Involvement of cell proliferation in the process of follicular atresia in the guinea pig

Cell morphology and proliferation was investigated in the atretic follicles during estrous cycles in the guinea pig. Ovarian samples on days 1, 4, 8, 12 and 16 of the estrous cycle in the guinea pig were taken in the morning for histologic staining with hematoxylin and eosin (HE), and immunohistochemical staining of the protein proliferating cell nuclear antigen (PCNA). The results indicated that the granulosa cells degenerated and eliminated first in atretic follicles, while the fibroblast-like cells appeared in the innermost layer of theca interna cells. When the fibroblast-like cells migrated to the antrum, they proliferated and formed a new tissue in peripheral to the zona pellucida of the oocyte. Our results also revealed that the orientation of the theca interna cell arrangement changed twice during the process of atresia, and the loose connective tissue in the antrum was critical for follicular atresia. Therefore, follicular atresia was not a simple process of cell death and elimination, but coexisted with cell proliferation. To our knowledge, we have for the first time confirmed cell proliferation and the presence of new tissue in atretic follicles in guinea pigs.     

Phylogenetic analyses of Cornales based on 26S rRNA and combined 26S rDNA-MATK-RBCL sequence data

Nuclear 26S rDNA sequences were used to corroborate and test previously published matK-rbcL-based hypotheses of phylogenetic relationships in Cornales. Sequences were generated for 53 taxa including Alangium, Camptotheca, Cornus, Curtisia, Davidia, Diplopanax, Mastixia, Nyssa, and four families: Grubbiaceae, Hydrangeaceae, Hydrostachyaceae, and Loasaceae. Fifteen taxa from asterids were used as outgroups. The 26S rDNA sequences were initially analyzed separately and then combined with matK-rbcL sequences, using both parsimony and maximum likelihood methods. Eight strongly supported major clades were identified within Cornales by all analyses: Cornus, Alangium, nyssoids (Nyssa, Davidia, and Camptotheca), mastixioids (Mastixia and Diplopanax), Hydrangeaceae, Loasaceae, Grubbia-Curtisia, and Hydrostachys. However, relationships among the major lineages are not strongly supported in either 26S rDNA or combined 26S rDNA-matK-rbcL topologies, except for the sister relationships between Cornus and Alangium and between nyssoids and mastixioids in the tree from combined data. Discrepancies in relationships among major lineages, especially the placement of the long-branched Hydrostachys, were found between parsimony and maximum likelihood trees in all analyses. Incongruence between the 26S rDNA and matK-rbcL data sets was suggested, where Hydrangeaceae was found to be largely responsible for the incongruence. The long branch of Hydrostachys revealed in previous analyses was reduced significantly with more sampling. Maximum likelihood analysis of combined 26S rDNA-matK-rbcL sequences suggested that Hydrostachys might be sister to the remainder of Cornales, that Cornus-Alangium are sisters, that nyssoids-mastixioids are sisters, and that Hydrangeaceae-Loasaceae are sisters, consistent with previous analyses of matK-rbcL sequence data.     

Mitochondrial genome nucleotide substitution pattern between domesticated silkmoth, Bombyx mori, and its wild ancestors, Chinese Bombyx mandarina and Japanese Bombyx mandarina

Bombyx mori and Bombyx mandarina are morphologically and physiologically similar. In this study, we compared the nucleotide variations in the complete mitochondrial (mt) genomes between the domesticated silkmoth, B. mori, and its wild ancestors, Chinese B. mandarina (ChBm) and Japanese B. mandarina (JaBm). The sequence divergence and transition mutation ratio between B. mori and ChBm are significantly smaller than those observed between B. mori and JaBm. The preference of transition by DNA strands between B. mori and ChBm is consistent with that between B. mori and JaBm, however, the regional variation in nucleotide substitution rate shows a different feature. These results suggest that the ChBm mt genome is not undergoing the same evolutionary process as JaBm, providing evidence for selection on mtDNA. Moreover, investigation of the nucleotide sequence divergence in the A+T-rich region of Bombyx mt genomes also provides evidence for the assumption that the A+T-rich region might not be the fastest evolving region of the mtDNA of insects.     

Interleukin-22 Mediates Early Host Defense against Rhizomucor pusilluscan Pathogens

Background

In recent years, the fungal infectious disease zygomycosis has increased in incidence worldwide, especially among the immunodeficient population. Despite the rates of zygomycosis-related death and deformation being very high, the mechanism(s) by which the fungal pathogens cause these severe manifestations remain unknown.

Methods

Using the associated Rhizomucor variabilis species, which can selectively induce cutaneous zygomycosis in otherwise healthy individuals, we investigated the host mechanisms of infection-related responses, including cytokine and chemokine expression as well as contributions of particular T cell subsets. siRNA specifically targeting IL-22,IL-17 and IFN-γ were used to down-regulate expression of those molecules.

Results

In mouse models of infection, IL-22 was implicated in development of Rhizomucor spp.-induced skin lesions. In cultured human peripheral blood monocytes, R. pusilluscan, which is often found in immunodeficient patients, induced the production of IL-22, while R. variabilis did not. Moreover, Rhizomucor spp.-induced secretion of Il-22 from CCR6⁺CCR4⁺CCR10⁺ cells was down-regulated by knockdown of IL-22 related signaling receptors, RORC and ARH.

Conclusion

Our data strongly suggest that avoidance of IL-22 may be one mechanism by which mucor species produce morbidity and mortality in infected individuals.     

Protein Kinase LTRPK1 Influences Cold Adaptation and Microtubule Stability in Rice

Rice LTRPK1, which encodes a member of the casein kinase I family, has been reported to be involved in root development, hormone response, and metabolic processes. Here we further show that LTRPK1 participates in stress resistance by regulating cytoskeleton rearrangement and formation of cold tolerance and adaptation. Semiquantitative RT-PCR analysis revealed enhanced expression of LTRPK1 in plants subject to low-temperature stress at 4 °C, suggesting a role in low-temperature-related cell responses and signal transduction pathways. Further analysis of LTRPK1-deficient transgenic plants showed that under low-temperature treatment, the growth rate of transgenic plant primary roots, which is commonly used as an indicator for cold stress response abilities, was less inhibited than that of control plants. Moreover, damage to the plasma membrane of root cells in LTRPK1-deficient plants was greater than that of controls as measured by relative electrical conductivity (REC). The malondialdehyde (MDA) content of LTRPK1-deficient plants also increased over that of the control, indicating increased plasma membrane permeability. Further immunofluorescence localization observations indicated that microtubules of transgenic plants subject to low temperature disassembled more rapidly, whereas the control plant microtubules in most cells of the root elongation zone kept their normal habitus, which suggested that LTRPK1-deficient plants had reduced capacity to resist low-temperature stress through regulation of microtubule assembly. These results demonstrate involvement of LTRPK1 in low-temperature stress and provide new insight for rice breeding and germplasm innovation to improve crop cold tolerance.     

Studies of ice melting using molecular dynamics

In this paper, the melting of ice 1h is studied using molecular dynamics (MD). Common potential functions employed in the MD simulations include SPC/E, TIP4P, TIP5P, TIP4/ice and TIP5P/E. We first conducted melting of ice bulks and then studied the melting speed of the ice/water interface during ice melting. It is found that various potentials result in similar ice-melting phenomena. The result is compared with the analytical solution for phase change problem. We also studied size effects and temperature gradient effects on ice melting.     

Development of software for human muscle force estimation

Muscle force estimation (MFE) has become more and more important in exploring principles of pathological movement, studying functions of artificial muscles, making surgery plan for artificial joint replacement, improving the biomechanical effects of treatments and so on. At present, existing software are complex for professionals, so we have developed a new software named as concise MFE (CMFE). CMFE which provides us a platform to analyse muscle force in various actions includes two MFE methods (static optimisation method and electromyographic-based method). Common features between these two methods have been found and used to improve CMFE. A case studying the major muscles of lower limb of a healthy subject walking at normal speed has been presented. The results are well explained from the effect of the motion produced by muscles during movement. The development of this software can improve the accuracy of the motion simulations and can provide a more extensive and deeper insight in to muscle study.     

Hepatitis C virus inhibits AKT-tuberous sclerosis complex (TSC), the mechanistic target of rapamycin (MTOR) pathway,through endoplasmic reticulum stress to induce autophagy

Hepatitis C virus (HCV) is able to induce autophagy via endoplasmic reticulum (ER) stress, but the exact molecular signaling pathway is not well understood. We found that the activity of the mechanistic target of rapamycin complex 1 (MTORC1) was inhibited in Huh7 cells either harboring HCV-N (genotype 1b) full-genomic replicon or infected with JFH1 (genotype 2a) virus, which led to the activation of UNC-51-like kinase 1 (ULK1) and thus to autophagy. We then analyzed activity upstream of MTORC1, and found that both protein kinase, AMP-activated, α (PRKAA, including PRKAA1 and PRKAA2, also known as AMP-activated protein kinase, AMPKα) and AKT (refers to pan AKT, including three isoforms of AKT1-3, also known as protein kinase B, PKB) were inhibited by HCV infection. The inhibition of the AKT-TSC-MTORC1 pathway contributed to upregulating autophagy, but inhibition of PRKAA downregulated autophagy. The net effect on autophagy was from AKT, which overrode the inhibition effect from PRKAA. It was further found that HCV-induced ER stress was responsible for the inhibition of the AKT pathway. Metformin, a PRKAA agonist, inhibited HCV replication not only by activating PRKAA as previously reported, but also by activating AKT independently of the autophagy pathway. Taken together, our data suggested HCV inhibited the AKT-TSC-MTORC1 pathway via ER stress, resulting in autophagy, which may contribute to the establishment of the HCV-induced autophagy.     

Modulation of retroviral restriction and proteasome inhibitor-resistant turnover by changes in the TRIM5alpha B-box 2 domain

An intact B-box 2 domain is essential for the antiretroviral activity of TRIM5alpha. We modeled the structure of the B-box 2 domain of TRIM5alpha based on the existing three-dimensional structure of the B-box 2 domain of human TRIM29. Using this model, we altered the residues predicted to be exposed on the surface of this globular structure. Most of the alanine substitutions in these residues exerted little effect on the antiretroviral activity of human TRIM5alphahu or rhesus monkey TRIM5alpharh. However, alteration of arginine 119 of TRIM5alphahu or the corresponding arginine 121 of TRIM5alpharh diminished the abilities of the proteins to restrict retroviral infection without affecting trimerization or recognition of the viral capsid. The abilities of these functionally defective TRIM5alpha proteins to accelerate the uncoating of the targeted retroviral capsid were abolished. Removal of the positively charged side chain from B-box 2 arginines 119/120/121 resulted in diminished proteasome-independent turnover of TRIM5alpha and the related restriction factor TRIMCyp. However, testing of an array of mutants revealed that the rapid turnover and retroviral restriction functions of this B-box 2 region are separable.     

Ataxin-10 is involved in Golgi membrane dynamics

<正>Cytokinesis is the final stage of cell division that generates two daughter cells(Fededa and Gerlich,2012).The textbook version di-vides the plant and animal cell cytokinesis into two categories.Plant cells form a mid-zone phragmoplast via vesicle delivering and fusion,and cell wall materials are thus deposited.Animal cells form actomyosin contractile rings,which are the sole force that drives abscission.However,recent evidence has been mounting and pinpointing a pivotal role of membrane transport and subse-