Objective To investigate the expression and significance of growth-associated protein 43 (GAP-43) in the dorsal root ganglion (DRG) and intervertebral disc in the rat model of intervertebral disc inflammation. Methods A total of 103 adult male Sprague Dawley rats (weighing, 200-250 g) were randomly divided into the experimental group (n=48), the control group (n=48), and the blank control group (n=7). Fluoro-gold (F-G) as tracer was injected into the L5, 6 intervertebral disc of 3 groups; after 7 days of F-G injection, complete Freund’s adjuvant (50 µL) and the same volume of saline were injected in the experimental group (to prepare the model of intervertebral disc inflammation) and the control group, respectively, and the blank control group had no further treatment. After 1, 3, 7, and 14 days, T13-L6 DRG and L5, 6 intervertebral disc of experimental group and control group were harvested to detect the GAP-43 by using fluorescent immunohistochemistry, in situ hybridization, and RT-PCR. The DRG and intervertebral disc of blank control group were also harvested after 8 days of F-G injection. Results Fluorescent immunohistochemistry results showed that the number of F-G-labeled GAP-43 immunoreaction (GAP-43-IR) cells of the DRGs in the experimental group was significantly higher than that in the control group (P lt; 0.05) at 3 days, and no significant difference was found at the other time points (P gt; 0.05). There was no significant difference in the cross-sectional area of F-G-labeled GAP-43-IR cells between the experimental group and the control group at each time point (P gt; 0.05). The co-expression of GAP-43 with calcitonin gene-related peptide (CGRP) and isolectin B4 (IB4)-binding glycoprotein exhibited that the expression of CGRP was 91.4% ± 7.4% in the control group and was 87.6% ± 7.8% in the experimental group, showing no significant difference between 2 groups (P gt; 0.05). There was no IB4-binding glycoprotein expression in GAP-43-IR cells of the DRGs in 2 groups. The expressions of GAP-43, CGRP, and IB4-positive nerve fibers in the intervertebral disc exhibited that the GAP-43-IR nerve fibers in the experimental group were significantly more than that in the control group (P lt; 0.05), but no significant difference was found in the expression of CGRP between 2 groups (P gt; 0.05); and there was no IB4-binding glycoprotein expression in GAP-43-IR nerve fibers of the intervertebral disc in 2 group. In situ hybridization and RT-PCR detection showed that the positive expression cells ratio of GAP-43 mRNA and the level of GAP- 43 mRNA were significantly higher in the experimental group than in the control group at 1 day (P lt; 0.05), and no significant difference was found at the other time points (P gt; 0.05). Conclusion Intradiscal inflammatory environment may induce the expression of GAP-43, and potentially promote the nerve fiber ingrowth of rat.
Abstract： Stem cell paracrine has been considered as the main mechanism to promote infarcted myocardium regeneration and repair of damaged cardiomyocytes. With further research, secreted frizzled-related protein 2 （Sfrp 2） and stem cell paracrine are closely linked to each other. Sfrp 2 can competitively bind to the specific receptor Fz in Wnt signaling pathway, inhibit Wnt signaling pathway to regulates apoptosis, differentiation, and other life processes of stem cells, and therefore becomes a research hotspot in recent years. This review focuses on the mechanism of Sfrp 2/Wnt signal way in stem cell therapy for myocardial infarction.
ObjectiveTo understand the genetics associations between low-density lipoprotein receptor-related protein 5 (LRP5) gene polymorphisms and susceptibility of osteoporosis in patients with chronic obstructive pulmonary disease (COPD).MethodsThree hundred and seventy-nine patients with acute exacerbation of COPD were divided into groups of non osteoporosis and osteoporosis. Genomic DNA was extracted from all patients. UCSC genome browser and Haploview 4.2 software were used to screen tag single nucleotide polymorphisms (tagSNP) of LRP5 gene. The tagSNP was genotyped by Sequenom MassARRAY SNP detection method. Logistic regression were used to analysis the odds ratio (OR) values and confidence intervals (CI) of each SNP in different genetic models to assess the association between single nucleotide polymorphisms in LRP5 gene and osteoporosis in COPD patients.ResultsEight tagSNPs of LRP5 gene (rs312016 T/C, rs312017 C/T, rs312018 A/G, rs3736228 C/T, rs901823 T/C, rs589963 G/A, rs638051 A/G, rs671494 C/A) were selected for association analysis. Patients of rs901823 carrying C/C genotype had a higher risk of osteoporosis than those carrying T/T and C/T genotypes in COPD patients (in recessive mode, C/C vs. T/T+C/T, OR=9.42, 95%CI=2.01–44.29), P=0.000 431 8).ConclusionsThere is a significant association between rs901823 of LRP5 gene and osteoporosis in patients with COPD. Further studies are needed to discover the mechanism of LRP5 gene polymorphism in the pathogenesis of osteoporosis in COPD patients.
ObjectiveTo investigate relationship between nod-like-receptor protein 3 (NLRP3) inflammasome and acute pancreatitis induced pancreas and extrapancreatic organs injury.MethodThe related literatures on the relationship between the nod-like-receptor protein 1 inflammasome (NLRP3 inflammasome) and the acute pancreatitis in recent years were reviewed.ResultsThe activation and regulation of NLRP3 inflammatory corpuscle are involved in the injury of various organs in acute pancreatitis. The more the activation of NLRP3 inflammatory corpuscle, the more severe the damage to the body. Through the regulation of the activation mechanism of NLRP3 inflammatory corpuscle, the activation of NLRP3 inflammatory corpuscle can be reduced, and finally the injury of various organs can be reduced.ConclusionThe activation of NLRP3 inflammatory corpuscle is involved in the process of acute pancreatitis, but it still needs to be verified by further clinical studies.
Objective To detect the expression of single immunoglobin IL-1 receptor related protein ( SIGIRR) in normal human lung tissues, and study its changes in alveolar epithelial cell acutely injured by lipopolysaccharide ( LPS) . Methods Twenty samples of human normal lung tissue were collected during the lobectomies. The expression of SIGIRR was detected by immunohistochemistry, western blot and RT-PCR. The human type II alveolar epithelial cell acute injury model was established by stimulating A549 cells with LPS of a final concentration of 10 μg/mL. The cells were collected at 0, 3, 6, 12, and 24 hours after the stimulation. The changes of SIGIRR expression at the same time points were observed by western blot. The expression vector containing full-length SIGIRR cDNA was transfected transiently into A549 cells to induce SIGIRR overexpression. MTT assay was performed to measure the injury of A549 cells caused by LPS. Results The immunohistochemistry, western blot and RT-PCR showed that there was a high expression of SIGIRR in normal human lung tissues. The expression of SIGIRR was located in alveolar epithelial cells by immunohistochemistry. The expression of SIGIRR at 3, 6, and 12 hours was down-regulated after LPSstimulation and raised again at 24 hours to the baseline. MTT assay showed that SIGIRR overexpression substantially reduced the growth inhibition ratio of A549 cells after LPS stimulation. Conclusions Expression of SIGIRR in normal human lung tissues was confirmed by different detection methods. SIGIRR alleviates the injury of alveolar epithelial cells caused by LPS, implying SIGIRR might be involved in the regulationof acute lung injury mediated by LPS.
Objective To review the progress of mechanism of parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP) on normal and osteoarthritis (OA) cartilage and subchondral bones. Methods Recent 1iterature about the effects of PTH and PTHrP on normal and OA cartilage was reviewed. Results PTH and PTHrP can repress the hypertrophic differentiation and apoptosis of chondrocytes and promote their prol iferation, which has a protection effect on chondrocytes of OA; osteoblasts from subchondral bone of OA show a decreased reaction to PTH. Conclusion PTHand PTHrP may delay and protect the progression of OA, which involves in regulating cartilage degeneration and subchondral bone remodl ing through many kinds of signal pathway.
【Abstract】ObjectiveTo construct a mrp1 expression vector and investigate its biological characteristics in HepG2 cells in vitro. MethodsThe 6.5 kb multidrug resistanceassociated protein （MRP) cDNA obtained from plasmid pGEM-mrp1 was cloned into the pCI-neo mammalian expression vector, which was later transferred into human hepatocarcinoma cell line HepG2 by liposome. Then the HepG2 cells resisting G418 were clustered and proliferated, and the mrp1 mRNA and MRP in these HepG2 cells were detected by means of RT-PCR and FCM respectively. ResultsThe mrp1 expression vector was established successfully, and the stable MDR hepatocarcinoma cell line (HepG2/mrp1) was developed as well. The content of the specific fragment of mrp1 mRNA was (56.8±6.37)% and MRP was 7.89 in the HepG2/mrp1 cells, the corresponding value in HepG2 cells was (9.67±3.26)% and 0.79 respectively. The difference was statistically significant (P＜0.05). ConclusionIt is practicable to establish MDR hepatocarcinoma cell line by transferring mrp1 cDNA into HepG2 cells, which is useful in the research of MDR mechanism.
Objective To construct human secreted apoptosis-related protein 1 (SARP1) gene yeast two-hybrid bait vector so as to study the biological functions of the SARP1 gene in the scar tissue. Methods The target gene from SARP1 gene full-length DNA segment was amplified by PCR, the upstream and downstream primers of the SARP1 gene with restriction enzymes Nde I and Sal I were designed. pGBKT7-SARP1 recombination plasmid was constructed by ligating the vector and the PCR production and identified by PCR and sequencing. Further more, pGBKT7-SARP1 was transformed into competent AH109 which contained kanamycin for selecting positive clones and screened the positive clony on the plate of SD/-Trp. The toxicity and transcriptional activation were tested by the phenotype assay. Results SARP1 was amplified and cloned into pGBKT7 successfully, SARP1 gene sequence in recombinant plasmid pGBKT7-SARP1 was verified by gel electrophoresis and DNA sequencing analysis. The sequence of inserted SARP1 gene was the same as the corresponding sequence found in GenBank database. The recombinant pGBKT7-SARP1 plasmids and empty pGBKT7 vector could form white colonies on SD/-Trp plates and none could survive on SD/-Leu plates. Conclusion The recombinant pGBKT7-SARP1 gene yeast two-hybrid bait vector is successfully constructed.
Objective To investigate the effects of chondroitinase ABC (ChABC) on axonal myelination and glial scar after spinal cord injury (SCI) in rats. Methods Seventy-two adult male Sprague Dawley rats were randomly assigned into ChABC treatment group (group A), saline treatment group (group B), and sham operation group (group C), 24 rats in each group. In groups A and B, the SCI model was established with modified Allen’s method and then the rats of groups A and B were administrated by subarachnoid injection of 6 μL ChABC (1 U/mL) and saline respectively at 1 hour after injury and every day for 1 week; the rats of group C served as control, which canal was opened without damage to spinal cord. At 1, 7, 14, and 28 days after operation, the locomotor functions were evaluated according to the Basso-Beattie-Bresnahan (BBB) score scale; and the spinal cord samples were harvested for HE staining, Nissl staining, and immunohistochemistry analysis to detect the change of myelin basic protein (MBP), growth associated protein 43 (GAP-43), and glial fibrillary acidic protein (GFAP) of the injured spinal cord. Results At different time points, the BBB score of group C was significantly higher than those of groups A and B (P lt; 0.05), and the BBB score of group A was significantly better than that of group B at 14 and 28 days after operation (P lt; 0.05). HE staining and Nissl staining showed that the morphous and the neuron number of the remainant injured spinal cord in group A were better than those in group B. The integral absorbance (IA) values of MBP and GAP-43 and the positive area of GFAP after SCI in groups A and B were significantly higher than those in group C at different time points (P lt; 0.05), and the IA values of MBP and GAP-43 were significantly higher in group A than those in group B at 7, 14, and 28 days after operation (P lt; 0.05), but the positive area of GFAP was significantly smaller in group A than that in group B (P lt; 0.05). Conclusion The ChABC can effectively improve the microenvironment of the injured spinal cord of rats, enhance the expressions of MBP and GAP-43, and inhibit the expression of GFAP, which promotes the axonal regeneration and myelination, attenuate glial scar formation, and promote the recovery of nerve function.