Exogenous gene expression in vitro and in vivo in bone marrow mesenchymal stem cells modified by hPDGF-A and hBD(2) / 中国实验血液学杂志

The objective of this study was to investigate the expression of exogenous hPDGF-A and hBD(2) in gene-modified bone marrow mesenchymal stem cells (BM-MSCs) in vitro and in vivo. Recombinant adenovirus vector expressing hPDGF-A/hBD(2) genes was constructed and packaged into virion. Primary isolated and cultured BM-MSCs were transfected by using hPDGF-A hBD(2), then the expressions of exogenous hPDGF-A/hBD(2) were detected by immunocytochemical staining in vitro. The conditioned medium (serum-free cultured supernatant of BM-MSCs transfected with recombinant adenovirus) collected from gene-modified BM-MSCs was applied to scratch wound on monolayer cells of multipotential cell line 10T1/2 in order to confirm the stimulative effect of hPDGF-A on cell migration. Gene-modified BM-MSCs were topically transplanted on wound of rats with radiation and skin excision combined injury. The distribution of BM-MSCs and expression of hPDGF-A/hBD(2) on the wound was observed by fluorescent microscopy and immunohistochemical staining respectively. The results indicated that the rat BM-MSCs transfected with recombinant adenovirus could express the EGFP in vitro. The immunofluorescent cytochemistry assay showed that the gene-modified BM-MSCs expressed the hPDGF-A and hBD(2). The scratch test confirmed that the percentage of healing area of wound in cultured supernatant group of gene-modified BM-MSCs was significant higher than that in control group on 8, 12, 24 and 48 hours (p < 0.05). The fluorescence microscopy of exogenous gene-modified BM-MSCs transplanted on wound revealed that the gene-modified BM-MSCs could higher express exogenous genes of EGFP at least within 2 weeks. The immunohistochemistry staining of wound indicated that the expression of exogenous genes began from day 3, reached to peak on day 7, and still visible on day 21 even though the expression became weak because of the possible dilution of the exogenous genes during cell division. It is concluded that efficient expression of exogenous hPDGF-A/hBD(2) in gene-modified BM-MSCs are demonstrated both in vitro and in vivo, which suggests that the molecular mechanism underlying chronic wound-healing accelerated by the strategy combining cell therapy with gene therapy.

Experimental study on human bone marrow mesenchymal stem cells transfected by SDF-1 cDNA / 中国实验血液学杂志

This study was aimed to investigate the expression of SDF-1 mRNA in SDF-1 cDNA-modified human bone marrow mesenchymal stem cells (hBMSCs) before and after transfection. The hBMSCs were isolated, cultured and identified, the SDF-1-pIRES2-EGFP eukaryotic expressing vector was constructed, and then the hBMSCs were transfected with the vector encapsulated by lipofectamine 2000. The transfection efficiency was measured by observing the expression of green fluorescence protein and detecting the mRNA by RT-PCR. The results indicated that the expression of SDF-1 mRNA increased by about 20% after hBMSCs were transfected instantaneously by SDF-1-pIRES2-EGFP. It is concluded that SDF-1 cDNA eukaryotic expression vector can be instantly transfected into hBMSCs by lipofectamine 2000, but the efficiency was too low to obtain enough steady transferred hBMSCs. Other procedures should be trialed to improve the transfection efficiency.

Influence of cervical sympathetic nerve block on blood flow volume and barrier function of intestinal mucosa after combined radiation and burn injury in rat / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of cervical sympathetic nerve block (SB) on blood flow volume and barrier function of intestinal mucosa after combined radiation and burn injury in rat.</p><p><b>METHODS</b>SD rats were divided into three groups: control (n = 18), combined injury group (n = 100, rats with Co gamma ray body irradiation with a dose of 5 Gy plus 15% TBSA full-thickness burn injury), and combined injury with SB treatment (n = 100, with the same dose of gamma-ray irradiation and burn injury, treated with SB). Twenty rats were sacrificed on 0, 1, 5, 7 days after combined injuries for various observations. SB was conducted with injection of ropivhydrochloride into the neck bilaterally for the SB group, and same amount of normal saline was injected instead in the combined injury group. Blood flow volume, changes in villus height and crypt depth in jejunum, Na(+)-K+ ATPase activity, permeability of small intestine were measured at different time-points.</p><p><b>RESULTS</b>The blood flow volume in small intestinal mucosal on 1 post-injury days (PID) [(0.29 +/- 0.07) ml x min(-1) x g(-1)] were obviously decreased than that in normal controls [(1.26 +/- 0.23) ml x min(-1) x g(-1), P < 0.01 ], with serious destruction of pit cells, decrease in intestinal mucosal Na(+)-K+ ATPase activity, and increase in intestinal mucosal permeability. Compared with combined injury group, the blood flow volume was [(0.82 +/- 0.11) ml x min(-1) x g(-1) 1 day after combined injury, P < 0.01], and the Na(+)-K+ ATPase activity was obviously increased, and the permeability of small intestine was ameliorated.</p><p><b>CONCLUSION</b>SB can increase blood flow volume of rat small intestine after combined radiation and burn injury, promote the repair of intestinal epithelium and improve the barrier function of the intestinal wall.</p>

Effects of blood serum from rats with combined radiation-thermal injury on the bone marrow hematopoietic progenitor cells growth / 中国实验血液学杂志

To observe the effects of blood serum from rats with radiation injury, thermal injury and combined radiation-thermal lesions on growth of hematopoietic progenitor cells and the change of their serum cytokine levels, total body irradiation of rats was performed with 12 Gy gamma ray from a (60)Co source, and 30% total body surface area III degree thermal lesion on the back was inflicted with a 5 kW bromotungsten lamp. The blood serum from these animals was collected at 3, 12, 24, 48, 72 and 96 hours after injury. Then the blood serum was added to the culture medium of erythrocyte progenitor cells (CFU-E, BFU-E) or granulocyte-macrophage progenitor cells (CFU-GM) at final concentration of 10 microg/ml. The results showed that the colony number of CFU-E, BFU-E and CFU-GM formed after addition of the blood serum from rats with thermal or combined radiation-thermal injury was significantly higher than that from normal rats at 3, 12, 24, 48, 72 and 96 hours after injury and reached its peak value at 24 hours after injury (342.8, 261.6 and 228.4% respectively from burned rats, 252.4, 205.1 and 174.2% respectively from rats with combined radiation-thermal injury as compared with that of normal rats). However, a few CFU-E, BFU-E or CFU-GM formation was found after addition of the blood serum from irradiated rats. At the same time, the level of TNF alpha and IL-6 in serum of burn group and combined radiation-thermal injury group was markedly higher than that of normal group, even more higher than that of irradiation injury group (P < 0.01). It is concluded that the blood serum from rats with thermal lesion or combined radiation-thermal injury improves the growth of erythrocyte and granulocyte progenitor cells. On the contrary, the blood serum from the irradiated rats shows the inhibiting effects, definitely related to their serum cytokines changes.

The role of p38 on the differentiation of MSCs to myoblasts / 中国应用生理学杂志

<p><b>AIM</b>Inducing mesenchymal stem cells (MSCs) differentiate to myoblasts with 5-azacytidine(5-Aza-CR), investigating the expression of Myf5 and the role of the signal transduction case of p38 in all the course of differentiation.</p><p><b>METHODS</b>Separating and purifying bone marrow-derived MSCs, inducing MSCs differentiation to myoblasts with 10 micromol/L 5-Aza-CR, assaying the gene expression time of Myf5 with RT-PCR method, the antigen expression of myosin with immunohistochemistry method and observing the changes of the activity of phosphorylation p38 before and after inhibited by SB203580 with Western-blot method.</p><p><b>RESULTS</b>MSCs begin to express Myf5 delayed to the 9th day after inhibited by SB203580. Some of MSCs express myosin at the 7th day after induced; The phosphorylation p38 activity of MSCs enhanced after induced by 5-Aza-CR but obviously decreased after inhibited by SB203580.</p><p><b>CONCLUSION</b>MSCs can express myogenic regulator factors and orientation differentiate to myoblasts after induced by 5-Aza-CR, p38 really have a positive signal transduction affection in this course.</p>

Cultivation and isolation of the bone marrow mesenchymal stem cells / 第三军医大学学报

Objective　To observe some biological features of bone marrow mesenchymal stem cells and explore the best conditions for isolatin g and culturing in vitro. Methods　Common cell culture techn ique, light and electron microscopy were used to study the effects of the growth , proliferation, morphology of the bone marrow mesenchymal stem cells in differe nt adherent time, concentration of serum and cell density. Results　The best culture condition in vitro for growth was 4-24 hours adherent time, 5%-10% fetal bovine serum, (4-8)×104/ml cell density. The cells were sp indle in shape and had a strong ability of proliferation. The time for cell duplication was 3 to 4 days. The cells showed the characteristics of stem cell s in electron microscope. Conclusion　The best condition for iso lation and culture of bone marrow mesemchymal stem cells was successfully establ ished and some biological features were obserred. It found a base for further in vestigation and using of mesenchymal stem cells.

Changes of glucocorticoid receptor in hepatic cytoplasm in scalded rats and its regulation by α-MSH and KPV peptide / 第三军医大学学报

Objective　To observe the changes of glucocorticoi d receptor (GR) in hepatic cytoplasm in rats after scalding-induced pathologic al stress and its regulation. Methods　The receptor binding capa city (R0) and the apparent dissociation constant (Kd) of GR in hepatic cytopla sm of normal, low-degree and heavy-degree scalded rats were measured with rad io-ligand binding assay, with ［3H］ dexamethasone as ligand. The changes of R0 and Kd of GR were regulated by injections of anti-rat TNFα, IL-1β a ntibodies, α-melanocyte-stimulating hormone (α-MSH), and KPV peptide( Ac- D-Lys-L-Pro-D-Val) respectively in vivo. Results　The R 0 of GR in hepatic cytoplasm in rats 12 h after heavy-degree scalding ［Mass action robust: （205.52±30.14） fmol/mg; Scatchard: （208.45±30.78） fmol/mg ］were significantly lower than that of control group ［Mass action robust:（307 .86±24.22） fmol/mg;Scatchard:（306.71±27.96） fmol/mg］(P<0.01), but no s ignificant difference was found in the R0 of GR between the control and the ra ts 12 h after low-degree scalding ［Mass action robust: （285.19±16.62） fmol/ mg ; Scatchard: （296.64±16.06） fmol/mg］. The injection of anti-rat TNFα, IL-1β antibodies, α-MSH and KVP all prevented the decline of R0 of GR in h epatic cytoplasm in rats with severe scalding. Conclusion　The injections of anti-rat TNFα, IL-1β antibodies, α-MSH or KPV can attenuate the reduction of GR in rat hepatic cytoplasm caused by severe scalding-induced pathological stress to some extent.

Effect of glucagon-like peptide 2 on mitogen-activated protein kinase activity in small intestinal epithelia of mice after radiation injury / 第三军医大学学报

Objective　To study the effect of glucagon-like peptide 2 (GLP-2) on mitogen-activated protein kinase (MAPK) activity in small intestinal epithelia in mice after radiation injury and its relation with the change of small intestinal epithelial proliferation. Methods　Mice were given a single dose of 8 Gy of total body 60Co gamma irradiation and then divided into GLP-2 and control groups. The activity of MAPK and proliferation rate in small intestinal epithelia were measured. Results　The activity of MAPK in small intestinal epithelia was higher in GLP-2-treated mice than in irradiated mice, and the proliferation rate in small intestinal epithelia significantly increased in GLP-2-treated mice. These two indices were of significantly positive correlated. Conclusion　GLP-2 can promote small intestinal epithelial proliferation in irradiated mice, and this may be related to activation of MAPK in small intestinal epithelia.

Effects of glucagon-like peptide 2 on recovery of small intestinal epithelia from radiation injury in mice / 第三军医大学学报

Objective　To investigate the effects of glucagon-like peptide 2 (GLP-2) on recovery of small intestinal epithelia from radiation injury in mice. Methods　Mice received a single 8 Gy dose of total body irradiation from 60Co gamma ray followed by treatment with GLP-2 or vehicle. DNA and protein content in small intestinal mucosa were measured, and small intestine was processed for histological examination with light microscope and scanning electron microscope. Results　Small intestinal mucosal DNA and protein content, villus height, and villus number significantly decreased in irradiated mice, partial villus tips were ulcerated. GLP-2 administration caused increase in DNA and protein content, villus height, and villus number as compared with irradiated control group. Meanwhile, the villus tips were lack of ulceration. Conclusion　GLP-2 can promote recovery of small intestinal epithelia from radiation injury in mice.

Cultivation and isolation of the bone marrow mesenchymal stem cells / 第三军医大学学报

Objective　To observe some biological features of bone marrow mesenchymal stem cells and explore the best conditions for isolatin g and culturing in vitro. Methods　Common cell culture techn ique, light and electron microscopy were used to study the effects of the growth , proliferation, morphology of the bone marrow mesenchymal stem cells in differe nt adherent time, concentration of serum and cell density. Results　The best culture condition in vitro for growth was 4-24 hours adherent time, 5%-10% fetal bovine serum, (4-8)×104/ml cell density. The cells were sp indle in shape and had a strong ability of proliferation. The time for cell duplication was 3 to 4 days. The cells showed the characteristics of stem cell s in electron microscope. Conclusion　The best condition for iso lation and culture of bone marrow mesemchymal stem cells was successfully establ ished and some biological features were obserred. It found a base for further in vestigation and using of mesenchymal stem cells.

Changes of glucocorticoid receptor in hepatic cytoplasm in scalded rats and its regulation by α-MSH and KPV peptide / 第三军医大学学报

Objective　To observe the changes of glucocorticoi d receptor (GR) in hepatic cytoplasm in rats after scalding-induced pathologic al stress and its regulation. Methods　The receptor binding capa city (R0) and the apparent dissociation constant (Kd) of GR in hepatic cytopla sm of normal, low-degree and heavy-degree scalded rats were measured with rad io-ligand binding assay, with ［3H］ dexamethasone as ligand. The changes of R0 and Kd of GR were regulated by injections of anti-rat TNFα, IL-1β a ntibodies, α-melanocyte-stimulating hormone (α-MSH), and KPV peptide( Ac- D-Lys-L-Pro-D-Val) respectively in vivo. Results　The R 0 of GR in hepatic cytoplasm in rats 12 h after heavy-degree scalding ［Mass action robust: （205.52±30.14） fmol/mg; Scatchard: （208.45±30.78） fmol/mg ］were significantly lower than that of control group ［Mass action robust:（307 .86±24.22） fmol/mg;Scatchard:（306.71±27.96） fmol/mg］(P<0.01), but no s ignificant difference was found in the R0 of GR between the control and the ra ts 12 h after low-degree scalding ［Mass action robust: （285.19±16.62） fmol/ mg ; Scatchard: （296.64±16.06） fmol/mg］. The injection of anti-rat TNFα, IL-1β antibodies, α-MSH and KVP all prevented the decline of R0 of GR in h epatic cytoplasm in rats with severe scalding. Conclusion　The injections of anti-rat TNFα, IL-1β antibodies, α-MSH or KPV can attenuate the reduction of GR in rat hepatic cytoplasm caused by severe scalding-induced pathological stress to some extent.

Effect of glucagon-like peptide 2 on mitogen-activated protein kinase activity in small intestinal epithelia of mice after radiation injury / 第三军医大学学报

Objective　To study the effect of glucagon-like peptide 2 (GLP-2) on mitogen-activated protein kinase (MAPK) activity in small intestinal epithelia in mice after radiation injury and its relation with the change of small intestinal epithelial proliferation. Methods　Mice were given a single dose of 8 Gy of total body 60Co gamma irradiation and then divided into GLP-2 and control groups. The activity of MAPK and proliferation rate in small intestinal epithelia were measured. Results　The activity of MAPK in small intestinal epithelia was higher in GLP-2-treated mice than in irradiated mice, and the proliferation rate in small intestinal epithelia significantly increased in GLP-2-treated mice. These two indices were of significantly positive correlated. Conclusion　GLP-2 can promote small intestinal epithelial proliferation in irradiated mice, and this may be related to activation of MAPK in small intestinal epithelia.

Effects of glucagon-like peptide 2 on recovery of small intestinal epithelia from radiation injury in mice / 第三军医大学学报

Objective　To investigate the effects of glucagon-like peptide 2 (GLP-2) on recovery of small intestinal epithelia from radiation injury in mice. Methods　Mice received a single 8 Gy dose of total body irradiation from 60Co gamma ray followed by treatment with GLP-2 or vehicle. DNA and protein content in small intestinal mucosa were measured, and small intestine was processed for histological examination with light microscope and scanning electron microscope. Results　Small intestinal mucosal DNA and protein content, villus height, and villus number significantly decreased in irradiated mice, partial villus tips were ulcerated. GLP-2 administration caused increase in DNA and protein content, villus height, and villus number as compared with irradiated control group. Meanwhile, the villus tips were lack of ulceration. Conclusion　GLP-2 can promote recovery of small intestinal epithelia from radiation injury in mice.

Advances in Gene-engineering Production of Defensins / 微生物学通报

This paper reviews the recent advances in recombinant expression and purification of defensins, including the choice of host cells, vectors and expression strategies in prokaryotic and eukaryotic cell ex- pression systems, as well as the status of purification processes. By summarizing the problems existed in the production and clinical applications of defensins, the authors here also pointed out the research directions for defensins, and conceived the prospects for its exploitation in the future.