result] A lot of proteins which included a peroxide B（D26484）,a methionine thioredoxin reductase（ABF96078）and an unknown function protein were gained.[Conclusion] It provided the theory basis for studying the signal transduction mechanism of CR4.

Changes of β_3 Integrins and Extracellular Matrix Proteins in the Endometrium of Unexplained Infertility

The purpose of this study was to investigate changes of β 3 integrins and extra cellular matrix proteins including fibronectin (FN), laminin (LN) and collagen type Ⅳ (CL typeⅣ) on the endometrium of secretory phase from 31 fertile women (fertility group)and 34 women with unexplained infertility (infertility group) by a histochemical method.The results were as follows:In glandular epithelium, β 3 integrin appeared in the mid secretory phase and continued to late secretory phase in the fertility group, but was not expressed during the secretory phase in the infertility group. Extracellular matrix proteins from the fertility group were expressed more strongly in mid secretory phase than that in the early secretory phase, and were weakest in the late secretory phase. Compared with the fertility group, the levels of extracellular matrix proteins in the infertility group were elevated in the secretory phase. In conclusion: our current study demonstrate that β 3 integrin and extracellular matrix proteins are expressed at different levels in the endometrium during the menstrual cycle. They are involved in endometrial changes during the menstrual cycle and during the implantation of the blastocyst. Their unusual expression result in the failure of implantation.

Ultrastructural and Extracellular Protein Changes in Cell Suspension Cultures of Populus euphratica Associated with Low Temperature-induced Cold Acclimation

Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A cell suspension culture was initiated from callus derived from plantlets of Populus euphratica. Cold acclimation was induced (LT50 of 17.5 ℃) in cell suspension at 45 ℃ in the dark for 30 days and the freezing tolerance increased from LT50 of 12.5 ℃ in nonacclimated cells to LT50 of 17.5 ℃ in cold-acclimated cells. Microvacuolation, cytoplasmic augmentation and accumulation of starch granules were observed in cells that were cold-acclimated by exposure to low temperatures. Several qualitative and quantitative changes in proteins were noted during cold acclimation. Antibodies to carrot extracellular (apoplastic) 36 kD antifreeze protein did not cross react on immunoelectroblots with extracellular proteins in cell suspension culture medium of Populus euphratica, indicating no common epitopes in the carrot 36 kD antifreeze protein and P. euphratica extracellular proteins. The relationship of these changes to cold acclimation in Populus euphratica cell cultures was discussed.

Effect of pH values on extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

The effect of pH values on the extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans was comparatively investigated in different phases of bacterial growth during chalcopyrite bioleaching. The results indicate that the extracellular protein is always more than the extracellular polysaccharide secreted by attached cells on the chalcopyrite, on the contrary, and is always less than the extracellular polysaccharide secreted by free cells in the solution at bacterial adaptive phase, logarithmic phase and stationary phase whenever pH value is at 1.0, 1.5, 2.0 or 2.5; free cells are mainly through the secretion of extracellular polysaccharide rather than the extracellular protein to fight against disadvantageous solution environment, such as high concentration of metal ions and unsuitable pH solution; both amounts of polysaccharide and protein secreted by attached cells are mainly positively related to the solution acidity rather than the total concentration of soluble metal ions. The experimental results imply that bacteria are mainly through secreting more extracellular polysaccharide to fight against disadvantageous environment and the extracellular protein perhaps plays an important role in oxidation？reduction reactions in the bioleaching system.

Influence of Ren and Du meridian electro-acupuncture on neural stem cell proliferation and extracellular signal-regulated kinase pathway in a rat model of focal cerebral ischemia injury

BACKGROUND： Studies have shown that electro-acupuncture at the Ren meridian could improve proliferation of subventricular zone neural stem cells in cerebral-ischemic rats. However, there are few reports on the influence of electro-acupuncture at the Du meridian on neural stem cell proliferation. OBJECTIVE： To observe the influence of electro-acupuncture at Ren and Du meridians on neural stem cell proliferation in the subventricular zone and altered signal transduction in cerebral ischemia rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Human Anatomy, Medical College of Sun Yat-sen University from May 2006 to February 2008. MATERIALS： Mouse anti-rat bromodeoxyuridine （BrdU） monoclonal antibody was provided by Sigma, USA; mouse anti-rat nestin monoclonal antibody and extracellular signal-regulated protein kinase （ERK） specific inhibitor PD98059 were provided by Calbiochem, Germany; acupuncture needle was provided by Suzhou Acupuncture Supplies, China. METHODS： A total of 126 rats were randomly assigned to four groups： model （n = 36）, Du meridian （n = 36）, Ren/Du meridian （n = 36）, and Ren/Du meridian ＋ PD98059 （n = 18）. Rats in the Ren/Du meridian ＋ PD98059 group were observed on days 7 （n = 6） and 14 （n = 12） after cerebral ischemia injury. Rats in the model, Du meridian, and Ren/Du meridian groups were observed on days 7, 14, and 28 after cerebral ischemia injury, with 12 rats per group at each time point. Thread occlusion was used to establish middle cerebral artery occlusion models. Electro-acupuncture was performed at Renzhong （DU 26） and Baihui （DU 20） acupoints in the Du meridian group, as well as Chengjiang （RN 24）, Guanyuan （RN 4）, Renzhong, and Baihuiacupoints in the Ren/Du meridian and Ren/Du meridian ＋ PD98059 groups 2 days after model establishment. In addition, electro-acupuncture stimulation with disperse-dense waves was performed, with 30 Hz disperse wave, 100 Hz dense wave, and 5 V intensity for 20 minutes. Rats in the Ren/Du meridian ＋ PD98059 group were treated with 0.2 pg PD98059 injection into the subventricular zone, 2 pL per rat. Rats in the model group were not treated with electro-acupuncture. MAIN OUTCOME MEASURES： BrdU/nestin immunofluorescent staining was used to detect proliferating neural stem cells in the subventricular zone of cerebral ischemia rats; Western blot was used to determine phosphorylated ERK1 and 2 （pERK1/2） expression in the subventricular zone. RESULTS： On days 14 and 28 after cerebral ischemia, there were significantly more BrdU-positive and BrdU/nestin-positive cells in the Ren/Du meridian group compared with the Du meridian group （P 〈 0.05）. PD98059 decreased the number of BrdU-positive and BrdU/nestin-positive cells induced by electro-acupuncture at the/：ten and Du meridians （P 〈 0.05）. On days 7, 14, and 28 after treatment, pERK1/2 expression was significantly greater in the Du meridian and Ren/Du meridian groups compared with the model group （P 〈 0.05）. The promoting effect of electro-acupuncture at Ren and Du meridians on ERK1/2 phosphorylation was superior to electro-acupuncture at the Du meridian alone on day 14 after model induction （P 〈 0.05）. However, PD98059 completely abolished the promoting effect of electro-acupuncture at Ren/Du meridians on pERK1/2 expression （P 〈 0.05）. CONCLUSION： Electro-acupuncture at Ren and Du meridians increased proliferation of subventricular zone neural stem cells, which was related to activation of the ERK pathway in a rat model of cerebral ischemia injury.

Nectin-like Molecule 1 Inhibits the Migration and Invasion of U251 Glioma Cells by Regulating the Expression of An Extracellular Matrix Protein Osteopontin

Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.

Cross-Talk between Extracellular S1P/S1P2 and P42/44 MAPK in bcr/abl Positive Chronic Myeloid Leukemia Cells

Objective： BCR/ABL oncoprotein-expression is associated with uncontrolled cell growth. Sphingosine kinase 1 （SPK1） regulates the production of sphingosine 1-phosphate （S1P）, a key lipid signal molecular in cell proliferation and survival. The objective of this study was to elucidate the roles of S1P and its receptors in bcr/abl positive chronic myeloid leukemia （CML） cells. Methods： The expressions of SIP receptors： S1P1, S1P2 and S1P3 in CML cells were detected by RT-PCR. SPK1 expression, activity and extracellular S1P were determined in ECV304 and HL-60 cells which were transfected with bcr/abl gene. To elucidate the relationship between the BCR/ABL, ERK/MAPK （extracellular signal-regulated kinase/mitogen-activated protein kinase）, SPK/S 1P and S 1P/S 1 P2 signal pathways, bcr/abl positive CML cell line K562 was treated with STI571, PD98059, N,N-dimethyl sphingosine （DMS） and JTE-013. Results： Retrovirus-mediated overexpression of bcr/abl gene in ECV304 and HL-60 cells resulted in upregulation of the expression, activity of SPK1 and increase of the secretion of SIP, whereas treatment of STI571 and PD98059 decreased the BCR/ABL-induced S1P secretion. Treatment of DMS reduced S1P secretion and P42/44MAPK phosphorylation. S1P2-selective antagonist JTE-013 could also decrease P42/44MAPK phosphorylation. Conclusion： These results suggest that BCR/ABL up-regulates extracellular sphingosine 1-phosphate through sphingosine kinase 1 and there is cross-talk between SPK1/S1P/S1P2 and P42/44MAPK in bcr/abl positive CML cells.

Regulation of enolase activation to promote neural protection and regeneration in spinal cord injury

Spinal cord injury(SCI)is a debilitating condition characterized by damage to the spinal cord resulting in loss of function,mobility,and sensation with no U.S.Food and Drug Administration-approved cure.Enolase,a multifunctional glycolytic enzyme upregulated after SCI,promotes pro-and anti-inflammatory events and regulates functional recovery in SCI.Enolase is normally expressed in the cytosol,but the expression is upregulated at the cell surface following cellular injury,promoting glial cell activation and signal transduction pathway activation.SCI-induced microglia activation triggers pro-inflammatory mediators at the injury site,activating other immune cells and metabolic events,i.e.,Rho-associated kinase,contributing to the neuroinflammation found in SCI.Enolase surface expression also activates cathepsin X,resulting in cleavage of the C-terminal end of neuron-specific enolase(NSE)and non-neuronal enolase(NNE).Fully functional enolase is necessary as NSE/NNE C-terminal proteins activate many neurotrophic processes,i.e.,the plasminogen activation system,phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B,and mitogen-activated protein kinase/extracellular signal-regulated kinase.Studies here suggest an enolase inhibitor,ENOblock,attenuates the activation of Rho-associated kinase,which may decrease glial cell activation and promote functional recovery following SCI.Also,ENOblock inhibits cathepsin X,which may help prevent the cleavage of the neurotrophic C-terminal protein allowing full plasminogen activation and phosphatidylinositol-4,5-bisphosphate 3-kinase/mitogen-activated protein kinase activity.The combined NSE/cathepsin X inhibition may serve as a potential therapeutic strategy for preventing neuroinflammation/degeneration and promoting neural cell regeneration and recovery following SCI.The role of cell membrane-expressed enolase and associated metabolic events should be investigated to determine if the same strategies can be applied to other neurodegenerative diseases.Hence,this review discusses the importance of enolase activation and inhibition as a potential therapeutic target following SCI to promote neuronal survival and regeneration.

Optimized new Shengmai powder(优化新生脉散方) inhibits myocardial fibrosis in heart failure by regulating the rat sarcoma/rapidly accelerated fibrosarcoma/mitogen-activated protein kinase kinase/extracellular regulated protein kinases signaling pathway

OBJECTIVE: Exploring the effect of Optimized New Shengmai powder(优化新生脉散方, ONSMP) on myocardial fibrosis in heart failure(HF) based on rat sarcoma(RAS)/rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase kinase(MEK)/extracellular regulated protein kinases(ERK) signaling pathway. METHODS: Randomized 70 Sprague-Dawley rats into sham(n = 10) and operation(n = 60) groups, then established the HF rat by ligating the left anterior descending branch of the coronary artery. We randomly divided the operation group rats into the model, ONSMP [including low(L), medium(M), and high(H) dose], and enalapril groups. After the 4-week drug intervention, echocardiography examines the cardiac function and calculates the ratios of the whole/left heart to the rat's body weight. Finally, we observed the degree of myocardial fibrosis by pathological sections, determined myocardium collagen(COL) Ⅰ and COL Ⅲ content by enzyme-linked immunosorbent assay, detected the m RNA levels of COL Ⅰ, COL Ⅲ, α-smooth muscle actin(α-SMA), and c-Fos proto-oncogene(c-Fos) by universal real-time, and detected the protein expression of p-RAS, p-RAF, p-MEK1/2, p-ERK1/2, p-ETS-like-1 transcription factor(p-ELK1), p-c-Fos, α-SMA, COL Ⅰ, and COL Ⅲ by Western blot. RESULTS: ONSMP can effectively improve HF rat's cardiac function, decrease cardiac organ coefficient, COL volume fraction, and COL Ⅰ/Ⅲ content, down-regulate the m RNA of COL Ⅰ/Ⅲ, α-SMA and c-Fos, and the protein of p-RAS, p-RAF, p-MEK1/2, p-ERK1/2, p-ELK1, c-Fos, COL Ⅰ/Ⅲ, and α-SMA. CONCLUSIONS: ONSMP can effectively reduce myocardial fibrosis in HF rats, and the mechanism may be related to the inhibition of the RAS/RAF/MEK/ERK signaling pathway.

Bio-solubilization of Chinese lignite I:extra-cellular protein analysis

A white rot fungus strain, Trichoderma sp.AH, was isolated from rotten wood in Fushun and used to study the mechanism of lignite bio-solubilization.The results showed that nitric acid pretreated Fushun lignite was solubilized by T.sp.AH and that extracellular proteins from T.sp.AH were correlated with the lignite bio-solubilization results.In the presence of Fushun lignite the extracellular protein concentration from T.sp.AH was 4.5 g/L while the concentration was 3 g/L in the absence of Fushun lignite.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) of the extracellular proteins detected at least four new protein bands after the T.sp.AH had solubilized the lignite.Enzyme color reactions showed that extracellular proteins from T.sp.AH mainly consisted of phenol-oxidases, but that lignin decomposition enzymes such as laccase, peroxidase and manganese peroxidases were not present.

Cyclooxygenase-2 inhibitor inhibits hippocampal synaptic reorganization in pilocarpine-induced status epilepticus rats

Objective： To examine modulations caused by cyclooxygenase-2 （COX-2） inhibitors on altered microenvironments and overbalanced neurotransmitters in pilocarpine-induced epileptic status rats and to investigate possible mechanisms. Methods： Celecoxib （a COX-2 inhibitor） was administered 45 min prior to pilocarpine administration. The effects of COX-2 inhibitors on mlPSCs （miniature GABAergic inhibitory postsynaptic currents） of CA3 pyramidal cells in the hippocampus were recorded. Expressions of COX-2, c-Fos, newly generated neurons, and activated microgliosis were analyzed by immunohistochemistry, and expressions of c^-subunit of y-amino butyric acid （GABAA） receptors and mitogen-activated protein kinase/extracellular signal-regulated protein kinase （MAPK/ERK） activity were detected by Western blotting. Results： Pretreatment with celecoxib showed protection against pilocarpine-induced seizures. Celecoxib prevented microglia activation in the hilus and inhibited the abnormal neurogenesis and astrogliosis in the hippocampus by inhibiting MAPK/ERK activity and c-Fos transcription. Celecoxib also up-regulated the expression of GABAA receptors. NS-398 （N-2-cyclohexyloxy-4-nitrophenyl-methanesulfonamide）, another COX-2 inhibitor, enhanced the frequency and decay time of mIPSCs. Conclusion： The COX-2 inhibitor celecoxib decreased neuronal excitability and prevented epileptogenesis in pilocarpine-induced status epilepticus rats. Celecoxib regulates synaptic reorganization by inhibiting astrogliosis and ectopic neurogenesis by attenuating MAPK/ERK signal activity, mediated by a GABAergic mechanism.

Establishment and characterization of a rat pancreatic stellate cell line by spontaneous immortalization

AIM: Activated pancreatic stellate cells (PSCs) have been implicated in the pathogenesis of pancreatic fibrosis and inflammation. Primary PSCs can be subcultured only several times because of their limited growth potential. A continuous cell line may therefore be valuable in studying molecular mechanisms of these pancreatic disorders. The aim of this study was to establish a cell line of rat PSCs by spontaneous immortalization.METHODS: PSCs were isolated from the pancreas of male Wistar rats, and conventional subcultivation was performed repeatedly. Telomerase activity was measured using the telomere repeat amplification protocol. Activation of transcription factors was assessed by electrophoretic mobility shift assay.Activation of mitogen-activated protein (MAP) kinases was examined by Western blotting using anti-phosphospecific antibodies. Expression of cytokine-induced neutrophil chemoattractant-1 was determined by enzyme immunoassay.RESULTS: Conventional subcultivation yielded actively growing cells. One clone was obtained after limiting dilution,and designated as SIPS. This cell line has been passaged repeatedly more than 2 years, and is thus likely immortalized.SIPS cells retained morphological characteristics of primary,culture-activated PSCs. SIPS expressed α-smooth muscle actin, glial acidic fibrillary protein, vimentin, desmin, type Ⅰ collagen, fibronectin, and prolyl hydroxylases. Telomerase activity and p53 expression were negative. Proliferation of SIPS cells was serum-dependent, and stimulated with platelet-derived growth factor-BB through the activation of extracellular signal-regulated kinase. Interleukin-1β activated nuclear factor-κB, activator protein-1, and MAP kinases.Interleukin-1β induced cytokine-induced neutrophil chemoattractant-1 expression through the activation of nuclear factor-κB and MAP kinases.CONCLUSION: SIPS cells can be useful for in vitro studies of cell biology and signal transduction of PSCs.

Role of ERK-MAPK signaling pathway in pentagastrin-regulated growth of large intestinal carcinoma

AIM: To explore the role and mechanisms of extracellular signal-regulated protein kinase-mitogen-activated protein kinase (ERK-MAPK) signaling in pentagastrin-regulated growth of large intestinal carcinoma.

Influence of acid and bile acid on ERK activity, PPAR_Y expression and cell proliferation in normal human esophageal epithelial cells

AIM： To observe the effects of acid and bile acid exposure on cell proliferation and the expression of extracellular signal-regulated protein kinase （ERK） and peroxisome proliferator-activated receptor γ （PPARγ） in normal human esophageal epithelial cells in vitro. METHODS： In vitro cultured normal human esophageal epithelial cells were exposed to acidic media （pH 4.0-6.5）, media containing different bile acid （250 μmol/ L）, media containing acid and bile acid, respectively. Cell proliferation was assessed using MTT and flow cytometry. The expressions of phosphorylated ERK1/2 and PPAR~ protein were determined by the immunoblotting technique. RESULTS： Acid-exposed （3 min） esophageal cells exhibited a significant increase in proliferation ratio, S phase of the cell cycle （P〈0.05） and the level of phosphorylated ERK1/2 protein. When the acid-exposure period exceeded 6 min, we observed a decrease in proliferation ratio and S phase of the cell cycle, with an increased apoptosis ratio （P〈0.05）. Bile acid exposure （3-12 min） also produced an increase in proliferation ratio, S phase of the cell cycle （P〈0.05） and phosphorylated ERKx/2 expression. On the contrary, deoxycholic acid （DCA） exposure （〉 20 rain） decreased proliferation ratio. Compared with bile acid exposure （pH 7.4）, bile acid exposure （pH 6.5, 4） significantly decreased proliferation ratio （P〈0.05）. There was no expression of PPARy in normal human esophageal epithelial cells.CONCLUSION： The rapid stimuli of acid or bile acid increase proliferation in normal human esophageal epithelial cells by activating the ERK pathway.

α1 and β1 integrins enhance the homing and differentiation of cultured prostate cancer stem cells

CD133＋ prostate cancer stem cells （PCSCs） have recently been identified in human prostate cancer tissues. The present study reports the integrin profile of prostate cancer progenitor cells and the role of α1 and β1 integrins in the homing and differentiation of PCSCs in vitro. PCSCs were isolated from the tissue specimens of patients with prostate cancer and the expression of surface integrins and adhesion patterns were determined. Our analysis of the expression of surface integrins and their adhesion patterns of prostate cancer stem cells derived from prostate cancer tissues revealed that the levels of β1 and α2β1 integrins were significantly higher （P 〈 0.05） than those of the other integrins. By contrast, peripheral blood-derived CD 133＋ cells from prostate cancer patients showed a high level of expression （P 〈 0.01） of α2β1,αvβ3, αvβ5, β1 and α1 integrins and a minimal expression of α4β1 integrins. Moreover, CD 133＋ cells derived from both prostate cancer tissues and peripheral blood exhibited an increased degree of attachment to extraceUular matrix proteins （P 〈 0.001） and a high expression level of α2β1 integrin. In vitro experiments using blocking antibodies indicated that α1 and β1 integrins have a role in the homing and differentiation of PCSCs. This is the first report to suggest the importance of integrins in mediating the homing and differentiation of PCSCs.

Comparative proteomic analysis of extracellular matrix proteins secreted by hypertrophic scar witb normal skin fibroblasts

The formation of hypertrophic scars (HSs) is a fibroproliferative disorder of abnormal wound healing. HSs usually characterize excessive proliferation of fibroblasts, abnormal deposition of extracellular matrix (ECM) during wound healing, associated with cosmetic, functional, and psychological problems. Owing to the role of ECM proteins in scar formation, we comparatively analyzed matrix proteins secreted by normal skin fibroblasts (NSFs) and HS fibroblasts (HSFs). The acetone-extracted secreted proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and identified by mass spectrometry (MS). Based on Go annotation of MS data, the profiling of ECM proteins was established and scar-related proteins have been screened out. The functions of several ECM proteins identified by MS have been discussed, such as collagens I, VI, XII, fibronectin, decorin, lumican, and protein procollagen C endopeptidase enhancer 1 (PCPE-1). Among them, the MS result of PCPE-1 was supported by Western blotting that PCPE-1 from HSFs were significantly upregulated than that from NSFs. It is suggested that PCPE-1 could be a potential target for scar treatment. The exploration of scar related proteins may provide new perspectives on understanding the mechanism of scar formation and open a new way to scar treatment and prevention.

N2L,a novel lipoic acid-niacin dimer,attenu⁃ates ferroptosis and decreases lipid peroxida⁃tion in HT22 cells

OBJECTIVE N2L is a novel lipoic acid-niacin dimer regulating lipid metabolism with multifunction,including antioxidant effect.We investigated the protective effect of N2L and the underlying mechanisms under the ferroptosis inducer RAS-selective lethality 3(RSL3)treat⁃ment in HT22 cells.METHODS HT22 cells were pretreated with N2L and then were treated with RSL3 to establish a ferroptosis cell model.MTT assay was used to detect the cell survival rate.Free radical probe(dihydroethidium,DHE)and ferrous probe FerroOrange were used to detect the contents of free radicals and ferrous ions in cells.The ultrastructure of mitochondria of treat⁃ed cells was observed by transmission electron microscope.The expression of ferroptosis-relat⁃ed proteins acyl-CoA synthetase long-chain family member 4(ACSL4),glutathione peroxidase 4(GPX4),cyclooxygenase-2(COX-2),ferritin Heavy Chain 1(FTH1),nuclear factor E2-related factor 2/heme oxygenase-1,and phosphoryla⁃tion levels of the c-Jun N-terminal kinase(JNK)/extracellular regulated protein kinases(ERK)pathway were detected by Western blotting.RE⁃SULTS RSL3 decreased the cell viability and induced excessive accumulation of(reactive oxy⁃gen species)ROS in HT22 cells.N2L pretreat⁃ment effectively protected HT22 cells against lipid peroxidation.What′s more,N2L recovered GPX4 protein expression and blocked the increase of COX-2 and ACSL4 expressions.Moreover,N2L also significantly prevented FTH1 from downregulation and maintained iron homeo⁃stasis.Finally,N2L pretreatment could decrease JNK/ERK activation induced by RSL3.CON⁃CLUSION N2L is an excellent ferroptosis inhibi⁃tor,and its anti-ferroptosis mechanism may be related to the reduction of lipid peroxidation and the regulation of iron homeostasis.

Insulin-like growth factor binding protein-5 influences pancreatic cancer cell growth

AIM： To investigate the functional significance of insulin-like growth factor binding protein-5 （IGFBP-5） overexpression in pancreatic cancer （PaC）.METHODS： The effects of IGFBP-5 on cell growth were assessed by stable transfection of BxPC-3 and PANC-1 cell lines and measuring cell number and DNA synthesis. Alterations in the cell cycle were assessed by flow cytometry and immunoblot analyses. Changes in cell survival and signal transduction were evaluated after mitogen and phosphatidylinositol activated protein kinase 3-kinase （PI3K） inhibitor treatment.RESULTS： After serum deprivation, IGFBP-5 expression increased both cell number and DNA synthesis in BxPC-3 cells, but reduced cell number in PANC-1 cells. Consistent with this observation, cell cycle analysis of IGFBP-5-expressing cells revealed accelerated cell cycle progression in BxPC-3 and G2/M arrest of PANC-1 cells. Signal transduction analysis revealed that Akt activation was increased in BxPC-3, but reduced in PANC-1 cells that express IGFBP-5. Inhibition of PI3K with LY294002 suppressed extracellular signal-regulated kinase-1 and -2 （ERK1/2） activation in BxPC-3, but enhanced ERK1/2 activation in PANC-1 cells that express IGFBP-5. When MEK1/2 was blocked, Akt activation remained elevated in IGFBP-5 expressing PaC cells; however, inhibition of PI3K or MEK1/2 abrogated IGFBP-5-mediated cell survival.CONCLUSION： These results indicate that IGFBP-5 expression affects the cell cycle and survival signal pathways and thus it may be an important mediator of PaC cell growth.

SIGNAL MECHANISM OF INHIBITION OF BIFIDOBACTERIA ON GROWTH OF COLON CANCER

Objective: To explore the antitumor mechanisms of bifidobacteria adolescence in vivo. Methods: The content of extracellular signal regulated proteins (ERK)1/2, C-Jun N-terminal kinase (JNK), p38, c-fos and c-jun in nude mouse transplanted large bowel carcinoma was detected by using laser confocal microscopy. The expression of NF-κB was determined by immunohistochemistry. Results: After the nude mouse transplanted tumor was treated with bifidobacteria, the average fluorescent strength of ERK1/2, JNK, c-fos and c-jun was significantly lower than that in tumor control group (P<0.01). The average fluorescent strength of p38 was not obvious difference in the two groups (P>0.05). The positive cell density of NF-κB in large bowel carcinoma transplantation tumors in Bifidobacterium injection group was markedly lower than that in tumor group(P<0.01). Conclusion: bifidobacteria adolescence could markedly decrease the activity of ERK1/2 and JNK, the expression c-fos and c-jun, and the activity of NF-κB.