Synthesis, characterization and luminescence of europium perchlorate with MABA-Si complex and coating structure SiO2 @Eu(MABA-Si) luminescence nanoparticles.

This article reports a novel category of coating structure SiO2 @Eu(MABA-Si) luminescence nanoparticles (NPs) consisting of a unique organic shell, composed of perchlorate europium(III) complex, and an inorganic core, composed of silica. The binary complex Eu(MABA-Si)3 ·(ClO4 )3 ·5H2 O was synthesized using HOOCC6 H4 N(CONH(CH2 )3 Si(OCH2 CH3 )3 )2 (MABA-Si) and was used as a ligand. Furthermore, the as-prepared silica NPs were successfully coated with the -Si(OCH2 CH3 )3 group of MABA-Si to form Si-O-Si chemical bonds by means of the hydrolyzation of MABA-Si. The binary complexes were characterized by elemental analysis, molar conductivity and coordination titration analysis. The results indicated that the composition of the binary complex was Eu(MABA-Si)3 ·(ClO4 )3 ·5H2 O. Coating structure SiO2 @Eu(MABA-Si) NPs were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and infrared (IR) spectra. Based on the SEM and TEM measurements, the diameter of core-SiO2 particles was ~400 and 600 nm, and the thickness of the cladding layer Eu(MABA-Si) was ~20 nm. In the binary complex Eu(MABA-Si)3 ·(ClO4 )3 ·5H2 O, the fluorescence spectra illustrated that the energy of the ligand MABA-Si transferred to the energy level for the excitation state of europium(III) ion. Coating structure SiO2 @Eu(MABA-Si) NPs exhibited intense red luminescence compared with the binary complex. The fluorescence lifetime and fluorescence quantum efficiency of the binary complex and of the coating structure NPs were also calculated. The way in which the size of core-SiO2 spheres influences the luminescence was also studied. Moreover, the luminescent mechanisms of the complex were studied and explained.

Luminescence enhancement of terbium(III) perchlorate by 2,2'-dipyridyl on bis(benzylsulfinyl)methane complex and luminescence mechanism.

A novel ternary complex, Tb(2)L4 · L'·(ClO4)6 · 8H2O, has been synthesized using bis(benzylsulfinyl)methane as the first ligand L and 2,2'-dipyridyl as the second ligand L'. The ternary complex was characterized by element analysis, molar conductivity, coordination titration analysis, infrared, thermogravimetric-differential scanning calorimetric and ultraviolet spectra. The results indicated that the composition of the complex was Tb2 L4 · L'·(ClO4)6 · 8H2O (L = C(6)H(5)CH(2) SOCH(2)SOCH(2)C(6)H(5); L' = Dipy). Fourier transform infrared results revealed that the perchlorate group was bonded with the Tb(III) ion by the oxygen atom, and the coordination was bidentate. The fluorescent spectra illustrated that the complex displayed characteristic fluorescence in the solid state. After the introduction of the second ligand, 2,2-dipyridyl, the relative emission intensity and fluorescence lifetime of the ternary complex Tb(2)L(4) · L'·(ClO(4))(6) · 8H2O were enhanced compared to the binary complex TbL(2.5)(ClO4)3 · 3H2O. This indicated that the presence of both organic ligand bis(benzylsulfinyl)methane and the second ligand 2,2-dipyridyl could sensitize the fluorescence intensity of Tb(III) ion, and introduction of the 2,2-dipyridyl group resulted in an enhancement of the fluorescence of the Tb(III) ternary rare earth complex. The strongest characteristic fluorescence emission intensity of the ternary complex was 9.36 times that of the binary complex. The phosphorescence spectra and fluorescence lifetime of the complex were also measured.

Lentiviral­mediated Shh reverses the adverse effects of high glucose on osteoblast function and promotes bone formation via Sonic hedgehog signaling.

Patients with diabetes tend to have an increased incidence of osteoporosis, which may be associated with hyperglycemia; however, the pathogenic mechanisms governing this interaction remain unknown. The present study sought to investigate whether elevated extracellular glucose levels of bone mesenchymal stem cells (BMSCs) could influence osteoblastic differentiation and whether the intracellular Sonic hedgehog (Shh) pathway could adjust the effects. Furthermore, to verify the results in vivo, a rat tooth extraction model was constructed. BMSCs were incubated in eight types of culture medium, including low glucose (LG), LG + lentivirus (Lenti), LG + Lenti­small interfering RNA (Lenti­siRNA), LG + Lenti­Shh, high glucose (HG), HG + Lenti, HG + Lenti­siRNA and HG + Lenti­Shh. The lentiviral transfection efficiency was observed using a fluorescence microscope; protein and mRNA expression was detected by western blotting and reverse transcription­quantitative polymerase chain reaction (RT­qPCR). The matrix mineralization and alkaline phosphatase (ALP) activity of BMSCs were examined by Alizarin red staining and ALP activity assays, respectively. The expression of osteogenesis­related genes in BMSCs were quantified by RT­qPCR. The alveolar ridge reduction was measured and histological sections were used to evaluate new bone formation in the tooth socket. With high concentrations of glucose, Shh expression, matrix mineralization nodules formation, ALP activity and the levels of bone morphogenic protein 4 (BMP4), bone sialoprotein (BSP) and osteopontin (OPN) expression were greatly reduced compared with LG and corresponding control groups. Whereas activated Shh signaling via Lenti­Shh could increase the number of matrix mineralization nodules, ALP activity, and the expression levels of BMP4, BSP and OPN in BMSCs. Additionally, in vivo assays demonstrated that Lenti­Shh induced additional bone formation. Collectively, the results of the present study indicated that HG inhibited the Shh pathway in osteoblasts and resulted in patterning defects during osteoblastic differentiation and bone formation, while the activation of Shh signaling could suppress these deleterious effects.

[Effect of "Xingnao Kaiqiao Zhenfa" (Acupuncture Technique for Restoring Consciousness) Combined with Rehabilitation Training on Nerve Repair and Expression of Growth-associated Protein-43 of Peri-ischemic Cortex in Ischemic Stroke Rats].

OBJECTIVE: To observe the effect of "Xingnao Kaiqiao Zhenfa" (acupuncture technique for restoring consciousness) combined with enriched rehabilitation training on motor function and expression of growth-associated protein-43 (GAP-43) of peri-ischemic cortex in ischemic stroke rats, so as to investigate its mechanism underlying improvement of ischemic stroke. METHODS: SD rats were randomly divided into sham operation, model, rehabilitation and comprehensive rehabilitation groups, which were further divided into 3 time-points:7, 14 and 21 d (n=6 in each). Cerebral ischemia(CI) model was established by occlusion of the middle cerebral artery with heat-coagulation. The rehabilitation group was treated by enriched rehabilitation training, once a day. The comprehensive rehabilitation group was treated by acupuncture combined with enriched rehabilitation training. Acupuncture was applied to bilateral "Neiguan"(PC 6) and "Shuigou"(GV 26) for 30 min, once a day. The neurological function score, balance-beam walking test and rotating-rod walking test were evaluated at the end of the corresponding treatment time. The expression of GAP-43 in peri-ischemic cortex was detected by immunohistochemistry. RESULTS: In comparison with the sham operation group, the scores of neurological function, beam walking test and rotating-rod walking test were significantly higher in the model group (P<0.01). There were no significant changes in the scores of balance-beam walking and rotating-rod walking tests in the rehabilitation group compared with the model group on day 7 (P>0.05). Compared with the model group at the other time points, the scores of neurological function, balance-beam walking test and rotating-rod walking test were significantly lower in the rehabilitation and comprehensive rehabilitation groups (P<0.05). Compared with the rehabilitation group, the scores of neurological function, balance-beam walking test and rotating-rod walking test were significantly lower in the comprehensive rehabilitation group (P<0.05). In comparison with the sham operation group, the number of GAP-43 positive cells of peri-ischemic cortex was significantly higher in the model group (P<0.01). Compared with the model group, the numbers of GAP-43 positive cells of peri-ischemic cortex were significantly increased in the rehabilitation and comprehensive rehabilitation groups (P<0.01). The number of GAP-43 positive cells of peri-ischemic cortex in the comprehensive rehabilitation group was significantly higher than that in the rehabilitation group (P<0.01). CONCLUSIONS: "Xingnao Kaiqiao Zhenfa" combined with enriched rehabilitation training can promote the recovery of nerve function in ischemic stroke rats, which may be associated with its effect in up-regulating the expression of GAP-43 in the peri-ischemic cortex.

Therapeutic effects of hepatocyte growth factor-overexpressing dental pulp stem cells on liver cirrhosis in a rat model.

Cirrhosis is the terminal stage of hepatic diseases and is prone to develop into hepatocyte carcinoma. Increasing evidence suggests that the transplantation of dental pulp stem cells (DPSCs) may promote recovery from cirrhosis, but the key regulatory mechanisms involved remain to be determined. In this study, we overexpressed human hepatocyte growth factor (hHGF) in primary rat DPSCs and evaluated the effects of HGF overexpression on the biological behaviors and therapeutic efficacy of grafted DPSCs in cirrhosis. Liver cirrhosis was induced via the intraperitoneal injection of CCl4 twice weekly for 12 weeks and was verified through histopathological and serological assays. HGF was overexpressed in DPSCs via transduction with a hHGF-lentiviral vector and confirmed based on the elevated expression and secretion of HGF. The HGF-overexpressing DPSCs were transplanted into rats intravenously. The HGF-overexpressing DPSCs showed increased survival and hepatogenic differentiation in host liver tissue at 6 weeks after grafting. They also exhibited a significantly greater repair potential in relation to cirrhosis pathology and impaired liver function than did DPSCs expressing HGF at physiological levels. Our study may provide an experimental basis for the development of novel methods for the treatment of liver cirrhosis in clinical practice.

Exome sequencing reveals novel IRXI mutation in congenital heart disease.

Genetic variation in specific transcription factors during heart formation may lead to congenital heart disease (CHD) or even miscarriage. The aim of the present study was to identify CHD­associated genes using next generation sequencing (NGS). The whole exome DNA sequence was obtained from a stillborn fetus diagnosed with tricuspid atresia and complete transposition of the great arteries using high­throughput sequencing methods. Subsequently, genetic variants of CHD­associated genes were selected and verified in 215 non­syndromic CHD patients and 249 healthy control subjects using polymerase chain reaction combined with Sanger sequencing. Genetic variants of previously reported CHD­inducing genes, such as cysteine rich with EGF like domains 1 and cbp/p300­interacting transactivator with Glu/Asp rich carboxy­terminal domain 2, were discovered through the NGS analysis. In addition, a novel non­synonymous mutation of the iroquois homeobox 1 (IRX1) gene (p.Gln240Glu) was identified. A total of three non­synonymous mutations (p.Gln240Glu, p.Ser298Asn and p.Ala381Glu) of the IRX1 gene were verified in 215 non­syndromic CHD patients, but not in 249 healthy volunteers. The results demonstrated that NGS is a powerful tool to study the etiology of CHD. In addition, the results suggest that genetic variants of the IRX1 gene may contribute to the pathogenesis of CHD.

[Therapeutic effect of human bone marrow mesenchymal stem cell lysates on rat arthritis induced by collagen].

Our previous work has shown that mesenchymal stem cells (MSC) have little therapeutic effect on rat arthritis induced by collagen. This study was aimed to further investigate whether the MSC lysates exhibit beneficial effects on rheumatoid arthritis. Aliquots of cell lysates from 1×10(7) human bone marrow MSC were intraperitoneally injected into collagen-induced arthritis (CIA) Wistar rats weekly for 4 consecutive weeks. Methotrexate at a dose of 1 mg/kg or normal saline was served as positive and negative controls respectively. On week 4 the symptom scores were recorded and the hind joints of the rats were pathologically examined and X-ray examination was performed. The results showed that on week 4, the symptom scores of the rats that received MSC lysates (6.87 ± 0.83) and MTX (6.44 ± 1.13) were significantly lower than that of control rats (7.33 ± 0.77, P < 0.01). Meanwhile, pathological examination on the involved ankle showed that the synovitis and arthritis scores of MSC lysates and control groups were 2.28 ± 0.48 and 2.28 ± 0.55 respectively, significantly higher than that of MTX treatment rats (0.71 ± 0.48, P < 0.05). However, X-ray examination on the ankle joints showed that the injury score of control rats was 4 ± 0.57, greatly higher than those from MSC lysates (2.71 ± 0.75) and MTX treatment groups (2.57 ± 0.78, P < 0.05 for both groups). It is concluded that MSC lysate infusion has beneficial effects on CIA rat, but the effectiveness seems inferior to MTX.

[Effect of human bone marrow mesenchymal stem cell transplantation on hematopoietic recovery of irradiated mice].

This study was aimed to investigate the effect of human bone marrow mesenchymal stem cells (hBMMSC) on the hematopoietic recovery of sublethally irradiated mice. Female BALb/c mice irradiated with (60)Co γ-ray at a single dose of 6 Gy received graded doses of hBMMSC (1×10(5), 1×10(6) and 5×10(6)) by intravenous infusion. The counts of leukocytes, platelets, erythrocytes and hemoglobin level in peripheral blood, the amount of bone marrow hematopoietic progenitors, and the serum levels of human TPO, SCF and G-CSF as well were evaluated at different time points after transplantation. The results showed that hBMMSC infusion had little protective effect on the survival of irradiated mice. Compared with the control mice, the peripheral blood cell counts of hBMMSC-treated mice were not obviously elevated during 3 weeks after infusion, however, blood cell counts were significantly greater at 4 weeks after cell treatment (P < 0.05). The amount of colony-forming unit of mononuclear cells and granulocyte/monocytes in bone marrow of mice that received middle and high doses of hBMMSC were dramatically greater than that in control mice (P < 0.05). Two days after hBMMSC administration, human G-CSF and SCF could be detected in the sera from hBMMSC-treated mice, and the G-CSF concentration of mice that received high-dose hBMMSC was significantly higher than that in other groups (P < 0.01). Nevertheless, human TPO was undetectable in the sera of all mice tested and serum human G-CSF and SCF could not be detected on days 9 and 16 in all groups. It is concluded that hBMMSC may promote the hematopoietic recovery of irradiated mice, probably by transient secretion of hematopoiesis-associated factors by the implanted cells.

[Effects of tumor necrosis factor-α on immunoregulatory activities of mesenchymal stem cells in vitro and in vivo].

Mesenchymal stem cells (MSC) are characterized by their potent immuno-regulatory activity, however our previous data have shown that MSC have no therapeutic effects on collagen-induced arthritis (CIA). To further clarify the complexity, the effects of tumor necrosis factor-alpha (TNF-α) on the in vitro and in vivo immunoregulatory activity of MSC were investigated in this study, as TNF-α is recognized as the key factor in the development of rheumatoid arthritis. The nuclear translocation of the inflammation-associated factor NF-κB was observed after human umbilical cord MSC were treated with TNF-α and the cell proliferation status was assessed by MTT test. The inhibitory effects of MSC or TNF-α-treated MSC on the mixed lymphocyte reaction, in which Wistar rat spleen mononuclear cells were served as the responders and the splenocytes from SD rat spleens as the stimulators, were also determined by the MTT test. Further, the therapeutic potentials of MSC or TNF-α-treated MSC were observed in a Wistar rat CIA model. The results showed that NF-κB translocated into the nuclei promptly after TNF-α treatment, though TNF-α had little effect on the MSC proliferation. MSC, whether pre-stimulated by TNF-α or not and when different doses were tested, exhibited obviously inhibitory effects on the proliferation of the lymphocytes (P < 0.001 for all groups tested), while MSC-treated by TNF-α displayed more potent suppression especially when low-density were used. Unexpectedly, the infiltration of inflammatory cells into the involved knees was aggravated by cell treatment and the pathological scores were significantly higher than those of controls (P < 0.05). It is concluded that the TNF-α exhibits different effects on immune regulation activity of MSC, and its underlying mechanism needs to further investigate.

[Human bone marrow mesenchymal stem cells have little preventive or therapeutic effect on rat arthritis induced by collagen].

The aim of this study was to investigate if transfusion of mesenchymal stem cells (MSC) could exhibit beneficial effects on rheumatoid arthritis. Human bone marrow MSC were intraperitoneally injected into Wistar rats with collagen-induced arthritis at a dose of 10(7) on the next day (preventive group) or 2 weeks (treatment group) after collagen II induction, once a week for 2 weeks (preventive group) or 4 weeks (treatment group). The control group was given normal saline (NS) at corresponding time. The symptom scorings were documented weekly from the second week of the induction. On week 6, the hind joints of the rats were pathologically examined and the activation status of splenocytes was analyzed by flow cytometry. The results showed that all the rats developed arthritis and subsequent joint abnormality. On the sixth week, symptom scores of the rats that received MSC preventive (9.5 ± 0.5) or therapeutic (9.4 ± 0.6) infusions had no significant difference between each other, but were significantly greater than those of the NS controls (7.6 ± 0.6, P < 0.05). Consistently, pathological examination on the involved knees showed that the synovitis and arthritis scorings of MSC treated rats were greatly elevated compared with NS controls. Furthermore, the ratios of CD86(+) cells in the spleens of MSC prevention, MSC treatment and NS control groups were (4.16 ± 1.48), (4.06 ± 1.97) and (4.15 ± 2.04) respectively, while those of CD11b/c(+)CD86(+) cells were (1.04 ± 0.68), (0.95 ± 0.56) and (0.98 ± 0.44), all of which were significantly higher than those of healthy controls [(0.97 ± 0.18) and (0.30 ± 0.17), P < 0.05 for both parameters]. It is concluded that MSC infusion has little beneficial effects on collagen-induced arthritis in rats, conversely, MSC therapy aggravated the damage of the involved joints, its underlying mechanisms need to be further investigated.

Microvesicles derived from human umbilical cord mesenchymal stem cells stimulated by hypoxia promote angiogenesis both in vitro and in vivo.

Although mesenchymal stem cells (MSCs) have been increasingly trialed to treat a variety of diseases, the underlying mechanisms remain still elusive. In this study, human umbilical cord (UC)-derived MSCs were stimulated by hypoxia, and the membrane microvesicles (MVs) in the supernatants were collected by ultracentrifugation, observed under an electron microscope, and the origin was identified with the flow cytometric technique. The results showed that upon hypoxic stimulus, MSCs released a large quantity of MVs of ~100 nm in diameter. The MVs were phenotypically similar to the parent MSCs, except that the majority of them were negative for the receptor of platelet-derived growth factor. DiI-labeling assay revealed that MSC-MVs could be internalized into human UC endothelial cells (UC-ECs) within 8 h after they were added into the culture medium. Carboxyfluorescein succinimidyl ester-labeling technique and MTT test showed that MSC-MVs promoted the proliferation of UC-ECs in a dose-dependent manner. Further, MVs could enhance in vitro capillary network formation of UC-ECs in a Matrigel matrix. In a rat hindlimb ischemia model, both MSCs and MSC-MVs were shown to improve significantly the blood flow recovery compared with the control medium (P<0.0001), as assessed by laser Doppler imaging analysis. These data indicate that MV releasing is one of the major mechanisms underlying the effectiveness of MSC therapy by promoting angiogenesis.