Perilipin and adipophilin, two significant lipid droplet (LD)-specific proteins, participate in storing fat or ectopic lipid deposition and fat mobilization in many types of mammalian cells. Acylation stimulating protein (ASP) is a novel adipocyte-derived hormone known for a major determinant for triglyceride synthesis (TGS) and lipid metabolism. The present study was aimed to investigate: (1) whether ASP, rather than insulin, is a powerful potentiator which could physiologically and directly influence TGS during 3T3-L1 preadipocyte differentiation; (2) whether ASP exposure at indicated time points during 3T3-L1 preadipocyte differentiation could influence the gene/protein expression of adipophilin and perilipin. 3T3-L1 preadipocytes were differentiated by traditional hormone cocktail and divided into control, ASP and insulin groups according to the treatment of ASP (1 mmol/L) or insulin (100 nmol/L). ASP-stimulated and insulin-stimulated TGS rate at indicated time points (0 d, 3 d, 6 d, 9 d) were assayed by measuring the incorporation of [(3)H]-oleic acid into TG, and the corresponding glucose transport was assayed by [(3)H]-2-DG uptake. The effects of ASP or insulin on gene/protein expression of adipophilin and perilipin at indicated time points were evaluated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The results obtained were as follows: (1) on the 3rd and 6th day of differentiation, ASP dramatically enhanced TGS rate compared with control group (P<0.05, P<0.01); There was no significant difference in TGS rate between insulin group and control group; (2) on the 6th and 9th day of differentiation, both ASP and insulin promoted glucose uptake (P<0.05, P<0.01), and the promoting effect in ASP group was greater than that in insulin group; (3) ASP elevated adipophilin gene and protein expression at the very early stage of differentiation (P<0.05, P<0.001) and had no significant effect from the 4th day of differentiation. Perilipin gene and protein expression increased throughout preadipocyte differentiation and its expression was up-regulated following ASP stimulation from the 3rd day of differentiation (P<0.05, P<0.001) to the end of differentiation (P<0.05); (4) Insulin did not affect gene and protein variation pattern of adipophilin and perilipin. Taken together, this study provides evidence that ASP-evoked changes in gene and protein expression of adipophilin and perilipin correlate with ASP-stimulated TGS acceleration, and adipophilin and perilipin are involved in the molecular mechanism of ASP-induced adipogenesis and LD formation.
3T3-L1 Cells ; Adipocytes ; cytology ; Animals ; Carrier Proteins ; metabolism ; Cell Differentiation ; Complement C3a ; pharmacology ; Gene Expression ; Insulin ; pharmacology ; Membrane Proteins ; metabolism ; Mice ; Perilipin-1 ; Perilipin-2 ; Phosphoproteins ; metabolism

OBJECTIVETo investigate more deeply the function and mechanism of DSPP during tooth development.

METHODSExplants of tooth germs from embryonic 17th day mice were divided into two groups. In the control experiment, explants were cultured in agarose semi-solid medium under serum-free and chemically defined conditions, while explants in the other group were cultured with 30 mumol/L, 15 bp antisense oligodeoxynucleotide targeted to DSPP mRNA. After 10 ds, the explants were examined by transmission electron microscope. The width of dentin matrix at the tip of the cusps were then measured and statistically analyzed with Student t-test.

RESULTSUltrastructure analyses showed that large cisternae of the rough endoplasmic reticulum (RER) existed in the odontoblasts at the tip of the cusps of antisense-treated explants and the average thickness of dentin matrix (2.5 microns) was thinner compared to the control ones (3 microns, P < 0.001). In addition, the collagen fibers in extracellular matrix were disorganized.

CONCLUSIONThese findings indicated that DSPP played an important role in keeping tooth normal development, as well as in dentin mineralization by maintaining odontoblasts' secreting ability and controlling fiber structure and orientation.

Animals ; Embryo, Mammalian ; Extracellular Matrix Proteins ; Mice ; Mice, Inbred BALB C ; Microscopy, Electron ; Molar ; Oligoribonucleotides, Antisense ; pharmacology ; Phosphoproteins ; Protein Precursors ; pharmacology ; Sialoglycoproteins ; Tooth Germ ; ultrastructure

Migration of adventitial fibroblasts (AF) is involved in the neointimal formation which is one of the common pathological processes in several vascular diseases. The observation of whether the migratory response of AF from hypertensive animal is different from that of controls may provide an explanation of vascular remodeling in hypertension. We examined whether there is any difference between the migratory activity of AF derived from spontaneously hypertensive rat (SHR) and that from their normotensive counterpart Wistar-Kyoto rats (WKY). In addition, the role of osteopontin (OPN) in cell migration was also examined. Primary cultures of aortic adventitial fibroblasts were derived from SHR and age-matched WKY. Migration of fibroblasts was determined with the Transwell method. The mRNA expression level of OPN was measured by a real-time quantitative PCR. When compared with WKY-derived cells, migration of adventitial fibroblasts from SHR exhibited an increased response when stimulated by 10% serum (cell number per field 35.20+/-5.26 vs 22.2+/-3.27, p<0.05). Chemotaxis induced by 10 ng/ml bFGF showed a similar difference (cell number per field 30.23+/-4.54 vs 19.20+/-4.47, p<0.05). We also found that SHR-derived fibroblasts expressed a higher level of OPN mRNA than the cells from WKY (1863.23+/-43.91 vs 326.24+/-68.29, p<0.01). To verify if OPN is associated with the enhanced migratory ability in AF from SHR, we designed the antisense oligonucleotide of OPN. The results showed that the antisense OPN oligonucleotide significantly inhibited AF migration (cell number per field 38.60+/-5.98 vs 26.61+/-3.84, p<0.05), while sense and mismatch OPN oligonucleotide had no effect on cell migration. Therefore, the migration of adventitial fibroblasts appeared to be enhanced in cultures derived from SHR. OPN might be involved in the difference observed.
Animals ; Aorta ; cytology ; Cell Movement ; drug effects ; Cells, Cultured ; Fibroblasts ; cytology ; Hypertension ; physiopathology ; Male ; Osteopontin ; Phosphoproteins ; pharmacology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Sialoglycoproteins ; pharmacology

We have shown that hyaluronic acid stimulates the proliferation of quiescent NIH 3T3 cells. We have shown that treatment of 1 mg/ml hyaluronic acid results in increase of tyrosine phosphorylation of two proteins, MW 124 kDa and 60 kDa as detected by anti-tyrosine antibodies by Western blot analysis. Maximum phosphorylation occurred within 2 h after addition of 1 mg/ml hyaluronic acid. Stimulation of proliferation was also accompanied by increase in c-Myc protein, which was inhibited by amlloride, an inhibitor of Na+/H+ antiporter and EGTA and increase in the steady state level of pRb, the RB gene product. These results suggest that the intracellular signal transduction pathways that mediate the stimulatory effects of hyaluronic acid on cellular proliferation are similar to those of growth factors.
3T3 Cells ; Amiloride/pharmacology ; Animal ; Cell Division ; Dose-Response Relationship, Drug ; Egtazic Acid/pharmacology ; Hyaluronic Acid/pharmacology* ; Mice ; Mitogens/pharmacology* ; Phosphoproteins/metabolism* ; Phosphorylation ; Proto-Oncogene Proteins c-myc/metabolism* ; Retinoblastoma Protein/metabolism* ; Signal Transduction ; Sodium-Hydrogen Antiporter/antagonists & inhibitors ; Tyrosine

OBJECTIVETo To establish a method of phosphoprotein affinity profiling for identifying phosphoproteomic differences between Thp-1 cells with or without lipopolysaccharide (LPS) stimulation, aiming to screen potential regulators involved in LPS pathway.

METHODSThp-1 cells were stimulated with 100 ng/ml PMA for 48 h to induce differentiation into mature macrophages, which, after culture for another 48 h in the absence of PMA, were either treated with 100 ng/ml LPS for 30 min or left untreated. After desalting procedure with ultrafiltration, the phosphoproteins enriched by phosphoprotein metal affinity column (PMAC) of both groups were run on 2-D electrophoresis to find the spots with different phosphorylation status. Finally, some of these spots were identified by mass spectrometry (MS) and subsequent bioinformatic analysis.

RESULTSCompared to untreated Thp-1 cells, LPS stimulated Thp-1 cells showed 29 spots with reproducible alterations on the 2-D map, including 8 representing up-regulated spots, 7 new spots, 10 down-regulated spots, and 4 absent spots. The newly emerged and absent protein spots were subjected to MS analysis, and 4 of them were identified to be involved in various cellular processes such as proteolysis, signal transduction and protein folding. Among these, phosphorylation of proteasome C2 subunit was dramatically up-regulated in LPS-stimulated cells, as was consistent with previous reports; the phosphorylation of Z-DNA-binding protein 1 has not been reported so far and needs further confirmation.

CONCLUSIONPhosphoprotein affinity profiling is an attractive method for screening novel regulators involved in LPS signaling pathways and can be widely used in systemic study of signal transduction.

Cell Line ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; drug effects ; metabolism ; Mass Spectrometry ; Phosphoproteins ; analysis ; metabolism ; Phosphorylation ; Proteomics ; methods ; Signal Transduction

OBJECTIVETo investigate the host-defense role of short palate, lung, and nasal epithelium clone 1 (SPLUNC1) in Streptococcus pneumoniae (SP) infection and the effect of resveratrol (Res) on SPLUNC1 expression, and to provide new thoughts for the treatment of diseases caused by SP infection.

METHODSAccording to the multiplicity of infection (MOI), BEAS-2B cells with SP infection were divided into control group, MOI20 SP group, and MOI50 SP group. According to the different concentrations of Res, the BEAS-2B cells with MOI20 SP infection pretreated by Res were divided into 12.5Res+SP group, 25Res+SP group, and 50Res+SP group (the final concentrations of Res were 12.5, 25, and 50 μmol/L, respectively). Cell Counting Kit-8 was used to measure cell activity and determine the optimal concentration and action time of SP and Res. In the formal experiment, the cells were divided into control group, Res group, SP group, and Res+SP group. Real-time PCR and ELISA were used to measure the mRNA and protein expression of SPLUNC1.

RESULTSOver the time of SP infection, cell activity tended to decrease. Compared with the control group and the MOI20 SP group, the MOI50 SP group had a reduction in cell activity. Compared with the MOI20 SP group, the 25Res+SP group had increased cell activity and the 50Res+SP group had reduced cell activity (P<0.05). MOI20 SP bacterial suspension and 25 μmol/L Res were used for the formal experiment. Over the time of SP infection, the mRNA expression of SPLUNC1 in BEAS-2B cells firstly increased and then decreased in the SP group and the Res+SP group (P<0.05). Compared with the SP group, the Res+SP group had significant increases in the mRNA and protein expression of SPLUNC1 at all time points (P<0.05). Compared with the control group, the Res group had no significant changes in the mRNA and protein expression of SPLUNC1 (P>0.05).

CONCLUSIONSSP infection can induce SPLUNC1 expression and the host-defense role of SPLUNC1. Res can upregulate SPLUNC1 expression during the development of infection and enhance cell protection in a concentration- and time-dependent manner.

Bronchi ; metabolism ; Cells, Cultured ; Cytoprotection ; Epithelial Cells ; metabolism ; Glycoproteins ; analysis ; genetics ; physiology ; Humans ; Phosphoproteins ; analysis ; genetics ; physiology ; RNA, Messenger ; analysis ; Stilbenes ; pharmacology ; Streptococcus pneumoniae ; pathogenicity

To explore the effect of chronic high dose of insulin on lipolysis in porcine adipocytes and the underlying molecular regulation mechanisms, we cultured primary porcine adipocytes and incubated them with different concentrations of insulin (0, 200, 400, 800, 1600 nmol/L) for 24-96 h in the absence or presence of specific protein kinase A (PKA) inhibitor or extracellular signal-related kinase (ERK) inhibitor. Then, we measured the glycerol release into the culture media as an indicator of the lipolysis, and observed the lipid accumulation morphology by phase-contrast microscopy. Further, we analyzed the gene expressions of perilipin A and peroxisome proliferator-activated receptor-gamma 2 (PPAR gamma 2) with semi-quantitative RT-PCR and Western blotting, respectively. The results showed that chronic high dose of insulin stimulated lipolysis in differentiated porcine adipocytes in a dose- and time-dependent manner, and significantly attenuated the lipolytic response to isoprenaline. Meanwhile, the protein and mRNA expressions of PPAR gamma 2 and perilipin A were significantly reduced. In addition, both PKA and ERK inhibitors significantly suppressed insulin-stimulated lipolysis, however, only ERK inhibitor reversed the insulin-induced down-regulation of perilipin A. These findings imply that chronic high dose of insulin stimulates lipolysis in porcine adipocytes by repressing perilipin A, which is involved in ERK pathway.
Adipocytes ; cytology ; drug effects ; metabolism ; Animals ; Carrier Proteins ; Dose-Response Relationship, Drug ; Down-Regulation ; drug effects ; Insulin ; pharmacology ; Lipolysis ; drug effects ; Perilipin-1 ; Phosphoproteins ; metabolism ; Swine

OBJECTIVETo investigate the influence of soluble phosphoprotein removal from artificial dentin caries lesions by pretreatment of NaCl on subsequent remineralization.

METHODSHuman root dentin samples were demineralized in an acidic gel (pH = 4.4) at 37 degrees C for 48 hours. Samples were pretreated with 0.5 mol/L NaCl solution and 0.5 mol/L disodium EDTA solution respectively. The histomorphologic changes of root caries surface were examined by scannings electronic microscope. Mineral profiles were assessed by means of microradiography.

RESULTSNo histomorphologic changes were present on root caries surface after treated with 0.5 mol/L NaCl solution, while many opened dentin tubules were seen after treated with 0.5 mol/L disodium EDTA solution. The remineralization results showed that pretreatment with 0.5 mol/L NaCl solution increased more remineralization than pretreated with 0.5 mol/L disodium EDTA solution.

CONCLUSION0.5 mol/L NaCl solution has no damage on the root caries surface. The in vitro results suggested that removal of soluble phosphoprotein from dentin lesions is an interesting approach to enhance remineralization.

Dental Caries ; diagnostic imaging ; pathology ; physiopathology ; Humans ; Microscopy, Electron, Scanning ; Phosphoproteins ; isolation & purification ; Radiography ; Sodium Chloride ; pharmacology ; Tooth Calcification ; drug effects

OBJECTIVETo investigate the anti-atherosclerosis mechanism of Astragalus mongholicus polysaccharides (APS) by examining its effect on gene expression profiles of the dendritic cells (DCs) from healthy donors.

METHODSPeripheral blood DCs from healthy donors were incubated with 200 mg/L APS overnight, and changes in the gene expression profiles were investigated using microarray technique and RT-PCR.

RESULTSCompared with the control cells, APS-treated DCs showed significantly up-regulated expressions of CD36 (0.97 ± 0.23 vs 5.45 ± 1.14) and IL-27 (1.08 ± 0.22 vs 2.97 ± 0.61) and down-regulated expression of expression of IFI16 (0.98 ± 0.18 vs 0.46 ± 0.11).

CONCLUSIONSAPS can promote the maturation and differentiation of DCs by up-regulating CD36 and IL-27 and down-regulating IFI16, and thus positively affects the occurrence and progression of the atherosclerosis.

Astragalus Plant ; chemistry ; CD36 Antigens ; metabolism ; Cell Differentiation ; Dendritic Cells ; drug effects ; Humans ; Interleukins ; metabolism ; Nuclear Proteins ; metabolism ; Phosphoproteins ; metabolism ; Polysaccharides ; pharmacology ; Transcriptome

OBJECTIVETo observe the effect of Tiancan Zhuangyang Powder (TCZYP) on the steroidogenic acute regulatory protein (stAR protein) expression of Leydig cells in model rats with partial androgen deficiency of aging male (PADAM).

METHODSPADAM rat model was prepared by cyclophosphamide induced reproductive system damage. Rats were randomly divided into four groups, i. e. the normal control group, the model group, the testosterone propionate group, and the TCZYP group. The general condition, body weight, tail suspension experiment and exhaustion swimming test, and the testicular index, etc. were observed to assess the state of rats. The serum total testosterone (TT), and free testosterone (FT) levels were detected by radioimmunoassay before and after treatment. The stAR protein expression level of Leydig cells were determined using immunohistochemical assay. Statistic analyses were performed.

RESULTSBy modeling with cyclophosphamide, serum TT and FT levels decreased (P<0.01), behavior changes were basically similar to PADAM (by tail suspension test), indicating a successful modeling. After treatment serum rTT and FT levels in the testosterone propionate group and the TCZYP group significantly increased when compared with before treatment and with the model group after treatment (P<0.01). There was no statistical difference between the TCZYP group and the testosterone propionate group (P>0.05). The immobility time in the tail suspension test were significantly shortened in the testosterone propionate group and the TCZYP group (P<0.05). The exhausted swimming time was more significantly prolongated than that of the model group (P<0.05). The stAR protein gray value significantly decreased (P<0. 01).

CONCLUSIONTCZYP could prevent serum TT and FT levels from decrease, improve stAR protein activities, and attenuate the depression state and muscular tension in PADAM rats. Its action was equivalent to that of testosterone propionate.

Androgens ; deficiency ; Animals ; Drugs, Chinese Herbal ; pharmacology ; Leydig Cells ; drug effects ; metabolism ; Male ; Phosphoproteins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Testis ; drug effects ; metabolism