Therapeutic potential of Polygonum multiflorum has been demonstrated in the conditions like Alzheimer׳s disease, Parkinson׳s disease, hyperlipidaemia, inflammation and cancer, which is attributed to the presence of various stilbenes, quinones, flavonoids, phospholipids and other compounds in the drug. On the other hand, the adverse effects (hepatotoxicity, nephrotoxicity, and embryonic toxicity) of this plant were caused by the quinones, such as emodin and rhein. Thus more pharmacological and toxicological mechanisms on main active compounds are necessary to be explored, especially the combined anthraquinones (Emodin-8-O-β-d-glucopyranoside, Physcion-8-O-β-d-glucopyranoside, etc.) and the variety of stilbenes.
Angiogenesis is a complicated and sequential process that plays an important role in different physiological processes. Mesenchymal stem cells (MSCs), which are pluripotent stem cells, are widely used for the treatment of ischemic and traumatic diseases, and exosomes derived from these cells can also promote angiogenesis. Therefore, we aimed to uncover mechanisms to improve MSC exosome-mediated angiogenesis. For this study, we isolated human adipose-derived MSCs (hAD-MSCs) and assessed differentiation ability and markers. Cells were divided into hypoxia-treated MSCs (H-MSCs) and normoxia-treated MSCs (N-MSC), and exosomes were extracted by ultrafiltration. Exosomes (100 μg/mL) from H-MSCs and N-MSCs were added to human umbilical vein endothelial cells (HUVECs). Exosome uptake and the ability of endothelial cells to form tubes were detected in real time. Protein samples were collected at different time points to detect the expression of inhibitors (Vash1) and enhancers (Angpt1 and Flk1) of angiogenesis; we also assessed their related signaling pathways. We found that exosomes from the hypoxia group were more easily taken up by HUVECs; furthermore, their angiogenesis stimulatory activity was also significantly enhanced compared to that with exosomes from the normoxia group. HUVECs exposed to exosomes from H-MSCs significantly upregulated angiogenesis-stimulating genes and deregulated angiogenesis-inhibitory genes. The expression of vascular endothelial growth factor (VEGF) and activation of the protein kinase A (PKA) signaling pathway in HUVECs were significantly increased by hypoxia-exposed exosomes. Moreover, a PKA inhibitor was shown to significantly suppress angiogenesis. Finally, we concluded that hypoxia-exposed exosomes derived from hAD-MSCs can improve angiogenesis by activating the PKA signaling pathway and promoting the expression of VEGF. These results could be used to uncover safe and effective treatments for traumatic diseases.
Purpose
How to free the potential power of the capital market while simultaneously protecting the investors is critical in equity-based crowdfunding. To realize these goals, the purpose of this study was to investigate the value of information disclosure and leader-follower mechanism which have been widely adopted by crowdfunding platforms.
Design/methodology/approach
Based on the Elaboration Likelihood Model (ELM), a research framework was developed. Then, the authors conducted an in-depth exploratory empirical study of Dajiatou (www.dajiatou.com) which is a typical equity-based crowdfunding service provider in China. Independent-samples t-test and linear regression were used to uncover the value of project information disclosure and the lead investor in terms of fundraising performance improvement.
Findings
First, the quality of entrepreneurial team information, especially the ratio of full-time staff, staff number and enterprise business age, significantly improve fundraising performance. Second, entrepreneurs’ behaviors, including project updates and project video, play important roles in crowdfunding. Third, whether or not the project has a lead investor, leader’s credibility information and his/her advocacy behaviors – percentage of their investment, identity certification, investment experience and comments for projects – are important factors affecting fundraising performance.
Research limitations/implications
The authors are one of the firsts to apply ELM to investigate the effects of diverse information on fundraising performance in equity-based crowdfunding. The value of lead investor which has been ignored in prior research was studied through second-hand data.
Practical implications
First, an equity-based crowdfunding platform should request the entrepreneur to disclose project quality-related information with more details. Second, crowdfunding platforms should set a high qualifications level for lead investor, and limit the lead investor’s committed percentage in a specific project.
Originality/value
This paper extended the research in crowdfunding by uncovering the value of information disclosure and lead investor based on ELM theory.
We previously demonstrated that curcumin reduces cholesterol absorption in Caco-2 cells through down-regulating Niemann-Pick C1-like 1 (NPC1L1) expression, but the in vivo effect of curcumin on intestinal cholesterol absorption remains unknown. The present study aimed to investigate the effects and mechanisms of curcumin consumption on cholesterol absorption in hamsters. Male hamsters were fed a high-fat diet supplemented with or without curcumin (0.05% w/w) for 12 weeks. Curcumin supplementation significantly decreased serum total cholesterol (TC) (from 6.86 ± 0.27 to 3.50 ± 0.24 mmol/L), triglyceride (TG) (from 5.07 ± 0.34 to 3.72 ± 0.40 mmol/L), and low-density lipoprotein cholesterol (from 2.58 ± 0.19 to 1.71 ± 0.15 mmol/L) levels as well as liver TC (from 11.6 ± 0.05 to 7.2 ± 0.03 mg/g) and TG (from 30.3 ± 0.22 to 25.2 ± 0.18 mg/g) levels (P < 0.05 for all). In contrast, curcumin treatment markedly enhanced fecal cholesterol output (P < 0.01). Moreover, curcumin supplementation down-regulated the mRNA and protein expressions of sterol regulatory element binding protein-2 (SREBP-2) and NPC1L1 in the small intestine (P < 0.05). Our current results indicate that curcumin inhibits cholesterol absorption in hamsters by suppressing SREBP-2 and subsequently down-regulating NPC1L1 expression, which may be responsible for the hypocholesterolemic effects of curcumin.
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