A one-stop integrated natural antimicrobial microneedles with anti-inflammatory, pro-angiogenic and long-term moisturizing properties to accelerate diabetic wound healing.

Diabetic ulcers present a formidable obstacle in diabetes management, typically leading to high mortality and amputation rates. To overcome traditional monotherapy drawbacks, We developed a novel microneedle strategy for combined antimicrobial action: ingeniously integrating quercetin with Platelet-derived Growth Factor-BB(PDGF-BB) and Sucrose Octasulfate(SOS) into the microneedle system(QPS MN). This method allows to penetrate through biofilms, administering quercetin nanocrystals and PDGF-BB deep into the tissue to combat microbial infection, mitigate inflammation, and promote angiogenesis. The accompanying backing material contains SOS, which absorbs wound exudate and forms a dressing that provides a moist environment for wound healing In an in vitro wound-scratch assay demonstrated that co-cultivating Human Umbilical Vein Endothelial Cells(HUVEC) with QPS MN for 48 h (90.3 ± 2.51 %) significantly enhanced cell migration compared to the control group (20.2 ± 1.41 %). Moreover, treatment of streptozotocin-induced diabetic wounds in rats with QPS MN for 14 days resulted in a wound healing rate of 96.56 ± 3.44 %, far surpassing the healing rate of only 40.34 ± 7.26 % observed in the untreated control group. Furthermore, the QPS MN treated wounds exhibited a notable increase in skin appendages and neovascularisation, indicating promising potential for achieving complete wound healing. These results suggest that QPS MN may offer substantial therapeutic benefits for addressing diabetic wounds.

[Mechanism of salidroside in inhibiting proliferation, migration and promoting phenotypic switching of arterial smooth muscle cells].

This study aims to examine the effect of salidroside(SAL) on the phenotypic switching of human aortic smooth muscle cells(HASMC) induced by the platelet-derived growth factor-BB(PDGF-BB) and investigate the pharmacological mechanism. Firstly, the safe concentration of SAL was screened by the lactate dehydrogenase release assay. HASMC were divided into control, model, and SAL groups, and the cells in other groups except the control group were treated with PDGF-BB for the modeling of phenotypic switching. Cell proliferation and migration were detected by the cell-counting kit(CCK-8) assay and Transwell assay, respectively. The cytoskeletal structure was observed by F-actin staining with fluorescently labeled phalloidine. The protein levels of proliferating cell nuclear antigen(PCNA), migration-related protein matrix metalloprotein 9(MMP-9), fibronectin, α-smooth muscle actin(α-SMA), and osteopontin(OPN) were determined by Western blot. To further investigate the pharmacological mechanism of SAL, this study determined the expression of protein kinase B(Akt) and mammalian target of rapamycin(mTOR), as well as the upstream proteins phosphatase and tensin homologue(PTEN) and platelet-derived growth factor receptor ß(PDGFR-ß) and the downstream protein hypoxia-inducible factor-1α(HIF-1α) of the Akt/mTOR signaling pathway. The results showed that the HASMCs in the model group presented significantly increased proliferation and migration, the switching from a contractile phenotype to a secretory phenotype, and cytoskeletal disarrangement. Compared with the model group, SAL weakened the proliferation and migration of HASMC, promoted the expression of α-SMA(a contractile phenotype marker), inhibited the expression of OPN(a secretory phenotype marker), and repaired the cytoskeletal disarrangement. Furthermore, compared with the control group, the modeling up-regulated the levels of phosphorylated Akt and mTOR and the relative expression of PTEN, HIF-1α, and PDGFR-ß. Compared with the model group, SAL down-regulated the protein levels of phosphorylated Akt and mTOR, PTEN, PDGFR-ß, and HIF-1α. In conclusion, SAL exerts a protective effect on the HASMCs exposed to PDGF-BB by regulating the PDGFR-ß/Akt/mTOR/HIF-1α signaling pathway.

Comprehensive analysis of serum cytokines in patients with multiple myeloma before and after lenalidomide and dexamethasone.

Multiple myeloma (MM) is an incurable B-cell malignancy often accompanied by profound immunodeficiency. Lenalidomide (Len) is an immunomodulatory drug that exerts promising therapeutic effects on MM through the immune system. However, predictive markers related to the effects of Len treatment are not fully understood. This study aimed to identify candidate biomarkers for predicting the clinical efficacy of Len and dexamethasone (Ld) therapy through a comprehensive analysis of serum cytokines. The levels of 48 cytokines in the serum of patients with MM just before Ld therapy (n = 77), at the time of best response (n = 56), and at disease progression (n = 49) were measured and evaluated. Patients with high IL-18 and M-CSF levels showed significantly shorter progression-free survival and overall survival (OS). In contrast, patients with high PDGF-BB levels had longer survival. Moreover, low levels of G-CSF, IL-7, IL-8, and SDF-1α were associated with shorter OS after Ld therapy. During Ld therapy, pro-inflammatory cytokines such as IL-2Rα, IL-18, and TNF-α were decreased, while IFN-γ was increased. IL-4 and IL-6 levels increased during disease progression. In conclusion, this study provides a better understanding of the association between cytokines and the efficacy of Ld therapy as well as the unique changes in cytokines related to inflammatory and immune responses during Ld therapy.

Comparing machine learning screening approaches using clinical data and cytokine profiles for COVID-19 in resource-limited and resource-abundant settings.

Accurate screening of COVID-19 infection status for symptomatic patients is a critical public health task. Although molecular and antigen tests now exist for COVID-19, in resource-limited settings, screening tests are often not available. Furthermore, during the early stages of the pandemic tests were not available in any capacity. We utilized an automated machine learning (ML) approach to train and evaluate thousands of models on a clinical dataset consisting of commonly available clinical and laboratory data, along with cytokine profiles for patients (n = 150). These models were then further tested for generalizability on an out-of-sample secondary dataset (n = 120). We were able to develop a ML model for rapid and reliable screening of patients as COVID-19 positive or negative using three approaches: commonly available clinical and laboratory data, a cytokine profile, and a combination of the common data and cytokine profile. Of the tens of thousands of models automatically tested for the three approaches, all three approaches demonstrated > 92% sensitivity and > 88 specificity while our highest performing model achieved 95.6% sensitivity and 98.1% specificity. These models represent a potential effective deployable solution for COVID-19 status classification for symptomatic patients in resource-limited settings and provide proof-of-concept for rapid development of screening tools for novel emerging infectious diseases.

Cyclosporin A inhibits PDGF-BB induced hyaluronan synthesis in orbital fibroblasts.

Orbital connective tissue changes are contributors to the pathogenesis in thyroid eye disease (TED). Activated fibroblasts respond to immune stimuli with proliferation and increased hyaluronan (HA) production. Cyclosporin A (CsA) was reported to be beneficial in the treatment of TED. PDGF isoforms are increased in orbital tissue of TED patients and enhance HA production. We aimed to study the effect of CsA on HA production and hyaluronan synthase (HAS1, 2 and 3) and hyaluronidase (HYAL1 and 2) mRNA expressions in orbital fibroblasts (OFs). Measurements were performed in the presence or absence of CsA (10 µM) in unstimulated or PDGF-BB (10 ng/ml) stimulated OFs. The HA production of TED OFs (n = 7) and NON-TED OFs (n = 6) were measured by ELISA. The levels of mRNA expressions were examined using RT-PCR. The proliferation rate and metabolic activity were measured by BrdU incorporation and MTT assays, respectively. Treatment with CsA resulted in an average 42% decrease in HA production of OFs (p < 0.0001). CsA decreased the expression levels of HAS2, HAS3 and HYAL2 (p = 0.005, p = 0.005 and p = 0.002, respectively.) PDGF-BB increased HA production (p < 0.001) and HAS2 expression (p = 0.004). CsA could reduce the PDGF-BB-stimulated HA production (p < 0.001) and HAS2 expression (p = 0.005) below the untreated level. In addition, CsA treatment caused a decrease in proliferation potential (p = 0.002) and metabolic activity (p < 0.0001). These findings point to the fact that CsA affects HA metabolism via HAS2, HAS3 and HYAL2 inhibition in OFs. In addition to its well characterized immunosuppressant properties, CsA's beneficial effect in TED may be related to its direct inhibitory effect on basal and growth factor stimulated HA production.

Research progress in the pathogenesis of hormone-induced femoral head necrosis based on microvessels: a systematic review.

Hormonal necrosis of the femoral head is caused by long-term use of glucocorticoids and other causes of abnormal bone metabolism, lipid metabolism imbalance and blood microcirculation disorders in the femoral head, resulting in bone trabecular fracture, bone tissue necrosis collapse, and hip dysfunction. It is the most common type of non-traumatic necrosis of the femoral head, and its pathogenesis is complex, while impaired blood circulation is considered to be the key to its occurrence. There are a large number of microvessels in the femoral head, among which H-type vessels play a decisive role in the "angiogenesis and osteogenesis coupling", and thus have an important impact on the occurrence and development of femoral head necrosis. Glucocorticoids can cause blood flow injury of the femoral head mainly through coagulation dysfunction, endothelial dysfunction and impaired angiogenesis. Glucocorticoids may inhibit the formation of H-type vessels by reducing the expression of HIF-1α, PDGF-BB, VGEF and other factors, thus causing damage to the "angiogenesis-osteogenesis coupling" and reducing the ability of necrosis reconstruction and repair of the femoral head. Leads to the occurrence of hormonal femoral head necrosis. Therefore, this paper reviewed the progress in the study of the mechanism of hormone-induced femoral head necrosis based on microvascular blood flow at home and abroad, hoping to provide new ideas for the study of the mechanism of femoral head necrosis and provide references for clinical treatment of femoral head necrosis.

Induced pluripotent stem cell derived pericytes respond to mediators of proliferation and contractility.

BACKGROUND: Pericytes are multifunctional contractile cells that reside on capillaries. Pericytes are critical regulators of cerebral blood flow and blood-brain barrier function, and pericyte dysfunction may contribute to the pathophysiology of human neurological diseases including Alzheimers disease, multiple sclerosis, and stroke. Induced pluripotent stem cell (iPSC)-derived pericytes (iPericytes) are a promising tool for vascular research. However, it is unclear how iPericytes functionally compare to primary human brain vascular pericytes (HBVPs). METHODS: We differentiated iPSCs into iPericytes of either the mesoderm or neural crest lineage using established protocols. We compared iPericyte and HBVP morphologies, quantified gene expression by qPCR and bulk RNA sequencing, and visualised pericyte protein markers by immunocytochemistry. To determine whether the gene expression of neural crest iPericytes, mesoderm iPericytes or HBVPs correlated with their functional characteristics in vitro, we quantified EdU incorporation following exposure to the key pericyte mitogen, platelet derived growth factor (PDGF)-BB and, contraction and relaxation in response to the vasoconstrictor endothelin-1 or vasodilator adenosine, respectively. RESULTS: iPericytes were morphologically similar to HBVPs and expressed canonical pericyte markers. However, iPericytes had 1864 differentially expressed genes compared to HBVPs, while there were 797 genes differentially expressed between neural crest and mesoderm iPericytes. Consistent with the ability of HBVPs to respond to PDGF-BB signalling, PDGF-BB enhanced and a PDGF receptor-beta inhibitor impaired iPericyte proliferation. Administration of endothelin-1 led to iPericyte contraction and adenosine led to iPericyte relaxation, of a magnitude similar to the response evoked in HBVPs. We determined that neural crest iPericytes were less susceptible to PDGFR beta inhibition, but responded most robustly to vasoconstrictive mediators. CONCLUSIONS: iPericytes express pericyte-associated genes and proteins and, exhibit an appropriate physiological response upon exposure to a key endogenous mitogen or vasoactive mediators. Therefore, the generation of functional iPericytes would be suitable for use in future investigations exploring pericyte function or dysfunction in neurological diseases.

PDGF-BB accelerates TSCC via fibroblast lactates limiting miR-26a-5p and boosting mitophagy.

The tumor microenvironment and cancer-associated fibroblasts (CAFs) play crucial roles in tumor development, and their metabolic coupling remains unclear. Clinical data showed a positive correlation between PDGF-BB, CAFs, and glycolysis in the tumor microenvironment of oral tongue squamous cell carcinoma patients. In vitro, CAFs are derived from hOMF cells treated with PDGF-BB, which induces their formation and promotes aerobic glycolysis. Mitophagy increased the PDGF-BB-induced formation of CAF phenotypes and aerobic glycolysis, while autophagy inhibition blocked PDGF-BB-induced effects. Downregulation of miR-26a-5p was observed in CAFs; upregulation of miR-26a-5p inhibited the expression of mitophagy-related proteins ULKI, Parkin, PINK1, and LC3 and aerobic glycolysis in PDGF-BB-induced CAFs. PDGF-BB-induced CAFs promoted tumor cell proliferation, invasion, metastasis, NF-κB signaling pathway activation, and PDGF-BB secretion. Thus, PDGF-BB is associated with lactate-induced CAF formation and glucose metabolism reprogramming. These findings indicate potential therapeutic targets in oral tongue squamous cell carcinoma.

Ultrasound-targeted microbubble destruction promotes PDGF-primed bone mesenchymal stem cell transplantation for myocardial protection in acute Myocardial Infarction in rats.

BACKGROUND: Ultrasound-targeted microbubble destruction (UTMD) has emerged as a promising strategy for the targeted delivery of bone marrow mesenchymal stem cells (MSCs) to the ischemic myocardium. However, the limited migration capacity and poor survival of MSCs remains a major therapeutic barrier. The present study was performed to investigate the synergistic effect of UTMD with platelet-derived growth factor BB (PDGF-BB) on the homing of MSCs for acute myocardial infarction (AMI). METHODS: MSCs from male donor rats were treated with PDGF-BB, and a novel microbubble formulation was prepared using a thin-film hydration method. In vivo, MSCs with or without PDGF-BB pretreatment were transplanted by UTMD after inducing AMI in experimental rats. The therapeutic efficacy of PDGF-BB-primed MSCs on myocardial apoptosis, angiogenesis, cardiac function and scar repair was estimated. The effects and molecular mechanisms of PDGF-BB on MSC migration and survival were explored in vitro. RESULTS: The results showed that the biological effects of UTMD increased the local levels of stromal-derived factor-1 (SDF-1), which promoted the migration of transplanted MSCs to the ischemic region. Compared with UTMD alone, UTMD combined with PDGF-BB pretreatment significantly increased the cardiac homing of MSCs, which subsequently reduced myocardial apoptosis, promoted neovascularization and tissue repair, and increased cardiac function 30 days after MI. The vitro results demonstrated that PDGF-BB enhanced MSC migration and protected these cells from H2O2-induced apoptosis. Mechanistically, PDGF-BB pretreatment promoted MSC migration and inhibited H2O2-induced MSC apoptosis via activation of the phosphatidylinositol 3-kinase/serine-threonine kinase (PI3K/Akt) pathway. Furthermore, crosstalk between PDGF-BB and stromal-derived factor-1/chemokine receptor 4 (SDF-1/CXCR4) is involved in the PI3K/AKT signaling pathway. CONCLUSION: The present study demonstrated that UTMD combined with PDGF-BB treatment could enhance the homing ability of MSCs, thus alleviating AMI in rats. Therefore, UTMD combined with PDGF-BB pretreatment may offer exciting therapeutic opportunities for strengthening MSC therapy in ischemic diseases.

Type H vessels: functions in bone development and diseases.

Type H vessels are specialized blood vessels found in the bone marrow that are closely associated with osteogenic activity. They are characterized by high expression of endomucin and CD31. Type H vessels form in the cancellous bone area during long bone development to provide adequate nutritional support for cells near the growth plate. They also influence the proliferation and differentiation of osteoprogenitors and osteoclasts in a paracrine manner, thereby creating a suitable microenvironment to facilitate new bone formation. Because of the close relationship between type H vessels and osteogenic activity, it has been found that type H vessels play a role in the physiological and pathological processes of bone diseases such as fracture healing, osteoporosis, osteoarthritis, osteonecrosis, and tumor bone metastasis. Moreover, experimental treatments targeting type H vessels can improve the outcomes of these diseases. Here, we reviewed the molecular mechanisms related to type H vessels and their associated osteogenic activities, which are helpful in further understanding the role of type H vessels in bone metabolism and will provide a theoretical basis and ideas for comprehending bone diseases from the vascular perspective.

Preoperative Serum Levels of PDGF-AB, PDGF-BB, TGF-α, EGF and ANG-2 in the Diagnosis of Endometrial Cancer.

(1) Background: It is relevant to find new diagnostic biomarkers for endometrial cancer. This study aimed to investigate whether PDGF-AB, PDGF-BB, TGF-α, EGF and ANG-2 could be considered new useful markers for diagnosis and survival of endometrial cancer. (2) Methods: A total of 93 women diagnosed with endometrial cancer (EC) and 66 patients with non-cancerous endometrial lesions (NCEL) were included in this study. (3) Results: Median serum levels of PDGF-AB, PDGF-BB, TGF-α, EGF and ANG-2 were significantly higher in the EC group compared to the NCEL group (for PDGF-AB, PDGF-BB, TGF-α and ANG-2, p = 0.0000; for EGF, p = 0.0186). The cut-off level of PDGF-AB was set at 127.69 pg/mL with a sensitivity of 87.1% and a specificity of 66.67% (AUC = 0.78, p < 0.000001). The cut-off level of PDGF-BB was set at 207.86 ng/L with a sensitivity of 82.8% and a specificity of 75.76% (AUC = 0.85, p < 0.000001). The cut-off level of TGF-α was set at 33.85 ng/L with a sensitivity of 82.8% and a specificity of 75.76% (AUC = 0.82, p < 0.000001). The cut-off level of EGF was set at 934.76 pg/mL with a sensitivity of 83.87% and a specificity of 28.79% (AUC = 0.61, p = 0.018472). The cut-off level of ANG-2 was set at 3120.68 pg/mL with a sensitivity of 72.04% and a specificity of 93.94% (AUC = 0.87, p < 0.000001). (4) Conlusion: It was concluded that all the proteins studied could be potential diagnostic markers in endometrial cancer.

MiR-3529-3p from PDGF-BB-induced cancer-associated fibroblast-derived exosomes promotes the malignancy of oral squamous cell carcinoma.

AIMS: This study aims to explore the role of exosomes from cancer-associated fibroblasts (CAFs) induced by PDGF-BB in promoting the malignancy of oral squamous cell carcinoma (OSCC) and provide new insight into the mechanism of OSCC progression and its treatment. MAIN METHODS: Exosomes were extracted from human oral mucosa fibroblasts (hOMFs) and CAFs. Differentially expressed miRNAs of exosomes between hOMFs and CAFs were analysed using high-throughput sequencing and self-programmed R software. Cal-27, a human tongue squamous carcinoma cell line, was treated with exosomes. Differentially expressed miRNAs between clinical cancer tissues and adjacent tissues and between hOMF and CAF exosomes were verified by qRT‒PCR. The effect of miR-3529-3p on Cal-27 cells was clarified by overexpressing or knocking down miR-3529-3p in Cal-27 cells. Sample expression and differentially expressed miRNA expression were compared between cancer and paracarcinoma tissues. KEY FINDINGS: We found that exosomes from CAFs (CAF-Exos) were internalized by tongue squamous carcinoma cells and promoted their proliferation, migration, invasion, and antiapoptotic effects. MiR-3529-3p was a significant differentially expressed miRNA between CAF-Exos and exosomes from hOMFs (hOMF-Exos). The overexpression of miR-3529-3p promoted proliferation, migration, and invasion and inhibited apoptosis of Cal-27 cells. SIGNIFICANCE: This study explores the role of PDGF-BB-induced CAFs in promoting malignancy in OSCC. This study will provide new insight into the mechanism of OSCC progression and its treatment.

Isolation and Cultivation of Vascular Smooth Muscle Cells from the Mouse Circle of Willis.

INTRODUCTION: Culturing cerebrovascular smooth muscle cells (CVSMCs) in vitro can provide a model for studying many cerebrovascular diseases. This study describes a convenient and efficient method to obtain mouse CVSMCs by enzyme digestion. METHODS: Mouse circle of Willis was isolated, digested, and cultured with platelet-derived growth factor-BB (PDGF-BB) to promote CVSMC growth, and CVSMCs were identified by morphology, immunofluorescence analysis, and flow cytometry. The effect of PDGF-BB on vascular smooth muscle cell (VSMC) proliferation was evaluated by cell counting kit (CCK)-8 assay, morphological observations, Western blotting, and flow cytometry. RESULTS: CVSMCs cultured in a PDGF-BB-free culture medium had a typical peak-to-valley growth pattern after approximately 14 days. Immunofluorescence staining and flow cytometry detected strong positive expression of the cell type-specific markers alpha-smooth muscle actin (α-SMA), smooth muscle myosin heavy chain 11 (SMMHC), smooth muscle protein 22 (SM22), calponin, and desmin. In the CCK-8 assay and Western blotting, cells incubated with PDGF-BB had significantly enhanced proliferation compared to those without PDGF-BB. CONCLUSION: We obtained highly purified VSMCs from the mouse circle of Willis using simple methods, providing experimental materials for studying the pathogenesis and treatment of neurovascular diseases in vitro. Moreover, the experimental efficiency improved with PDGF-BB, shortening the cell cultivation period.

Prognostic Values of Tissue and Serum Angiogenic Growth Factors Depend on the Phenotypic Subtypes of Colorectal Cancer.

We classified colorectal cancer (CRC) patients into four phenotypic subgroups and investigated the prognostic value of angiogenic growth factors across subgroups. Preoperative serum concentrations and tissue expressions of VEGF, bFGF, and PDGF-bb were determined among 322 CRC patients. We classified patients into phenotypic subgroups (immune, canonical, metabolic, and mesenchymal) according to a method described in our earlier work. Among the metabolic subgroup, patients with high serum concentrations of VEGF, bFGF, or PDGF-bb exhibited a significantly improved prognosis. Moreover, those with high VEGF tissue expressions exhibited a significantly improved prognosis among patients in the metabolic subgroup. Among immune patients, a high VEGF serum expression is associated with a worse prognosis. A high serum bFGF concentration is associated with a favorable prognostic factor among patients with a canonical tumor phenotype. A high PDGF-bb tissue expression is associated with non-metastasized disease and with the immune, canonical, and metabolic subtypes. To our knowledge, this is the first study to show that the prognostic value of angiogenic growth factors differs between phenotypic subtypes.

Platelet-Derived Growth Factor-BB Priming Enhances Vasculogenic Capacity of Bone Marrow-Derived Endothelial Precursor Like Cells.

BACKGROUND: Human endothelial progenitor cells (EPCs) were first identified in the peripheral blood and later in the cord blood and bone marrow (BM) with different vascularization capacity and different surface marker profiles. However, their identity and functional roles in neovascularization have not been clearly demonstrated in vivo and in vitro. METHODS: Characterization of BM-EPC like cells were performed by fluorescence-activated cell sorting, immunofluorescence staining, enzyme-linked immunosorbent assay, Matrigel tube formation assay, and western blot analysis. RESULTS: BM-EPC like cells were identified by selective adhesion to fibronectin and collagen from BM mononuclear cells, which generate fast-growing colonies with spindle morphology, express surface markers of CD105, vWF, UEA-I lectin binding, secrete HGF, VEGF, TGF-beta1 but can be distinguished from circulating EPC and endothelial cells by no expression of surface markers such as CD31, CD309, CD45, and CD34. These BM-EPC like cells shared many cell surface markers of BM-mesenchymal stem cells (MSC) but also can be distinguished by their vasculogenic property and other unique surface markers. Furthermore, the vasculogenic capacity of BM-EPC like cells were enhanced by co-culture of BM-MSC or PDGF-BB priming. PDGF-BB stimulated cell migration, proliferation, and secretion of laminin ß-1, which was proposed as one of the mechanisms involved in the better vascularization of BM-EPC like cells. CONCLUSION: PDGF-BB priming may be applied to improve the potency and function of BM-EPC like cells as vasculogenic cell therapy for the ischemic vascular repair.

Melatonin Inhibits VEGF-Induced Endothelial Progenitor Cell Angiogenesis in Neovascular Age-Related Macular Degeneration.

Neovascular age-related macular degeneration (AMD) is described as abnormal angiogenesis in the retina and the leaking of fluid and blood that generates a huge, dark, blind spot in the center of the visual field, causing severe vision loss in over 90% of patients. Bone marrow-derived endothelial progenitor cells (EPCs) contribute to pathologic angiogenesis. Gene expression profiles downloaded from the eyeIntegration v1.0 database for healthy retinas and retinas from patients with neovascular AMD identified significantly higher levels of EPC-specific markers (CD34, CD133) and blood vessel markers (CD31, VEGF) in the neovascular AMD retinas compared with healthy retinas. Melatonin is a hormone that is mainly secreted by the pineal gland, and is also produced in the retina. Whether melatonin affects vascular endothelial growth factor (VEGF)-induced EPC angiogenesis in neovascular AMD is unknown. Our study revealed that melatonin inhibits VEGF-induced stimulation of EPC migration and tube formation. By directly binding with the VEGFR2 extracellular domain, melatonin significantly and dose-dependently inhibited VEGF-induced PDGF-BB expression and angiogenesis in EPCs via c-Src and FAK, NF-κB and AP-1 signaling. The corneal alkali burn model demonstrated that melatonin markedly inhibited EPC angiogenesis and neovascular AMD. Melatonin appears promising for reducing EPC angiogenesis in neovascular AMD.

Rat bone marrow mesenchymal stem cells induced by rrPDGF-BB promotes bone regeneration during distraction osteogenesis.

Background: In the clinical treatment of large bone defects, distraction osteogenesis can be used. However, some patients may suffer from poor bone regeneration, or even delayed healing or non-union. Problems with the aggregation and proliferation of primary osteoblasts, or problems with the differentiation of primary osteoblasts will lead to poor bone regeneration. Therefore, supplementing exogenous primary osteoblasts and growth factors when using distraction osteogenesis may be a treatment plan with great potential. Methods: Bone marrow mesenchymal stem cells (BMSCs) were extracted from rats and cultured. Subsequently, Recombinant Rat Platelet-derived Growth Factor BB (rrPDGF-BB) was used to induce bone marrow mesenchymal stem cells. At the same time, male adult rats were selected to make the right femoral distraction osteogenesis model. During the mineralization period, phosphate buffer salt solution (control group), non-induction bone marrow mesenchymal stem cells (group 1) and recombinant rat platelet-derived growth factor BB intervened bone marrow mesenchymal stem cells (group 2) were injected into the distraction areas of each group. Then, the experimental results were evaluated with imaging and histology. Statistical analysis of the data showed that the difference was statistically significant if p < 0.05. Results: After intervention with recombinant rat platelet-derived growth factor BB on bone marrow mesenchymal stem cells, the cell morphology changed into a thin strip. After the cells were injected in the mineralization period, the samples showed that the callus in group 2 had greater hardness and the color close to the normal bone tissue; X-ray examination showed that there were more new callus in the distraction space of group 2; Micro-CT examination showed that there were more new bone tissues in group 2; Micro-CT data at week eight showed that the tissue volume, bone volume, percent bone volume, bone trabecular thickness, bone trabecular number and bone mineral density in group 2 were the largest, and the bone trabecular separation in group 2 was the smallest. There was a statistical difference between the groups (p < 0.05); HE staining confirmed that group 2 formed more blood vessels and chondrocytes earlier than the control group. At 8 weeks, the bone marrow cavity of group 2 was obvious, and some of them had been fused. Conclusion: The study confirmed that injecting bone marrow mesenchymal stem cellsBB into the distraction space of rats can promote the formation of new bone in the distraction area and promote the healing of distraction osteogenesis.

Evaluation of Platelet-Rich Plasma by means of PRGF®-Endoret® protocol in leukemia cats: PDGF-BB and TGF-ß1 valuation.

Introduction: Feline leukemia virus (FeLV) is a chronic disease that leads to the weakening of a cat's immune system. Platelet-rich plasma (PRP) offers therapeutic effects for multiple diseases, the use of PRP and growth factors (GFs) determination could be an alternative treatment to improve the quality of life in these patients. The objectives of this study were to determine and compare the concentration of platelets (PLTs), red blood cells (RBCs) and white blood cells (WBCs) between samples of whole blood (WB), PRP and platelet-poor plasma (PPP) fractions, and to evaluate the concentration of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor ß1 (TGF-ß1) in both fractions in FeLV cats using a PRGF®-Endoret® protocol previously standardized in this species. Methods: WB was collected from 11 asymptomatic FeLV-positive cats. PRP and PPP was obtained following PRGF®-Endoret® technology according to centrifugation at 265 g for 10 min. Cellular components, RBCs, WBCs, PLTs, and the PDGF-BB and TGF-ß1 concentrations in PRP and PPP fractions were determined. Results: PLT in the PRP fraction was statistically higher than WB and PPP fraction, with no statistical differences between WB and PPP. PLT concentration increased 1.4 times in PRP fraction compared to WB. Mean platelet volume (MPV) did not differ significantly between the WB, PRP, and PPP fractions. Compared to WB, the absolute numbers of RBCs and WBCs were decreased by 99% and more than 95% in the PRP and PPP fractions, respectively. TGF-ß1 concentrations increased in PRP vs. PPP, with no changes in PDGF-BB. Discussion: Based on the degree of PLT enrichment and the absence of RBCs and WBCs, this blood product could be classified as a Pure Platelet-Rich Plasma (P-PRP). The presence of GFs in PRP and PPP samples suggests that the PRGF®-Endoret® methodology is suitable for obtaining PRP in FeLV cats, despite future studies are necessary to optimize the technique, standardize the results and assess clinical efficacy.

The role of tribbles homolog 2 in vascular smooth muscle cell proliferation.

Tribbles homolog 2 (TRIB2) functions as an adapter protein that regulates signal transductions involved in a variety of cellular functions, including tumorigenesis. However, the role of TRIB2 in the proliferation of vascular smooth muscle cells (VSMCs) and the underlying expression mechanisms remain unclear. The present study investigated the role of TRIB2 in VSMC proliferation and revealed that TRIB2 expression increases following vascular injury and platelet-derived growth factor (PDGF)-BB-stimulated VSMCs. We found that pretreatment with diphenyleneiodonium (a nicotinamide adenine dinucleotide phosphate oxidase inhibitor), U0126 (an inhibitor of mitogen-activated protein kinase kinase 1 [MEK1]), or siRNA targeting the gene encoding early growth response 1 (EGR-1) significantly inhibits PDGF-BB-induced TRIB2 expression in VSMCs. Furthermore, TRIB2 knockdown significantly inhibits PDGF-BB-induced proliferation of VSMCs but does not affect the phosphorylation of AKT. However, phosphorylation of ERK1 and expression of proliferating cell nuclear antibody are significantly suppressed in VSMCs by PDGF-BB stimulation. Thus, PDGF-BB-induced TRIB2 expression is mediated by ROS/ERK/EGR-1 pathways and plays a critical role in VSMC proliferation via modulation of ERK activity. We propose TRIB2 as a promising therapeutic target for the prevention of neointima formation and vascular disease.

PDGF-BB prevents destructive repair and promotes reparative osteogenesis of steroid-associated osteonecrosis of the femoral head in rabbits.

Destructive repair characterized by inadequate angiogenesis and osteogenesis is the main pathological progression in steroid-associated osteonecrosis of the femoral head (SONFH). Platelet-derived growth factor-BB (PDGF-BB) is an "angiogenesis and osteogenesis coupling" factor that has been used for the treatment of bone defects in clinic. This study was designed to analyze the ability of PDGF-BB for preventing destructive repair and promoting reparative osteogenesis in SONFH. Steroid-associated osteonecrosis (SAON) was induced and triggered destructive repair of the femoral head by repeated lipopolysaccharide (LPS) and methylprednisolone (MPS) injections in rabbits. At 2, 4, and 6 weeks after induction, recombinant human PDGF-BB, neutralizing PDGF-BB antibody, or saline was intramedullary injected into the proximal femora. At week 6 after SAON induction, the proximal femora were dissected for bone architecture and histological analysis. C3H10T1/2 cells and HUVECs were used for further mechanistic investigation. After PDGF-BB treatment, type H vessels and leptin receptor-positive (LepR+) mesenchymal stem cells (MSCs) increased in the affected femoral head, and more osteoblastic osteogenesis along the bone surfaces but scattered adipocytes in bone marrow tissue than that in the SAON group. PDGF-BB treatment prevented destructive repair progression and led to 50-70 % of osteonecrotic femoral heads undergoing reparative osteogenesis. In particular, we found that PDGF-BB could mediate MSC self-renewal and maintain their osteogenic potency by activating PDGFR/Akt/GSK3ß/CERB signaling in the presence of steroids. Moreover, PDGF-BB also stabled the newly formed vascular tubes by recruiting MSCs for improving intraosseous vascular integration. PDGF-BB may be a candidate for the promotion of reparative osteogenesis in SONFH.