BackgroundPlatelet-rich plasma (PRP) is an autologous blood product that contains a high concentration of several growth factors. Platelet-derived growth factor (PDGF)-BB is a potential mitogen for human adipose-derived stem cells (hASCs). PRP stimulates proliferation of hASCs; however, the signaling pathways activated by PRP remain unclear.MethodshASCs were cultured with or without PRP or PDGF-BB, and proliferation was assessed. hASCs were also treated with PRP or PDGF-BB with or without imatinib, which is a PDGF receptor tyrosine kinase inhibitor, or sorafenib, which is a multikinase inhibitor. Inhibition of cell proliferation was examined using anti-PDGF antibody (Abcam, Cambridge, UK), by cell counting. We assessed the effects of inhibitors of various protein kinases such as ERK1/2, JNK, p38, and Akt on the proliferation of hASCs.ResultsThe proliferation was remarkably promoted in cells treated with either 1% PRP or 10 ng/ml PDGF-BB, and both imatinib and sorafenib inhibited this proliferation. Anti-PDGF antibody (0.5 and 2 μg/ml) significantly decreased the proliferation of hASCs compared with control. PRP-mediated hASC proliferation was blocked by inhibitors of ERK1/2, Akt, and JNK, but not by an inhibitor of p38.ConclusionsPRP promotes hASC proliferation, and PDGF-BB in PRP plays a major role in inducing the proliferation of hASCs. PRP promotes hASC proliferation via ERK1/2, PI3K/Akt, and JNK signaling pathways.

BackgroundHuman adipose-derived stem cells (hASCs) are a subset of mesenchymal stem cells (MSCs); it has been regarded as one of the most promising stem cells. We previously found that fibroblast growth factor-2 (FGF-2) enhanced the proliferation and differentiation of hASC. However, the mechanisms involved in the growth of hASCs by FGF-2 have not been investigated.MethodsHuman adipose-derived stem cells (hASCs) were cultured with FGF-2, and cell growth was assessed. Effects of FGF Receptor (FGFR) inhibitor (NVP-BGJ398), ERK1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38 MAPK inhibitor (SB203580) and Src inhibitor (PP1) on the proliferation were investigated. At the same time, we assessed the effect of FGFR inhibitor on several signaling enzymes such as ERK1/2, JNK, p38, and Akt, in protein level. The involvement of Src activation by FGF-2 was also examined.ResultsFGF-2 markedly promoted proliferation of hASCs at concentrations lower than 10 ng/ml and stimulated cell progression to the S and G2/M phases. Proliferation was blocked by the FGFR inhibitor (NVP-BGJ398) and various signaling pathway inhibitors, such as Erk1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38MAPK inhibitor (SB203580). The FGFR inhibitor reduced the activation of protein kinases, such as AKT, Erk1/2, JNK, and p38, in several signaling pathways. The downstream kinase of FGFR, Src, was activated by FGF-2, and its activation was canceled by the FGFR inhibitor. MEK1/2, a downstream kinase of Src, was parallelly regulated by FGF-2. The Src inhibitor (PP1) markedly blocked the proliferation of hASCs via inhibition of Src and MEK1/2.ConclusionSrc activation is indispensable for FGF-2-mediated proliferation of ASCs, as well as the subsequent activation of multi-signaling pathways.

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Platelet-rich plasma (PRP) contains a high concentration of several growth factors and contributes to soft-tissue engineering and wound healing. However, the effect of PRP on human dermal fibroblast proliferation and responses is unknown. This was investigated in the present study using PRP prepared from the whole human blood using the double-spin method. Human dermal fibroblast cultures were established from skin samples collected during plastic surgery. Platelet concentration and growth factor levels in PRP were estimated, and a cell proliferation assay was carried out after PRP treatment. The role of Ras-dependent extracellular signal-regulated kinase (ERK)1/2 in the effects of PRP was investigated in human dermal fibroblasts by suppressing ERK1/2 expression with an inhibitor or by short interfering (si)RNA-mediated knockdown, and assessing ERK1/2 phosphorylation by western blotting as well as proliferation in PRP-treated cells. We found that PRP stimulated human dermal fibroblast proliferation, which was suppressed by ERK1/2 inhibitor treatment (P < 0.01). ERK1/2 phosphorylation was increased in the presence of PRP, while siRNA-mediated knockdown of ERK1/2 blocked cell proliferation normally induced by PRP treatment (P < 0.01). These results demonstrate that PRP induces human dermal fibroblast proliferation via activation of ERK1/2 signaling. Our findings provide a basis for the development of agents that can promote wound healing and can be applied to soft-tissue engineering.

BackgroundSemen is a critical vector for human immunodeficiency virus (HIV) sexual transmission and harbors seminal amyloid fibrils that can markedly enhance HIV infection. Semen-derived enhancer of viral infection (SEVI) is one of the best-characterized seminal amyloid fibrils. Due to their highly cationic properties, SEVI fibrils can capture HIV virions, increase viral attachment to target cells, and augment viral fusion. Some studies have reported that myricetin antagonizes amyloid β-protein (Aβ) formation; myricetin also displays strong anti-HIV activity in vitro.ResultsHere, we report that myricetin inhibits the formation of SEVI fibrils by binding to the amyloidogenic region of the SEVI precursor peptide (PAP248–286) and disrupting PAP248–286 oligomerization. In addition, myricetin was found to remodel preformed SEVI fibrils and to influence the activity of SEVI in promoting HIV-1 infection. Moreover, myricetin showed synergistic effects against HIV-1 infection in combination with other antiretroviral drugs in semen.ConclusionsIncorporation of myricetin into a combination bifunctional microbicide with both anti-SEVI and anti-HIV activities is a highly promising approach to preventing sexual transmission of HIV.Electronic supplementary materialThe online version of this article (10.1186/s12977-018-0432-3) contains supplementary material, which is available to authorized users.

HIV-1 transmembrane protein gp41 plays a crucial role by forming a stable six-helix bundle during HIV entry. Due to highly conserved sequence of gp41, the development of an effective and safe small-molecule compound targeting gp41 is a good choice. Currently, natural polyanionic ingredients with anti-HIV activities have aroused concern. Here, we first discovered that a glycosylated dihydrochalcone, trilobatin, exhibited broad anti-HIV-1 activity and low cytotoxicity in vitro. Site-directed mutagenesis analysis suggested that the hydrophobic residue (I564) located in gp41 pocket-forming site is pivotal for anti-HIV activity of trilobatin. Furthermore, trilobatin displayed synergistic anti-HIV activities combined with other antiretroviral agents. Trilobatin has a good potential to be developed as a small-molecule HIV-1 entry inhibitor for clinical combination therapy.

Aims This study aimed to review the studies evaluating the effect of the inflammatory state on voriconazole (VRZ) levels. Methods The study included randomized clinical trials, cohort studies, and case–control studies that focused on the influence of the inflammatory state on VRZ levels. Following the preferred reporting items for systematic reviews and meta‐analyses (PRISMA) guidelines, relevant articles published until 2021 were searched in several databases, including PubMed, Embase, Web of Science and the Cochrane Library. Results Twenty studies were included in this review, of which 15 described adult populations, three described paediatric populations, and two included both adult and paediatric populations. Seventeen studies used C‐reactive protein (CRP) as an indicator of inflammation, six described a dose–response relationship for the effect of inflammation represented by CRP on VRZ concentrations, and four examined the effect of CRP on the metabolic rate of VRZ. Conclusions Our findings showed that the level of inflammation can significantly affect VRZ levels. However, the effect of inflammation on VRZ concentrations in children is controversial and must be analysed along with age. Clinicians dosing VRZ should take into account the patient's inflammatory state. The impact of inflammation on genotype‐based dosing decisions requires further study to explain the high pharmacokinetic variability of VRZ.

The grafting of fat mixed with adipose-derived stem cells (ASCs) is being increasingly applied to compensate for the disadvantages of previous fat grafting methods. Devices that automatically isolate fat stem cells also have recently been developed. ASCs were isolated from the inguinal region of White rabbits using Icellator, and the number of cells and their viability were measured. The cell count per fat graft (mL) was adjusted to the following concentrations and subcutaneously transplanted into the back: Control group, Fat + PBS; Fat + ASCs (×0.5) group, 1.6 × 10 cells/mL; and Fat + ASCs (×1) group, 3.2 × 10 cells/mL. Grafted fat weight was measured after 8 weeks, and histological, immunohistological, and specifically stained sections were prepared. Fat absorption was reduced in Fat + ASCs (×0.5) and Fat + ASCs (×1) groups. The number of blood vessels was higher in Fat + ASCs (×1) than in the control group, and blood vessel areas were higher in Fat + ASCs (×0.5) and Fat + ASCs (×1) groups than in the control group. The usefulness of the automated cell processing apparatus, Icellator, was confirmed, and the results obtained suggest that grafted ASCs promote the vascularization and engraftment of fat grafts.