Transition of autophagy and apoptosis in fibroblasts depends on dominant expression of HIF-1α or p53 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

It has been revealed that hypoxia is dynamic in hypertrophic scars; therefore, we considered that it may have different effects on hypoxia-inducible factor-1α (HIF-1α) and p53 expression. Herein, we aimed to confirm the presence of a teeterboard-like conversion between HIF-1α and p53, which is correlated with scar formation and regression. Thus, we obtained samples of normal skin and hypertrophic scars to identify the differences in HIF-1α and autophagy using immunohistochemistry and transmission electron microscopy. In addition, we used moderate hypoxia in vitro to simulate the proliferative scar, and silenced HIF-1α or p53 gene expression or triggered overexpression to investigate the changes of HIF-1α and p53 expression, autophagy, apoptosis, and cell proliferation under this condition. HIF-1α, p53, and autophagy-related proteins were assayed using western blotting and immunofluorescence, whereas apoptosis was detected using flow cytometry analysis, and cell proliferation was detected using cell counting kit-8 (CCK-8) and 5-bromo-2'-deoxyuridine (BrdU) staining. Furthermore, immunoprecipitation was performed to verify the binding of HIF-1α and p53 to transcription cofactor p300. Our results demonstrated that, in scar tissue, HIF-1α expression increased in parallel with autophagosome formation. Under hypoxia, HIF-1α expression and autophagy were upregulated, whereas p53 expression and apoptosis were downregulated in vitro. HIF-1α knockdown downregulated autophagy, proliferation, and p300-bound HIF-1α, and upregulated p53 expression, apoptosis, and p300-bound p53. Meanwhile, p53 knockdown induced the opposite effects and enhanced HIF-1α, whereas p53 overexpression resulted in the same effects and reduced HIF-1α. Our results suggest a teeterboard-like conversion between HIF-1α and p53, which is linked with scar hyperplasia and regression.

Effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts / 中华烧伤杂志

Objective@#To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts.@*Methods@#A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test.@*Results@#(1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01).@*Conclusions@#Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

Application of different doses of ropivacaine combined with sufentanil in epidural stepwise labor analgesia LI / 临床麻醉学杂志

Objective To evaluate the efficacy of epidural anesthesia combined with different doses ropivacaine and sufentanil for stepwise labor analgesia in latent phase.Methods Two hundred and ten ASA Ⅰ or Ⅱ primiparas with a singleton and vertex presentation at full term in our hospital from February 201 5 to April 201 5 were randomized into seven groups (n =30 each):0.125% ropiva-caine with 0.5 μg/ml sufentanil (group 1);0.075% ropivacaine with 0.5 μg/ml sufentanil (cervical dilatation dural block between groups at each time.The latent period of group 2 and 3 were shorter than that in group 1 (P <0.05)and that of group 5 and 6 were shorter than that in group 4 (P <0.05);the ac-tive phase of group 4 were longer than that in group 1 (P <0.05 ).The postpartum hemorrhage of group 2 and 3 were less than that in group 1 (P <0.05),the postpartum hemorrhage of group 5,6 and 7 were more than that in group 2 (P <0.05)and group 3 (P <0.05).The motor nerve block of group 2 and 3 were slightly less than that in group 1 (P <0.05)and the motor nerve block of group 5,6 and 7 were slightly less than that in group 4 (P <0.05).There was no difference of the postpar-tum adverse reactions of maternal and Apgar score in the neonates.Conclusion The dosage of 0.075% or 0.1% ropivacaine with 0.5 μg/ml sufentanil (cervical dilatation < 3 cm),0.125% ropiv-acaine with 0.5 μg/ml sufentanil (cervical dilatation ≥ 3 cm),while producing the exact analgesic effect,hardly interferes with the 1abor process,the amount of postpartum hemorrhage and the lower limb activity,thus they have no significant effect on the safety of the maternal and the infant.

Histology of collagen nodules from hypertrophic scars / 中华创伤杂志

Objective To detect the histological characteristics of collagen nodules from hypertrophic scars (HS) and investigate the origin of collagen nodules.Methods The scar tissues were collected from patients with plastic operation.Morphological characteristics of collagen nodules were observed by light microscopy of HE-stained sections; expressions of type Ⅰ /Ⅲ collagens were observed by polarized light microscopy of sirius red-stained sections; expression and distribution of myofibroblasts (MFb)-specific protein (α-smooth muscle actin,α-SMA) were observed by immunostaining in order to observe level of local tissue tension.Results Collagen nodules varied in shape,not only sphereshaped,and in size.Moreover,abundant fibroblasts (Fb) with large and light-stained nuclei were seen in the nodules compared to non-nodule area,indicating that the cells located in the modules were active.Some collagen nodules were composed largely of collagen type Ⅲ (green),but some mainly contained collagen type Ⅰ (red or yellow),indicating the difference in the time of nodule formation.α-SMA was expressed mainly in the deep dermis equivalent to the level of reticular layer of the new scar tissues (2 months after injury) ; α-SMA was expressed mainly in the nodules of the old scar tissues (2-10 years after injury),but almost not in non-nodule areas except for a strongly positive staining in the vessels.Moreover,α-SMA presented a heterogeneous distribution in the collagen nodules,with stronger expression in the epidermal end than in the subcutaneous tissue end and stronger expression in the superficial dermis than that in the deeper part.It was suggested that there existed massive amount of MFb and high tension in the nodules arid that the tension distribution was not uniform in or between the nodules.Conclusions Collagen nodules are of varying shape and size and collagen types are associated with the time of nodule formation.Moreover,Formation of the collagen nodules may be closely related to the distribution and evolution of the local tissue tension.

Effect of tension on collagen arrangement / 中华创伤杂志

Objective To study the effect of mechanical tension on collagen arrangement and illustrate the relationship between tissue architecture and tension properties. Methods Cell morphologies, orientation and collagen arrangement of fibroblasts cultured in three different types of collagen gels with variation of mechanical tension were observed by phase contrast photomicrographs, light microscopy and transmission electron microscopy. Expression and distribution of a-smooth muscle actin (α-SMA) were investigated by immunohistochemistry. Results Phase contrast photomicrographs, light microscopy and transmission electron microscopy showed high level of tension distributed anisotropically in the monolayer gels and the anchored collagen gels, with bipolar shape of the fibroblasts, obvious polarity, arrangement of exogenous collagen fibres parallel to the long axis of the fibroblasts, especially prominent in monolayer gels. Low level of tension distributed isotropically was observed in floating collagen gels, with stellate morphology and arrangement of exogenous collagen fibres in a reticular array. Immunofluorescence showed that fibroblasts expressed high level of α-SMA protein distributed along the long axis of fibroblasts in the monolayer gels and the anchored collagen gels, especially in former ones. In contrast, few expression of α-SMA protein was found in floating collagen gels. Cell morphologies and orientation, expression and distribution of α-SMA as well as collagen arrangement of fibroblasts in the monolayer gels and the anchored collagen gels were similar to those in granulation tissue, whereas floating collagen gels resembled normal dermis or remodelled tissues. Conclusions Tissue architecture or morphology of the dermis are corresponding to tension proporties. Different tissue architectures are closely correlated with particular tension proporties.