(±)-LY 395756

Clinical and immunohistochemical performance of lyophilized platelet-rich fibrin (Ly-PRF) on tissue regeneration.[Pubmed:28192870]

Clin Implant Dent Relat Res. 2017 Jun;19(3):466-477.

BACKGROUND: Platelet-rich fibrin (PRF) has been widely used in oral implantology and other fields, but benefits of the fresh PRF (FPRF (fresh platelet-rich fibrin)) were consequently limited because of its short-term application. Thus, a protocol for the combination of PRF and lyophilization comes up in the present study to address the issue of PRF storage and delayed clinical application, which has little been reported in this field at home and abroad by now. PURPOSE: The aim of the present study was to evaluate the applicability of lyophilized platelet-rich fibrin (Ly-PRF) used as the scaffold material for craniofacial tissue regeneration and to compare its biochemical properties with commonly used fresh PRF. MATERIALS AND METHODS: Two volunteers with both genders were selected as the source of PRF and Ly-PRF samples. Macro- and micro-scopic appearance evaluation as well as immunohistochemical comparison were performed on PRF samples before and after freeze-drying at -196 degrees C. The second experimental phase was to observe clinical performance when fresh and lyophilized PRF were applied in guided bone regeneration (GBR) operations in 39 patients losing teeth in the anterior maxillary region who required an oral implantation followed by labial bone grafting. RESULTS: The conventional histological and transmission electron microscopy images showed the microstructure of Ly-PRF, which resembled a mesh containing apparently irregularly shaped platelets with less alpha-granule than fresh PRF in micro and a translucent membrane with less elasticity than fresh PRF in macro. Simultaneous immunohistological staining results showed positive expression of PDGF-BB, IL-1, IL-4, TNF, TGF-beta1 in both fresh and lyophilized PRF, while the expression of PDGF-BB, IL-1, TNF, TGF-beta1 has no statistical difference between them (P > .05) but that of IL-4 in Ly-PRF is statistically higher than in fresh PRF (P < .05). When applied in GBR operations, there were no significant differences between Ly-PRF and FPRF in factors of histological and clinical evaluations (i.e., color, swelling, bleeding of the mucosa, pain leveland, and remodeling of hard tissue) performed 3 days, 7 days, and 4 months after the surgery (P > .05). CONCLUSIONS: This study strongly supports that lyophilization at -196 degrees C does not largely influence the expression of bioactive factors, the microstructure of fibrinogen or the clinical effects of PRF.

Expansion of CD11b(+)Ly-6C(+) myeloid-derived suppressor cells (MDSCs) driven by galectin-9 attenuates CVB3-induced myocarditis.[Pubmed:28110209]

Mol Immunol. 2017 Mar;83:62-71.

Galectin-9 is known to play a role in the modulation of innate and adaptive immunity to ameliorate CVB3-induced myocarditis. In the present study, we found that galectin-9 induced the expansion of CD11b(+)Ly-6C(+) myeloid-derived suppressor cells (MDSCs) in the heart from CVB3-infected mice. Adoptive transfer of CD11b(+)Ly-6C(+) MDSCs significantly alleviated myocarditis accompanied by increased Th2 and Treg frequency and anti-inflammatory cytokines expression in the heart tissue. Moreover, Ly6C(+) MDSCs, but not Ly6G(+) cells, expressed Arg-1 and NOS2, and suppressed CD4(+) T cell proliferation in vitro in an Arg-1-dependent mechanism; an event that was reversed with treatment of either an Arg-1 inhibitor or addition of excess l-arginine. Furthermore, Ly6C(+) MDSCs co-expressed higher levels of F4/80, Tim-3, and IL-4Ralpha, and had the plasticity to up-regulate NOS2 or Arg-1 in response to IFN-gamma or IL-4 treatment. The present results indicate that galectin-9 expands CD11b(+)Ly-6C(+) MDSCs to ameliorate CVB3-induced myocarditis.

Assessment of roles for the Rho-specific guanine nucleotide dissociation inhibitor Ly-GDI in platelet function: a spatial systems approach.[Pubmed:28148498]

Am J Physiol Cell Physiol. 2017 Apr 1;312(4):C527-C536.

On activation at sites of vascular injury, platelets undergo morphological alterations essential to hemostasis via cytoskeletal reorganizations driven by the Rho GTPases Rac1, Cdc42, and RhoA. Here we investigate roles for Rho-specific guanine nucleotide dissociation inhibitor proteins (RhoGDIs) in platelet function. We find that platelets express two RhoGDI family members, RhoGDI and Ly-GDI. Whereas RhoGDI localizes throughout platelets in a granule-like manner, Ly-GDI shows an asymmetric, polarized localization that largely overlaps with Rac1 and Cdc42 as well as microtubules and protein kinase C (PKC) in platelets adherent to fibrinogen. Antibody interference and platelet spreading experiments suggest a specific role for Ly-GDI in platelet function. Intracellular signaling studies based on interactome and pathways analyses also support a regulatory role for Ly-GDI, which is phosphorylated at PKC substrate motifs in a PKC-dependent manner in response to the platelet collagen receptor glycoprotein (GP) VI-specific agonist collagen-related peptide. Additionally, PKC inhibition diffuses the polarized organization of Ly-GDI in spread platelets relative to its colocalization with Rac1 and Cdc42. Together, our results suggest a role for Ly-GDI in the localized regulation of Rho GTPases in platelets and hypothesize a link between the PKC and Rho GTPase signaling systems in platelet function.

Short-term dabigatran interruption before cardiac rhythm device implantation: multi-centre experience from the RE-LY trial.[Pubmed:28339794]

Europace. 2017 Oct 1;19(10):1630-1636.

Aims: Cardiac implantable electronic device (CIED) surgery is commonly performed in patients with atrial fibrillation (AF). The current analysis was undertaken to compare peri-operative anticoagulation management, bleeding, and thrombotic events in AF patients treated with dabigatran vs. warfarin. Methods and results: This study included 611 patients treated with dabigatran vs. warfarin who underwent CIED surgery during the RE-LY trial. Among 201 warfarin-treated patients, warfarin was interrupted a median of 144 (inter-quartile range, IQR: 120-216) h, and 37 (18.4%) patients underwent heparin bridging. In dabigatran-treated patients (216 on 110 mg bid and 194 on 150 mg bid), the duration of dabigatran interruption was a median of 96 (IQR: 61-158) h. Pocket hematomas occurred in 9 (2.20%) patients on dabigatran and 8 (3.98%) patients on warfarin (P = 0.218). The occurrence of pocket hematomas was lower with dabigatran compared with warfarin with heparin bridging (RD: -8.62%, 95% CI: -24.15 to - 0.51%, P = 0.034) but not when compared with warfarin with no bridging (P = 0.880). Ischemic stroke occurred in 2 (0.3%) patients; one in the warfarin group (without bridging) and one in the dabigatran 150 mg bid group (P = 0.735). Conclusion: In patients treated with dabigatran undergoing CIED surgery, interruption of dabigatran is associated with similar or lower incidence of pocket hematoma, when compared with warfarin interruption without or with heparin bridging, respectively. Whether uninterrupted dabigatran can reduce pocket hematoma or ischemic stroke remains to be evaluated.

Methyl substitution of 2-aminobicyclo[3.1.0]hexane 2,6-dicarboxylate (LY354740) determines functional activity at metabotropic glutamate receptors: identification of a subtype selective mGlu2 receptor agonist.[Pubmed:15887967]

J Med Chem. 2005 May 19;48(10):3605-12.

LY354740 (1) is a highly potent and selective agonist of metabotropic glutamate (mGlu) receptors 2 and 3. In the present study, we have prepared C3- and C4-methyl-substituted variants of rac-1, compounds 5, 9, and 13. Each of these racemic methyl-substituted analogues displaced specific binding of the mGlu2/3 receptor antagonist (3)H-2S-2-amino-2-(1S,2S-2-carboxycycloprop-1-yl)-3-(xanth-9-yl)propanoic acid ((3)H-LY341495) from membranes expressing mGlu2 or mGlu3 receptor subtypes. Evaluation of the functional effects of this series on second messenger responses in cells expressing human mGlu2 or mGlu3 receptors revealed C3beta-methyl analogue 5 to possess antagonist properties at both mGlu2 and mGlu3 receptors while C4beta-methyl analogue 9 acts as a full agonist at each of these targets. Unexpectedly, we found that incorporation of a methyl substituent at the C4alpha-position as in analogue 13 results in a mixed mGlu2 agonist/mGlu3 antagonist pharmacological profile. All of the mGlu2 agonist and mGlu3 antagonist activity of rac-13 was found to reside in its resolved (+)-isomer.