Objective To investigate the expression of SAPCD2 in the lung adenocarcinoma cells, and to study the effect of SAPCD2 regulating Hippo signaling pathway on the proliferation, invasion, migration and apoptosis of the lung adenocarcinoma cells and its mechanism. Methods Quantitative real-time PCR (qRT-PCR) and Western blot were used to detect the expression levels of SAPCD2 mRNA and protein in four types of lung cancer cells (HCC827, H1650, SK-MES-1, A549) and human normal lung epithelial cells (BESA-2B), respectively. Then, lung cancer cells with relatively high levels of SAPCD2 expression were selected for subsequent experiments. The experiment cells were divided into a normal control group (NC group), a si-SAPCD2 group, and a pathway inhibitor group (si-SAPCD2+XMU-MP-1 group). Firstly, SAPCD2 mRNA was silenced using small interfering RNA (siRNA) technology, and then qRT-PCR was used to detect the expression of SAPCD2 in transfected lung cancer cells; using clone plate assay to detect the proliferation of lung cancer cells after silencing; using flow cytometry to detect the apoptosis of lung cancer cells after silencing; observe the number of lung cancer cells at different stages through cell cycle experiments; then Transwell experiment was used to analyze the effect of silencing SAPCD2 on the migration and invasion of lung cancer cell migration. Finally, Western blot was used to detect the expression of ki-67, Bcl-2, Caspase-3, NF2, P-MST1, P-LATS1, P-YAP, YAP, and TAZ proteins.Results SAPCD2 had the highest expression level in lung adenocarcinoma A549 cells (P<0.01). Silencing SAPCD2 significantly decreased the proliferation ability of A549 cells (P<0.01), inhibited their migration (P<0.05) and invasion (P<0.01), and promoted A549 cell apoptosis (P<0.01); more than half of the cells remained in the G0/G1 phase. Compared with the NC group, A549 cells showed a significant increase in G0/G1 phase cells (P<0.01), a significant decrease in G2/M and S phase cells (P<0.01), and a significant increase in the proportion of early apoptotic cells (P<0.01). Western blot results showed that silencing SAPCD2 down-regulated the expression of ki-67, Bcl-2, YAP, and TAZ proteins compared to the NC group (P<0.01), and up-regulated the expression of Caspase-3, NF2, P-MST1, P-LATS1, and P-YAP proteins (P<0.01). Conclusions The expression of SAPCD2 in lung adenocarcinoma A549 cells is significantly higher than that in normal lung epithelial cells (BESA-2B), which promotes the proliferation, migration and invasion of A549 cells and inhibits apoptosis. The mechanism may be related to the inhibition of Hippo signaling pathway.
Objective Bone marrow mesenchymal stem cells (BMSCs), as replacement cells of Schwann cells, can increase the effect of peripheral nerve repair. However, it has not yet reached any agreement to add the appropriate number of seeded cells in nerve scaffold. To investigate the effect of different number of BMSCs on the growth of rat dorsal root gangl ia(DRG). Methods Three 4-week-old Sprague Dawley (SD) rats (weighing 80-100 g) were selected to isolate BMSCs, whichwere cultured in vitro. Three 1- to 2-day-old SD rats (weighing 4-6 g) were selected to prepare DRG. BMSCs at passage 3 were used to prepare BMSCs-fibrin glue complex. According to different number of BMSCs at passage 3 in fibrin glue, experiment was divided into group A (1 × 103), group B (1 × 104), group C (1 × 105), and group D (0, blank control), and BMSCs were cocultured with rat DRG. The axon length of DRG, Schwann cell migration distance, and axon area index were quantitatively evaluated by morphology, neurofilament 200, and Schwann cells S-100 immunofluorescence staining after cultured for 48 hours. Results Some long cell processes formed in BMSCs at 48 hours; migration of Schwann cells and axons growth from the DRG were observed, growing in every direction. BMSCs in fibrin glue had the biological activity and could effect DRG growth. The axon length of DRG and Schwann cell migration distance in groups A, B, and C were significantly greater than those in group D (P lt; 0.05). The axon length of DRG and Schwann cell migration distance in group C were significantly less than those in group B (P lt; 0.05), but there was no significant difference between group A and group C, and between group A and group B (P gt; 0.05). The axon area index in groups A and B was significantly greater than that in group D (P lt; 0.05), but there was no significant difference between group C and group D (P gt; 0.05); there was no significant difference in groups A, B, and C (P gt; 0.05). Conclusion In vitro study on DRG culture experiments is an ideal objective neural model of nerve regeneration. The effect of different number of BMSCs in fibrin glue on the growth of DRG has dose-effect relationship. It can provide a theoretical basis for the appropriate choice of the BMSCs number for tissue engineered nerve.
Objective Poly (propylene carbonate) (PPC), a newly reported polymer, has good biodegradabil ity and biocompatibil ity. To explore the feasibil ity of using electrospinning PPC materials in nerve tissue engineering, and to observe the effect of al igned and random PPC materials on axonal growth of rat dorsal root gangl ions (DRGs) in vitro. Methods Either al igned or randomly oriented sub-micron scale polymeric fiber was prepared with an electrospinning process. DRGs were harvested from 3 newborn Sprague-Dawley rats (female or male, weighing 4-6 g), and were incubated into 12-pore plate containing either al igned (the experimental group, n=6) or randomly oriented sub-micron scale polymeric fiber (the control group, n=6). The DRGs growth was observed with an inverted microscope; at 7 days immunofluorescent staining and scanning electronic microscope (SEM) observation were performed to quantify the extent of neurite growth andSchwann cells (SCs) migration. Results Either al igned or random fibers were fabricated by an electrospinning process. The diameter of the individual fiber ranged between 800 nm and 1 200 nm. In al igned PPC material, 90% fibers arranged in long axis direction, but the fibers in random PPC material arranged in all directions. The DRGs grew well in 2 PPC materials. Onthe al igned fiber film, the majority of neurite growth and SCs migration from the DRGs extended unidirectionally, parallel to the al igned fibers; however, neurite growth and SCs migration on the random fiber films oriented randomly. The extents of neurite growth were (2 684.7 ± 994.8) μm on the al igned fiber film and (504.7 ± 52.8) μm on the random fiber films, showing significant difference (t= —5.360, P=0.000). The distances of SCs migration were (2 770.6 ± 978.4) μm on the al igned fiber film and (610.2 ± 56.3) μm on the random fiber films, showing significant difference (t= —5.400, P=0.000). The extent of neurite growth was fewer than the distances of SCs migration in 2 groups. Conclusion The orientation structure of sub-micron scalefibers determines the orientation and extent of DRGs neurite growth and SCs migration. Al igned electrospinning PPC fiber is proved to be a promising biomaterial for nerve regeneration.
Objective Native extracellular matrix (ECM) is comprised of a complex network of structural and regulatory proteins that are arrayed into a tissue-specific, biomechanically optimal, fibrous matrix. The multifunctional nature of the native ECM will need to be considered in the design and fabrication of tissue engineering scaffolds. To investigate the extraction techniques of naturally derived nerve ECM and the feasibil ity of nerve tissue engineering scaffold. Methods Ten fresh canine sciatic nerves were harvested; nerve ECM material was prepared by hypotonic freeze-thawing, mechanicalgrinding, and differential centrifugation. The ECM was observed by scanning electron microscope. Immunofluorescencestaining was performed to detect specific ECM proteins including collagen type I, laminin, and fibronectin. Total collagen and glycosaminoglycan (GAG) contents were assessed using biochemical assays. The degree of decellularization was evaluated with staining for nuclei using Hoechst33258. The dorsal root gangl ion and Schwann cells of rats were respectively seeded onto nerve tissue-specific ECM films. The biocompatibil ity was observed by specific antibodies for cell markers. Results Scanning electron microscope analysis revealed that nerve-derived ECM consisted of a nanofibrous structure, which diameter was 30-130 nm. Immunofluorescence staining confirmed that the nerve-derived ECM was made up of collagen type I, laminin, and fibronectin. The histological staining showed that the staining results of sirius red, Safranin O, and toluidine blue were positive. Hoechst33258 staining showed no DNA within the decellularized ECM. Those ECM films had good biocompatibil ity for dorsal root gangl ion and Schwann cells. The cotents of total collagen and GAG in the nerve-derived ECM were (114.88 ± 13.33) μg/ mg and (17.52 ± 2.34) μg/mg, showing significant difference in the content of total collagen (P lt; 0.01) and no significant difference in the content of GAG (P gt; 0.05) when compared with the contents of normal nerve tissue [(54.07 ± 5.06) μg/mg and (25.25 ± 1.56) μg/mg)]. The results of immunofluorescence staining were positive for neurofilament 200 after 7 days and for S100 after 2 days. Conclusion Nerve-derived ECM is rich in collagen type I, laminin, and fibronectin and has good biocompatibil ity, so it can be used as a nerve tissue engineering scaffold.
Objective To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) embedded in fibrin glue around chemical extracted acellular nerve allograft (CEANA) on the peripheral nerve regeneration. Methods Twenty-oneadult male C57 mice (weighing 25-30 g) and 15 adult male Balb/c mice (weighing 25-30 g) were selected. The sciatic nerves were harvested from the Balb/c mice to prepare CEANA. The BMSCs were isolated from 3 C57 mice and were cultured; BMSCs embedded in fibrin glue were cultured for 3, 7, 14, and 21 days. Then the supernatant was obtained and co-cultured with PC12 cells for 2 days to observe the PC12 cell growth in vitro. The other 18 C57 mice were used to establ ish the left sciatic nerve defect models of 10 mm and divided into 3 groups: autogenous nerve graft with fibrin glue (group A, n=6), CEANA graft with BMSCs (5 × 106) embedded in fibrin glue (group B, n=6), and CEANA graft with fibrin glue (group C, n=6). The right sciatic nerves were exposed as the controls. At 2, 4, 6, and 8 weeks, the mouse static sciatic index (SSI) was measured. The histomorphometric assessment of triceps surae muscles and nerve grafts were evaluated by Masson staining, toluidine blue staining, and transmission electron microscope (TEM) observationat 8 weeks after operation. Results BMSCs were uniform distribution in fibrin glue, which were spherical in shape, and the cells began to grow apophysis at 3 days. PC12 cells differentiated into neuron-l ike cells after addition supernatant co-cultured after 2 days. Incisions healed well in each group. At 2, 4, 6, and 8 weeks, the SSI increased gradually in 3 groups. SSI in group A was higher than that in groups B and C at 4, 6, and 8 weeks after operation (P lt; 0.05). SSI in group B was sl ightly higher than that in group C, but had no significant difference (P gt; 0.05). At 8 weeks, the wet weight recovery rate of triceps surae muscles and fibers number of myel inated nerve were better in group B than in group C, but worse in group B than in group A, showing significant differences (P lt; 0.05). The triceps surae muscle fibers area and myel in sheath thickness had significant differences between group B and group C (P lt; 0.01), but there was no significant difference between group A and group B (P gt; 0.05). Conclusion BMSCs embedded in fibrin glue around CEANA can improve functional recovery of peripheral nerve injury.
Objective Using chemically extracted acellular methods to treat extracranial section of the canine whole facial nerve, to evaluated its effects on nerve structure and the removal extent of Schwann cells and myel in. Methods Twenty whole facial nerves were exposed from 10 canines [weighing (18 ± 3) kg]. The extracranial trunk of canine facial nerve and its branches (temporal branch, zygomatic branch, buccal branch, marginal mandibular branch, and cervical branch) were dissected under l ight microscope. Twenty facial nerves were divided into the experimental group (n=12) and control group (n=8) randomly. In experimental group, the nerve was extracted with the 3%TritonX-100 and 4% sodium deoxycholate. In control group, the nerve was not extracted. HE staining and immunofluorescence histological stainings for Hoechst33258, P75, Zero, and Laminin were performed. Results After histological staining, it was found that myel in and Schwann cells were removed from the facial nerve while the basal lamina tube remained intact. The whole canine facial nerves (one nerve trunk and multiple nerve branches) had the similar result. Conclusion The canine whole facial nerve has natural structure (one nerve trunk and multiple nerve branches) by extracted with chemically extracted acellular methods, so it is an available graft for repairing the defect of the whole facial nerve.
Objective To construct chemically extracted acellular nerve allograft (CEANA) with Schwann cells (SCs) from different tissues and to compare the effect of repairing peripheral nerve defect. Methods Bone marrow mesenchymal stem cells (BMSCs) and adi pose-derived stem cells (ADSCs) were isolated and cultured from 3 4-week-old SD mice with weighing 80-120 g. BMSCs and ADSCs were induced to differentiated MSC (dMSC) and differentiated ADSC (dADSC) in vitro.dMSC and dADSC were identified by p75 protein and gl ial fibrillary acidic protein (GFAP). SCs were isolated and culturedfrom 10 3-day-old SD mice with weighing 6-8 g. CEANA were made from bilateral sciatic nerves of 20 adult Wistar mice with weighing 200-250 g. Forty adult SD mice were made the model of left sciatic nerve defect (15 mm) and divided into 5 groups (n=8 per group) according to CEANA with different sources of SCs: autografting (group A), acellular grafting with SCs (5 × 105) (group B), acellular grafting with dMSCs (5 × 105) (group C), acellular grafting with dADSCs (5 × 105) (group D), and acellular grafting alone (group E). Motor and sensory nerve recovery was assessed by Von Frey and tension of the triceps surae muscle testing 12 weeks after operation. Then wet weight recovery ratio of triceps surae muscles was measured and histomorphometric assessment of nerve grafts was evaluated. Results BMSCs and ADSCs did not express antigens CD34 and CD45, and expressed antigen CD90. BMSCs and ADSC were differentiated into similar morphous of SCs and confirmed by the detection of SCs-specific cellsurface markers. The mean 50% withdrawal threshold in groups A, B, C, D, and E was (13.8 ± 2.3), (15.4 ± 6.5), (16.9 ± 5.3), (16.3 ± 3.5), and (20.0 ± 5.3) g, showing significant difference between group A and group E (P lt; 0.01). The recovery of tension of the triceps surae muscle in groups A, B, C, D, and E was 87.0% ± 9.7%, 70.0% ± 6.6%, 69.0% ± 6.7%, 65.0% ± 9.8%, and 45.0%± 12.1%, showing significant differences between groups A, B, C, D, and group E (P lt; 0.05). No inflammatory reactionexisted around nerve graft. The histological observation indicated that the number of myel inated nerve fiber and the myel in sheath thickness in group E were significantly smaller than that in groups B, C, and D (P lt; 0.01). The fiber diameter of group B was significantly bigger than that of groups C and D (P lt; 0.05) Conclusion CEANA supplementing with dADSC has similar repair effect in peripheral nerve defect to supplementing with dMSC or SCs. dADSC, as an ideal seeding cell in nerve tissue engineering, can be benefit for treatment of peripheral nerve injuries.