ObjectiveTo observe the influence of heat shock protein 27 (HSP27) sensibilization to retinal ganglion cells (RGC) apoptosis of rats.
MethodsThirty-five female Wistar rats were randomly divided into HSP27 sensibilization group (15 rats), borate buffer solution (BBS) control group (15 rats) and normal group (5 rats). The rats in HSP27 sensibilization group were received hypodermic injection in rear limb with 100 μg HSP27 and complete freund adjuvant, intraperitoneal injection with 1 μg pertussis toxin. The BBS control group received the same volume of BBS at the same site. The normal group received no intervention. The intraocular pressure was measured 3 days before injection and 1, 2, 4, 6, 8 weeks after injection. Four, 6 and 8 weeks after injection, the retinal frozen sections was made to observe RGC apoptosis by terminal-deoxynucleoitidyl transferase mediated nick end labeling. The anti-HSP27 level in serum and cerebrospinal fluid were detected by enzyme linked immunosorbent assay.
ResultsThere was no obvious change of intraocular pressure in rats in 3 groups before injection (P>0.05). RGC apoptosis was observed in HSP27 sensibilization group 4 weeks after injection, and increased significantly at 6 weeks after injection. There was no RGC apoptosis in BBS control group and normal group. The level of anti-HSP27 in serum and cerebrospinal fluid of HSP27 sensibilization group occurred at 4 and 6 weeks after injection respectively, decreased with prolongation of injection time. Compared with BBS control group and normal group, the RGC apoptosis rate, anti-HSP27 level in serum and cerebrospinal fluid of HSP27 sensibilization group were significantly increased (P<0.05). There was no significant difference of the RGC apoptosis rate, anti-HSP27 level in serum and cerebrospinal fluid between BBS control group and normal group (P>0.05).
ConclusionsHSP27 sensibilization could promote the RGC apoptosis. The variation trend of anti-HSP27 level in cerebrospinal fluid is consistent with the RGC apoptosis.
ObjectiveTo observe the effect of TGF-β receptor inhibitor Compound C on the directed differentiation of human embryonic stem cells (hESC) into retinal pigment epithelial (RPE) cells.
MethodsH1 hESC were divided into control group and experimental group. When the hESC reached over confluence, the medium was changed to knockout serum replacement medium without bFGF to induce RPE differentiation. The experimental group was supplemented with 1 μmol/L TGF-β receptor inhibitor Compound C at the first six days of induction. Real-time PCR was carried out to examine the expression of paired-box gene 6 (PAX6), microphthalmia-associated transcription factor (MITF), cellular retinaldehyde blinding protein (CRALBP), and RPE65 in both groups at the 1, 3, 5 weeks of the induction process. hESC-derived RPE (hESC-RPE) cells were isolated mechanically and purified. Real-time PCR, Western blot and immunofluorescence were used to characterize the purified hESC-RPE cells.
ResultsPigmented colonies were observed in experimental group at the 4 weeks of the induction process, while no pigmented colony could be detected in the control group. All the purified pigmented cells from experimental group showed polygons morphology. Experimental group showed significantly higher expression of RPE marker genes PAX6, MITF, CRALBP and RPE65 than the control group(P<0.05). Compared with the hESC and ARPE-19 cells line, purified hESC-RPE cells showed much higher expression of PAX6, MITF, CRALBP and RPE65(P<0.05).High expression level of PAX6 and RPE65 proteins were observed in hESC-RPE cells. Immunofluorescence verified the expression of PAX6 and ZO-1 in hESC-RPE cells.
ConclusionTGF-β receptor inhibitor Compound C significantly improved the differentiation efficiency of hESC into RPE.
Objective
To observe the effect of shRNA interference lentivirus vector targeting rat Sirt1 gene on the expression of Sirt1 in retinal ganglion cell (RGC).
Methods
Four short hairpin (sh) RNA interference sequences targeting rat Sirt1 gene were designed. The target sequences of Oligo DNA were synthesized and annealed to double strand DNA, which was subsequently connected with pGLV3 lentivirus vector to build the lentiviral vector. The positive clones were identified by polymerase chain reaction (PCR) and DNA sequencing. The lentiviral vector construct and lentiviral packaging plasmids were co-transfected into 293T cells, then the titer of lentivirus were determined. The RGC were divided into 6 groups including blank group, negative control group and si-Sirt1-1, si-Sirt1-2, si-Sirt1-3, si-Sirt1-4 groups. Real-time PCR and Western blotting were used to detect the expression of Sirt1 mRNA and protein in the RGC cells.
Results
PCR and DNA sequencing analysis confirmed that the shRNA sequence was successfully inserted into the lentivirus vector. The concentrated titer of virus suspension was 8×108 TU/ml after the recombinant lentiviral vector successfully transfected and harvested in 293T cells. Comparing with NC group, the expression of Sirt1 mRNA and protein were significantly decreased in the si-Sirt1-1, si-Sirt1-2, si-Sirt1-3 and si-Sirt1-4 groups (F=27.682, 1 185.206; P=0.000, 0.000). The si-Sirt1-2 group had the strongest effect in reducing the expression of Sirt1 mRNA and protein.
Conclusion
The 4 lentiviral vectors harboring RNAi targeting rat Sirt1 gene can effectively down regulate the expression of Sirt1 mRNA and protein in RGC cells.
ObjectiveTo observe the expression of Toll-like receptor 4 (TLR4) and inflammatory cytokines, leucocytic density and permeability in retina of diabetic rat.
MethodsA total of 106 Brown Norway rats were randomly divided into experimental group and control group with 53 rats in each group. Diabetic model was established in experimental group by intraperitoneal injection of streptozotocin, and control rats received intraperitoneal injection of an equal volume of citric acid-sodium citrate buffer. Four weeks later, the retinas were collected for further analysis. TLR4 RNA and protein expression were measured by quantitative polymerase chain reaction and Western blot. Inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemo-attractant protein-1 (MCP-1), were measured by enzyme-linked immunosorbent assay in rat retina homogenate. Leukocyte density in the retina was measured by acridine orange fundus angiography. The retinal permeability was evaluated by Evans blue (EB) staining.
ResultsTLR4 expression was significantly increased in diabetic rats of experimental group compared with non-diabetic rats of control group (F=1.606, 0.789; P < 0.05). Inflammatory cytokines (TNF-α, IL-1β and MCP-1) were significantly increased in retina of diabetic rats of experimental group versus non-diabetic rat of control group (F=24.622, 5.758, 4.829; P < 0.05). The retinal leukocyte density was (6.2±0.5)×10-5, (2.2±0.3)×10-5 cells/pixel2 in experimental and control group respectively, the difference was statistically significant (F=2.025, P < 0.05). The amount of retinal EB leakage was (23.41±4.47), (13.22±3.59) ng/mg in experimental and control group respectively, the difference was statistically significant (F=21.08, P < 0.05).
ConclusionTLR4 and inflammatory cytokines expression, leucocytic density and permeability increased significantly in retina of diabetic rat.
ObjectiveTo study the hydrophilicity and the cell biocompatibility of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) coated with a fusion protein polyhydroxyalkanoates granule binding protein (PhaP) fused with Arg-Gly-Asp (RGD) peptide (PhaP-RGD).
MethodsPHBV and PHBHHx films were fabricated by solvent evaporation.Scanning electronic microscope (SEM) was used to study the morphology of the films.PhaP-RGD fusion proteins were expressed and purified by the technology of protein engineering; PHBV and PHBHHx films were immersed in the PhaP-RGD with an amount of 3.5 mg/mL protein/per sample respectively.The hydrophilicity of the surface were detected by the contact angle measurements.Septal cartilage cells obtained from human septal cartilage were cultured in vitro.The 2nd passage chondrocytes were incubated on PHBV unmodified with PhaP-RGD in group A1,PHBV modified with PhaP-RGD in group A2,PHBHHx unmodified with PhaP-RGD in group B1,PHBHHx modified with PhaP-RGD in group B2,and on the cell culture plates in group C.After cultured for 3 days,the proliferation of cells was detected by the DAPI staining; the proliferation viability of cells was detected by the MTT assay after cultured for 3 and 7 days; after cultured for 7 days,the adhesion and morphology of the cells on the surface of the biomaterial films were observed by SEM and the matrix of the cells was detected through the toluidine blue staining.
ResultsSEM observation showed that PHBV and PHBHHx films had porous structures.The contact angle of the surface of the PHBV and PHBHHx films modified with PhaP-RGD fusion proteins were significantly reduced when compared with the films unmodified with PhaP-RGD fusion proteins (P<0.05).Chondrocytes of human nasal septal cartilage incubated on the films could grow in all groups.After 3 days of cultivation in vitro,the cell proliferation and viability of group B2 were the strongest among all groups (P<0.05); the cell proliferation after cultured for 7 days was significantly stronger than that after cultured for 3 days in groups A1,A2,B1,and B2 (P<0.05); and the cell proliferation was significantly stronger in groups B1 and B2 than groups A1,A2 and C,in group B2 than group B1,and in group A1 than group A2 (P<0.05).The results of toluidine blue staining showed that blue metachromasia matrixes were observed in groups A1,A2,B1,and B2; group A1 and group A2 had similar staining degree,and the staining of group B2 was deeper than that of group B1.The adhesion of cells in all groups was good through SEM observation; and the connection of cells formed and stretched into the pores of the materials.
ConclusionThe biomaterial films of PHBHHx modified with PhaP-RGD fusion protein can promote its biocompatibility with chondrocytes.
Objective To observe the expression and investigate the significance of suppressor of cytokine signaling (SOCS) in peripheral blood mononuclear cells (PBMC) of experimental autoimmune uveitis (EAU). Methods 100 Lewis rats were immunized with interphotoreceptor retinoid-binding protein (IRBP) to induce EAU animal model, and they were divided into control group and treatment group randomly. The treatment group was administered cyclosporine A 20mg/（kgmiddot;d）after 1 to 28 days of immunization; the control group received saline buffer at equal quantity. All eyes were evaluated by slit-lamp microscopy before and after 7, 14, 21, 28 days of immunization; IL-4，IL-12，IFN-gamma; in the serum were measured by enzyme linked immunosorbent assay(ELISA); the SOCS mRNA and protein level in PBMC were measured by quantitative polymerase chain reaction (q-PCR) and western blot. Results The inflammation was most obvious at 14 days after immunization. The control group showed obvious iridocyclitis; the treatment group showed mild anterior chamber inflammation but no posterior synechia and hypopyon. The highest level of IL-12 and IFN-gamma; were observed at 14 days after immunization, followed by decline to the baseline at 28 days after immunization in control group; the highest level of IL-12 and IFN-gamma; were found at 14 days after immunization in treatment group, but the level was lower than control group obviously. Compared with the level before immunization, there are no differences at other time-point. The concentration of IL-4 decreased indistinctly in control group but increased in treatment group. SOCS1、Both of SOCS1 and SOCS5 increased to the highest level at 14 days after immunization, as 4.05 and 383 times of preimmunization in control group respectively, as 1.15 and 1.16 times in treatment group respectively. The CIS and SOCS3 mRNA increased lightly in two groups and treatment group milder than control group. Marked increased expression of SOCS1 and SOCS5 protein was detected at 7, 14, 21days than preimmunization, both of CIS and SOCS3 protein were significantly increased on 14, 21 days in control group; only SOCS1 protein was significantly increased on 14 days in treatment group and there are no differences at other time-point compared to pre-immunization. Conclusion Up-regulation of SOCS1 and SOCS5 expression maybe related to intensive response of Th1 in the development of EAU. Mild up-regulation of CIS and SOCS3 maybe associated with intensive response of Th2 which against the reaction of Th1 to carry out the dynamic immune balance.
Objective To investigate the relationship of the expression between heat shock protein (HSP) 70 and 90, and Survivin and its effects on the proliferative activity in retinoblastoma (RB) cells. Methods Expression of Survivin, HSP70 and 90, and Ki-67 in conventional paraffin samples from 43 patients with RB and 6 healthy people was detected by streptavidin-biotin peroxidase (SP) immunohistochemical method. Ki67 labeling index was used to evaluate the proliferative activity in RB. Results In 43 cases of RB, positive expression of HSP70 and 90 and Survivin was found in 28 (65.12%), 37 (86.05%) and 27 (62.79%) cases, respectively. None of the 6 normal retinal tissue expressed HSP70, HSP90 or Survivin. Positive expression of Survivin was more frequent in positive expressions of HSP90 than that in negative expressions of HSP90 (P＜0.05). Ki67 labeling index was higher in positive expressions of HSP90 and positive expressions of Survivin than that in their negative expressions respectively (P＜0.05). Meanwhile, higher Ki67 labeling index was found in positive HSP90Survivin expressions than that in negative HSP90Survivin expressions and those cases where only HSP90 or Survivin was found (P＜0.05). Expression of HSP70 did not correlate with that of Survivin, nor had any significant effect on Ki67 labeling index (P＞0.05). Expression of HSPs and Survivin and Ki67 labeling index did not correlate with histological types (P＞0.05). Conclusion Expression of HSP90 correlates with that of Survivin in RB. Co-existence of Survivin and HSP90 probably plays an important role in the genesis of RB.
Objective To investigate the effect of lung volume reduction surgery （LVRS） on messenger RNA expression levels of cytoskeletal proteins in diaphragmatic muscle tissues of emphysematous rabbits. Methods A total of 40 rabbits were randomly divided into 4 groups （10 rabbits in each group） ：normal control group, emphysema group, sham operation group and LVRS group. Rabbits in control group were intratracheally administered with 0.9% normal sodium, but those in other groups were intratracheally administered with 0.4% papain at the dose of 0.5 ml/kg and inhaled cigarette smoke to induce emphysema model. Then, rabbits in emphysema group were fed routinely, however, after median sternotomy , bilateral LVRS was performed in LVRS group but not in sham operation group. The mRNA expression levels of titin and nebulin in the diaphragmatic muscles of rabbits in each group were detected by reverse transcription-polymerase chain reaction（RT-PCR）. Results Compared with control group, the mRNA expression levels of titin and nebulin in the rabbit diaphragm of emphysema groups and sham operation group decreased significantly （P〈0.01 ）, so did those in LVRS group （P〈0.05）. But it increased significantly in LVRS group compared with emphysema group and sham operation group （P〈0.05）. Conclusion LVRS can increase the mRNA expression levels of titin and nebulin in diaphragmatic muscle tissues of emphysematous rabbits, which may be the associated mechanisms at the molecular level in restoring the functions of the emphysematous diaphragm by LVRS.
OBJECTIVE: To clarify the mechanisms of the signal transduction of bone morphogenetic proteins (BMPs) inducing bone formation and to provide theoretical basis for basic and applying research of BMPs. METHOD: We looked up the literature of the role of Smads and related transcription factors in the signal transduction of BMPs inducing bone formation. RESULTS: The signal transduction processes of BMPs included: 1. BMPs combined with type II and type I receptors; 2. the type I receptor phosphorylated Smads; and 3. Smads entered the cell nucleus, interacted with transcription factors and influenced the transcription of related proteins. Smads could be divided into receptor-regulated Smads (R-Smads: Smad1, Smad2, Smad3, Smad5, Smad8 and Smad9), common-mediator Smad (co-Smad: Smad4), and inhibitory Smads (I-Smads: Smad6 and Smad7). Smad1, Smad5, Smad8, and probable Smad9 were involved in the signal transduction of BMPs. Multiple kinases, such as focal adhesion kinase (FAK), Ras-extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K), and Akt serine/threonine kinase were related to Smads signal transduction. Smad1 and Smad5 related with transcription factors included core binding factor A1 (CBFA1), smad-interacting protein 1 (SIP1), ornithine decarboxylase antizyme (OAZ), activating protein-1 (AP-1), xenopus ventralizing homeobox protein-2 (Xvent-2), sandostatin (Ski), antiproliferative proteins (Tob), and homeodomain-containing transcriptian factor-8 (Hoxc-8), et al. CBFA1 could interact with Smad1, Smad2, Smad3, and Smad5, so it was involved in TGF-beta and BMP-2 signal transduction, and played an important role in the bone formation. Cleidocranial dysplasia (CCD) was thought to be caused by heterozygous mutations in CBFA1. The CBFA1 knockout mice showed no osteogenesis and had maturational disturbance of chondrocytes. CONCLUSION: Smads and related transcription factors, especially Smad1, Smad5, Smad8 and CBFA1, play an important role in the signal transduction of BMPs inducing bone formation.
Objective To investigate the role of vascular endothelial growth factor ( VEGF) in the pathogenesis of emphysema and its relationship with tumor necrosis factor alpha ( TNF-α) . Methods 48 rats were randomly divided into four groups, ie. a normal control group, an emphysema group, a rhTNFR∶Fc intervention group, and a sham intervention group. The rats in the emphysema group, the rhTNFR: Fc intervention group, and the shamintervention group were exposed to cigarette smoking for 80 days. After 30 days of exposure, rhTNFR: Fc hypodermic injection was administered in the rhTNFR: Fc intervention group while placebo was injected in the sham intervention group as control. Lung tissue sections were stained by hematoxylin and eosin. Mean linear intercept ( MLI) and mean alveolar numbers ( MAN) were measured to estimate the extent of emphysema. The level of TNF-αin serumand BALF, and the level of VEGF in BALF were measured with ELISA. Results In the emphysema group, MLI was higher and MAN was lower than those in the normal control group. Moreover, the levels of TNF-αin serum and BALF were higher, and thelevel of VEGF in BALF was lower significantly ( P lt;0. 05) . After the intervention with rhTNFR∶Fc, MAN increased and the serum TNF-αdecreased significantly compared with the emphysema group ( P lt; 0. 05) .However there were no significant differences in MLI, VEGF, and TNF-α in BALF ( P gt; 0. 05 ) . No correlation was found between the level of TNF-αand VEGF in BALF in the emphysema group. Conclusion VEGF and TNF-αare related to the pathogenesis of emphysema of smoking rats, and may contribute to the development of emphysema in different pathways.
