Glycine improves the remodeling process of tenocytes in vitro.

Tendinitis changes the biochemical and morphological properties of the tendon, promoting an increase of activity of metalloproteinases and disorganization of collagen bundles. Tenocytes, the primary cells in tendon, are scattered throughout the collagenic fibers, and are responsible of tendon remodeling and tissue repair in pathological condition. In vivo, glycine, component of the typical Gly-X-Y collagen tripeptide, showed beneficial effects in biochemical and biomechanical properties of Achilles tendon with tendinitis. In this study, we analyzed the effect of glycine in tenocytes subjected to inflammation. Tenocytes from Achilles tendon of rats were treated with TNF-α (10 ng/mL) with and without previous treatment with glycine (20 mM). Cell proliferation and migration were evaluated, as well as the expression of matrix molecules such as glycosaminoglycans, metalloproteinases (MMPs), TIMPs, and collagen I. Glycine can revert the inflammation due to the action of TNF-α by controlling the MMPs quantity and activity. These data indicated that the molecules involved to remodeling process of extracellular matrix are modulated both by TNF-α and the availability of collagen precursors; in fact, this study indicates the glycine can be useful for treatment of inflammation and for modulating tenocytes metabolism in tendons.

DLK1-DIO3 region as a source of tumor suppressor miRNAs in papillary thyroid carcinoma.

BACKGROUND: In previous studies, we demonstrated the downregulation of several miRNAs from the DLK1-DIO3 genomic region in papillary thyroid carcinoma (PTC). Due to the large number of miRNAs within this region, the individual contribution of these molecules to PTC development and progression remains unclear. OBJECTIVE: In this study, we aimed to clarify the contribution of DLK1-DIO3-derived miRNAs to PTC. METHODS: We used different computational approaches and in vitro resources to assess the biological processes and signaling pathways potentially modulated by these miRNAs. RESULTS: Our analysis suggests that, out of more than 100 mature miRNAs originated from the DLK1-DIO3 region, a set of 12 miRNAs accounts for most of the impact on PTC development and progression, cooperating to modulate distinct cancer-relevant biological processes, such as cell migration, extracellular matrix remodeling, and signal transduction. The restoration of the expression of one of these miRNAs (miR-485-5p) in a BRAFT199A-positive PTC cell line impaired proliferation and migration, suppressing the expression of GAB2 and RAC1, validated miR-485-5p targets. CONCLUSIONS: Overall, our results shed light on the role of the DLK1-DIO3 region, which harbors promising tumor suppressor miRNAs in thyroid cancer, and open prospects for the functional exploration of these miRNAs as therapeutic targets for PTC.

A collagen I derived matricryptin increases aorta vascular wall remodeling after induced thrombosis in mouse.

Matricryptins are collagen fragments proteolytically released from the extracellular matrix (ECM) with biological activity that can regulate several processes involved in ECM remodeling. Vessel wall matrix reorganization after lesion is important to the recovery of vascular function. This study aimed to analyze the effect of the peptide p1158/59 (Lindsey, 2015) on thrombosis, neointimal formation, and vascular remodeling of C57BL6 mice abdominal aorta. We used a FeCl3 induced vascular injury mice model and analyzed thrombus size, neointima formation, gelatinase activities in situ, re-endothelization, and collagen fibers organization on the arterial wall using polarization microscopy. As result, we observed that 2 days after injury the treatment with p1158/59 increased thrombus size and gelatinase activity, vascular lesion and it did not recover the endothelium loss induced by the chemical injury. We also observed that the peptide increased neointima growth and collagen birefringence, indicating collagen fibers reorganization. It also promoted increased re-endothelization and decreased activity of gelatinases 14 days after injury. Thus, we conclude that the peptide p1158/59 impaired the initial thrombosis recovery 2 days after injury but was able to induce vascular ECM remodeling after 14 days, improving vessel re-endothelization, collagen fibers deposition, and organization.

The role of platelet-rich plasma in the mild and severe stages of atherosclerotic disease in mice.

Background: Platelet-rich plasma (PRP) has a high concentration of growth factors (GFs), which present a therapeutic wound healing effect. Despite having been correlated with an immunomodulatory function, the administration of PRP has not yet been investigated in atherosclerosis models. Aim: Evaluate the effect of lyophilized PRP on atherosclerosis in mice models through serum analysis. Methods: Animals received a high-fat diet for disease induction and a weekly PRP retro-orbital application. Effectiveness was evaluated by measuring inflammatory markers in plasma following the treatment of mice with either PRP or saline solution. Results: PRP was well characterized for platelet and GF concentrations; the atherosclerotic profile was established. Cytokine concentrations were altered after PRP applications. Conclusion: PRP could modulate the inflammatory pattern in the early stages of atherosclerosis.

Platelet-rich plasma (PRP) contains growth factors, which stimulate normal wound healing. This product seems to be a good modulator of white blood cells and has not been investigated in atherosclerosis. This study aimed to evaluate PRP in atherosclerosis using mice models. The PRP was produced from animals and preserved using the lyophilization technique; the product was then applied weekly in the vein. For atherosclerosis induction, genetically modified animals were fed a high-fat diet. The effectiveness was evaluated by measuring plasma inflammatory markers after treatment, and PRP seemed to alter cell-signaling molecules (cytokines). This study concluded that PRP was capable of modulating the inflammatory pattern during the early stages of atherosclerosis.

The sodium-glucose cotransporter-2 (SGLT2) inhibitors synergize with nitric oxide and prostacyclin to reduce human platelet activation.

Gliflozins (canagliflozin, dapagliflozin and empagliflozin) are the newest anti-hyperglycemic class and have offered cardiovascular and renal benefits. Because platelets are involved in the atherothrombosis process, this study is aimed to evaluate the direct effect of gliflozins on platelet reactivity. Platelet-rich plasma (PRP) or washed platelets (WP) were obtained from healthy volunteers. Aggregation, flow cytometry for glycoprotein IIb/IIIa, cyclic nucleotides and intracellular calcium levels, Western blot, thromboxane B2 (TXB2) measurement and COX-1 activity were performed in the presence of gliflozins (1-30 µM) alone or in combination with sodium nitroprusside (SNP, 10 or 100 nM) + iloprost (ILO, 0.1 or 1 nM). SGLT2 protein is not expressed on human platelets. Gliflozins produced little inhibitory effect in agonists-induced aggregation and this effect was greatly potentiated by ~10-fold in the presence of SNP + ILO, accompanied by lower levels of TXB2 (58.1 ± 5.1%, 47.1 ± 7.2% and 43.4 ± 9.2% inhibition for canagliflozin, dapagliflozin and empagliflozin, respectively). The activity of COX-1 was not affected by gliflozins. Collagen increased Ca2+ levels and α(IIb)ß(3) activation, both of which were significantly reduced by gliflozins + SNP + ILO. The intracellular levels of cAMP and cGMP and the protein expression of p-VASPSer157 and p-VASPSer239 were not increased by gliflozins while the expression of the serine-threonine kinase, AktSer473 was markedly reduced. Our results showed that the antiplatelet activity of gliflozins were greatly enhanced by nitric oxide and prostacyclin, thus suggesting that the cardiovascular protection seen by this class of drugs could be in part due to platelet inhibition.

Inhibitory effect of red LED irradiation on fibroblasts and co-culture of adipose-derived mesenchymal stem cells.

The objective of this study was to evaluate the effects of red Light Emiting Diode (red LED) irradiation on fibroblasts in adipose-derived mesenchymal stem cells (ASC) co-culture on the scratch assay. We hypothesized that red LED irradiation could stimulate paracrine secretion of ASC, contributing to the activation of genes and molecules involved in cell migration and tissue repair. ASC were co-cultured with NIH/3T3 fibroblasts through direct contact and subjected to red LED irradiation (1.45 J/cm2/5min6s) after the scratch assay, during 4 days. Four groups were established: fibroblasts (F), fibroblasts + LED (FL), fibroblasts + ASC (FC) and fibroblasts + LED + ASC (FLC). The analyzes were based on Ctgf and Reck expression, quantification of collagen types I and III, tenomodulin, VEGF, TGF-ß1, MMP-2 and MMP-9, as well as viability analysis and cell migration. Higher Ctgf expression was observed in FC compared to F. Group FC presented higher amount of tenomodulin and VEGF in relation to the other groups. In the cell migration analysis, a higher number of cells was observed in the scratched area of the FC group on the 4th day. There were no differences between groups considering cell viability, Reck expression, amount of collagen types I and III, MMP-2 and TGF-ß1, whereas TGF-ß1 was not detected in the FC group and the MMP-9 in none of the groups. Our hypothesis was not supported by the results because the red LED irradiation decreased the healing response of ASC. An inhibitory effect of the LED irradiation associated with ASC co-culture was observed with reduction of the amount of TGF-ß1, VEGF and tenomodulin, possibly involved in the reduced cell migration. In turn, the ASC alone seem to have modulated fibroblast behavior by increasing Ctgf, VEGF and tenomodulin, leading to greater cell migration. In conclusion, red LED and ASC therapy can have independent effects on fibroblast wound healing, but the combination of both does not have a synergistic effect. Therefore, future studies with other parameters of red LED associated with ASC should be tested aiming clinical application for tissue repair.

Low-level laser and adipose-derived stem cells altered remodelling genes expression and improved collagen reorganization during tendon repair.

OBJECTIVES: The cellular therapy using adipose-derived mesenchymal stem cells (ASCs) aims to improve tendon healing, considering that repaired tendons often result in a less resistant tissue. Our objective was to evaluate the effects of the ASCs combination with a low-level laser (LLL), an effective photobiostimulation for the healing processes. MATERIALS AND METHODS: Rats calcaneal tendons were divided into five groups: normal (NT), transected (T), transected and ASCs (SC) or LLL (L), or with ASCs and LLL (SCL). RESULTS: All treated groups presented higher expression of Dcn and greater organization of collagen fibres. In comparison with T, LLL also up-regulated Gdf5 gene expression, ASCs up-regulated the expression of Tnmd, and the association of LLL and ASCs down-regulated the expression of Scx. No differences were observed for the expression of Il1b, Timp2, Tgfb1, Lox, Mmp2, Mmp8 and Mmp9, neither in the quantification of hydroxyproline, TNF-α, PCNA and in the protein level of Tnmd. A higher amount of IL-10 was detected in SC, L and SCL compared to T, and higher amount of collagen I and III was observed in SC compared to SCL. CONCLUSIONS: Transplanted ASCs migrated to the transected region, and all treatments altered the remodelling genes expression. The LLL was the most effective in the collagen reorganization, followed by its combination with ASCs. Further investigations are needed to elucidate the molecular mechanisms involved in the LLL and ASCs combination during initial phases of tendon repair.

TNF induces neutrophil adhesion via formin-dependent cytoskeletal reorganization and activation of ß-integrin function.

Although essential for inflammatory responses, leukocyte recruitment to blood vessel walls in response to inflammatory stimuli, such as TNF-α, can contribute to vascular occlusion in inflammatory diseases, including atherosclerosis. We aimed to further characterize the mechanisms by which TNF stimulates adhesive and morphologic alterations in neutrophils. Microfluidic and intravital assays confirmed the potent effect that TNF has on human and murine neutrophil adhesion and recruitment in vitro and in vivo, respectively. Inhibition of actin polymerization by cytochalasin D significantly diminished TNF-induced human neutrophil adhesion in vitro and abolished TNF-induced membrane alterations and cell spreading. In contrast, TNF-induced increases in ß2-integrin (Mac-1 and LFA-1) expression was not significantly altered by actin polymerization inhibition. Consistent with a role for cytoskeletal rearrangements in TNF-induced adhesion, TNF augmented the activity of the Rho GTPase, RhoA, in human neutrophils. However, inhibition of the major RhoA effector protein, Rho kinase (ROCK), by Y-27632 failed to inhibit TNF-induced neutrophil adhesion. In contrast, the formin FH2 domain inhibitor, SMIFH2, abolished TNF-induced human neutrophil adhesion and diminished leukocyte recruitment in vivo. SMIFH2 also inhibited TNF-induced cytoskeletal reorganization in human neutrophils and abolished the alterations in ß2-integrin expression elicited by TNF stimulation. As such, Rho GTPase/mDia formin-mediated cytoskeletal reorganization appears to participate in the orchestration of TNF-induced neutrophil-adhesive interactions, possibly mediated by formin-mediated actin nucleation and subsequent modulation of ß2-integrin activity on the neutrophil surface. This pathway may represent a pharmacologic target for reducing leukocyte recruitment in inflammatory diseases.

Injured Achilles Tendons Treated with Adipose-Derived Stem Cells Transplantation and GDF-5.

Tendon injuries represent a clinical challenge in regenerative medicine because their natural repair process is complex and inefficient. The high incidence of tendon injuries is frequently associated with sports practice, aging, tendinopathies, hypertension, diabetes mellitus, and the use of corticosteroids. The growing interest of scientists in using adipose-derived mesenchymal stem cells (ADMSC) in repair processes seems to be mostly due to their paracrine and immunomodulatory effects in stimulating specific cellular events. ADMSC activity can be influenced by GDF-5, which has been successfully used to drive tenogenic differentiation of ADMSC in vitro. Thus, we hypothesized that the application of ADMSC in isolation or in association with GDF-5 could improve Achilles tendon repair through the regulation of important remodeling genes expression. Lewis rats had tendons distributed in four groups: Transected (T), transected and treated with ADMSC (ASC) or GDF-5 (GDF5), or with both (ASC+GDF5). In the characterization of cells before application, ADMSC expressed the positive surface markers, CD90 (90%) and CD105 (95%), and the negative marker, CD45 (7%). ADMSC were also differentiated in chondrocytes, osteoblast, and adipocytes. On the 14th day after the tendon injury, GFP-ADMSC were observed in the transected region of tendons in the ASC and ASC+GDF5 groups, and exhibited and/or stimulated a similar genes expression profile when compared to the in vitro assay. ADMSC up-regulated Lox, Dcn, and Tgfb1 genes expression in comparison to T and ASC+GDF5 groups, which contributed to a lower proteoglycans arrangement, and to a higher collagen fiber organization and tendon biomechanics in the ASC group. The application of ADMSC in association with GDF-5 down-regulated Dcn, Gdf5, Lox, Tgfb1, Mmp2, and Timp2 genes expression, which contributed to a lower hydroxyproline concentration, lower collagen fiber organization, and to an improvement of the rats' gait 24 h after the injury. In conclusion, although the literature describes the benefic effect of GDF-5 for the tendon healing process, our results show that its application, isolated or associated with ADMSC, cannot improve the repair process of partial transected tendons, indicating the higher effectiveness of the application of ADMSC in injured Achilles tendons. Our results show that the application of ADMSC in injured Achilles tendons was more effective in relation to its association with GDF-5.

Rapid purification and procoagulant and platelet aggregating activities of Rhombeobin: a thrombin-like/gyroxin-like enzyme from Lachesis muta rhombeata snake venom.

We report a rapid purification method using one-step chromatography of SVSP Rhombeobin (LMR-47) from Lachesis muta rhombeata venom and its procoagulant activities and effects on platelet aggregation. The venom was fractionated by a single chromatographic step in RP-HPLC on a C8 Discovery BIO Wide Pore, showing high degree of molecular homogeneity with molecular mass of 47035.49 Da. Rhombeobin showed amidolytic activity upon BA ρ NA, with a broad optimum pH (7-10) and was stable in solution up to 60°C. The amidolytic activity was inhibited by serine proteinase inhibitors and reducing agents, but not chelating agents. Rhombeobin showed high coagulant activity on mice plasma and bovine fibrinogen. The deduced amino acid sequence of Rhombeobin showed homology with other SVSPs, especially with LM-TL (L. m. muta) and Gyroxin (C. d. terrificus). Rhombeobin acts, in vitro, as a strong procoagulant enzyme on mice citrated plasma, shortening the APTT and PT tests in adose-dependent manner. The protein showed, "ex vivo", a strong defibrinogenating effect with 1 µg/animal. Lower doses activated the intrinsic and extrinsic coagulation pathways and impaired the platelet aggregation induced by ADP. Thus, this is the first report of a venom component that produces a venom-induced consumptive coagulopathy (VICC).

In vivo and in vitro Leishmania amazonensis infection induces autophagy in macrophages.

Autophagy is the primary mechanism of degradation of cellular proteins and at least two functions can be attributed to this biological phenomenon: increased nutrient supply via recycling of the products of autophagy under nutrient starvation; and antimicrobial response involved in the innate immune system. Many microorganisms induce host cell autophagy and it has been proposed as a pathway by which parasites compete with the host cell for limited resources. In this report we provide evidence that the intracellular parasite Leishmania amazonensis induces autophagy in macrophages. Using western blotting, the LC3II protein, a marker of autophagosomes, was detected in cell cultures with a high infection index. Macrophages infected with L. amazonensis were examined by transmission electronic microscopy, which revealed enlarged myelin-like structures typical late autophagosome and autolysosome. Other evidence indicating autophagy was Lysotracker red dye uptake by the macrophages. Autophagy also occurs in the leishmaniasis skin lesions of BALB/c mice, detected by immunohistochemistry with anti-LC3II antibody. In this study, autophagy inhibitor 3-methyladenine (3MA) reduced the infection index, while autophagy inductors, such as rapamycin or starvation, did not alter the infection index in cultivated macrophages, suggesting that one aspect of the role of autophagy could be the provision of nutritive support to the parasite.