Low-magnitude vibration promotes osteogenesis of osteoblasts in ovariectomized osteoporotic rats via the estrogen receptor / 生物医学工程学杂志

The purpose of this study was to investigate the effect of low-magnitude vibration on osteogenesis of osteoblasts in ovariectomized rats with osteoporosis via estrogen receptor α(ERα). The mRNA expression of osteogenic markers were examined with qRT-PCR, based on which the optimal vibration parameter for promoting osteogenesis was determined (45 Hz × 0.9 g, g = 9.8 m/s

Bone marrow mesenchymal stem cells differentiate into cartilage and bone:roles of Wnt5a/PCP signaling pathways / 中国组织工程研究

BACKGROUND:Wnt5a is able to inhibit canonical Wnt signaling and activate non-canonical Wnt signaling pathway. In recent years, it has been found that non-classical Wnt5a/PCP signaling pathway mediated by Wnt5a plays an important role in the process of bone marrow mesenchymal stem cel proliferation and differentiation, but the underlying mechanism is unclear. OBJECTIVE:To summarize the progress in downstream effector molecules related to Wnt5a/PCP signaling pathway, and its roles in the chondrogenic and osteogenic differentiation of bone marrow mesenchymal stem cel s. METHODS:A computer-based online search of CqVip, CNKI and PubMed databases between January 2000 and February 2016 was performed using the Chinese keywords of“BMSCs, Wnt signaling pathways, chondrogenic differentiation, osteogenic differentiation”and English keywords of“BMSCs, chondrogenic differentiation, osteogenic differentiation, Wnt, Fzd, Ror2, RhoA, ROCK, JNK”, respectively. Literatures related to bone marrow mesenchymal stem cel chondrogenic and osteogenic differentiation were selected. Final y, 43 eligible articles were included for analysis through excluding the old and repeated research. RESULTS AND CONCLUSION:Wnt5a, a representative protein in non-canonical Wnt signaling pathway, paticipates in the cytoskeleton, cel migration and cel polarization and other activities by mediating its downstream signaling molecules such as Fzd, Ror, RhoA, ROCK, JNK, thereby regulating its proliferation and differentiation. But it is unclear how Wnt5a/PCP participates in the bone marrow mesenchymal stem cel chondrogenic and osteogenic differentiation and how the downstream effector molecules interact or function independently, which requires further studies.

Expression of Myocardial Specificity Markers MEF-2C and Cx43 in Rat Bone Marrow-derived Mesenchymal Stem Cells Induced by Electrical Stimulation In Vitro / 生物医学工程学杂志

Bone marrow-derived mesenchymal stem cells (BMSCs) for repairing damaged heart tissue are a new kind of important treatment options because of their potential to differentiate into cardiomyocytes. We in this experiment investigated the effect of different electrical stimulation time on the expression of myocardial specificity gene and protein in rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. The rBMSCs of second or third generation were randomly divided into three groups, i.e, electrical stimulation (ES) group, 5-Azacytidine (5-Aza) group and the control group. The rBMSCs in the ES groups with complete medium were exposed to 2 V, 2 Hz, 5 ms electrical stimulation for 0. 5 h, 2 h, 4 h, and 6 h respectively every day for 10 days. Those in the 5-Aza group were induced by 5-Aza (10 μmol/L) for 24 h, and then cultured with complete medium for 10 days. Those in the control group were only cultured with complete medium, without any treatment, for 10 days. The rBMSCs' morphological feature in each group was observed with inverted phase microscope. The mRNA expression of myocyte-specific enhancer factor 2C (MEF-2C) and connexin 43 (Cx43) were examined with Real-Time quantitative PCR and the protein expression of MEF-2C, Cx43 were detected with Western Blot method. The results showed that the mRNA expression level of the MEF-2C, Cx43 and the protein expression level of MEF-2C, Cx43 were significantly higher in the ES group and 5-Aza group than those in the relative control group (P < 0.05). It suggests that electrical stimulation could play a part of role in the induction of the rBMSCs to differentiate into the cariomyocyte-like cells in vitro and the effectiveness of the electrical stimulation with 2 h/d had the best in our experiment. But the mechanism how electrical stimulation promotes the differentiation of rBMSC into cardiomyocyte is still unclear.

Differentiation of rat bone marrow-derived mesenchymal stem cells into cardiomyocyte-like cells induced by cyclic stretching strain / 生物医学工程学杂志

Bone marrow-derived mesenchymal stem cells (BMSCs) are multipotent stem cells that differentiate into a variety of cell types and widely used in tissue regeneration engineering. The purpose of this study is to investigate whether the cyclic biaxial stretching strain could promote the rat BMSCs (rBMSCs) to differentiate into cardiomyocyte-like cells in vitro. The second or third generation of rBMSCs were randomly divided into the cyclic stretching stain group, the control group and the blank group. Those rBMSCs in the cyclic stretching strain group were seeded on a silicone membrane with complete medium were exposed to biaxial stretching strain of 10% of membrane at a frequency of 1 Hz lasting for 6 h, 12 h and 24 h. Those in the control group were seeded on silicone membrane with complete medium. Those in the blank group were seeded in the 6-wells plates with complete medium. The mRNA expression of GATA4 and myocyte-specific enhancer factor 2C (MEF-2C) were detected by the real-time fluorescent quantification PCR and the protein expression of connexin 43 (Cx43) was detected by using the Western blot method. The results showed that the mRNA expression level of the GATA4 and MEF-2C, and the protein expression level of Cx43 were significantly higher in the cyclic stretching strain groups, compared with those in the relative control groups (P < 0.05). It suggests that cyclic biaxial stretching strain could play a part in the induction of rBMSCs to differentiate into cardiomyocyte-like cells in vitro, but the differentiation mechanism is still unclear.

Characteristics and Related Factors of Wechsler Memory Scale-Fourth Edition of Chinese Version for Mental Retardation / 中国康复理论与实践

@#Objective To investigate the memory characteristics and related factors of patients with mental retardation. Methods 73 patients with mental retardation (patient group) and 73 normal subjects (control group) matched with the patient group were respectively tested with Wechsler Memory Scale-Fourth Edition of Chinese Version (WMS-IV). Results The scores of each subtest and composite scores of WMS-IV were significantly lower in the patient group than in the control group (P<0.01). All the composite scores positively correlated with each other in the patient group (r=0.38-0.90, P<0.01) and in the control group (r=0.31-0.94, P<0.01). Age and education level positively correlated with all the composite scores (except the Visual Working Memory Index) in the patient group (P<0.05). Conclusion The patients with mental retardation present an overall decline in memory, especially in the immediate memory. The memory function in patients is related with their ages and education levels.

Effects of electrical stimulation on the differentiation of mesenchymal stem cells into cardiomyocyte-like cells / 生物医学工程学杂志

The aim of this study is to investigate the effects of electrical stimulation ES) on the induction of rat bone marrow mesenchymal stem cells (rBMSCs) to differentiate into cardiomyocyte-like cells in vitro. The third or fourth-generation of the rBMSCs was randomly divided into three groups, i. e. ES group, 5-Azacytidine (5-Aza) group, and control group. Those in the ES group with complete medium were exposed to 1,2,4 and 6V, 2Hz, 5ms ES for 2h everyday,lasting for 10d. Those in the 5-Aza group were induced by 10 micromol/L 5-Aza for 24h, then the medium was changed to complete medium without 5-Aza. Those in the control group were only cultured with complete medium. The growth status and morphological features of rBMSCs were observed by inverted phase microscope. The mRNA expressions of GATA4, a-actin, ACTN2 and TNNT2 were determined by Real-time fluorescent quantification PCR, and the protein expression of TNNT2 was detected with immunofluorescence staining. The results showed that the mRNA expression level of the GATA4, a-actin, ACTN2 and TNNT2 and the protein expression level of the TNNT2 were significantly higher in the ES group and 5-Aza group, compared to those in the control group(P<0. 05). It suggested that ES could induce rBMSCs differentiation into cardiomyocyte-like cells in vitro.

Low frequence pulsed electromagnetic fields induce chondrocyte-like cells differentiation of rat bone marrow-derived mesenchymal stem cells in vitro / 生物医学工程学杂志

Mesenchymal stem cells (MSCs) are multipotent stem cells that differentiate into a variety of cell types. Low frequency pulsed electromagnetic fields (LFPEMFs) therapy can causes biochemical changes at the cellular level to accelerate tissue repair in mammals. So, we tested the hypothesis that LFPEMFs can promote chondrogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs) in vitro. The rBMSCs were isolated by adherence method and the third-generation of the rBMSCs were randomly divided into LFPEMFs groups, chondrocyte-induced group and control group. LFPEMFs groups with complete medium were exposed to 50Hz, 1mT PEMFs for 30 min every day, lasting for 10, 15 and 20 d, respectively. Chondrocyte-induced group were treated with chondrogenic media, while control groups were only cultured with complete medium. The mRNA expressions of type II-collagen (Col II) and aggrecan were determined by Real-time fluorescent quantitation PCR. The protein expression of Col II and aggrecan were detected with toluidine blue stain or immunocytochemical stain, respectively. The result showed that the mRNA and protein expression level of Col-II and aggrecan were significantly higher in the LFPEMFs group or chondrocyte-induced group, compared to the control group. It suggest that LFPEMFs could contribute to rBMSCs to differentiate into chondrogenic differentiation in vitro.

The effects of pulsed electromagnetic fields on the induction of rat bone marrow mesenchymal stem cells to differentiate into cardiomyocytes-like cells in vitro / 生物医学工程学杂志

The aim of this study is to investigate the effects of pulsed electromagnetic fields (PEMFs) on the induction of rat bone marrow mesenchymal stem cells (rBMSCs) to differentiate into cardiomyocytes-like cells in vitro. rBMSCs were randomly divided into PEMFs groups, 5-Azacytidine (5-Aza) groups and control groups. PEMFs groups were exposed to 50 Hz, 1 mT PEMFs for 30 min every day, lasting for 10 d, 15 d and 20 d, respectively. 5-Aza groups were induced by 10 micromol/L 5-Aza for 1 day, then the medium was changed to complete medium without 5-Aza. And control groups were only cultured with complete medium, rBMSCs growth status and morphological features were observed by inverted phase microscope every day. The mRNA expressions of cardiac troponin T (TNNT2) and alpha-actinin (ACTN2) were determined by Real-Time PCR. The results showed that rBMSCs were spindle, polygon or fusiform in control groups. The cells gradually got longer and grew close together after being stimulated by PEMFs and 5-Aza, and with the extension of induction time, the tendency became obvious. At 20th day after PEMFs or 5-Aza treatment, rBMSCs gathered like a long chain, got much longer obviously at the high magnification, and some of them even fused with their neighbors. Compared with control groups, the levels of TNNT2 mRNA expression in 5-Aza groups were 19.40 fold (P < 0.01), 21.02 fold (P < 0.01) and 2.38 fold at 10 d, 15 d, 20 d and the levels of ACTN2 mRNA expression in 5-Aza groups were 6.64 fold (P < 0.01), 6.67 fold (P < 0.01) and 0.76 fold at 10 d, 15 d, 20 d. However, the levels of TNNT2 mRNA expression in PEMFs groups were 15.78 fold (P < 0.01), 6.73 fold (P < 0.05) and 2.73 fold (P < 0.01) of control groups at 10 d, 15 d, 20 d and the levels of ACTN2 mRNA expression in PEMFs groups were 4.93 fold (P < 0.01), 1.89 fold and 0.64 fold, respectively. Compared with 5-Aza groups, the levels of TNNT2 mRNA expression in PEMFs groups were 0.81 fold, 0.32 fold (P < 0.01) and 1.15 fold at 10 d, 15 d, 20 d and the levels of ACTN2 mRNA expression in PEMFs groups were 0.74 fold, 0.28 fold (P < 0.01) and 0.83 fold at 10 d, 15 d, 20 d. PEMFs could contribute to the induction of rat marrow rBMSCs to differentiate into cardiomyocytes-like cells in vitro, and the best exposure time might be 10 days, but further investigation is still needed.

Adenovirus-mediated delivery of nm23-H1 gene inhibits growth of colorectal carcinoma cell line Lovo / 生物医学工程学杂志

This experimental study sought to find out the inhibitory effects of Ad-GFP-nm23-H1 on proliferation and metastasis of human colorectal carcinoma cell line Lovo, and, further, to gain an insight into some theoretical and methodical basis for instituting nm23-H1 gene therapy of cancers. MTT assay and Transwell chamber were used to detect the rates of proliferation and invasion as well as the adhesion of Lovo cells in vitro. The results demonstrated that the proliferation inhibition rates of Lovo cells treated with Ad-GFP-nm23-H1 of 10(10) PFU/ml, 10(9) PFU/ml and 10(8) PFU/ml were 84.9% +/- 1.51%, 48.5% +/- 7.23% and 22.5% +/- 5.47%, that the adherence inhibition rates of Lovo cells treated with Ad-GFP-nm23-H1 of 10(10) PFU/ml, 10(9) PFU/ml and 10(8) PFU/ml were 70.3% +/- 2.40%, 60.1% +/- 5.68% and 18.5% +/- 3.61%, and that the invasiveness inhibition rates of Lovo cells treated with Ad-GFP-nm23-H1 of 10(10) PFU/ml, 10(9) PFU/ml and 10(8) PFU/ml were 83.2% +/- 5.71%, 52.2% +/- 6.94% and 28.1% +/- 8.21%. These data suggested that Ad-GFP-nm23-H1 exerted significant inhibitory effects on the proliferation and metastasis of human colorectal carcinoma cell line Lovo in a dose-dependent way.

Rac1 mediates the migration of endothelial cells induced by IL-8 / 生物医学工程学杂志

This study sought to elucidate whether Rac1 mediates the migration of endothelial cell induced by IL-8. The Transwell chamber motility assay was conducted to disclose the effect of different matrigel dilution and different time of IL-8 treatment on the migration of endothelial cells. The mRNA of Rac1 was detected by RT-PCR. The results demonstrated that when the concentration of Matrigel was 1:2, there is significant difference on the amounts of migration cells than that of the concentration of 1:3 or 1:8; When the dilution of Matrigel was 1:4, 1:5 or 1:6, there is no significant difference on the amounts of migration cells than that of other dilution groups. So we choose the Matrigel concentration as 1:4. With the increase of IL-8 stimulation time, the cells which migrated from upper reservoirs to lower reservoirs progressively increased. After six hours stimulation by IL-8, the expression of Rac1 mRNA in migrated cells was increased, compared with that of other groups. The results suggest that Rac1 may mediate the migration of endothelial cells induced by IL-8. It can also be the foundation for further investigation on the role of Rac1 in the migration of endothelial cells induced by IL-8.

Effects of ovariectomy and estradiol on microarchitecture and biomechanical properties in rat vertebrae / 生物医学工程学杂志

This study was aimed at observing the effects of ovariectomy and estradiol on the microarchitecture of cancellous bone and exploring the influence of microarchitectural change on the biomechanical properties. Thirty 6-month-old unmated female SD rats were randomly divided into 3 groups (10 rat each): sham-operated control group (Sham), ovariectomized group (OVX)and Estradiol Benzoate treated group (EBT). All rats were housed in standard environmental conditions. Five months after operation, the rats were sacrificed. The biomechanical properties of the third lumbar vertebras (L3) were measured with compression testing in vitro. Micro-CT scanning was performed on the fourth lumbar vertebras (L4) in vitro. In comparison with the corresponding variables of Sham, the bone volume fraction (BV/TV) and the trabecular number (Tb. N) of OVX were reduced remarkably, and the trabecular separation (Tb. Sp) and the structural model index (SMI) of OVX were enhanced obviously. These facts implicated that the bone trabecular plate-like structure of OVX were decreased. BV/TV, Tb. N and the trabecular thickness (Tb. Th) of EBT were greater than those of OVX. Tb. Sp and SMI of EBT were much smaller than those of OVX. The results of mechanical test showed that the maximum forioe (Fmax), the maximum stress (sigmamax) and the elastic modeulus (E) of the lumbar vertebral cancellous bone of OVX were declined sharply, while the aforesaid biomechanical index of EBT was improved distinctly. The performance of three-dimensional micro-CT and the mechanical testing to assess microarchitecture of cancellous bone are useful for evaluating the state of osteoporosis and the antiosteoporotic effect of agents.

Impedance effects of interleukin-6 on cyclophosphamide-induced hematopoietic damnification in dogs / 生物医学工程学杂志

The aim of this study is to evaluate the effect of Interleukin-6 on cyclophosphamide-induced hematopoietic damnification. The doses of Interleukin-6 in 3 different regimens were hypodermally injected into dogs for 7 days respectively to establish the cyclophosphamide-induced hematopoietic damnification model. The effect of Interleukin-6 on the production of platelets and the amount of other cells in the dogs' bone marrow were determined on the 21st day. The results showed that Interleukin-6 significantly alleviated the reduction of platelet count and recovered the platelets level faster. The impedance effects of Interleukin-6 directed against hematopoietic damnification of bone marrow and spleen were shown by pathological examination. These suggest that the Interleukin-6 can significantly impede cyclophosphamide-induced hematopoietic damnification.

Restoring the skin from traumatism by means of collagen-konjac glucomannan-chondroitin sulfate blend film / 生物医学工程学杂志

This study aims at restoring the skin from traumatism by use of the collagen(from piglet skin) and konjac glucomannan-chondroitin sulfate blend film. The 2 cm x 4 cm skin traumatism model was established on both sides of the waist spinal column in 14 New Zealand rabbits each weighing 1.5-2.0 kg. One side was covered with blend film, the other side was used as a control. Then the changes of the skin traumatism were observed at different time-points after the operation, the wound tissue samples were taken for histological examination. The blend film could prevent skin traumatism from bleeding and infection. The skin traumatism treated by blend film showed signs of rectangle scab and the control showed signs of linear scab after healing. No obvious immune rejection was seen. The collagen-konjac glucomannan-chondroitin sulfate blend film can accelerate the restoration of skin from traumatism.