More attention should be paid on the interpretation of gene expression data

Salivary gland proteome analysis of developing adult female Haemaphysalis longicornis ticks: molecular motor and TCA cycle-related proteins play an important role throughout development

Background

Ticks are notorious blood-feeding arthropods that can spread a variety of deadly diseases. The salivary gland is an important organ for ticks to feed on blood, and this organ begins to develop rapidly when ixodid ticks suck blood. When these ticks reach a critical weight, the salivary glands stop developing and begin to degenerate. The expression levels of a large number of proteins during the development and degeneration of salivary glands change, which regulate the biological functions of the salivary glands. Furthermore, to the best of our knowledge, there are only a few reports on the role of molecular motor and TCA cycle-related proteins in the salivary glands of ticks.

Results

We used iTRAQ quantitative proteomics to study the dynamic changes in salivary gland proteins in female Haemaphysalis longicornis at four feeding stages: unfed, partially fed, semi-engorged and engorged. Using bioinformatics methods to analyze the dynamic changes of a large number of proteins, we found that molecular motor and TCA cycle-related proteins play an important role in the physiological changes of the salivary glands. The results of RNAi experiments showed that when dynein, kinesin, isocitrate dehydrogenase and citrate synthase were knocked down independently, the weight of the engorged female ticks decreased by 63.5%, 54.9%, 42.6% and 48.6%, respectively, and oviposition amounts decreased by 83.1%, 76.0%, 50.8%, and 55.9%, respectively, and the size of type III acini of females salivary glands decreased by 35.6%, 33.3%, 28.9%, and 20.0%, respectively.

Conclusions

The results showed that the expression of different types of proteins change in different characteristics in salivary glands during the unfed to engorged process of female ticks. Corresponding expression changes of these proteins at different developmental stages of female ticks are very important to ensure the orderly development of the organ. By analyzing these changes, some proteins, such as molecular motor and TCA cycle-related proteins, were screened and RNAi carried out. When these mRNAs were knocked down, the female ticks cannot develop normally. The research results provide a new protein target for the control of ticks and tick-borne diseases.

Exosomes derived from miR-375-overexpressing human adipose mesenchymal stem cells promote bone regeneration

Objectives

The present study aimed to investigate whether exosomes derived from miR‐375‐overexpressing human adipose mesenchymal stem cells (hASCs) could enhance bone regeneration.

Materials and Methods

Exosomes enriched with miR‐375 (Exo [miR‐375]) were generated from hASCs stably overexpressing miR‐375 after lentiviral transfection and identified with transmission electron microscopy, nanosight and western blotting. The construction efficiency of Exo (miR‐375) was evaluated with qRT‐PCR and incubated with human bone marrow mesenchymal stem cells (hBMSCs) to optimize the effective dosage. Then, the osteogenic capability of Exo (miR‐375) was investigated with ALP and ARS assays. Furthermore, dual‐luciferase reporter assay and western blotting were conducted to reveal the underlying mechanism of miR‐375 in osteogenic regulation. Finally, Exo (miR‐375) were embedded with hydrogel and applied to a rat model of calvarial defect, and μ‐CT analysis and histological examination were conducted to evaluate the therapeutic effects of Exo (miR‐375) in bone regeneration.

Results

miR‐375 could be enriched in exosomes by overexpressing in the parent cells. Administration of Exo (miR‐375) at 50 μg/mL improved the osteogenic differentiation of hBMSCs. With miR‐375 absorbed by hBMSCs, insulin‐like growth factor binding protein 3 (IGFBP3) was inhibited by binding to its 3′UTR, and recombinant IGFBP3 protein reduced the osteogenic effects triggered by Exo (miR‐375). After incorporated with hydrogel, Exo (miR‐375) displayed a slow and controlled release, and further in vivo analysis demonstrated that Exo (miR‐375) enhanced the bone regenerative capacity in a rat model of calvarial defect.

Conclusions

Taken together, our study demonstrated that exosomes derived from miR‐375‐overexpressing hASCs promoted bone regeneration.

Chrysin Suppresses Vascular Endothelial Inflammation via Inhibiting the NF-κB Signaling Pathway

The vascular endothelium is a continuous layer of flat polygonal cells that are in direct contact with the blood and participate in responses to inflammation. Chrysin is a flavonoid compound extracted from plants of the genus Asteraceae with a wide range of pharmacological activities and physiological activities. Here, we studied the effects of chrysin on the regulation of the proadhesion and pro-inflammatory phenotypes of the endothelium both in vitro and in vivo. Our results revealed that chrysin strongly inhibited Tohoku Hospital Pediatrics-1 (THP-1) cell adhesion to primary human umbilical vein endothelial cells and concentration-dependently attenuated interleukin 1β-induced increases in intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin messenger RNA levels and ICAM-1 and VCAM-1 protein levels. Previous studies reported that nuclear factor κB (NF-κB) is important in the inflammatory response in endothelial cells, particularly in regulating adhesion molecules, and our data shed light on the mechanisms whereby chrysin suppressed endothelial inflammation via the NF-κB signaling pathway. In addition, our in vivo findings demonstrated the effects of chrysin in the permeability and inflammatory responses of the endothelium to inflammatory injury. Taken together, we conclude that chrysin inhibits endothelial inflammation both in vitro and in vivo, which could be mainly due to its inhibition of NF-κB signaling activation. In conclusion, chrysin may serve as a promising therapeutic candidate for inflammatory vascular diseases.