Comparative study of different anticoagulants and coagulants in the evaluation of clinical application of platelet-rich plasma (PRP) standardization.

To investigate the impact of different anticoagulants and coagulants with autologous platelet-rich plasma (PRP) in order to evaluate the clinical application of PRP standardization. Bone marrow stem cells (BMSCs) were seeded into autologous PRP gel scaffolds with different anticoagulants (EDTA, heparin sodium HS, and sodium citrate SC) as well as control group (the whole blood group). Quality of PRP was evaluated and flow cytometric assay was used to detect the activity of the platelet (CD62p, PAC-1). BMSCs were also seeded into PRP with different coagulants (Thrombin, Collagen-I, ADP) as well as PRP un-activated (negative group) and L-DMEM complete culture without PRP (control group). The effects of different coagulants with PRP on proliferation, osteogenic differentiation of BMSCs were analyzed by methyl thiazolyl tetrazolium assay (MTT), ALP staining, Von Kossa staining, Confocal microscopic observation, RT-PCR and Western Blot at the morphological, cellular and molecular levels. Different anticoagulants (EDTA, HS, and SC) could affect the quality of PRP. EDTA group revealed the best quality and activity (CD62p, PAC-1). With different coagulants (Thrombin, Collagen-I and ADP) in the proliferation of BMSCs, the MTT assay showed that the proliferation of BMSCs was increased in all groups with time. On the sixth day of culture, the cell number of each PRP group was significantly higher than that in the control group (P < 0.05), while the most rapidly increasing was found in Collagen-I group. The cumulative release of growth factor (TGF-ß1, PDGF) at each time point in the PRP gel of the four groups was higher than that in the control group (P < 0.05). Collagen-I was considered as the best PRP coagulant. When thrombin was used as a platelet coagulant, the release of growth factor in PRP was rapid and direct, while the release of growth factor in Collagen-I-activated PRP was sustained and slow, and the total release of ADP-activated PRP growth factors was the lowest. The study demonstrated the similar outcome in osteogenic differentiation. In terms of gene expression and western bolt, the PCR results showed that the expression levels of OCN gene and RUNX2 protein in each PRP group were higher than that in the control group (P < 0.05). Different anticoagulants caused different degrees of lysis and spontaneous activation of platelets, which lead to different quality of PRP. Compared with HS and SC, EDTA could maintain the structural integrity of platelets, reduce their spontaneous activation, and increase the release of PRP growth factors for a longer period of time, thus ensuring the biomass of PRP. In addition, different coagulants also showed different results in the proliferation as well as osteogenic differentiation of BMSCs. Compared with Thrombin and ADP, Collagen-I may be a better choice.

RNA-seq transcriptome analysis of breast cancer cell lines under shikonin treatment.

Shikonin is a naphthoquinone isolated from the dried root of Lithospermum erythrorhizon, an herb used in Chinese medicine. Although several studies have indicated that shikonin exhibits antitumor activity in breast cancer, the mechanism of action remains unclear. In the present study, we performed transcriptome analysis using RNA-seq and explored the mechanism of action of shikonin in regulating the growth of different types of breast cancer cells. The IC50 of shikonin on MCF-7, SKBR-3 and MDA-MB-231 cells were 10.3 µΜ, 15.0 µΜ, 15.0 µΜ respectively. Our results also demonstrated that shikonin arrests the progression of cell cycle and induces apoptosis in MDA-MB-231 cells. Using RNA-seq transcriptome analysis, we found 38 common genes that significantly express in different types of breast cancer cells under shikonin treatment. In particular, our results indicated that shikonin induces the expression of dual specificity phosphatase (DUSP)-1 and DUSP2 in both RNA and protein levels. In addition, shikonin also inhibits the phosphorylation of JNK and p38, the downstream signaling molecules of DUSP1 and DUSP2. Therefore, our results suggest that shikonin induces the expression of DUSP1 and DUSP2 which consequently switches off JNK and p38 MAPK pathways and causes cell cycle arrest and apoptosis in breast cancer cells.

Deconvoluting the Dual Antiplatelet Activity of a Plant Extract.

A thorough evaluation of the antiplatelet activity profile of hexane olive leaf extract in human platelets indicated a potent activity accomplished through a two axis inhibition of platelet activation triggered both by ADP and thrombin. To delineate the extract components responsible for this dual activity, an NMR based method was established to determine and quantify the triterpenoid content leading to the characterization of uvaol, erythrodiol, and oleanolic acid. The antiplatelet profile of the total extract and of the 3 determined triterpenoids was evaluated against in vitro platelet aggregation induced by several platelet agonists as also on PAC-1 binding and P-selectin membrane expression both in healthy volunteers and in platelets from patients with an acute coronary syndrome receiving dual antiplatelet therapy with aspirin and ticagrelor. The extract was identified to inhibit ADP-induced platelet activation due to its erythrodiol content and TRAP-induced platelet activation due to the activity of uvaol and oleanolic acid.

Homeodomain protein otp and activity-dependent splicing modulate neuronal adaptation to stress.

Regulation of corticotropin-releasing hormone (CRH) activity is critical for the animal's adaptation to stressful challenges, and its dysregulation is associated with psychiatric disorders in humans. However, the molecular mechanism underlying this transcriptional response to stress is not well understood. Using various stress paradigms in mouse and zebrafish, we show that the hypothalamic transcription factor Orthopedia modulates the expression of CRH as well as the splicing factor Ataxin 2-Binding Protein-1 (A2BP1/Rbfox-1). We further show that the G protein coupled receptor PAC1, which is a known A2BP1/Rbfox-1 splicing target and an important mediator of CRH activity, is alternatively spliced in response to a stressful challenge. The generation of PAC1-hop messenger RNA isoform by alternative splicing is required for termination of CRH transcription, normal activation of the hypothalamic-pituitary-adrenal axis and adaptive anxiety-like behavior. Our study identifies an evolutionarily conserved biochemical pathway that modulates the neuronal adaptation to stress through transcriptional activation and alternative splicing.