Food preference strategy of four sympatric rodents in a temperate forest in northeast China.

Rodents are well known as both seed predators and dispersers of various plant species in forest ecosystems, and they play an important role in the regeneration of vegetation. Thus, the research on seed selection and vegetation regeneration by sympatric rodents is an interesting topic. To understand the characteristics of preferences of rodents for different seeds, a semi-natural enclosure experiment was performed with four rodent species (Apodemuspeninsulae, Apodemusagrarius, Tscherskiatriton, and Clethrionomysrufocanus) and the seeds of seven plant species (Pinuskoraiensis, Corylusmandshurica, Quercusmongolica, Juglansmandshurica, Armeniacasibirica, Prunussalicina, and Cerasustomentosa) to investigate the differentiation in niches and patterns of resource utilization of sympatric rodents. The results showed that all the rodents had consumed many seeds of Pi.koraiensis, Co.mandshurica, and Q.mongolica but differed significantly in how they selected the different seeds. The rate of utilization (Ri) of Pi.koraiensis, Co.mandshurica, and Q.mongolica exhibited the highest values. The Ei values indicated that the rodents tested exhibited differences in their priorities used to select the seeds from different plant species. All four species of rodents exhibited obvious preferences for certain seeds. Korean field mice preferentially consumed the seeds of Q.mongolica, Co.mandshurica, and Pi.koraiensis. Striped field mice favor the seeds of Co.mandshurica, Q.mongolica, P.koraiensis, and Nanking cherry. Greater long-tailed hamsters prefer to consume the seeds of Pi.koraiensis, Co.mandshurica, Q.mongolica, Pr.salicina, and Ce.tomentosa. Clethrionomysrufocanus likes to eat the seeds of Pi.koraiensis, Q.mongolica, Co.mandshurica, and Ce.tomentosa. The results supported our hypothesis that sympatric rodents overlap in food selection. However, each rodent species has a marked preference for food selection, and different rodent species differ in their food preferences. This reflects the role of distinct food niche differentiation in their coexistence.

Effects of habitat differences on the scatter-hoarding behaviour of rodents (Mammalia, Rodentia) in temperate forests.

To discover the differences in hoarding strategies of rodents for different seeds in different habitats, we labelled and released three different types of seeds, including Pinuskoraiensis, Corylusmandshurica, and Quercusmongolica, in temperate forests of northeastern China and investigated the fate of seeds in four different habitats that included a broad-leaved forest, mixed-forest edge, mixed forest, and artificial larch forest. Our research showed that the hoarding strategy of rodents was found to vary substantially in different habitats. The survival curves of seeds from different habitats showed the same trend, but the rates of consumption in different habitats varied. More than 50% of the seeds in the four habitats were consumed by the tenth day. It took 20 days to consume more than 70% of the seeds. The rate of consumption of P.koraiensis seeds reached 96.70%; 99.09% of the C.mandshurica seeds were consumed, and 93.07% of the Q.mongolica seeds were consumed. The seeds were consumed most quickly in the artificial larch forest. In general, most of the early seeds were quickly devoured. After day 20, the consumption gradually decreased. Rodents found the seeds in the artificial larch forest in a shorter average time than those in the other types of forests. The average earliest discovery time was 1.4 ± 0.9 d (1-3 d). The average earliest discovery time in all the other three habitats exceeded 7 d. The median removal times (MRT) was distributed around the seeds at 14.24 ± 10.53 d (1-60 d). There were significant differences in the MRT among different habitats. It was shortest in the artificial larch forest at 7.67 ± 6.80 d (1-28 d). In contrast, the MRT in the broad-leaved forest was the longest at 17.52 ± 12.91 d (4-60 d). There were significant differences in the MRT between the artificial larch forest and the other habitats. There was less predation of the three types of seeds at the mixed-forest edge, and the most seeds were dispersed. The rates of predation of the P.koraiensis, C.mandshurica, and Q.mongolica seeds were 28.33%, 15.83%, and 44.0%, and 59.17%, 84.17%, and 48.0% of the seeds were dispersed, respectively. The average dispersal distances of all the seeds were less than 6 m, and the longest distance recorded was 18.66 m. The dispersal distances and burial depths differed significantly among the four types of habitats. The distance of seed dispersal was primarily distributed in 1-6 m.

Downregulation of miR-223 and miR-153 mediates mechanical stretch-stimulated proliferation of venous smooth muscle cells via activation of the insulin-like growth factor-1 receptor.

Autologous venous grafts, used to circumvent occluded coronary arteries during coronary artery bypass, often develop thrombosis and neointimal hyperplasia. During neointimal hyperplasia, vascular smooth muscle cells (VSMCs), exposed to substantially higher pressure and hemodynamic forces, proliferate and extracellular matrix accumulate causing narrowing of the vessel lumen. Activation of insulin-like growth factor-1 receptor (IGF-1R) has been confirmed to be critically involved in mechanical stretch-stimulated VSMC proliferation. However, the comprehensive mechanisms responsible for activation of IGF-1R in VSMCs by mechanical stretch remain unclear. This study found that miR-223 and miR-153, targeted to IGF-1R, were down-regulated in VSMCs under stretch stress by miRNA microarray analysis in conjunction with Target Scan analysis. Overexpression of miR-223 or miR-153 down-regulated IGF-1R expression and activity in VSMCs under stretch stress. Specifically, overexpression of miR-223 and miR-153 inhibited stretch stress-enhanced VSMC proliferation and the activity of PI3K-AKT signaling. In conclusion, our study indicates that miR-153 and miR-223 are reduced in VSMCs by stretch stress, contributing to IGF-1R activation and resultant VSMC proliferation. Thus, miR-153 and miR-223 may be viable therapeutic targets for mechanical stretch-induced neointimal hyperplasia in vein grafts.

Chemical constitutes and anti-obesity potential of seedlings of purple-leafed rice in high-fat diet induced obese mice.

The seedlings of purple leafed rice (SPLR) are characterized by high contents of anthocyanins and various polyphenols, whose total anthocyanin content can reach 15.16 mg g-1, indicating that SPLR may have many bioactivities. Therefore, in order to evaluate the anti-obesity potential value of SPLR, the nutrient components were first identified, and the anti-obesity effect of SPLR was evaluated with a high-fat diet (HFD) induced obese mouse model for 12 weeks. The results demonstrated that SPLR supplementation could alleviate HFD-induced obesity and suppress pro-inflammatory cytokine production and macrophage infiltration in epididymal white adipose tissue of HFD-induced obese mice. The findings indicated that supplementation with SPLR may contribute to preventing obesity and related complications.

RNA-seq reveals transcriptional differences in anthocyanin and vitamin biosynthetic pathways between black and white rice.

Anthocyanins and vitamins in black rice are the micronutrients vital to human health, both of which predominantly accumulate in the bran fraction. Some studies have demonstrated that black rice contains more vitamins compared with common white rice, indicating potential association between anthocyanin and vitamin accumulation. In this study, transcriptomes of pericarps collected from 27 black rice accessions and 49 white rice accessions at 10 days after flowering (DAF) were sequenced and analyzed. We identified 830 differentially expressed genes (DEGs) including 58 transcription factors (TFs) between black and white rice. Among 58 differentially expressed transcription factors, OsTTG1 was confirmed to be the one and only WD40 repeat protein regulating anthocyanin biosynthesis in the pericarp. Moreover, we identified 53 differentially expressed synthetic-related genes among 42 main synthesis enzymes in the biosynthesis pathway of seven vitamins including ß-carotene, vitamin B1, vitamin B2, vitamin B5, vitamin B7, vitamin B9 and vitamin E. Collectively, our results provide valuable insights into the molecular mechanism of biosynthesis of anthocyanins and vitamins and the potential effect of anthocyanin biosynthesis on vitamin biosynthesis in black rice.

Effects of season and food on the scatter-hoarding behavior of rodents in temperate forests of Northeast China.

To explore the differences in hoarding strategies of rodents for different seeds in various seasons, we labeled and released the seeds of Pinus koraiensis, Corylus mandshurica, Quercus mongolica and Prunus sibirica in temperate forests of Northeast China and investigated the fate of the seeds in spring and autumn. The analysis showed that the hoarding strategies of the rodents varied substantially between seasons. The seeds were consumed faster in the spring than in the autumn. More than 50% of the seeds in the two seasons were consumed by the 16th day. It took 36 days to consume 75% of the seeds in the spring and 44 days in the autumn. The rate of consumption of the seeds in the spring was greater than in the autumn, and the rate of spread of the seeds was greater in the autumn. The distances of removal for the consumption and dispersal of seeds in the spring (3.26 ± 3.21 m and 4.15 ± 3.52 m, respectively) were both shorter than those in the autumn (3.74 ± 3.41 m and 4.87 ± 3.94 m, respectively). In addition, the fate of different seeds varied significantly owing to differences in hoarding strategies. The seeds of the three preferred species, P. koraiensis, C. mandshurica, and Q. mongolica, were quickly consumed. More than 90% of the seeds of these species were consumed. Only 21% of Pr. sibirica seeds were slowly consumed, and the two seasons had the same seed consumption rate patterns: the consumption rate of P. koraiensis seeds was the highest, followed by C. mandshurica, then Q. mongolica, and finally Pr. sibirica. The median removal times of the two seasons were different, but the rules were the same: P. koraiensis was the shortest, followed by C. mandshurica, and the third was Q. mongolica. In both seasons, the most predated in situ seeds were those of P. koraiensis; the most hoarded seeds were those of C. mandshurica, and the most unconsumed seeds were those of Pr. sibirica.

Observations of the foraging behavior and activity patterns of the Korean wood mouse, Apodemus peninsulae, in China, using infra-red cameras.

Apodemus peninsulae, a dominant rodent species in temperature forests of northeastern China, is a model animal to explore the ecological functions of reciprocal coevolution of animals and plants. From August to October 2016, 24 infra-red cameras were installed to study the feeding behavior and activity patterns of A. peninsulae in its natural environment. By analyzing 5618 video records, we found that feeding behavior, followed by motor and sentinel behaviors, was their main activity. In the behavior spectra, motor behavior (creep, walk, and skip), feeding behavior (forage, feeding, transport, hoarding, and clean), and sentinel behavior (alert, flee, banishment, and coexistence) accounted for 57.96%, 40.36%, and 1.68% of their behavior, respectively. The peak of feeding behavior occurred between 18:00 and 23:00, and feeding behavior frequency, duration, and activity rhythms differ among August to October. Furthermore, activity was the greatest after sunset and before sunrise, indicating a nocturnal lifestyle; however, from August to October, the start time of the activity was earlier, and the end time was later than usual. On average, mice spent 21.6 ± 11.6 times/night feeding, with a duration of 63.58 ± 98.36 s; while they spent less time in foraging, 39.05 ± 51.63 s. We found a significant difference in feeding and foraging frequency, with mice spending on average 10.84 ± 9.85 times/night and 9.23 ± 11.17 times/night, respectively. Our results show that feeding and foraging behavior is also influenced by light intensity, suggesting a preference for crepuscular periods of the day. Infra-red cameras are very useful in detecting activity patterns of animals that are not easily observable; these cameras are able to capture a large amount of valuable information for research into ecological functions.

Solid-State Fermentation of Aspergillus niger to Optimize Extraction Process of Isoliquiritigenin from Glycyrrhiza uralensis.

We successfully extracted isoliquiritigenin from Glycyrrhiza uralensis via fermentation with Aspergillus niger and ultrasonic-assisted extraction. In brief, we used A. niger fermentation to culture G. uralensis powder, and we optimized some key parameters such as reaction conditions of pH, inoculation concentration of A. niger, fermentation time, and solid-liquid ratio. Based on a single-factor experiment, we utilized the response surface methodology (RSM) approach to optimize this extraction procedure. Using the RSM approach, optimized conditions of pH = 3.694, the solid-liquid ratio = 1 : 2.155, and the inoculation concentration of A. niger = 1466745 were selected. Optimized conditions resulted in an extraction efficiency of 1.525 mg/g. These results showed that the extraction of isoliquiritigenin was most affected by pH and then the time of fermentation and the solid-liquid ratio. Overall, the developed extraction technique yielded 5 times the amount of isoliquiritigenin when compared to traditional methods.

[Genetic diversity and genetic structure of Sorex isodon in Northeast China]. / ä¸­å›½ä¸œåŒ—åœ°åŒºè¿œä¸œé¼©é¼±é—ä¼ å¤šæ ·æ€§ä¸Žé—ä¼ ç»“æž„.

A total of 64 haplotypes were obtained from the complete Cytochrome b gene (Cyt b) of 77 Sorex isodon collected from three populations (Daxing'anling, Xiaoxing'anling, and Changbai Mountains) in Northeast China. The haplotype diversity was 0.9920 and the nucleotide diversity was 0.0105, indicating high genetic diversity. The genetic diversity of Changbai Mountains population was significantly higher than that of Daxing'anling and Xiaoxing'anling populations. The F-statistics, the number of migrants per generation and the genetic distance results showed that the genetic distances among the populations and among the sampling sites were generally consistent with geographical distance. Analysis of molecular variance showed that the differentiation among populations, among sampling sites, and within sampling site accounted for 33.4%, 10.2% and 56.4% of total variation, respectively. The analysis of population history showed that S. isodon in Northeast China experienced no population expansion. The reported complete sequence of Cyt b gene of S. isodon (GenBank) of Europe and other parts of Asia was downloaded to examine the genetic structure of S. isodon. The phylogenetic tree was divided into two large branches. One branch consisted mainly of Daxing'anling and Xiaoxing'anling samples. The other branch was departed into two sub-branches. Median-joining network analysis showed that there were three lineages: one lineage mainly consisted of haplotypes from Daxing'anling and Xiaoxing'anling, and also four haplotypes of Changbai Mountains, while the other lineage included a few haplotypes of three populations in Northeast China, and those from Baikal Lake, Russia and Finland. The last lineage was entirely composed of haplotypes from Changbai Mountains. The results of genetic diversity, phylogenetic tree and median-joining network all suggested that the Changbai Mountains was the refuge for S. isodon during last glacial.

miR-125a Promotes the Progression of Giant Cell Tumors of Bone by Stimulating IL-17A and ß-Catenin Expression.

Giant cell tumors of bone (GCTBs) exhibit high recurrence and aggressive bone lytic behavior; but, the mechanism of GCTB progression is largely unknown. In GCTB, we detected abundant levels of miR-125a, which were associated with tumor extension, grade, and recurrence. miR-125a stimulates stromal cell tumorigenicity and growth in vivo by promoting the expression of interleukin-17A (IL-17A) and ß-catenin. In contrast, inhibition of miR-125a suppressed stromal cell tumorigenicity and growth. Then, we found that miR-125a stimulates IL-17A by targeting TET2 and Foxp3, and it stimulates ß-catenin expression by targeting APC and GSK3ß in stromal cells. Furthermore, we identified that IL-17A stimulates miR-125a by activating nuclear factor κB (NF-κB) signaling in stromal cells. Finally, our data show that simultaneous inhibition of IL-17A signaling and miR-125a more significantly inhibits stromal cell growth than miR-125a inhibition alone. miR-125a stimulates the progression of GCTB, and it might represent a useful candidate marker for progression. Simultaneously blocking miR-125a and IL-17A might represent a new therapeutic strategy for GCTB.

A high risk of osteosarcoma in individuals who are homozygous for the p.D104N in endostatin.

The D104N polymorphism (p.D104N) in endostatin has been previously identified in many types of cancer, and this polymorphism is believed to be a phenotypic modulator in some tumors. However, it is unknown whether endostatin p.D104N affects the risk and progression of osteosarcoma (OS). Here, we analyzed the p.D104N endostatin variant in 236 patients with OS and 418 healthy individuals. Similar frequencies of wild type and heterozygous p.104DN endostatin were observed in controls and OS patients. Interestingly, the frequency of the homozygous p.D104N (p.104NN) genotype was higher in OS patients group compared to control group, suggesting that individuals with p.104NN endostatin have a significantly increased risk for OS. In addition, OS patients with p.104NN endostatin had a shorter survival time and a higher rate of metastasis than OS patients with wild type endostatin. Animal experiments revealed that overexpression of p.104NN endostatin did not significantly inhibit OS lung metastasis. Interestingly, administration of endostatin dramatically inhibited OS lung metastasis in the p.104NN endostatin xenograft model. Together, these results suggest that p.104NN of endostatin is associated with the risk of OS and demonstrates predictive significance for clinical outcome in OS patients. In addition, endostatin therapy may be necessary for OS patients harboring p.104NN endostatin.

Fabrication of electrospun poly(L-lactide-co-ε-caprolactone)/collagen nanoyarn network as a novel, three-dimensional, macroporous, aligned scaffold for tendon tissue engineering.

Tissue engineering techniques using novel scaffolding materials offer potential alternatives for managing tendon disorders. An ideal tendon tissue engineered scaffold should mimic the three-dimensional (3D) structure of the natural extracellular matrix (ECM) of the native tendon. Here, we propose a novel electrospun nanoyarn network that is morphologically and structurally similar to the ECM of native tendon tissues. The nanoyarn, random nanofiber, and aligned nanofiber scaffolds of a synthetic biodegradable polymer, poly(L-lactide-co-ε-caprolactone) [P(LLA-CL)], and natural collagen I complex were fabricated using electrospinning. These scaffolds were characterized in terms of fiber morphology, pore size, porosity, and chemical and mechanical properties for the purpose of culturing tendon cells (TCs) for tendon tissue engineering. The results indicated a fiber diameter of 632 ± 81 nm for the random nanofiber scaffold, 643 ± 97 nm for the aligned nanofiber scaffold, and 641 ± 68 nm for the nanoyarn scaffold. The yarn in the nanoyarn scaffold was twisted by many nanofibers similar to the structure and inherent nanoscale organization of tendons, indicating an increase in the diameter of 9.51 ± 3.62 µm. The nanoyarn scaffold also contained 3D aligned microstructures with large interconnected pores and high porosity. Fourier transform infrared analyses revealed the presence of collagen in the three scaffolds. The mechanical properties of the sample scaffolds indicated that the scaffolds had desirable mechanical properties for tissue regeneration. Further, the results revealed that TC proliferation and infiltration, and the expression of tendon-related ECM genes, were significantly enhanced on the nanoyarn scaffold compared with that on the random nanofiber and aligned nanofiber scaffolds. This study demonstrates that electrospun P(LLA-CL)/collagen nanoyarn is a novel, 3D, macroporous, aligned scaffold that has potential application in tendon tissue engineering.

Successful development of small diameter tissue-engineering vascular vessels by our novel integrally designed pulsatile perfusion-based bioreactor.

Small-diameter (<4 mm) vascular constructs are urgently needed for patients requiring replacement of their peripheral vessels. However, successful development of constructs remains a significant challenge. In this study, we successfully developed small-diameter vascular constructs with high patency using our integrally designed computer-controlled bioreactor system. This computer-controlled bioreactor system can confer physiological mechanical stimuli and fluid flow similar to physiological stimuli to the cultured grafts. The medium circulating system optimizes the culture conditions by maintaining fixed concentration of O(2) and CO(2) in the medium flow and constant delivery of nutrients and waste metabolites, as well as eliminates the complicated replacement of culture medium in traditional vascular tissue engineering. Biochemical and mechanical assay of newly developed grafts confirm the feasibility of the bioreactor system for small-diameter vascular engineering. Furthermore, the computer-controlled bioreactor is superior for cultured cell proliferation compared with the traditional non-computer-controlled bioreactor. Specifically, our novel bioreactor system may be a potential alternative for tissue engineering of large-scale small-diameter vascular vessels for clinical use.

[Proliferation of tissue-engineered cartilage cells under compressive stress].

OBJECTIVE: To investigate the proliferation of tissue-engineered cartilage cells stimulated by different intensities of compressive stress. METHODS: Human embryonic cartilage cells were seeded into type II collagen sponge scaffold. The cells of the pressure groups were stimulated by different compression rate (0-5%, 0-10%, and 0-20%) at a cyclical frequency of 0.1 Hz. The cells of the control group were cultured without pressure. Gross observation, histological section, MTT assay and flow cytometry were used to observe the morphology, cell number and distribution and detect the cell proliferation and cell cycle. RESULTS: Tissue-engineered cartilage cells in 0-10% group showed the largest size and greatest thickness with normal morphology. Tissue biopsies showed the largest number of cartilage cells with more uniform distribution, close alignment, more matrix secretion. The cartilage cell activity was significantly enhanced and the percentage of S phase cells significantly increased in the pressure group compared with those in the control group, and such changes were especially obvious in 0-10% group in which the S phase cells increased by 59.0% compared with that in the control group. CONCLUSION: The proliferation of tissue-engineered cartilage cells is regulated by the cyclic stress intensity, and a pressure frequency of 0.1 Hz with compression rate of 0-10% can better promote the cell proliferation.