Observations on the Ultrastructure of the Root Nodules and Its Endophyte of Elaeagnus mollis Diels

The ultrastructure of the root nodule infecting cell of Elaeagnus mollis Diels and its shapes of the endophyte were observed by light microscope, scanning electron microscope and transmission electron microscope. The endophyte in the root nodules of Elaeagnus mollis D. has five different developing forms: hyphae, nitrogen fixing vesicles, sporangia, sporangio-spores and bacteroid-like cells. The roles played by the different forms of the endophytes in symbiotic nitrogen fixation arc discussed also.     

The coiled-coil domain of Escherichia coli FtsLB is a structurally detuned element critical for modulating its activation in bacterial cell division

The FtsLB complex is a key regulator of bacterial cell division, existing in either an off state or an on state, which supports the activation of septal peptidoglycan synthesis. In Escherichia coli, residues known to be critical for this activation are located in a region near the C-terminal end of the periplasmic coiled-coil domain of FtsLB, raising questions about the precise role of this conserved domain in the activation mechanism. Here, we investigate an unusual cluster of polar amino acids found within the core of the FtsLB coiled coil. We hypothesized that these amino acids likely reduce the structural stability of the domain and thus may be important for governing conformational changes. We found that mutating these positions to hydrophobic residues increased the thermal stability of FtsLB but caused cell division defects, suggesting that the coiled-coil domain is a “detuned” structural element. In addition, we identified suppressor mutations within the polar cluster, indicating that the precise identity of the polar amino acids is important for fine-tuning the structural balance between the off and on states. We propose a revised structural model of the tetrameric FtsLB (named the “Y-model”) in which the periplasmic domain splits into a pair of coiled-coil branches. In this configuration, the hydrophilic terminal moieties of the polar amino acids remain more favorably exposed to water than in the original four-helix bundle model (“I-model”). We propose that a shift in this architecture, dependent on its marginal stability, is involved in activating the FtsLB complex and triggering septal cell wall reconstruction.     

Impact of Human Cytomegalovirus Infection and its Immune Response on Survival of Patients with Ovarian Cancer

Human cytomegalovirus (HCMV) has been detected in various types of tumors. We studied the prevalence of HCMV in ovarian cancer and its relation to clinical outcome. Paraffin-embedded tissues obtained prospectively from 45 patients with ovarian cancer and 30 patients with benign ovarian cystadenoma were analyzed for expression of HCMV immediate-early protein (IE) and HCMV tegument protein (pp65) by immunohistochemistry. Plasma was analyzed for HCMV serology. HCMV-IgG levels were higher in patients with ovarian cancer or benign cystadenoma than in age-matched controls (P?=?.002, P?<?.0001, respectively). HCMV IgM was detected in 12% of ovarian cancer patients and 3% of patients with benign tumors but was absent in controls. In patients with ovarian cancer, higher IgG levels were associated with better outcomes (P?=?.04). Extensive HCMV-IE protein expression was detected in 75% of ovarian cancers and 26% of benign tumors; pp65 was detected in 67% of ovarian cancers and 14% of benign tumors. A higher grade of HCMV infection was associated with higher stage of disease. Extensive HCMV-pp65 expression was associated with shorter median overall survival than focal expression (39 versus 42.5?months, P?=?.03). At study closure, 58% of ovarian cancer patients with focal pp65 expression were alive versus 27% of patients with extensive pp65 expression (P?=?.03). Thus, HCMV proteins are detected at different levels in ovarian tumors and benign cystadenomas. Ovarian cancer patients with focal HCMV-pp65 expression in their tumors and high IgG levels against HCMV lived longer, highlighting a need for in-depth studies of the oncomodulatory role of HCMV in ovarian cancer.     

IgE induces hypotension in asthma mice by down-regulating vascular NCX1 expression through activating MiR-212-5p

Immunoglobulin E (IgE) has been suggested as a risk factor for allergy-induced low blood pressure, which has not been well explained in molecular details. Our current study shows a novel mechanism involving IgE, Fc?R1, miRNA-212-5p (miR-212-5p), and sodium/calcium exchanger protein 1(NCX1) for asthma to induce hypotension. In arterial smooth muscle cells, IgE up-regulated miR212-5p via its receptor Fc?R1, which resulted in down-regulation of NCX1 that is a regulating factor for blood pressure. In mice, asthma induced hypotension by interfering vasoconstrictive function; knockout of Fc?R1 kept the asthmatic mice from developing hypotension; knock-down of miR-212-5p in asthmatic mice resulted in a significant restoration of blood pressure. In human, asthma and IgE were positively correlated with hypotension in cohort study on NIH epidemiological data. This study suggests a novel therapeutic target (miR-212-5p) for treatment of asthma-induced hypotension.     

Geniposide Increases Unfolded Protein Response-Mediating HRD1 Expression to Accelerate APP Degradation in Primary Cortical Neurons

Altered proteostasis induced by amyloid peptide aggregation and hyperphosphorylation of tau protein, is a prominent feature of Alzheimer’s disease, which highlights the occurrence of endoplasmic reticulum stress and triggers the activation of the unfolded protein response (UPR), a signaling pathway that enforces adaptive programs to sustain proteostasis. In this study, we investigated the role of geniposide in the activation of UPR induced by high glucose in primary cortical neurons. We found that high glucose induced a significant activation of UPR, and geniposide enhanced the effect of high glucose on the phosphorylation of IRE1α, the most conserved UPR signaling branch. We observed that geniposide induced the expression of HRD1, an ubiquitin-ligase E3 in a time dependent manner, and amplified the expression of HRD1 induced by high glucose in primary cortical neurons. Suppression of IRE1α activity with STF-083010, an inhibitor of IRE1 phosphorylation, prevented the roles of geniposide on the expression of HRD1 and APP degradation in high glucose-treated cortical neurons. In addition, the results from RNA interfere on HRD1 revealed that HRD1 was involved in geniposide regulating APP degradation in cortical neurons. These data suggest that geniposide might be benefit to re-establish proteostasis by enhancing the UPR to decrease the load of APP in neurons challenged by high glucose.     

Aligned electrospun fibers for neural patterning

Objectives

To test a 3D approach for neural network formation, alignment, and patterning that is reproducible and sufficiently stable to allow for easy manipulation.

Results

A novel cell culture system was designed by engineering a method for the directional growth of neurons. This uses NG108-15 neuroblastoma x glioma hybrid cells cultured on suspended and aligned electrospun fibers. These fiber networks improved cellular directionality, with alignment angle standard deviations significantly lower on fibers than on regular culture surfaces. Morphological studies found nuclear aspect ratios and cell projection lengths to be unchanged, indicating that cells maintained neural morphology while growing on fibers and forming a 3D network. Furthermore, fibronectin-coated fibers enhanced neurite extensions for all investigated time points. Differentiated neurons exhibited significant increases in average neurite lengths 96 h post plating, and formed neurite extensions parallel to suspended fibers, as visualized through scanning electron microscopy.

Conclusions

The developed model has the potential to serve as the basis for advanced 3D studies, providing an original approach to neural network patterning and setting the groundwork for further investigations into functionality.

     

Chitosan enhanced gene delivery of cationic liposome via non-covalent conjugation

Two new types of stable ternary complexes were formed by mixing chitosan with DOTAP/pDNA lipoplex and DOTAP with chitosan/pDNA polyplex via non-covalent conjugation for the efficient delivery of plasmid DNA. They were characterized by atomic force microscopy, gel retarding, and dynamic light scattering. The DOTAP/CTS/pDNA complexes were in compacted spheroids and irregular lump of larger aggregates in structure, while the short rod- and toroid-like and donut shapes were found in CTS/DOTAP/pDNA complexes. The transfection efficiency of the lipopolyplexes showed higher GFP gene expression than DOTAP/pDNA and CTS/pDNA controls in Hep-2 and Hela cells, and luciferase gene expression 2–3-fold than DOTAP/pDNA control and 70–120-fold than CTS/pDNA control in Hep-2 cells. The intracellular trafficking was examined by confocal laser scanning microscopy. Rapid pDNA delivery to the nucleus enchanced by chitosan was achieved after 4 h transfection.     

A robust six-miRNA prognostic signature for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) remains a major health problem worldwide. We aimed to identify a robust microRNA (miRNA)-based signature for predicting HNSCC prognosis. The miRNA expression profiles of HNSCC were obtained from The Cancer Genome Atlas (TCGA) database. The TCGA HNSCC cohort was randomly divided into the discovery and validation cohort. A miRNA-based prognostic signature was built up based on TGCA discovery cohort, and then further validated. The downstream targets of prognostic miRNAs were subjected to functional enrichment analyses. The role of miR-1229-3p, a prognosis-related miRNA, in tumorigenesis of HNSCC was further evaluated. A total of 305 significantly differentially expressed miRNAs were found between HNSCC samples and normal tissues. A six-miRNA prognostic signature was constructed, which exhibited a strong association with overall survival (OS) in the TCGA discovery cohort. In addition, these findings were successfully confirmed in TCGA validation cohort and our own independent cohort. The miRNA-based signature was demonstrated as an independent prognostic indicator for HNSCC. A risk signature-based nomogram model was constructed and showed good performance for predicting the OS for HNSCC. The functional analyses revealed that the downstream targets of these prognostic miRNAs were closely linked to cancer progression. Mechanistically, in vitro analysis revealed that miR-1229-3p played a tumor promoting role in HNSCC. In conclusion, our study has developed a robust miRNA-based signature for predicting the prognosis of HNSCC with high accuracy, which will contribute to improve the therapeutic outcome.