Up-regulation of CREB-1 regulates tendon adhesion in the injury tendon healing through the CREB-1/TGF-ß3 signaling pathway.

AIM: To explore the mechanism of the healing of tendon tissue and anti-adhesion, and to discuss the role of the transforming growth factor-ß3 (TGF-ß3)/cAMP response element binding protein-1 (CREB-1) signaling pathway in the healing process of tendons. METHOD: All mice were divided into four groups of 1, 2, 4, and 8 weeks respectively. Each time group was divided into four treatment groups: the amplification group, the inhibition group, the negative group, and the control group. When the tendon injury model was established, the CREB-1 virus was injected into the tendon injury parts. A series of methods such as gait behaviourism, anatomy, histological examination, immunohistochemical examination and collagen staining were employed to assess the tendon healing and the protein expression of TGF-ß3, CREB-1, Smad3/7 and type I/III collagen (COL-I/III). CREB-1 virus was sent to tendon stem cells to assess the protein expression of TGF-ß1, TGF-ß3, CREB-1, COL-I/III by methods such as immunohistochemistry and Western blot. RESULTS: The amplification group showed better gait behaviourism than the inhibition group in the healing process. The amplification group also had less adhesion than the negative group. Hematoxylin-eosin (HE) staining of tendon tissue sections showed that the number of fibroblasts in the amplification group was less than the inhibition group, and the immunohistochemical results indicated that the expression of TGF-ß3, CREB-1, and Smad7 at each time point was higher than the inhibition group. The expression of COL-I/III and Smad3 in the amplification group was lower than the inhibition group at all time points. The collagen staining indicated that the ratio of type I/III collagen in the amplification group was higher than the negative group at 2,4,8 week. The CREB-1 amplification virus could promote the protein expression of TGF-ß3, CREB-1 and inhibit the protein expression of TGF-ß1 and COL-I/III in the tendon stem cells. CONCLUSION: In the process of tendon injury healing, CREB-1 could promote the secretion of TGF-ß3, so as to promote the tendon healing and have the effect of anti-adhesion in tendons. It might provide new intervention targets for anti-adhesion treatment of tendon injuries.

Changes of soil bacterial community structure at the secondary successional stages in the Pinus yunnanensis forest.

Soil bacterial diversity is a key factor for the maintanence of forest ecosystem function. Soil bacterial community would change along forest succession. We analyzed the variations of soil bacterial diversity and community composition at different successional stages in the Pinus yunnanensis forest, which would help understand the mechanism underlying forest restoration. We investigated soil bacterial diversity, community composition, and effect factors at different successional stages (including coniferous forest, mixed coniferous and broadleaf forest, and evergreen broadleaf forest) using Illumina Hiseq platform. The results showed that OTUs, Chao1 index, Ace index, and Shannon index of soil bacterial community decreased with the process of secondary succession. The highest soil bacterial total OTUs, richness, and complexity appeared at early successional stage. Soil bacterial community composition varied across different stages, with the mixed coniferous and broadleaf forest showing largest variation. Proteobacteria and Acidobacteria were common dominant phyla at secondary successional stages. Actinobacteria, Chloroflexi, and Patescibacteria were dominant phyla at the early successional stage, the abundance of which decreased with successional process in the P. yunnanensis forest. Proteobacteria and WPS-2 increased with the succession. Soil pH and tree species richness were key factors in driving soil bacterial community structure. The soil bacterial diversity decreased with forest succession, while the variations of soil bacterial community composition became larger.

[Non-structural carbohydrates characteristics of different forest layers in monsoon broad-leaved evergreen forest in Pu'er, Yunnan Province, China]. / 云南普洱季风常绿阔叶林不同林层非结构性碳水化合物特征.

Based on cluster analysis of species vertical stratification, the variations in concentration, allocation and seasonal dynamics of non-structural carbohydrates were investigated in a monsoon broad-leaved evergreen forest in Pu'er, Yunnan Province. The results showed that the concentrations of soluble sugar (3.9%) and nonstructural carbohydrates (NSC, 13.3%) were the highest in the sub-canopy. In contrast, the sugar/starch (0.76) of understory was the lowest. There was no significant difference in starch content among three forest layers. For all forest stories, the soluble sugar was mainly allocated to leaves and the roots had more starch and NSC. The soluble sugar contents in leaves and trunks of sub-canopy species were higher than canopy and understory species. There were no significant differences in soluble sugar content of twigs and roots among three different forest layers. The starch content of leaves increased with decreasing height of forest layers. In contrast, the lowest starch content (10.7%) of roots was in understory. There was no significant difference in starch content of twigs and trunks among three different forest layers. The NSC content of leaves was lower in canopy (10.7%) than that in sub-canopy (12.3%) and understory (12.0%). The lowest NSC content of roots was in understory (14.2%). The lowest sugar/starch of leaves, twigs, and trunks presented in understory, while the lowest sugar/starch of roots presented in canopy (0.79). There were dramatic seasonal variations in concentrations and components of NSC. The concentration of soluble sugar and the sugar/starch were higher in the rainy season than that in the dry season. However, the concentration of starch and NSC were higher in the dry season than in the rainy season. The variations in concentration of NSC and its components among forest layers indicated that species with different heights varied in their utilization strategies of carbon, which partly explained species coexistence.

[Species-area relationship at different succession stages of monsoon evergreen broad-leaved forest in south subtropical area of Yunnan Province].

Based on the investigation data of monsoon evergreen broad-leaved forest at its different succession stages (primary, CP; 15 years of succession, CF; and 30 years of succession, CT) in Pu' er of Yunnan Province, this paper studied the species-area relationship of this forest at each succession stage. It was found that in the communities at each succession stage, the number of total species, trees, shrubs, and lianas had a significant correlation with sampling area, with the area explained over 94% of the total variation. The Z value of the total species (0.334) and trees (0.394) was the lowest at CT, whereas that of shrubs (0.437) and lianas (0.326) was the lowest at CF. No significant differences were observed in the intercepts of the species-area curve of total species, trees, shrubs, and lianas among different succession stages, but the coefficient of determination (R2) of the species-area curve of total species and lianas was the highest at CP. The richness of trees and shrubs at CF explained 99.9% of the variance of Z value, but the richness of total species, trees, shrubs, and lianas at CP and CT had no significant correlations with the Z value.