Platelet-Derived Growth Factor-BB Promotes Proliferation and Osteogenic Differentiation of Rat Bone Marrow Mesenchymal Stem Cells

Background: Previous research has indicated that platelet-rich plasma (PRP) promotes fracture healing and aids in the treatment of nonunion. A key component of PRP, platelet-derived growth factor BB (PDGF-BB), may play a crucial role in PRP, enhancing the biological functions of bone marrow mesenchymal stem cells (BMSCs). This study aims to investigate whether PDGF-BB is a key effector in PRP that promotes proliferation and osteogenic differentiation of BMSCs. Methods: Rat BMSCs were isolated and cultured, then expanded to the third generation for morphological observation. Flow cytometry analysis was conducted to assess the expression of CD44, CD29, CD45, and CD11b. The BMSCs were cultured under different conditions: the control group received only basic culture medium, while experimental groups received 10 ng/mL, 25 ng/mL, 50 ng/mL, 100 ng/mL, and 200 ng/mL PDGF-BB. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay at 1, 3, 5, 7, and 10 days. The optimal PDGF-BB concentration was determined based on the CCK-8 results for subsequent experiments. Blood was collected from the rats heart and used to prepare and activate platelet-rich plasma (PRP), which was then stored in liquid nitrogen for later use. According to the culture conditions for BMSCs, the experimental groups were as follows: a blank control group, a 10% PRP group, a 50 ng/mL PDGF-BB group, and a 10% PRP + 100 μM AG1295 [platelet-derived growth factor β receptor (PDGFR-β) inhibitor] group. Each experimental group was replicated three times. Cell proliferation was assessed using the CCK-8 assay, the cell cycle was analyzed using flow cytometry, and the expression of osteogenic differentiation markers was evaluated by Western blot. Results: The cell viability of BMSCs treated with 50 ng/mL of PDGF-BB for 5 days was significantly higher than that of other concentration groups and time points. CCK-8 and flow cytometry results indicated that compared to the control group, both 10% PRP and 50 ng/mL PDGF-BB significantly promoted BMSCs proliferation and increased the proportion of BMSCs in the S phase of the cell cycle. Western blot results demonstrated that compared to the control group, both 10% PRP and 50 ng/mL PDGF-BB significantly upregulated the protein expression levels of osteogenic differentiation markers. The use of the PDGFR-β inhibitor AG1295 markedly attenuated the proliferative and osteogenic effects of 10% PRP on BMSCs. Conclusions: A concentration of 50 ng/mL PDGF-BB significantly enhances the proliferation and osteogenic differentiation of rat BMSCs. PDGF-BB may play a key role in PRP, contributing to the enhancement of BMSCs proliferation and osteogenic differentiation

ShennongAlpha: an AI-driven sharing and collaboration platform for intelligent curation, acquisition, and translation of natural medicinal material knowledge

Natural Medicinal Materials (NMMs) have a long history of global clinical applications and a wealth of records and knowledge. Although NMMs are a major source for drug discovery and clinical application, the utilization and sharing of NMM knowledge face crucial challenges, including the standardized description of critical information, efficient curation and acquisition, and language barriers. To address these, we developed ShennongAlpha, an AI-driven sharing and collaboration platform for intelligent knowledge curation, acquisition, and translation. For standardized knowledge curation, the platform introduced a Systematic Nomenclature to enable accurate differentiation and identification of NMMs. More than fourteen thousand Chinese NMMs have been curated into the platform along with their knowledge. Furthermore, the platform pioneered chat-based knowledge acquisition, standardized machine translation, and collaborative knowledge updating. Together, our study represents the first major advance in leveraging AI to empower NMM knowledge sharing, which not only marks a novel application of AI for Science, but also will significantly benefit the global biomedical, pharmaceutical, physician, and patient communities.Comment: 53 pages, 6 figures, 10 supplementary figures, 2 supplementary table

Increased levels of soluble CD226 in sera accompanied by decreased membrane CD226 expression on peripheral blood mononuclear cells from cancer patients

<p>Abstract</p> <p>Background</p> <p>As a cellular membrane triggering receptor, CD226 is involved in the NK cell- or CTL-mediated lysis of tumor cells of different origin, including freshly isolated tumor cells and tumor cell lines. Here, we evaluated soluble CD226 (sCD226) levels in sera, and membrane CD226 (mCD226) expression on peripheral blood mononuclear cells (PBMC) from cancer patients as well as normal subjects, and demonstrated the possible function and origin of the altered sCD226, which may provide useful information for understanding the mechanisms of tumor escape and for immunodiagnosis and immunotherapy.</p> <p>Results</p> <p>Soluble CD226 levels in serum samples from cancer patients were significantly higher than those in healthy individuals (<it>P </it>< 0.001), while cancer patients exhibited lower PBMC mCD226 expression than healthy individuals (<it>P </it>< 0.001). CD226-Fc fusion protein could significantly inhibit the cytotoxicity of NK cells against K562 cells in a dose-dependent manner. Furthermore, three kinds of protease inhibitors could notably increase mCD226 expression on PMA-stimulated PBMCs and Jurkat cells with a decrease in the sCD226 level in the cell culture supernatant.</p> <p>Conclusion</p> <p>These findings suggest that sCD226 might be shed from cell membranes by certain proteases, and, further, sCD226 may be used as a predictor for monitoring cancer, and more important, a possible immunotherapy target, which may be useful in clinical application.</p

Interferon-γ-Induced Intestinal Epithelial Barrier Dysfunction by NF-κB/HIF-1α Pathway

Interferon-? (IFN-?) plays an important role in intestinal barrier dysfunction. However, the mechanisms are not fully understood. As hypoxia-inducible factor-1 (HIF-1) is a critical determinant response to hypoxia and inflammation, which has been shown to be deleterious to intestinal barrier function, we hypothesized that IFN-? induces loss of barrier function through the regulation of HIF-1α activation and function. In this study, we detected the expressions of HIF-1α and tight junction proteins in IFN-?-treated T84 intestinal epithelial cell line. IFN-? led to an increase of HIF-1α expression in time- and dose-dependent manners but did not change the expression of HIF-1?. The IFN-?-induced increase in HIF-1α was associated with an activation of NF-?B. Treatment with the NF-?B inhibitor, pyrolidinedithiocarbamate (PDTC), significantly suppressed the activation of NF-?B and the expression of HIF-1α. In addition, IFN-? also increased intestinal epithelial permeability and depletion of tight junction proteins; inhibition of NF-?B or HIF-1α prevented the increase in intestinal permeability and alteration in tight junction protein expressions. Interestingly, we demonstrated that a significant portion of IFN-? activation NF-kB and modulation tight junction expression is mediated through HIF-1α. Taken together, this study suggested that IFN-? induced the loss of epithelial barrier function and disruption of tight junction proteins, by upregulation of HIF-1α expression through NF-?B pathway.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140108/1/jir.2013.0044.pd

The emerging role of DOT1L in cell proliferation and differentiation: Friend or foe

Cell proliferation and differentiation are the basic physiological activities of cells. Mistakes in these processes may affect cell survival, or cause cell cycle dysregulation, such as tumorigenesis, birth defects and degenerative diseases. In recent years, it has been found that histone methyltransferase DOT1L is the only H3 lysine 79 methyltransferase, which plays an important role in the process of cell fate determination through monomethylation, dimethylation and trimethylation of H3K79. DOT1L has a pro-proliferative effect in leukemia cells; however, loss of heart-specific DOT1L leads to increased proliferation of cardiac tissue. Additionally, DOT1L has carcinogenic or tumor suppressive effects in different neoplasms. At present, some DOT1L inhibitors for the treatment of MLL-driven leukemia have achieved promising results in clinical trials, but completely blocking DOT1L will also bring some side effects. Thus, this uncertainty suggests that DOT1L has a unique function in cell physiology. In this review, we summarize the primary findings of DOT1L in regulating cell proliferation and differentiation. Correlations between DOT1L and cell fate specification might suggest DOT1L as a therapeutic target for diseases