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BACKGROUND:Caffeic acid phenethyl ester (CAPE) can inhibit lipid peroxidation after rat brain injury. However, the trend of 5-lipoxygenaseis (5-LOX) and cysteinyl leukotrienes (CysLTs) in model of Parkinson’s disease, and whether CAPE protects against rotenone-induced cel ular injuries by inhibiting the levels of 5-LOX and CysLTs stil need further research. OBJECTIVE:To investigate the protective effect of CAPE on the rotenone-induced Parkinson-like injury, and to determine whether 5-LOX involved. METHODS:(1) PC12 cel s in good-growth were col ected and divided into five groups cultured with different concentrations of rotenone (0, 0.01, 0.1, 1, 10μmol/L). 24 and 48 hours later, changes of cel ular morphology and activity were observed to single out the optimum concentration of rotenone;at 24 hours, the levels of 5-LOX and CysLTs were detected by western blotting and ELISA, respectively. (2) PC12 cel s were pretreated with different concentrations of CAPE (0, 0.01, 0.1, 1, 10 μmol/L) for 30 minutes, and 1 μmol/L rotenone was then added. The other cel s received no intervention as blank control group. Subsequently, the cel activity was detected, and the CysLTs production was detected by ELISA at 24 hours. RESULTS AND CONCLUSION:(1) Rotenone (0.1-10μmol/L) could induce PC12 cel injury with overt morphological and cel activity changes at 24 hours, especial y the 1 μmol/L rotenone. (2) Rotenone also significantly increased the 5-LOX expression and CysLTs production in a concentration-dependant manner. (3) CAPE (1-10μmo/L) significantly attenuated rotenone-induced CysLTs production and cel viability reduction in a concentration-dependant manner. (4) These results suggest that CAPE protects against PC12 cel injuries in the model rat with Parkinson’s disease induced by rotenone involving 5-Lox.
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BACKGROUND:Brahma-related gene 1 (Brg1), a catalytic subunit of an important chromatin remodeling complex, has been considered as a key nuclear transcriptional factor, and tends to be decreased in diabetic cardiomyopathy. OBJECTIVE:To construct an adenovirus vector carrying Brg1, and observe its protective role in oxidative stress induced-cardiomyocyte apoptosis. METHODS:The recombinant adenovirus plasmid was linearized and transfected into HEK293 cel s using Fugene HD for packaging and amplification. The adenovirus particles were further purified, quantified, and sequential y transfected to cardiomyocytes of neonatal Sprague-Dawley rats. The Adeno-EGFP transfected and non-transfected cardiomyocytes were used as control group. 24 hours later, the transfection efficiency was observed by fluorescent microscope, and expressions of Brg1 mRNA and protein were detected by quantified PCR and western blotting. After treatment with 100 μmol/L H2O2 for 12 hours, the expressions of Brg1 protein and cleaved-Caspase 3 were measured by western blotting, and cel apoptosis was analyzed by flow cytometry. RESULTS AND CONCLUSION:(1) The recombinant adenovirus vector of Brg1 had been successful y transfected into cardiomyocytes with higher expressions of Brg1 mRNA and protein, and the transfection efficiency reached more than 90%. (2) After H2O2 treatment, the Brg1 was significantly down-regulated in contrast to the up-regulation of cleaved-Caspase 3;the flow cytometry data showed that the apoptotic cel s were increased. But in Adeno-Brg1 transfected cardiomyocytes, the H2O2 induced cel apoptosis was significantly decreased compared with non-transfected cel s and empty vector transfected cel s. (3) These results suggest that oxidative stress can directly inhibit the Brg1 expression, and overexpression of Brg1 can protect the cardiomyocytes from cel apoptosis induced by oxidative stress.
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Increasing studies have shown that endothelial progenitor cel s can not only promote the damaged endothelial cel s and vascular repair in ischemic brain tissue, but also promote neurogenesis, and thus promote neurological function recovery. Endothelial progenitor cel s transplantation may become an effective approach for the treatment of ischemic stroke.
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ObjectiveToinvestigatetheroleofimmuneinflammatoryreactionintheformationof intracranial aneurysm. Methods The intracranial aneurysms in 40 patients of craniotomy ( intracranial aneurysm group) and the vascular specimens in 20 craniotomy patients w ith traumatic brain injury (control group) w ere col ected. Fluorescence quantitative polymerase chain reaction w as used to detect the expression of interleukin (IL)-17 receptor in the arterial w al . Flow cytometry w as used to detect the Th-17 cel s in peripheral blood. Enzyme-linked immunosorbent assay w as used to measure the levels of IL-17, IL-6 in the arterial w al and tumor necrosis factor-α( TNF-α) in peripheral blood. Results There w ere no significant differences in the age (62.6 ±8.7 years vs.61.4 ±7.9 years;t=0.342;P=0.681), proportions of male (60.0%vs.65.0%; χ2 =0.246, P=0.434), hypertension ( 12.5%vs.10.0%; χ2 =0.315, P=0.492), diabetes (75.0%vs.10.0%; χ2 =0.284, P=0.482), and smoking (35.5%vs.30.0%; χ2 =0.224, P=0.413) betw een the intracranial aneurysms group and the control group. The expression of IL -17 receptor in the arterial w al (0.106 ±0.032 vs.0.264 ±0.071; t=5.115, P=0.001) and the proportion of Th17 cels in peripheral blood (2.75%±0.53%vs.7.18%±1.54%; t=8.436, P<0.001) and IL-17 level ( 7.32 ±1.82 μg/L vs.22.64 ±4.51 μg/L; t= 8.357, P< 0.001 ) in the control group w ere significantly low er than those in the intracranial aneurysm group. The levels of IL-6 (1.15 ±0.24 μg/L vs. 19.64 ±4.16 μg/L; t=9.527, P<0.001) and TNF-α(1.43 ±0.31 μg/L vs.26.17 ±4.32 μg/L; t=9.816, P<0.001) in the arterial wal in the control group were significantly lower than those in the intracranial aneurysm group. Conclusions The expression of IL-17 receptor in the arterial w al , the proportion of the Th17 cels and IL-17 level in peripheral blood were increased in patients with intracranial aneurysms. Immune inflammation may be involved in the formation of intracranial aneurysm.
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BACKGROUND:Hematopoietic microenvironment regulates hematopoietic stem cel s mainly through the cel-cel , cel-soluble regulator and cel-extracel uar matrix modes. OBJECTIVE:To review the molecular mechanism underlying regulation of hematopoietic stem cel s under the cel-cel , cel-soluble factors and cel-extracel ular matrix modes. METHODS:A computer-based online search of PubMed database was performed to search related articles with the key words of“Niche, HSC, VCAM-1, VLA-4, TPO, MPL, ECM, Integrin, N-cadherin, ANG-1, Tie2, VLA-5, Jagged-1, Notch, CXCL12, CXCR4, SCF, Kit, BMPs/TGF-β, TGF-βR, IFNα, IFNαR”in English. Irrelevant or repetitive studies as wel as old literature were excluded, and final y 80 articles were included in result analysis. RESULTS AND CONCLUSION:Cel s on the endosteal surface, vascular endothelial cel s, perivascular cel s, and some unknown or certain cel s or smal molecules in the bone marrow cavity constitute the specialized microenvironment for hematopoietic stem cel s. Hematopoietic stem cel s in the hematopoietic microenvironment remain a relatively steady state, which is the result of mutual contact of hematopoietic stem cel s and hematopoietic microenvironment under the regulation of some important molecules, such as Pten and osteopontin, via the pathway between cel-intercel ular adhesions, intercel ular soluble factors, and cel s and extracel ular matrix.
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BACKGROUND:Bone morphogenetic protein 9 is proved to promote the osteogenic differentiation of various kinds of stem cel s, but whether it can induce the osteogenic differentiation of dental fol icle cel s in vitro is yet unclear. OBJECTIVE:To investigate whether bone morphogenetic protein 9 can induce the osteogenic differentiation of rat dental fol icle cel s in vitro. METHODS:Purified rat dental fol icle cel s at passage 3 were transfected with bone morphogenetic protein 9 adenovirus. Then, alkaline phosphatase activity, calcium deposition and expression of osteogenesis-related factors at mRNA and protein levels were detected in the dental fol icle cel s. RESULTS AND CONCLUSION:After transfection with bone morphogenetic protein 9, the dental fol icle cel s showed continuously enhanced alkaline phosphatase activities and obviously enhanced calcium deposition. Real-time PCR results demonstrated that the mRNA expressions of alkaline phosphatase, osteocalcin, bone sialoprotein, osteopontin and core binding factor were increased significantly. The western blot assay showed that the expression of osteopontin enhanced in the dental fol icle cel s after transfection with bone morphogenetic protein 9. In summary, bone morphogenetic protein 9 can induce the osteogenic differentiation of dental fol icle cel s.
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BACKGROUND:Ten-eleven translocation (TET) family proteins are recently discovered DNA dioxygenases that convert methylcytosine to hydroxymethyl cytosine, which is essential for regulating cel proliferation and differentiation, but the expression pattern of TET family proteins in human dental pulp cel s is stil unclear. OBJECTIVE:To investigate the expression pattern of TET family proteins during the differentiation of human dental pulp cel s. METHODS:Cel ular distribution and expression of TET family proteins were determined by immunofluorescence in human dental pulp cel s that were cultured and isolated using digestion method. The protein levels of TETs during cel passage (P1-P7) were detected with western blot assay, and their potential changes during odontogenic induction (7 and 14 days) were confirmed using real-time quantitative PCR and western blot analyses at mRNA and protein levels, respectively. RESULTS AND CONCLUSION:Al TETs were expressed in the nucleus and the cytoplasm of human dental pulp cel s During serial cel passage, TET1 protein expression was increased until the 6th passage, TET2 significantly increased at the 2nd and 3rd passages and then decreased (P0.05). Both mRNA and protein expression levels of al TETs were elevated during odontogenic induction (P<0.05). These results indicated that TETs may contribute to cel differentiation of human dental pulp cel s.
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BACKGROUND:Cdh1 has been shown to express in rat hippocampus and cortex in a large number. Moreover, in vitro test demonstrated that Cdh1 expression was higher in neurons than in neural stem cel s, which possibly associated with the differentiation of neural stem cel s into neurons. However, the effects of anaphase promoting complex Cdh1 on ischemic neuronal damage remain unclear. OBJECTIVE:To investigate the expression of Cdh1 and its downstream substrate in primary cultured neurons with oxygen-glucose deprivation. METHODS:Primary neurons from cortex of postnatal 24-hour rat pups were cultured in vitro, and identified by immunofluorescence staining. The oxygen-and glucose-deprived models were established by three gas incubator fil ed with nitrogen in sugar-free Earle’s solution. After 1 hour of hypoxia, reoxygenation was conducted. Real-time fluorescent quantitative PCR was used to detect the mRNA expression of Cdh1 and its downstream substrates Skp2, Cyclin B1 before hypoxia, 6 hours, 1, 3, 7 days after oxygen glucose deprivation. RESULTS AND CONCLUSION:After oxygen glucose deprivation, the expression of Cdh1 and Cyclin B1 in primary neurons was increased (P<0.05), while Skp2 expression was decreased (P<0.05). Above data indicated that Cdh1 expression in neurons increased after oxygen-glucose deprivation. It may degrade Skp2 and participate in hypoxic neuronal apoptosis by ubiquitination.
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BACKGROUND:The linkage and synergistic effect of adaptor proteins can effectively regulate signal transduction of T cel s, which can form a limit or amplification cascade to realize the complex immune function of T cel s. C-terminal Src kinase (Csk)-binding protein (Cbp) is an adaptor protein, which mainly exert the negative feedback regulation of Src kinase activity. This negative feedback effect depends on Y317 of Cbp, which may be involved in the SH2 domain of Csk. OBJECTIVE:To explore the effects of high expression of Cbp on ultrastructure and related biological function of Jurkat cel s. METHODS:The virus particles were constructed with expressing enhanced green fluorescent protein (EGFP) only and Cbp-EGFP fusion protein to transfect Jurkat cel s. There were untransfected group (Jurkat group), negative control group (transfected with expression of EGFP virus only), and Cbp group (transfected with Cbp-EGFP virus). RESULTS AND CONCLUSION:Confocal microscope showed that cel transfection efficiency was more than 95%and Cbp was located on the cel membrane. Optical microscope showed after transfection with Cbp-EGFP virus, more Jurkat cel s shrunk, with poor size uniformity. Apoptosis detection showed that after transfection with Cbp-EGFP virus, the number of apoptotic and necrotic cel s was greatly increased. Cbp mRNA expression was increased, Csk expression was decreased obviously and lymphocyte-specific protein tyrosine kinase expression was increased. So, in Jurkat cel s, the high expression of Cbp can decrease the uniformity of cel s and increase the necrosis cel s, thus inhibiting the signal transduction.
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BACKGROUND:Bone marrow mesenchymal stem cel s have attracted widespread attention for the capabilities of self-renewal and muti-differentiation, which have been used in treatment of various diseases. OBJECTIVE:To study the effect of three-dimensional spheroid culture system on the stemness and senescence of bone marrow mesenchymal stem cel s. METHODS:Mesechyaml stem cel s were isolated from the bone marrow of C57/B6 mice, 3 weeks old, and cultured onto the culture plates coated with or without chitosan. After 5 days of culture, the cel phenotype and expression of stemness related markers CD44 and Sca-1 were analyzed by flow cytometry. PI and Annexin-V staining were used to detect cel apoptosis. Also,β-Gal staining was applied for identification of aging. RESULTS AND CONCLUSION:The mouse mesenchymal stem cel s began to form spheroids on day 3. The stemness-related markers, including CD44 and Sca-1, expressed higher in spheroid mesenchymal stem cel s than the cel s under normal culturing. Compared with the normal culture group, the apoptosis and senescence of cel s from spheroid culture were lower. The results indicate that the formation of spheroids on chitosan films can increase the stemness, decrease the apoptosis and slow the senescence of mesenchymal stem cel s.
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BACKGROUND:Previous studies have found that embryonic bone marrow mesenchymal stem cel s can promote human Th17 cel proliferation, but the inherent regulatory mechanisms stil need to be elucidated. OBJECTIVE:To investigate the role of Tol-like receptor 3 in the immunoregulation of Th17 cel s by mesenchymal stem cel s. METHODS:Human CD4+T cel s from healthy donors were isolated by immunomagnetic bead method, and then cultured alone or co-cultured with embryonic bone marrow mesenchymal stem cel s for 4 days. The mRNA expression level of interleukin-17, Tol-like receptor 3 and MyD88 was detected by real-time PCR. RESULTS AND CONCLUSION:Compared with CD4+T cel cultured alone group, the mRNA level of interleukin-17 was significantly higher in the co-culture group (3.59±0.11 vs. 1.14± 0.08, P<0.01). Consistent with the expression of interleukin-17 mRNA, increased level of Tol-like receptor 3 mRNA was detected in the co-culture group compared with the CD4+T cel cultured alone group (3.10±1.60 vs. 0.94± 0.01, P<0.05). Furthermore, MyD88 in the co-culture group was significantly higher than that in CD4+T cel cultured alone group (2.29±0.05 vs. 1.85±0.31, P<0.01). Tol-like receptor 3 may be involved in the immunoregulation of Th17 cel s by embryonic bone marrow mesenchymal stem cel s, which provides experimental evidence for potential cel therapeutic strategy.
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BACKGROUND:Studies have found that bone marrow mesenchymal stem cel s, under certain conditions, can be induced to differentiate into neurons and glial cel s, which to some extent solves the problem of the source of seed cel s. Induction methods currently used are different, and their efficiencies are not the same. OBJECTIVE:To observe the effects of different antioxidants on differentiation of rat bone marrow mesenchymal stem cel s into neuron-like cel s in vitro. METHODS:Bone marrow mesenchymal stem cel s from Wistar rats were divided into four groups:non-intervention group,β-mercaptoethanol group, retinoic acid group,β-mercaptoethanol+retinoic acid group. Changes in cel morphology and positive rate of neuron-specific enolase and microtubule-associated protein 2 were observed and detected at 5 hours, 12 hours, 1 day, 3 days, 5 days, 7 days, and 10 days after induction. RESULTS AND CONCLUSION:Except non-intervention group, bone marrow mesenchymal stem cel s in the other three groups were gradual y becoming spindle-shaped, and gave birth to many smal protrusions that were interconnected into a network, showing neuron-like cel morphology. Immunocytochemical staining showed that the efficiency of theβ-mercaptoethanol+retinoic acid group was the highest at 10 days after induction, and the positive rates of neuron-specific enolase and microtubule-associated protein 2 were 71.63%and 79.72%, respectively. The results show thatβ-mercaptoethanol can be combined with retinoic acid to accelerate the differentiation of bone marrow mesenchymal stem cel s into neuron-like cel s.
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BACKGROUND:Mesenchymal stem cel s can differentiate into nerve cel s by chemical induction or co-culture method, but whether mesenchymal stem cel s co-cultured with Schwann cel s differentiate into neuronal-like cel s or Schwann-like cel s is stil controversial. OBJECTIVE:To explore the inductive role of Schwann cel s derived from rats in the differentiation of human umbilical cord mesenchymal stem cel s. METHODS:Cocultures of human umbilical cord mesenchymal stem cel s (1×109/L) and Schwann cel s (1×109/L) from neonatal rats were performed using transwel culture dishes. After 2 weeks of cocultures, morphology of the cultured human umbilical cord mesenchymal stem cel s was observed, and the phenotypic changes of cel s were also detected with immumocytochemistry techniques. RESULTS AND CONCLUSION:After 2 weeks of cocultures, some differentiated cel s showed neuron-like morphology, and expressed nestin, NF-200 andβ-III-tubulin, but did not express Schwann cel special marker S100 and oligodendrocytes special marker MAB1580. These findings indicate that human umbilical cord mesenchymal stem cel s can transdifferentiate into neuronal-like cel s by cocultures with rat’s Schwann cel s.
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BACKGROUND:The quantity and quality of seed cel s is a critical bottleneck of the development of vascular tissue engineering. To address this issue, stem cel-derived endothelial cel s have been a hot spot in this field due to their potential in providing the ideal seed cel s. OBJECTIVE:To elucidate the effect of vascular endothelial growth factor (VEGF) supplementation combined with hypoxic culture condition on the lineage-specific differentiation of embryonic stem cel s into endothelial cel s. METHODS:Serum-free medium mTeSR?1 was applied to cultivate H9 cel s in vitro. A conditioned medium containing 50μg/L vascular endothelial growth factor was utilized to induce H9 cel s to differentiate into endothelial cel s under the hypoxic culture condition (5%O2). The cel under normal condition (5%CO2) with or without vascular endothelial growth factor served as controls. The phenotype and function of human embryonic stem cel s-derived endothelial cel s were assayed by immunofluorescence staining, quantitative RT-PCR, and low-density lipoprotein uptake experiment. RESULTS AND CONCLUSION:Compared with the control group, the H9 cel s were induced to be differentiated into endothelial-like cel s more efficiently when they were cultivated under a conditioned medium with vascular endothelial growth factor supplementation under the hypoxic condition. These differentiated cel s not only expressed some important surface markers of endothelia cel s, including kdr, pecam, but also took in low-density lipoprotein to form microvessle-like structures. This culture system supports a synergy effect of vascular endothelial growth factor and hypoxic environment that can efficiently promotes the lineage-specific differentiation of embryonic stem cel s into endothelial cel s with good phenotype and functionality.
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BACKGROUND:Neuroblastoma is a common solid tumor in children. Pediatric tumors are little affected by environmental factors, but closely related to child development. The suspension method is an effective and reliable method to harvest neoplastic stem cel s. OBJECTIVE:To culture the cel clones of human neuroblastoma cel line SK-N-SH and to assess the biological properties of the cel clones. METHODS:Using the suspension method with no serum media, tumor cel clones were obtained. Immunofluorescence method was used to identify whether tumor cel clones exhibit stem cel properties. SK-N-SH neuroblastoma was labeled by luciferase, and tumor cel clones and tumor cel s were seeded onto the back of nude mice to monitor cel proliferative properties in nude mice using in vivo imaging. RESULTS AND CONCLUSION:Using the suspension culture method, SK-N-SH neuroblastoma cel s could successful y develop into cloning bal s. Under serum-free culture, cloning bal s were immunofluorescently used to detect molecular markers that showed strong positive expression. Cloning bal s subcutaneously implanted into nude mice showed the strong ability of self-renewal and differentiation as stem cel s. The cel clones cultured by the suspension method strongly expressed Nestin, but weakly expressed glial fibril ary acidic protein, neuron-specific tubulin, possessing stem cel characteristics and strong proliferation and metastasis in nude mice.
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BACKGROUND:To in vitro isolate neural stem cel s with high purity and uniform biological properties and to establish a complete set of neural stem cel culture system is the basis for neural stem cel research. OBJECTIVE:To establish an isolation and culture system for neural stem cel s from newborn mouse hippocampus, olfactory bulb and cortex and to analyze the biological properties of cel s. METHODS:Neural stem cel s were isolated from the hippocampus, olfactory bulb and cortex tissue of newborn Kunming mice by mechanical separation and trypsin digestion. Serum-free culture technology, mechanical pipetting and trypsin digestion were used for subculture of neural stem cel s. 10%fetal bovine serum was used to induce differentiation of neural stem cel s. Neural stem cel s and their differentiated products were identified by immunofluorescent staining of Nestin, CD133,β-TubulinIII, glial fibril ary acidic protein. RESULTS AND CONCLUSION:The neural stem cel obtained from newborn mouse hippocampus, olfactory bulb and cortex had the capacity of self-renewal and differentiation which were positive for Nestin and CD133. After induction with fetal bovine serum, neural stem cel could differentiation toβ-tubulinIII or glial fibril ary acidic protein positive cel s that were neurons and astrocytes. This experiment has successful y established the neural stem cel isolation, culture, identification and induction system, providing experimental basis for subsequent studies of neural stem cel s.
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BACKGROUND:It is important to produce and save a large amount of high-activity feeder cel s for the culture of human embryonic stem cel s. OBJECTIVE:To establish the optimal method for isolation and culture of Kunming mouse embryonic fibroblasts, and to evaluate the feasibility of preparing feeder layers for culture of human embryonic stem cel s. METHODS:Embryonic fibroblasts were isolated and cultured by different concentrations of trypsin from Kunming mouse fetuses in vitro. The biological characteristics and growth rule of mouse embryonic fibroblasts were investigated, and then the feeder layers for human embryonic stem cel s culture were produced. The growth of human embryonic stem cel s on the prepared feeder layer was tested. RESULTS AND CONCLUSION:The optimal fetal age for preparing Kunming mouse embryonic fibroblast feeder layer was 13.5 days. Kunming mouse embryonic fibroblasts at different concentrations grew wel with high purity and active proliferation by trypsin digestion method. There was no significant difference in the survival rate of cel s after cryopreservation for 2 weeks, 1 month, 3 months and 6 months. The cel s were proliferative from the second to fourth passage and declined sharply after the fifth passage. Human embryonic stem cel s which grew on Kunming mouse embryonic fibroblasts feeder layers were stil to remain the typical undifferentiated morphology and were strongly positive for alkaline phosphatase and periodic acid-Schiff after long-term subculture. The mouse embryonic fibroblasts can be used as the stable and high-quality feeder cel s for human embryonic stem cel s.
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BACKGROUND:It has been proved that erythropoietin can promotes angiogenesis in injured tissue, which is closely related to the proliferation and differentiation of endothelial progenitor cel s. However, the involved mechanism remains unclear yet. OBJECTIVE:To investigate the effect of erythropoietin on the function and activity of bone marrow-derived endothelial progenitor cel s in mice, and to explore the signal pathway. METHODS:The endothelial progenitor cel s from the bone marrow of mice were separated by means of density gradient centrifugation and then cultured. The cel s were preconditioned by specific inhibitor of PI3K (LY294002), and were divided into the fol owing groups:EGM-2 group, three erythropoietin preconditioned groups (the concentrations of erythropoietin in medium were 1, 5, 10 U/mL respectively), erythropoietin+LY group (10 U/mL erythropoietin and 10 mmol/L LY294002 in medium), LY group (10 mmol/L LY294002 in medium), dimethyl sulfoxide group (1 mL/L dimethyl sulfoxide in medium). The cel proliferation and apoptosis were evaluated by cel counting kit-8 and flow cytometry respectively. The contents of endothelial nitric oxide synthase and vascular endothelial growth factor in cel lysates were detected by the method of ELISA, and the expressions of Akt and p-Akt were by western blot assay. RESULTS AND CONCLUSION:Erythropoietin could promote the proliferation of endothelial progenitor cel s in a dose-dependent manner, which was, however, completely inhibited by LY294002. The apoptosis rate in the erythropoietin preconditioned groups was significantly lower than that in the erythropoietin+LY group. The contents of endothelial nitric oxide synthase and vascular endothelial growth factor in cel lysates of LY group and erythropoietin+LY group were significantly lower than those in the erythropoietin groups. There was no difference in Akt expression found in each group, while the p-Akt expression in the erythropoietin+LY group was significantly lower than that in the erythropoietin groups. The above results reveal that erythropoietin can promote the proliferation of endothelial progenitor cel s and decrease the cel apoptosis, which is depending on PI3K/Akt signal pathway.
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BACKGROUND:Chronic tendinopathy is a tendon disorder extremely common in athletes and in the general population with repetitive strain injuries of tendons. The pathogenesis of tendinopathy remains unclear and hence treatment of tendinopathy is usual y pal iative. OBJECTIVE:To investigate the of adipogenic and tenogenic ability of patel ar tendon-derived stem cel s isolated from chronic tendinopathy and healthy rats in vitro. METHODS:Tendon-derived stem cel s were isolated from patel ar tendons of chronic tendinopathy and healthy rats respectively. The tendon-derived stem cel s were cultured to the 3rd passage in complete culture medium, and cel morphology was observed. The cel s were divided into adipogenic induction group and control group. Cel s in the adipogenic induction group were cultured in adipogenic induction medium, while those in the control group cultured in complete culture medium. The ability of adipogenic differentiation between tendon-derived stem cel s isolated from the tendon of chronic tendinopathy and healthy rats in vitro was examined by oil red O staining and quantification assay. The mRNA expressions of C/EBPαand PPARγ2 were detected by real-time quantitative PCR. When 70%-80%cel s were confluent, the mRNA expressions of Col1a1, Scx, Tnmd and Dcn were also detected by real-time quantitative PCR. RESULTS AND CONCLUSION:At the third passage, slender spindle-shaped cel s were seen in both two groups, but there was a little change in the cel morphology in the chronic tendinopathy group. Lipid droplets were formed after the cel s were cultured in adipogenic induction medium for 21 days. This was not observed in the control group. We observed more oil red O-positive oil droplets in tendon-derived stem cel s from the tendons of chronic tendinopathy rats than healthy rats. The difference between them was statistical y significant (P=0.004). The results of real-time quantitative PCR showed that the mRNA expressions of C/EBPαand PPARγ2 in the tendon-derived stem cel s from the tendons of chronic tendinopathy rats were significantly higher than those in tendon-derived stem cel s from the tendons of healthy rats (P=0.004);the mRNA expressions of Col1a1, Scx, Tnmd and Dcn in the tendon-derived stem cel s from the tendons of chronic tendinopathy rats were significantly lower than those in tendon-derived stem cel s from the tendons of healthy rats (P=0.009). In conclusion, tendon-derived stem cel s from chronic tendinopathy rats showed a higher ability of adipogenic differentiation, but a lower capacity of tenogenic differentiation compared to tendon-derived stem cel s from healthy rats, which might contribute to better understand the pathogenesis of tendinopathy.
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BACKGROUND:The development of tissue engineering techniques provides new methods and ideas for the repair and functional reconstruction of articular cartilage defects. OBJECTIVE:To summarize the research progress in the application of mesenchymal stem cel s, as seed cel s, in articular cartilage tissue engineering. METHODS:A computer-based retrieval was performed to search articles describing articular cartilage tissue engineering and mesenchymal stem cel s published between January 1st, 2000 and September 30th, 2014 in PubMed database with the key words of“articular cartilage defects;cartilage tissue engineering;mesenchymal stem cel s”in English. Seventy articles were retrieved initial y, and only 49 were included in further analysis. RESULTS AND CONCLUSION:The ability of the articular cartilage for defect self-repair is limited, and current clinical treatments cannot be satisfactory. Development of tissue engineering provides a new idea for problem-solving. In the selection of seed cel s, chondrocyte is limited to dedifferentiate, and embryonic stem cel is restricted by ethical, legal and other aspects. Autologous mesenchymal stem cel s, which are easy to be amplified and exhibit excel ent cartilage differentiation potential, have gained widespread attention. But there is stil some controversy on the current application of tissue engineering techniques for repair of articular cartilage defects, including a certain gap between the long-term effects and the clinical applications. So the effect of mesenchymal stem cel s on biological structure and mechanical function stil needs further studies.