Platelet-derived Growth factor-AB Research Articles

Comparison between 100% autologous serum and 100% platelet‐rich plasma eye drops and their impact on the treatment efficacy of dry eye in primary Sjogren syndrome

Purpose: The aim of the study was to compare the difference in the composition of 100% autologous serum (AS) and 100% platelet‐rich plasma (PRP) eye drops and assess their impact on the clinical out‐comes after the treatment of severe dry eye (DE) in primary Sjogren Syndrome patients (pSS).Methods: 22 patients with severe DE in pSS were treated with 100% AS (22 eyes) and 100% PRP (22 eyes) eye drops 5 times per day as monotherapy. The quantification of growth factors (GFs) as fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), platelet‐derived growth factor (PDGF), nerve growth factor (NGF), transforming growth factor (TGF‐b), insulin‐like growth factor(IGF), fibronectin and substance P in hemoderivates was performed. The main outcomes: Ocular Surface Disease Index (OSDI), Best Corrected Visual Acuity (BCVA), the Schirmer test, tear break‐up time (TBUT), corneal and conjunctival staining according to the Oxford scale, conjunctival hyperaemia and Meibomian gland parameters. The results were compared at the baseline, 1 and 3 months after the treatment. The clinical results were correlated with the concentration of GFs.Results: Significant differences were observed in the concentration of FGF, EGF, fibronectin, VEGF, PDGF AB, NGF, PDGF, substance P, TGF‐β in PRP compared to AS. There was a statistically significant improvement in BCVA, the Schirmer test, TBUT, Meibomian gland parameters, and the reduction of the OSDI scores, Oxford staining and conjunctiva hyperaemia in each group. There were many correspondences between the level of GFs and the mean change of the clinical outcomes. No adverse events were reported.Conclusions: Despite the fact that blood derivatives differ in their composition, they seem to be effective, safe in the treatment of severe DE in pSS patients. The signs and symptoms of DE were reduced in both groups. The obtained clinical results and the composition of hemoderivates may indicate the superiority of PRP in relieving the signs and symptoms of DE in pSS patients.

Associations of potential plasma biomarkers with suicide attempt history, current suicidal ideation and subsequent suicidal events in patients with depression: A discovery study

A growing body of evidences suggests that suicidal ideation (SI) and suicidal behaviors have biological bases. However, no biological marker is currently available to evaluate the suicide risk in individuals with SI or suicide attempt (SA). Moreover, the current risk assessment techniques poorly predict future suicidal events. The aim of this study was to examine the association of 39 new and already described peripheral cells and proteins (implicated in the immune system, oxidative stress and plasticity) with lifetime SA, past month SA, current SI, and future suicidal events (visit to the Emergency Department for SI or SA) in 266 treatment-seeking individuals with mood disorders. Equal parts of patients with and without past history of SA were recruited. All individuals at inclusion gave blood, were evaluated for SA recency, current SI, and were followed for two years afterwards. The 39 peripheral blood cellular and protein markers were entered separately for each outcome in Elastic Net models with 10-fold cross-validation, followed by single-analyte covariate-adjusted regression analyses for pre-selected analytes. Past month SA was associated with increased plasma levels of thrombospondin-2 and C-reactive protein, whereas current SI was associated with lower plasma serotonin levels. These associations were robust to adjustments for key covariates and corrections for multiple testing. The Cox proportional hazards regression showed that higher levels of thrombospondin-1 and of platelet-derived growth factor-AB predicted a future suicidal event. These two associations remained after adjustment for sex, age, and SA history, and outperformed the predictive value of past SA. Thrombospondins and platelet-derived growth factors have never been investigated in the context of suicide. Altogether, our results highlight the involvement in the suicidal process of platelet biological response and plasticity modifiers and also of inflammatory factors. They also suggest that SI and SA may have different biological correlates and that biomarkers associated with past SA or current SI do not automatically also predict future events.

Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice

Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice

Plasma polymerized nanoparticles are a safe platform for direct delivery of growth factor therapy to the injured heart.

Introduction: Heart failure due to myocardial infarction is a progressive and debilitating condition, affecting millions worldwide. Novel treatment strategies are desperately needed to minimise cardiomyocyte damage after myocardial infarction and to promote repair and regeneration of the injured heart muscle. Plasma polymerized nanoparticles (PPN) are a new class of nanocarriers which allow for a facile, one-step functionalization with molecular cargo. Methods: Here, we conjugated platelet-derived growth factor AB (PDGF-AB) to PPN, engineering a stable nano-formulation, as demonstrated by optimal hydrodynamic parameters, including hydrodynamic size distribution, polydisperse index (PDI) and zeta potential, and further demonstrated safety and bioactivity in vitro and in vivo. We delivered PPN-PDGF-AB to human cardiac cells and directly to the injured rodent heart. Results: We found no evidence of cytotoxicity after delivery of PPN or PPN-PDGFAB to cardiomyocytes in vitro, as determined through viability and mitochondrial membrane potential assays. We then measured contractile amplitude of human stem cell derived cardiomyocytes and found no detrimental effect of PPN on cardiomyocyte contractility. We also confirmed that PDGF-AB remains functional when bound to PPN, with PDGF receptor alpha positive human coronary artery vascular smooth muscle cells and cardiac fibroblasts demonstrating migratory and phenotypic responses to PPN-PDGF-AB in the same manner as to unbound PDGF-AB. In our rodent model of PPN-PDGF-AB treatment after myocardial infarction, we found a modest improvement in cardiac function in PPN-PDGF-AB treated hearts compared to those treated with PPN, although this was not accompanied by changes in infarct scar size, scar composition, or border zone vessel density. Discussion: These results demonstrate safety and feasibility of the PPN platform for delivery of therapeutics directly to the myocardium. Future work will optimize PPN-PDGF-AB formulations for systemic delivery, including effective dosage and timing to enhance efficacy and bioavailability, and ultimately improve the therapeutic benefits of PDGF-AB in the treatment of heart failure cause by myocardial infarction.

Intraocular Pressure-Lowering and Retina-Protective Effects of Exosome-Rich Conditioned Media from Human Amniotic Membrane Stem Cells in a Rat Model of Glaucoma.

Glaucoma is one of the most devastating eye diseases, since the disease can develop into blindness and no effective therapeutics are available. Although the exact mechanisms and causes of glaucoma are unknown, increased intraocular pressure (IOP) has been demonstrated to be an important risk factor. Exosomes are lipid nanoparticles secreted from functional cells, including stem cells, and have been found to contain diverse functional molecules that control body function, inhibit inflammation, protect and regenerate cells, and restore damaged tissues. In the present study, exosome-rich conditioned media (ERCMs) were attained via hypoxic culture (2% O2) of human amniotic membrane mesenchymal stem cells (AMMSCs) and amniotic membrane epithelial stem cells (AMESCs) containing 50 times more exosome particles than normoxic culture (20% O2) medium (NCM). The exosome particles in ERCM were confirmed to be 77 nm in mean size and contain much greater amounts of growth factors (GFs) and neurotrophic factors (NFs) than those in NCM. The glaucoma-therapeutic effects of ERCMs were assessed in retinal cells and a hypertonic (1.8 M) saline-induced high-IOP animal model. CM-DiI-labeled AMMSC exosomes were found to readily penetrate the normal and H2O2-damaged retinal ganglion cells (RGCs), and AMMSC-ERCM not only facilitated retinal pigment epithelial cell (RPEC) proliferation but also protected against H2O2- and hypoxia-induced RPEC insults. The IOP of rats challenged with 1.8 M saline increased twice the normal IOP (12-17 mmHg) in a week. However, intravitreal injection of AMMSC-ERCM or AMESC-ERCM (3.9-4.5 × 108 exosomes in 10 μL/eye) markedly recovered the IOP to normal level in 2 weeks, similar to the effect achieved with platelet-derived growth factor-AB (PDGF-AB, 1.5 μg), a reference material. In addition, AMMSC-ERCM, AMESC-ERCM, and PDGF-AB significantly reversed the shrinkage of retinal layers, preserved RGCs, and prevented neural injury in the glaucoma eyes. It was confirmed that stem cell ERCMs containing large numbers of functional molecules such as GFs and NFs improved glaucoma by protecting retinal cells against oxidative and hypoxic injuries in vitro and by recovering IOP and retinal degeneration in vivo. Therefore, it is suggested that stem cell ERCMs could be a promising candidate for the therapy of glaucoma.

Fibrin clot and Leukocyte-rich platelet-rich fibrin show similar release kinetics and amount of growth factors: a pilot study

BackgroundIn knee arthroscopic surgery, fibrin clot (FC) and leukocyte-rich platelet-rich fibrin (L-PRF) may be used in augmentation for meniscal repair. Studies have investigated growth factors released from FC and L-PRF; however, it is difficult to compare FC and L-PRF between different studies. Direct comparison of growth factors that may support meniscal healing released from FC and L-PRF may be beneficial in deciding whether to use FC or L-PRF. If no significant difference is seen, the surgeon may decide to use FC which is easier to prepare compared to L-PRF. The purpose of this pilot study is to investigate the release amount and pattern of basic fibroblast growth factor (bFGF), platelet-derived growth factor AB (PDGF-AB), transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1 (SDF-1) from FC and L-PRF.MethodTwenty milliliters (ml) of whole blood was collected from each of the four volunteers. Ten milliliters of whole blood was allocated for preparation of FC and 10 ml for L-PRF. FC and L-PRF were separately placed in 5 ml of culture media. Five milliliters of the culture media was sampled and refilled at 15 min, 1 day, 3 days, 1 week and 2 weeks. The collected culture was used to quantify bFGF, PDGF-AB, TGF-β1, VEGF, and SDF-1 release by Enzyme-linked immune-sorbent assay (ELISA). Mann–Whitney U test was performed to assess significance of differences in amount of each growth factor released between FC and L-PRF. Significance was accepted at P value less than 0.05.ResultsAt two weeks, the cumulative release of TGF-β1 was the highest among all the growth factors in both FC and L-PRF (FC:19,738.21 pg/ml, L-PRF: 16,229.79 pg/ml). PDGF-AB (FC: 2328 pg/ml, L-PRF 1513.57 pg/ml) had the second largest amount, followed by VEGF (FC: 702.06 pg/ml, L-PRF 595.99 pg/ml) and bFGF (FC: 23.48 pg/ml, L-PRF 18.2 pg/ml), which order was also common in both FC and L-PRF. No significant difference in final release amount and pattern was seen between FC and L-PRF.ConclusionThe current pilot study showed that cumulative release amount and release pattern of PDGF-AB, VEGF, TGF-β1, and bFGF did not significantly differ between FC and L-PRF during the two weeks of observation.

Berberine regulates pulmonary inflammatory microenvironment and decreases collagen deposition in response to bleomycin-induced pulmonary fibrosis in mice.

The purpose of this study was to explore the protective effect and potential mechanism of berberine on bleomycin (BLM)-induced fibrosis after lung injury in conjunction with network pharmacology. Berberine and pulmonary fibrosis prediction targets were collected for Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and so forth. A single intranasal dose of BLM (2.5 mg/kg) was administered to establish a model of fibrosis after lung injury, and berberine (50 mg/kg) was administered intraperitoneally daily for treatment. Network pharmacology results suggested that the mitogen-activated protein kinase (MAPK) signalling pathway may be a potential mechanism of berberine in delaying pulmonary fibrosis. The results of animal experiments showed that compared with the BLM group, after 14 days of berberine treatment, lung inflammatory cell aggregation was reduced and the expression levels of tumour necrosis factor-α (TNF-α), interleukin (IL)-8 and IL-6 were down-regulated in mice (p < 0.05); after 42 days of berberine treatment, the expression levels of transforming growth factor (TGF)-β1, platelet-derived growth factor-AB (PDGF-AB), hydroxyproline (HYP) and α-smooth muscle actin (α-SMA) were significantly down-regulated (p < 0.05), and the expression levels of total p38 MAPKα and p38 MAPKα (pT180/Y182) were down-regulated also (p < 0.05), inhibited collagen production and deposition, and increased the survival rate of mice to 70%. In conclusion, berberine attenuated inflammation mice, inhibited collagen production and showed some anti-pulmonary fibrosis potential in the MAPK signalling pathway.

Red blood cell distribution width derivatives in alcohol-related liver cirrhosis and metabolic-associated fatty liver disease

BACKGROUNDLooking for undiscovered blood markers of liver fibrosis and steatosis still remains an issue worth exploring. There are still plenty of unresolved issues related to the actual role of hematological indices as potential markers of liver function.AIMTo study red blood cell distribution width (RDW), RDW-to-platelet ratio (RPR) and RDW-to-lymphocyte ratio (RLR) in alcohol-related liver cirrhosis (ALC) and metabolic-associated fatty liver disease (MAFLD).METHODSThe study group was composed of 302 people: 142 patients with ALC and 92 with MAFLD; 68 persons were included as controls. RDW, RPR and RLR were measured in each person. Indirect and direct parameters of liver fibrosis were also assessed [aspartate transaminase to alkaline transaminase ratio, aspartate transaminase to platelet ratio index (APRI), fibrosis-4 (FIB-4), gamma-glutamyl transpeptidase to platelet ratio (GPR), procollagen I carboxyterminal propeptide, procollagen III aminoterminal propeptide, transforming growth factor-α, platelet-derived growth factor AB, laminin]. MELD score in ALC patients and non-alcoholic fatty liver disease (NAFLD) fibrosis score together with BARD score were obtained in the MAFLD group. The achieved results were compared to controls. Then a correlation between assessed markers was done. Diagnostic value of each investigated parameter and its suggested cut-off in the research group were evaluated with area under the curve (AUC).RESULTSRDW, RPR and RLR values turned out to be significantly higher in ALC and MAFLD groups compared to controls (ALC: P < 0.0001; NAFLD: P < 0.05, P < 0.0001 and P < 0.0001, respectively). RPR correlated positively with MELD score (P < 0.01) and indirect indices of liver fibrosis (FIB-4 and GPR; P < 0.0001) in ALC patients; negative correlations were found between PDGF-AB and both: RDW and RPR (P < 0.01 and P < 0.0001, respectively). RPR correlated positively with NAFLD fibrosis score and APRI (P < 0.0001) in the MAFLD group; a positive relationship was observed between RDW and FIB-4, too (P < 0.05). AUC values and suggested cut-offs for RDW, RPR and RLR in ALC patients were: 0.912 (> 14.2%), 0.965 (> 0.075) and 0.914 (> 8.684), respectively. AUC values and suggested cut-offs for RDW, RPR and RLR in MAFLD patients were: 0.606 (> 12.8%), 0.724 (> 0.047) and 0.691 (> 6.25), respectively.CONCLUSIONRDW with its derivatives appear to be valuable diagnostic markers in patients with ALC. They can also be associated with a deterioration of liver function in this group.

Comparison of epitheliotrophic factors in platelet-rich plasma versus autologous serum and their treatment efficacy in dry eye disease

Current treatment of severe dry eye disease (DED) includes blood-derived eye drops, such as autologous serum (AS), which lubricate the eyes and provide factors that improve ocular surface and aid in wound healing. Recent studies indicated that platelet-rich plasma (PRP) was also effective. This study aims to compare the concentration and stability of epitheliotrophic factors in AS and PRP and their efficacy in DED patients. Epitheliotrophic factors of interest are epidermal growth factor (EGF), fibronectin, platelet-derived growth factor-AB (PDGF-AB), and transforming growth factor-beta1 (TGF-β1). We determined that all epitheliotrophic factors were present in AS and PRP at baseline and did not decrease in concentrations in all storage conditions (4 °C for 1 week and at − 20 °C for 1 and 3 months). However, differences in concentrations in AS and PRP were observed. PRP was also shown not to be inferior to AS in terms of efficacy in DED treatment in a prospective randomized control trial which evaluated ocular surface disease index, dry eye questionnaire, ocular surface staining, tear breakup time, and Schirmer test at baseline and at 1-month follow-up. Therefore, with its shorter preparation time, PRP could be considered as an alternative to AS for the treatment of DED.

Preparation of a biomimetic bi-layer chitosan wound dressing composed of A-PRF/sponge layer and L-arginine/nanofiber

To better mimic the structure of skin tissue, the use of a multi-layered wound dressing has been proposed. In the present study, a sponge-nanofibrous bi-layer dressing is designed. For this purpose, a chitosan/polyethylene glycol (CsPEG) sponge with advanced platelet-rich fibrin (A-PRF) was prepared as the upper layer of wound dressing, and a Cs/L–arginine electrospun nanofiber layer as the bottom layer. After physical, chemical and mechanical evaluations, the release of platelet-derived growth factor-AB (PDGF-AB), vascular endothelial growth factor (VEGF) and L-arginine were investigated. The antibacterial activity, cell viability and attachment of Bi-layer1.5 dressing (CsPEG/1.5A-PRF sponge coated with Cs/0.5 L-arginine nanofibers) were significantly higher than other dressings. Also, Bi-layer1.5 dressing increased the angiogenic potential and accelerated the wound healing, compared to other samples. Given the promising obtained results, the use of Bi-layer1.5 wound dressing with the ability to release growth factors and L-arginine is highly recommended to treat full-thickness wounds.

Effects of advanced platelet-rich fibrin combined with xenogenic bone on human periodontal ligament stem cells.

ObjectivesIn this study, we aimed to investigate the effects of a mixture of advanced platelet‐rich fibrin (A‐PRF) and xenogenic bone substitute material (XBSM) on the proliferation and migration of human periodontal ligament stem cells (hPDLSCs) based on the in vitro release of growth factors.Material and MethodsThe concentrations of platelet‐derived growth factor‐AB (PDGF‐AB) and vascular endothelial growth factor (VEGF) released by the A‐PRF‐XBSM mixture were estimated using enzyme‐linked immunoassay for up to 7 d. The A‐PRF‐XBSM mixture exudate was incubated with hPDLSCs. At Days 1, 3, 5, and 7, cell proliferation and migration were investigated by cell counting and wound‐healing assays.ResultsPDGD‐AB and VEGF were released from the A‐PRF‐XBSM mixture exudate for up to 7 days. hPDLSCs were cultured in media with various concentrations of the A‐PRF‐XBSM mixture exudate and exhibited their proliferation and migration ability. Furthermore, the factors released from the 100% A‐PRF‐XBSM mixture exudate had a substantial effect on cell migration, whereas those released from 4% and 20% A‐PRF‐XBSM mixture exudates stimulated hPDLSC proliferation.ConclusionsA‐PRF‐XBSM mixture continuously released growth factors over 7 days and enhanced hPDLSC proliferation and migration. Therefore, A‐PRF in combination with XBSM might provide potential advantages for periodontal tissue regeneration.

Leukocyte-Rich Platelet-Rich Plasma Has Better Stimulating Effects on Tenocyte Proliferation Compared With Leukocyte-Poor Platelet-Rich Plasma.

Background:Rotator cuff (RC) tendinopathy is one of the most common causes of shoulder pain. Platelet-rich plasma (PRP) has been frequently used in clinical scenarios, but its efficacy remains inconsistent.Purpose:To investigate the different responses of human tenocytes from torn RCs to leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) in a 2-chamber coculture device.Study Design:Controlled laboratory study.Methods:PRP was prepared using different platelet and leukocyte concentrations according to 5 groups: (1) LR-PRP with 5000 platelets/µL, (2) LR-PRP with 10,000 platelets/µL, (3) LP-PRP with 5000 platelets/µL, (4) LP-PRP with 10,000 platelets/µL, and (5) control with only culture medium supplementation and without PRP stimulation. Platelet-derived growth factor–AB (PDGF-AB) and transforming growth factor–β1 (TGF-β1) were measured in LR-PRP and LP-PRP via enzyme-linked immunosorbent assay. Microscopy, water-soluble tetrazolium salt assay, and quantitative real-time polymerase chain reaction were used to investigate the morphology, proliferation, and gene expression of RC tenocytes exposed to different PRP formulations. Data were collected from at least 3 independent measurements. The results were analyzed via 1-way analysis of variance, followed by the post hoc Bonferroni test.Results:The ratio of leukocytes to 5000 platelets/µL was 29.5 times higher in LR-PRP than in LP-PRP (P < .05). In the 5000 platelets/µL groups, the levels of TGF-β1 and PDGF-AB were both significantly higher in LR-PRP versus LP-PRP (TGF-β1: 367.0 ± 16.5 vs 308.6 ± 30.3 pg/mL, respectively [P = .043]; PDGF-AB: 172.1 ± 1.8 vs 94.1 ± 4.2 pg/mL, respectively [P < .001]). Compared with the control group, RC tenocyte proliferation was 1.42 ± 0.01 and 1.41 ± 0.03 times higher in the LR-PRP groups with 5000 platelets/µL and 10,000 platelets/µL, respectively (P < .05). The expression of tenocyte-related genes was higher in tenocytes cultured in LR-PRP.Conclusion:Both the LR-PRP groups with 5000 platelets/µL and 10,000 platelets/µL induced more growth factor release and increased RC tenocyte proliferation than did the LP-PRP groups.Clinical Relevance:In RC repair, LR-PRP may be better than LP-PRP for increasing the proliferation of tenocytes.

Two Hits for Bone Regeneration in Aged Patients: Vertebral Bone Marrow Clot as a Biological Scaffold and Powerful Source of Mesenchymal Stem Cells.

Recently, the use of a new formulation of bone marrow aspirate (BMA), the BMA clot, has been described. This product entails a naturally formed clot from the harvested bone marrow, which retains all the BMA components preserved in a matrix biologically molded by the clot. Even though its beneficial effects were demonstrated by some studies, the impact of aging and aging-associated processes on biological properties and the effect of BMA cell-based therapy are currently unknown. The purpose of our study was to compare selected parameters and properties of clotted BMA and BMA-derived mesenchymal stem cells (MSCs) from younger (<45 years) and older (>65 years) female donors. Clotted BMA growth factors (GFs) expression, MSCs morphology and viability, doubling time, surface marker expression, clonogenic potential, three-lineage differentiation, senescence-associated factors, and Klotho synthesis from younger and older donors were analyzed. Results indicated that donor age does not affect tissue-specific BMA clot regenerative properties such as GFs expression and MSCs morphology, viability, doubling time, surface antigens expression, colony-forming units, osteogenic and adipogenic differentiation, and Klotho and senescence-associated gene expression. Only few differences, i.e., increased platelet-derived growth factor-AB (PDGF-AB) synthesis and MSCs Aggrecan (ACAN) expression, were detected in younger donors in comparison with older ones. However, these differences do not interfere with all the other BMA clot biological properties. These results demonstrated that BMA clot can be applied easily, without any sample processing and avoiding potential contamination risks as well as losing cell viability, proliferation, and differentiation ability, for autologous transplantation in aged patients. The vertebral BMA clot showed two successful hits since it works as a biological scaffold and as a powerful source of mesenchymal stem cells, thus representing a novel and advanced therapeutic alternative for the treatment of orthopedic injuries.

Platelet Derived Growth Factor-AB Accelerates Scar Maturity in a Porcine Model of Ischaemia/Reperfusion

We have previously shown that Platelet Derived Growth Factor-AB (PDGF-AB) improved cardiac function 28 days (D28) after myocardial infarction (MI) in a porcine ischaemia/reperfusion model. [1] We sought to assess the effects of PDGF-AB administration at an earlier timepoint at 11 days (D11) post MI.

Thrombopoietin and collagen in low doses cooperatively induce human platelet activation.

AimIn acute medicine, we occasionally treat life‐threatening conditions such as sepsis and trauma, which cause severe thrombocytopenia. Serum thrombopoietin levels have been reported to increase under the condition of thrombocytopenia related to severity. Collagen is a crucial activator of platelets, and Rho family members, such as Rho/Rho‐kinase and Rac, play roles as active molecules involved in the intracellular signaling pathways in platelet activation. The present study aimed to elucidate the effects of thrombopoietin (TPO) on subthreshold low‐dose collagen‐stimulated human platelets in terms of Rho/Rho‐kinase and Rac.MethodsPlatelet‐rich plasma donated from healthy volunteers was stimulated by the subthreshold low‐dose of collagen after pretreatment with TPO and/or NSC23766, an inhibitor of the Rac‐guanine nucleotide exchange factor interaction, or Y27632, an inhibitor of Rho‐kinase. Platelet aggregation was measured using an aggregometer based on laser‐scattering methods. Proteins involved in intracellular signaling were analyzed using western blotting, and the secretion of platelet‐derived growth factor‐AB from activated platelets was determined using an enzyme‐linked immunosorbent assay.ResultsUnder the existence of TPO, the low dose of collagen remarkably elicited the aggregation and platelet‐derived growth factor‐AB secretion of platelets, which were suppressed by NSC23766 and Y27632. The combination of TPO and collagen considerably induced a transient increase of guanosine triphosphate (GTP)‐binding Rac and GTP‐binding Rho followed by an increase of phosphorylated cofilin, a Rho‐kinase substrate.ConclusionThese results strongly suggest that TPO and collagen in low doses cooperatively potentiate human platelet activation through both Rac and Rho/Rho‐kinase mediated pathways.

Amyloid β protein negatively regulates human platelet activation induced by thrombin receptor-activating protein.

Amyloid β protein deposition in cerebral vessels, a characteristic of Alzheimer's disease, is a risk factor for intracerebral hemorrhage. Amyloid β protein directly modulates human platelet function; however, the exact mechanism of action is unclear. Therefore, we investigated the effects of amyloid β protein on human platelet activation using an aggregometer with laser scattering. Amyloid β protein decreased platelet aggregation induced by thrombin receptor-activating protein, but not by collagen and ADP. Amyloid β protein also suppressed platelet aggregation induced by SCP0237 and A3227. Platelet-derived growth factor-AB secretion and phosphorylated-heat shock protein 27 release by thrombin receptor-activating protein were inhibited by amyloid β protein. Additionally, thrombin receptor-activating protein-induced phosphorylation of JNK and p38 MAP kinase was reduced by amyloid β protein. Collectively, our results strongly suggest that amyloid β protein negatively regulates protease-activated receptor-elicited human platelet activation. These findings may indicate a cause of intracerebral hemorrhage due to amyloid β protein.

Potential role of intermittent fasting on decreasing cardiovascular disease in human immunodeficiency virus patients receiving antiretroviral therapy.

Cardiovascular disease (CVD) has become one of the commonest causes of comorbidity and mortality among People living with human immunodeficiency virus (HIV) (PLWH) on antiretroviral therapy (ART). Nearly 50% of PLWH are likely to have an increased risk of developing CVD, including coronary heart disease, cerebrovascular disease, peripheral artery disease and aortic atherosclerosis. Aside from the common risk factors, HIV infection itself and side effects of antiretroviral therapy contribute to the pathophysiology of this entity. Potential non-pharmacological therapies are currently being tested worldwide for this purpose, including eating patterns such as Intermittent fasting (IF). IF is a widespread practice gaining high level of interest in the scientific community due to its potential benefits such as improvement in serum lipids and lipoproteins, blood pressure (BP), platelet-derived growth factor AB, systemic inflammation, and carotid artery intima-media thickness among others cardiovascular benefits. This review will focus on exploring the potential role of intermittent fasting as a non-pharmacological and cost-effective strategy in decreasing the burden of cardiovascular diseases among HIV patients on ART due to its intrinsic properties improving the main cardiovascular risk factors and modulating inflammatory pathways related to endothelial dysfunction, lipid peroxidation and aging. Intermittent fasting regimens need to be tested in clinical trials as an important, cost-effective, and revolutionary coadjutant of ART in the fight against the increased prevalence of cardiovascular disease in PLWH.

Cell Attachment Capacity and Compounds of Fibrin Membranes Isolated from Fresh Frozen Plasma and Cryoprecipitate.

Fibrin membranes are widely used in regenerative medicine because they are biocompatible, biodegradable, contain growth factors, and support cell attachment. Most commonly they are produced from serum, but they can also be isolated from activated plasma. To increase the fibrinogen concentration of plasma, cryoprecipitate isolation is a possible solution. In this work, cryoprecipitate was prepared from fresh frozen plasma, isolated by plasmapheresis. The concentration of cellular elements, fibrinogen, total protein, and immunoglobulins among others was measured in different concentrations of cryoprecipitates. After activation with Ca-gluconate, fibrin membranes were produced in different thicknesses, and human mesenchymal stem cells were seeded onto the membranes. They were visualized by live-dead staining and their viability was determined by XTT. The platelet-derived growth factor AB content was quantified by ELISA. Our results showed that fibrinogen and platelet concentration can be multiplied in plasma by cryoprecipitate isolation, which affects the thickness and slightly the growth factor content of the membranes. According to live-dead staining, the thickness of the membranes does not influence cell attachment, and XTT measurement did not reveal a significant difference in cell attachment capacity either; however, a growing trend could be observed in the case of some membranes.

A platelet-derived hydrogel improves neovascularisation in full thickness wounds

Platelets are a reservoir of growth factors, cytokines and chemokines involved in spontaneous wound repair. In this study, a platelet-rich and fibrin-rich hydrogel was generated from expired platelet components that would have otherwise been transfused. The material contained physiological concentrations of transforming growth factor β1 (TGF-β1, platelet-derived growth factor AB (PDGF-AB), PDGF-BB, insulin-like growth factor-1 (IGF-1), fibroblast growth factor 2 (FGF-2), and epidermal growth factor (EGF). The effect of the hydrogel on wound repair was investigated in SKH-1 mice. Full thickness dorsal wounds were created on the mice and treated with the hydrogel at various concentrations. Immunohistochemical staining with CD31 (endothelial cell marker) revealed that wounds treated with the hydrogel showed significantly enhanced vascularisation in the wound bed. Moreover, high levels of interleukin-6 (IL-6) and KC (IL-8 functional homologue) in treated wounds were sustained over a longer period of time, compared to untreated wounds. We postulate that sustained IL-6 is a driver, at least partly, of enhanced vascularisation in full thickness wounds treated with the hydrogel. Future work is needed to explore whether this hydrogel can be utilised as a treatment option when vascularisation is a critical limitation. Statement of significanceThe economic cost of wound repair is estimated in billions of dollars each year. In many cases time required to vascularise wounds is a major contributor to slow wound repair. In this study, we developed a blood-derived platelet- and fibrin-rich hydrogel. It contains a number of growth factors actively involved in spontaneous wound healing. This hydrogel significantly improved dermal repair and vascularisation in a full-thickness wound mouse model. This study provides an action mechanism for modulation of localised inflammation.

Time-Dependent Cytokine-Release of Platelet-Rich Plasma in 3-Chamber Co-Culture Device and Conventional Culture Well

Platelet-rich plasma (PRP) contains bioactive cytokines to enhance tissue healing. The best PRP preparation protocol and timing of the treatment have not been determined yet. To screen the best-fit PRP, a 3-chamber co-culture device was developed. We hypothesized the concentrations of the cytokines from different PRPs in the co-culture plates had a high correlation with those in conventional 24-well culture plates at different time points. The concentrations of the cytokine from PRPs would be correlated with platelet concentrations. The correlation of transforming growth factor beta-1 (TGF-β1) and platelet-derived growth factor AB (PDGF-AB) in both devices were compared at 0, 24, 48, 72, and 96 h from two PRPs as well as that of platelet and cytokines concentrations. The results revealed that there was a moderate to high correlation in TGF-β1 concentrations between the 3-chamber co-culture and conventional culture device until 96 h. The correlation of PDGF-AB concentrations in both devices had moderate to high correlation in the first 24 h, and then it became modestly correlated from 48 to 96 h. A high correlation was found between platelet and TGF-β1 concentration at 96 h. However, they were modestly correlated in other time points. A negative or modest correlation was found between platelet and PDGF-AB concentration in all time points. In conclusion, TGF-β1 and PDGF-AB revealed a time-dependent manner of release at five time points. There is a moderate to high correlation of the TGF-β1 and PDGF-AB concentration in both devices at different time points. However, TGF-β1 and PDGF-AB concentrations are not always proportional to the platelet concentration of the PRPs.