c-erbB(2) and c-myb induce oocyte maturation via activation of mitogen-activated protein kinase and maturation promoting factor / 生理学报

It is important to study the mechanism of oocyte maturation because oocyte maturation is essential for the female procreation. The present study was designed to observe the effects of protooncogenes c-erbB(2) and c-myb on oocyte maturation and the upstream and downstream relationship with mitogen-activated protein kinase (MAPK) and maturation promoting factor (MPF). The investigation was designed as follows: (1) In order to explore the effects of protooncogenes on oocyte maturation, the dose- and time-dependent effects of c-erbB(2) antisense oligodeoxynucleotide (ASODN) and c-myb ASODN on oocyte maturation were examined, and the effects of oocyte microinjection with recombinant c-erbB(2) and c-myb proteins on oocyte maturation were investigated; (2) In order to study the upstream and downstream relationship among protooncogenes of c-erbB(2), c-myb and protein kinases of MAPK and MPF in regulating oocyte maturation, mouse oocytes were cultured in the medium treated with c-erbB(2) ASODN, c-myb ASODN, PD98059 (the MAPK inhibitor) or roscovitine (the MPF inhibitor) for 8 h, respectively, and the expressions of c-erbB(2) mRNA, c-myb mRNA, MAPK and MPF were examined. The results showed that both c-erbB(2) ASODN and c-myb ASODN inhibited the rate of germinal vesicle breakdown (GVBD) and the first polar (PB1) extrusion of denuded oocytes (DOs) in a dose- and time-dependent way, and delayed their maturation time significantly. When recombinant c-erbB(2) and c-myb proteins were microinjected into cytoplasm of germinal vesicle stage oocyte, we found that the GVBD rate increased by 23.1% (P<0.05) and 32.2% (P<0.05), respectively, for 6-hour culture, and the PB1 extrusion rate increased by 17.3% (P<0.05) and 23.5% (P<0.05), respectively, for 12-hour culture. RT-PCR showed that the mRNA expressions of c-erbB(2) and c-myb were detected in oocytes; c c-erbB(2) ASODN inhibited c-erbB(2) mRNA and c-myb mRNA expressions; c-myb ASODN inhibited c-myb mRNA expression but had no effect on c-erbB(2) mRNA expression. Nonsense tat ODN had no effects on the expressions of c-erbB(2) mRNA and c-myb mRNA. Neither PD98059 nor roscovitine changed the expressions of c-erbB(2) mRNA and c-myb mRNA though both of them inhibited recombinant c-erbB(2) and c-myb proteins-induced oocyte maturation. Furthermore, MAPK phosphorylation and cyclin B1 synthesis in oocytes were inhibited remarkably when oocytes were treated with c-erbB(2) ASODN, c-myb ASODN, PD98059 and roscovitine. Nonsense tat ODN had no effects on MAPK phosphorylation and cyclinB1 content. The results suggest that protooncogenes c-erbB(2) and c-myb play an important role in oocyte maturation; the effects of c-erbB(2) and c-myb depend upon the action of MAPK and MPF, and their activation is the event that occurs downstream of c-erbB(2) and c-myb in the maturation signal pathway.

The protection of heme oxygenase-1 from acute cardiocyte injury in rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the protection of Heme oxygenase-1 (HO-1) from lipopolysaccharide (LPS)-induced cardiocyte injury and its mechanism.</p><p><b>METHODS</b>Cardiocyte was isolated from SD neonate rat and cultured in vitro, and was divided into control group (normal culture), LPS group (with stimulation of 30 micromoL/L LPS for 1 hour), LPS + Hemin group (with same treatment to LPS group after stimulation of 5 micromoL/L Hemin for 1 hour), and LPS + ZnPP group (with same treatment to LPS group after stimulation of 3 micromoL/L ZnPP for 1 hour). The level of lactic-dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) were measured by thio-barbituric acid and xanthine oxidase techniques. The cell heart rhythm, survival rate and apoptosis rate were examined. The expressions of nuclear factor kappaB (NF-kappaB), HO-1 and tumor necrosis factor-alpha (TNF-alpha) were measured with Western blotting. The HO-1 mRNA was examined by RT-PCR.</p><p><b>RESULTS</b>The level of LDH and MDA in LPS, LPS + Hemin, and LPS + ZnPP groups were (113 +/- 15), (79 +/- 13), (154 +/- 22) U/L, and (1.88 +/- 0.36), (1.16 +/- 0.32), (2.84 +/- 0.44) mmoL/L respectively, which were all obviously higher than those in control group [(69 +/- 10) U/L, (0.87 +/- 0.25) mmol/L, P < 0.05]. The level of SOD in LPS, PS + Hemin, and LPS + ZnPP groups (17.8 +/- 1.8, 22.5 +/- 2.4, 13.4 +/- 1.5 U/mL, respectively) was all obviously lower than that in control group (24.3 +/- 3.6 U/mL, P < 0.05). The apoptosis rate and heart rhythm were obviously higher and survival rate significantly lower in LPS, LPS + Hemin, and LPS + ZnPP groups than those in control group (P < 0.05). The level of HO-1mRNA in LPS, LPS + Hemin, and LPS + ZnPP groups was higher than that in control group (P < 0.01), among which LPS + Hemin group was the highest. The level of HO-1, TNF-alpha and NF-kappaB in LPS, LPS + Hemin, and LPS + ZnPP groups was higher than those in control group (P < 0.05), among which the level of HO-1 protein in LPS + Hemin group was the highest, the level of TNF-alpha and NF-kappaB in LPS + ZnPP group was highest.</p><p><b>CONCLUSION</b>LPS can induce cardiocyte injury, which can be inhibited through the anti-inflammatory, anti-oxidant, and anti-apoptosis functions by HO-1.</p>

Construction of a tissue engineering skin with epidermal stem cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>To constitute a composite skin substitute that can proliferate well with epidermal stem cells and fibroblasts on collagen sponge.</p><p><b>METHODS</b>Epidermal stem cells were selected by rapid attachment to collagen IV for 10-15 min and cultured on 3T3 feeder layers. Collagen was extracted from rat tail. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde. Fibroblasts were inoculated on collagen sponge and cultured for 4 days prior to inoculation of epidermal stem cells to construct composite skin substitute. The composite skin substitute were examined by means of histology, immunohistochemistry and electron microcopy, the histologic appearance was similar to that of normal epidermis.</p><p><b>RESULTS</b>The epidermal stem cells formed large colonies at 7-8 days, expressed K19 antigen. The percentages of cells at G0/G1 phase of cell cycle and the percentage of alpha6 briCD71dim cells in ESC groups were higher than those in the control group. The skin substitute had epidermis and dermis, the histologic appearance was similar to that of normal skin. The artificial skin expressed keratin antigen by immunocytochemical methods.</p><p><b>CONCLUSIONS</b>Epidermal stem cells proliferated well and differentiated properly on this artificial skin dermis which contained fibroblasts. It seemed that the composite skin to be a good equivalent.</p>

Study on the biological features of human epidermal stem cells cultured in serum-free medium / 中华烧伤杂志

<p><b>OBJECTIVE</b>To establish a methodology of serum-free culture of human epidermal stem cells in vitro, and observe their biological characteristics.</p><p><b>METHODS</b>Epidermal stem cells were isolated from child foreskin and purified with type IV collagen. They were then cultured in regular medium (S group), serum-free medium (SF1 group) and bovine pituitary extract but serum-free medium (SF2 group), respectively. The morphological changes, clone counting, passage time, expression of surface alpha(6) and CD(71), cell cycle analysis, and the expression of cytokeratin (CK) 19, CK5/8, CK10 in each group were determined 20 days after culture.</p><p><b>RESULTS</b>There was no significant difference in morphology, CK19, 5/8 and 10 positive cells between SF1 group and S group. The cells in these two groups could both form about 43 clones and be passaged for 10 times. About (48 + 6)% cells were alpha(6)(bri)CD71(dim) positive, (72.2 + 6.2)% cells were at G0-G1 phase, with similar expression of CK19, CK5/8, CK10. Despite more clone numbers were found in SF2 group, the levels of all other parameters were lower than those in S and SF1 groups.</p><p><b>CONCLUSION</b>Human epidermal stem cells can be cultured successfully in serum-free culture for the study of their biological characteristics.</p>

Effects of rare earth compounds on human peripheral mononuclear cell telomerase and apoptosis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effects of rare earth exposure on human telomerase and apoptosis of human peripheral mononuclear cells (PBMNs).</p><p><b>METHODS</b>Rare earth mine lot in Xunwu county, the biggest ion absorptive rare earth mine lot of China, was selected as the study site. Another village of Xunwu county, with comparable geological structure and social environment was selected as the control site. Thirty healthy adults were randomly selected from the study site as exposure group and another 30 healthy adults randomly selected from the control site as control group. The blood content of 15 rare earth elements, including La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y, were determined by inductive coupled plasma-source mass spectrometry (ICP-MS). The total contents of rare earth elements in the blood were calculated. The TRAP and FCM assays were carried out to analyse the telomerase and apoptosis of human PBMNCs respectively.</p><p><b>RESULTS</b>In the exposure group, the concentration of La, Ce, Dy and Y were significantly higher (P<0.001), and Pr, Nd, Sm, Gd and Yb were higher than those in the control group (P<0.05). The total content of rare earth in the blood of exposure group showed significant difference compared with control group (P<0.001). Telomerase activity in PBMNs of the exposure group was higher than that in the control group (P<0.05); there were 11 adults in the exposure group (30 adults) and 5 adults in control group (30 adults) showed positive telomerase activity. The average age of the exposure group was (38.69 +/- 8.02) years-old, while the control group was (40.45 +/- 9.02) years-old (P >0.05). It was found that there was a significant relationship between telomerase activity and the total content of rare earth elements (P <0.01). 3. The proportion of apoptosis was not different between the two groups (P >0.05), but the cells in the S-phase and G2-M phase were increased (P <0.01) in the exposed group.</p><p><b>CONCLUSION</b>The telomerase activity of PBMNs in the rare earth elements exposed group was higher than that of the control group, and there is no effect on apoptotic rate of PBMNs, but may promote the diploid DNA replication, and increase the percentage of G2/M and S phase cells.</p>

Effect of lanthanum chloride on expressions of collagen protein in a wound tissue / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of lanthanum chloride on expressions of collagen protein and find a way to prevent and treat scar.</p><p><b>METHODS</b>Four linear incisions were made on the dorsal skin of an adult, female Sprague-Dawley rat as an animal model. One was non-manipulated as a control; the second was injected with distilled water as a sham-control; the third was injected with 50 mmol/L of lanthanum chloride, and the fourth was injected with 50 micrograms neutralizing antibody of TGF-beta 1 as a positive control. All of the wound tissues were harvested and assayed with ABC method in 14 days and 28 days after the surgery.</p><p><b>RESULTS</b>The expressions of type I, III and IV of collagen protein in the third group significantly reduced in 14 and 28 days after the operation, compared with the control or sham-control group. Its values wen as similar as the fourth group.</p><p><b>CONCLUSION</b>Lanthanum chloride could inhibit the expressions of collagen protein, and it may be used to prevent and treat scars.</p>

Effects of lanthanum chloride on the apoptosis of fibroblasts in trauma tissue / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of lanthanum chloride on the apoptosis of fibroblasts in trauma tissue.</p><p><b>METHODS</b>Fifty adult female SD rats were used and linear incisions were made on the back near the joints of extremities of the rats. One of the cuts receiving no treatment was designated as blank control (C). 0.25 ml of distilled water, lanthanum chloride (50 mmol/L) and the antibody of (TGFbeta(1)) transforming growth factor beta(1) (0.2 mg/ml) were respectively injected into the both sides of the other three wounds subcutaneously and the wounds were divided into simulating control (SC), lanthanum chloride (LC) and antibody (A) groups. The fibroblast apoptosis in the wound tissue samples and the change in intracellular calcium concentration (Ca(2+)) were determined by flow cytometry (FCM) and TUNEL methods on the 14th and 28th day after the injection.</p><p><b>RESULTS</b>Apoptosis of fibroblasts was enhanced significantly after 14 days of injection in LC and A groups compared with that in C and SC groups (P < 0.05 approximately 0.01). Furthermore, intracellular Ca(2+) was increased evidently in LC group (P < 0.01).</p><p><b>CONCLUSION</b>It is indicated that lanthanum chloride might be effective in preventing scar development.</p>