Macrophage-derived PDGF-BB modulates glycolytic enzymes expression and pyroptosis in nucleus pulposus cells via PDGFR-ß/TXNIP pathway.

OBJECTIVE: Intervertebral Disc Degeneration (IVDD) is one of the leading causes of low back pain, significantly impacting both individuals and society. This study aimed to investigate the significance of macrophage infiltration and the role of macrophage-secreted platelet-derived growth factor-BB (PDGF-BB) in IVDD progression. METHODS: To confirm the protective function of macrophage-derived PDGF-BB on nucleus pulposus cells (NPCs), we employed Lysm-Cre transgenic mice to genetically ablate PDGF-B within the myeloid cells. Immunohistochemistry was utilized to detect the expression of glycolytic enzymes and pyroptosis-related proteins during the process of IVDD. Western blot, RT-PCR, ELISA and immunofluorescence were used to detect the protective effect of recombinant PDGF-BB on NPCs. RESULTS: Macrophage-derived PDGF-BB deficiency resulted in the loss of NPCs and the increased ossification of cartilage endplates during lumbar disc degeneration. Also, PDGF-BB deficiency triggered the inhibition of glycolytic enzymes' expression and the activation of pathways related to pyroptosis in the nucleus pulposus. Mechanistically, our results suggest that PDGF-BB predominantly conveys its protective influence on NPCs through the PDGF receptor- beta (PDGFR-ß)/ thioredoxin-interacting protein pathway. CONCLUSIONS: The absence of PDGF-BB originating from macrophages expedites the advancement of IVDD, whereas the application of PDGF-BB treatment holds the potential for retarding intervertebral disc degeneration in the human body.

Bone-derived PDGF-BB enhances hippocampal non-specific transcytosis through microglia-endothelial crosstalk in HFD-induced metabolic syndrome.

BACKGROUND: It is well known that high-fat diet (HFD)-induced metabolic syndrome plays a crucial role in cognitive decline and brain-blood barrier (BBB) breakdown. However, whether the bone-brain axis participates in this pathological process remains unknown. Here, we report that platelet-derived growth factor-BB (PDGF-BB) secretion by preosteoclasts in the bone accelerates neuroinflammation. The expression of alkaline phosphatase (ALPL), a nonspecific transcytosis marker, was upregulated during HFD challenge. MAIN BODY: Preosteoclast-specific Pdgfb transgenic mice with high PDGF-BB concentrations in the circulation recapitulated the HFD-induced neuroinflammation and transcytosis shift. Preosteoclast-specific Pdgfb knockout mice were partially rescued from hippocampal neuroinflammation and transcytosis shifts in HFD-challenged mice. HFD-induced PDGF-BB elevation aggravated microglia-associated neuroinflammation and interleukin-1ß (IL-1ß) secretion, which increased ALPL expression and transcytosis shift through enhancing protein 1 (SP1) translocation in endothelial cells. CONCLUSION: Our findings confirm the role of bone-secreted PDGF-BB in neuroinflammation and the transcytosis shift in the hippocampal region during HFD challenge and identify a novel mechanism of microglia-endothelial crosstalk in HFD-induced metabolic syndrome.

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.

Predominant control of PDGF/PDGF receptor signaling in the migration and proliferation of human adipose­derived stem cells under culture conditions with a combination of growth factors.

Human adipose-derived stem cells (hASCs) play important roles in regenerative medicine and tissue engineering. However, their clinical applications are limited because of their instability during cell culture. Platelet lysates (PLTs) contain large amounts of growth factors that are useful for manufacturing cellular products. Platelet-derived growth factor (PDGF) is a major growth factor in PLTs and a potent mitogen in hASCs. To optimize growth conditions, the effects of a combination of growth factors on the promotion of hASC proliferation were investigated. Moreover, PDGF-BB combined with vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) markedly enhanced the viability of hASCs compared with the effects of PDGF-BB alone. Neither VEGF nor HGF had any effect alone. All growth factor receptor inhibitors inhibited cell proliferation. Wound healing assays revealed that VEGF and HGF stimulated PDGF-dependent cell migration. The effects of these growth factors on the activation of their cognate receptors and signaling enzymes were assessed using immunoblotting. Phosphorylation of PDGF receptor (PDGFR)ß, VEGF receptor (VEGFR)2 and MET proto-oncogene and receptor tyrosine kinase was induced by PDGF-BB treatment, and was further increased by treatment with PDGF-BB/VEGF and PDGF-BB/HGF. The levels of phospho-ERK1/2 and phospho-p38MAPK were increased by these treatments in parallel. Furthermore, the expression levels of SRY-box transcription factor 2 and peroxisome proliferator-activated receptor g were increased in PDGF-BB-treated cells, and PDGF-BB played a dominant role in spheroid formation. The findings of the present study highlighted that PDGF/PDGFR signaling played a predominant role in the proliferation and migration of hASCs, and suggested that PDGF was responsible for the efficacy of other growth factors when hASCs were cultured with PLTs.

Evaluation of platelet derived growth factor-BB levels in injectable platelet rich fibrin coated graft using gingival pedicle split thickness tunnel technique for isolated gingival recession: A randomized controlled trial.

Background: Use of injectable-platelet rich fibrin (i-PRF) in the field of periodontal regeneration is quite well known due to its efficacy. The study was aimed to evaluate the platelet derived growth factor-BB (PDGF-BB) levels in cases of isolated gingival recession using gingival pedicle split thickness tunnel technique (GPST) and de-epithelialized gingival graft (DGG) with or without coating it with i-PRF. Methodology: 20 patients exhibiting Miller's class I/II isolated gingival recession were selected for this parallel arm randomized controlled trial. Recipient site was prepared using GPST technique, free gingival graft was harvested and de-epithelialized, further graft was coated with i-PRF and wound fluid samples from surgical site were collected at baseline, 3rd day and 7th day for group A. The same procedure without coating the graft in i-PRF was carried out for group B. Clinical parameters like probing depth, recession depth, recession width, width of keratinized gingiva, wound healing index (WHI), complete root coverage was recorded at baseline and after 4 months. Results: Significant intergroup difference was seen in WHI and the levels of PDGF-BB from baseline to the last estimated time point (p < 0.05). Conclusion: The study emphasizes on the use of novel GPST technique in conjunction with DGG coated with liquid PRF, which has shown sustained release of PDGF-BB resulting in better wound healing.

Comprehensive analyses of m6A RNA methylation patterns and related immune microenvironment in idiopathic pulmonary arterial hypertension.

Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening disease with a poor prognosis and high heritability, characterized by elevated pulmonary vascular resistance (PVR) and pulmonary artery pressure. N6-methyladenosine (m6A) RNA modification influences many RNA metabolism pathways. However, the position of m6A methylation regulators in IPAH remains unknown. Therefore, the study aims to disclose the function m6A regulators exert in the pathological mechanisms of IPAH and the immune microenvironment involved. The GSE117261 dataset was downloaded from the Gene Expression Omnibus (GEO) to screen the differentially expressed genes (DEGs) between normal and IPAH samples. Functional and pathway enrichment analyses of DEGs were then conducted by Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG). We also identified the differentially-expressed m6A (DEm6A) regulators between normal and IPAH samples. Key m6A regulators related to the prediction of IPAH were selected using the random forest model. The results showed that FMR1, RBM15, HNRNPA2B1 and IGFBP3 were upregulated in IPAH. In contrast, LRPPRC was downregulated. The single sample gene set enrichment analysis (ssGSEA) method was then adopted to estimate the immune microenvironment in distinct m6A clusters and m6A phenotype-related genes (PRGs) clusters, respectively. Furthermore, we calculated the m6A score via principal component analysis (PCA), and the Sankey diagram was selected to present the correlation among the m6A clusters, m6A PRGs clusters and m6A score. Finally, quantitative RT-PCR and Western blotting were used to validate the key genes in human pulmonary artery smooth muscle cells (HPASMCs) treated by human platelet-derived growth factor-BB (PDGF-BB). The relative mRNA and protein expression levels of FMR1 were significantly elevated, however, the relative mRNA and protein expression levels of LRPPRC were downregulated. Besides, the relative mRNA level of HNRNPA2B1 was increased. Generally, this bioinformatics analysis might provoke more insights into diagnosing and treating IPAH.

[Role and mechanism of platelet-derived growth factor BB in thrombocytosis in Kawasaki disease]. / è¡€å°æ¿è¡ç”Ÿç”Ÿé•¿å› å­BBåœ¨å·å´Žç— è¡€å°æ¿å¢žå¤šä¸­çš„ä½œç”¨åŠæœºåˆ¶ç ”ç©¶.

OBJECTIVES: To study the role and mechanism of platelet-derived growth factor BB (PDGF-BB) on platelet production in Kawasaki disease (KD) mice and human megakaryocytic Dami cells through in vitro and invivo experiments. METHODS: ELISA was used to measure the expression of PDGF in the serum of 40 children with KD and 40 healthy children. C57BL/6 mice were used to establish a model of KD and were then randomly divided into a normal group, a KD group, and an imatinib group (30 mice in each group). Routine blood test was performed for each group, and the expression of PDGF-BB, megakaryocyte colony forming unit (CFU-MK), and the megakaryocyte marker CD41 were measured. CCK-8, flow cytometry, quantitative real-time PCR, and Western blot were used to analyze the role and mechanism of PDGF-BB in platelet production in Dami cells. RESULTS: PDGF-BB was highly expressed in the serum of KD children (P<0.001). The KD group had a higher expression level of PDGF-BB in serum (P<0.05) and significant increases in the expression of CFU-MK and CD41 (P<0.001), and the imatinib group had significant reductions in the expression of CFU-MK and CD41 (P<0.001). In vitro experiments showed that PDGF-BB promoted Dami cell proliferation, platelet production, mRNA expression of PDGFR-ß, and protein expression of p-Akt (P<0.05). Compared with the PDGF-BB group, the combination group (PDGF-BB 25 ng/mL + imatinib 20 µmol/L) had significantly lower levels of platelet production, mRNA expression of PDGFR-ß, and protein expression of p-Akt (P<0.05). CONCLUSIONS: PDGF-BB may promote megakaryocyte proliferation, differentiation, and platelet production by binding to PDGFR-ß and activating the PI3K/Akt pathway, and the PDGFR-ß inhibitor imatinib can reduce platelet production, which provides a new strategy for the treatment of thrombocytosis in KD.

Syndecan-4 proteoliposomes enhance revascularization in a rabbit hind limb ischemia model of peripheral ischemia.

Regenerative therapeutics for treating peripheral arterial disease are an appealing strategy for creating more durable solutions for limb ischemia. In this work, we performed preclinical testing of an injectable formulation of syndecan-4 proteoliposomes combined with growth factors as treatment for peripheral ischemia delivered in an alginate hydrogel. We tested this therapy in an advanced model of hindlimb ischemia in rabbits with diabetes and hyperlipidemia. Our studies demonstrate enhancement in vascularity and new blood vessel growth with treatment with syndecan-4 proteoliposomes in combination with FGF-2 or FGF-2/PDGF-BB. The effects of the treatments were particularly effective in enhancing vascularity in the lower limb with a 2-4 increase in blood vessels in the treatment group in comparison to the control group. In addition, we demonstrate that the syndecan-4 proteoliposomes have stability for at least 28 days when stored at 4°C to allow transport and use in the hospital environment. In addition, we performed toxicity studies in the mice and found no toxic effects even when injected at high concentration. Overall, our studies support that syndecan-4 proteoliposomes markedly enhance the therapeutic potential of growth factors in the context of disease and may be promising therapeutics for inducing vascular regeneration in peripheral ischemia. STATEMENT OF SIGNIFICANCE: Peripheral ischemia is a common condition in which there is a lack of blood flow to the lower limbs. This condition can lead to pain while walking and, in severe cases, critical limb ischemia and limb loss. In this study, we demonstrate the safety and efficacy of a novel injectable therapy for enhancing revascularization in peripheral ischemia using an advanced large animal model of peripheral vascular disease using rabbits with hyperlipidemia and diabetes.

Nanofluidic Aptamer Nanoarray to Enable Stochastic Capture of Single Proteins at Normal Concentrations.

Single-molecule experiments allow understanding of the diversity, stochasticity, and heterogeneity of molecular behaviors and properties hidden by conventional ensemble-averaged measurements. They hence have great importance and significant impacts in a wide range of fields. Despite significant advances in single-molecule experiments at ultralow concentrations, the capture of single molecules in solution at normal concentrations within natural biomolecular processes remains a formidable challenge. Here, a high-density, well-defined nanofluidic aptamer nanoarray (NANa) formed via site-specific self-assembly of well-designed aptamer molecules in nanochannels with nano-in-nano gold nanopatterns is presented. The nanofluidic aptamer nanoarray exhibits a high capability to specifically capture target proteins (e.g., platelet-derived growth factor BB; PDGF-BB) to form uniform protein nanoarrays under optimized nanofluidic conditions. Owing to these fundamental features, the nanofluidic aptamer nanoarray enables the stochastic capture of single PDGF-BB molecules at a normal concentration from a sample with an ultrasmall volume equivalent to a single cell by following Poisson statistics, forming a readily addressable single-protein nanoarray. This approach offers a methodology and device to surpass both the concentration and volume limits of single-protein capture in most conventional methodologies of single-molecule experiments, thus opening an avenue to explore the behavior of individual biomolecules in a manner close to their natural forms, which remains largely unexplored to date.

The role of platelet-derived growth factor BB signaling pathway in the regulation of stem and progenitor Leydig cell proliferation and steroidogenesis in male rats.

Platelet-derived growth factor BB (BB) regulates cell proliferation and function. However, the roles of BB on proliferation and function of Leydig stem (LSCs) and progenitor cells (LPCs) and the underlying signaling pathways remain unclear. This study aimed to analyze the roles of PI3K and MAPK pathways in the regulation of proliferation-related and steroidogenesis-related gene expression in rat LSCs/LPCs. In this experiment, BB receptor antagonist, tyrosine kinase inhibitor IV (PKI), the PI3K inhibitor, LY294002, and the MEK inhibitor, U0126, were used to measure the effects of these pathways on the expression of cell cycle-related genes (Ccnd1 and Cdkn1b) and steroidogenesis-related genes (Star, Cyp11a1, Hsd3b1, Cyp17a1, and Srd5a1), as well as Leydig cell maturation gene Pdgfra [1]. These results showed that BB (10 ng/mL)-stimulated EdU-incorporation into LSCs and BB-mediated inhibition on its differentiation was mediated through the activation of its receptor, PDGFRB, as well as MAPK and PI3K pathways. The results of LPC experiment also showed that LY294002 and U0126 decreased BB (10 ng/mL)-upregulated Ccnd1 expression while only U0126 reversed BB (10 ng/mL)-downregulated Cdkn1b expression. U0126 significantly reversed BB (10 ng/mL)-mediated downregulation of Cyp11a1, Hsd3b1, and Cyp17a1 expression. On the other hand, LY294002 reversed the expression of Cyp17a1 and Abca1. In conclusion, BB-mediated induction of proliferation and suppression of steroidogenesis of LSCs/LPCs are dependent on the activation of both MAPK and PI3K pathways, which show distinct regulation of gene expression.

Elevated PDGF-BB from Bone Impairs Hippocampal Vasculature by Inducing PDGFRß Shedding from Pericytes.

Evidence suggests a unique association between bone aging and neurodegenerative/cerebrovascular disorders. However, the mechanisms underlying bone-brain interplay remain elusive. Here platelet-derived growth factor-BB (PDGF-BB) produced by preosteoclasts in bone is reported to promote age-associated hippocampal vascular impairment. Aberrantly elevated circulating PDGF-BB in aged mice and high-fat diet (HFD)-challenged mice correlates with capillary reduction, pericyte loss, and increased blood-brain barrier (BBB) permeability in their hippocampus. Preosteoclast-specific Pdgfb transgenic mice with markedly high plasma PDGF-BB concentration faithfully recapitulate the age-associated hippocampal BBB impairment and cognitive decline. Conversely, preosteoclast-specific Pdgfb knockout mice have attenuated hippocampal BBB impairment in aged mice or HFD-challenged mice. Persistent exposure of brain pericytes to high concentrations of PDGF-BB upregulates matrix metalloproteinase 14 (MMP14), which promotes ectodomain shedding of PDGF receptor ß (PDGFRß) from pericyte surface. MMP inhibitor treatment alleviates hippocampal pericyte loss and capillary reduction in the conditional Pdgfb transgenic mice and antagonizes BBB leakage in aged mice. The findings establish the role of bone-derived PDGF-BB in mediating hippocampal BBB disruption and identify the ligand-induced PDGFRß shedding as a feedback mechanism for age-associated PDGFRß downregulation and the consequent pericyte loss.

[Effect of platelet-derived growth factor-BB on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension and its mechanism]. / è¡€å°æ¿æºæ€§ç”Ÿé•¿å› å­-BBå¯¹ç¼ºæ°§æ€§è‚ºåŠ¨è„‰é«˜åŽ‹æ–°ç”Ÿå¤§é¼ è‚ºè¡€ç®¡é‡å¡‘çš„å½±å“åŠæœºåˆ¶ç ”ç©¶.

OBJECTIVES: To study the effect of platelet-derived growth factor-BB (PDGF-BB) on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension (HPH). METHODS: A total of 128 neonatal rats were randomly divided into four groups: PDGF-BB+HPH, HPH, PDGF-BB+normal oxygen, and normal oxygen (n=32 each). The rats in the PDGF-BB+HPH and PDGF-BB+normal oxygen groups were given an injection of 13 µL 6×1010 PFU/mL adenovirus with PDGF-BB genevia the caudal vein. After 24 hours of adenovirus transfection, the rats in the HPH and PDGF-BB+HPH groups were used to establish a neonatal rat model of HPH. Right ventricular systolic pressure (RVSP) was measured on days 3, 7, 14, and 21 of hypoxia. Hematoxylin-eosin staining was used to observe pulmonary vascular morphological changes under an optical microscope, and vascular remodeling parameters (MA% and MT%) were also measured. Immunohistochemistry was used to measure the expression levels of PDGF-BB and proliferating cell nuclear antigen (PCNA) in lung tissue. RESULTS: The rats in the PDGF-BB+HPH and HPH groups had a significantly higher RVSP than those of the same age in the normal oxygen group at each time point (P<0.05). The rats in the PDGF-BB+HPH group showed vascular remodeling on day 3 of hypoxia, while those in the HPH showed vascular remodeling on day 7 of hypoxia. On day 3 of hypoxia, the PDGF-BB+HPH group had significantly higher MA% and MT% than the HPH, PDGF-BB+normal oxygen, and normal oxygen groups (P<0.05). On days 7, 14, and 21 of hypoxia, the PDGF-BB+HPH and HPH groups had significantly higher MA% and MT% than the PDGF-BB+normal oxygen and normal oxygen groups (P<0.05). The PDGF-BB+HPH and HPH groups had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group at all time points (P<0.05). On days 3, 7, and 14 of hypoxia, the PDGF-BB+HPH group had significantly higher expression levels of PDGF-BB and PCNA than the HPH group (P<0.05), while the PDGF-BB+normal oxygen group had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group (P<0.05). CONCLUSIONS: Exogenous administration of PDGF-BB in neonatal rats with HPH may upregulate the expression of PCNA, promote pulmonary vascular remodeling, and increase pulmonary artery pressure.

Cellular Localization and Distribution of TGF-ß1, GDNF and PDGF-BB in the Adult Primate Central Nervous System.

The available data on the localization of transforming growth factor beta1 (TGF-ß1), glial cell line-derived neurotrophic factor (GDNF), and platelet-derived growth factor-BB (PDGF-BB) in the adult primate and human central nervous system (CNS) are limited and lack comprehensive and systematic information. This study aimed to investigate the cellular localization and distribution of TGF-ß1, GDNF, and PDGF-BB in the CNS of adult rhesus macaque (Macaca mulatta). Seven adult rhesus macaques were included in the study. The protein levels of TGF-ß1, PDGF-BB, and GDNF in the cerebral cortex, cerebellum, hippocampus, and spinal cord were analyzed by western blotting. The expression and location of TGF-ß1, PDGF-BB, and GDNF in the brain and spinal cord was examined by immunohistochemistry and immunofluorescence staining, respectively. The mRNA expression of TGF-ß1, PDGF-BB, and GDNF was detected by in situ hybridization. The molecular weight of TGF-ß1, PDGF-BB, and GDNF in the homogenate of spinal cord was 25 KDa, 30 KDa, and 34 KDa, respectively. Immunolabeling revealed GDNF was ubiquitously distributed in the cerebral cortex, hippocampal formation, basal nuclei, thalamus, hypothalamus, brainstem, cerebellum, and spinal cord. TGF-ß1 was least distributed and found only in the medulla oblongata and spinal cord, and PDGF-BB expression was also limited and present only in the brainstem and spinal cord. Besides, TGF-ß1, PDGF-BB, and GDNF were localized in the astrocytes and microglia of spinal cord and hippocampus, and their expression was mainly found in the cytoplasm and primary dendrites. The mRNA of TGF-ß1, PDGF-BB, and GDNF was localized to neuronal subpopulations in the spinal cord and cerebellum. These findings suggest that TGF-ß1, GDNF and PDGF-BB may be associated with neuronal survival, neural regeneration and functional recovery in the CNS of adult rhesus macaques, providing the potential insights into the development or refinement of therapies based on these factors.

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.

Comparison of Cytokine Profile between Postmenopausal Women with and Without Osteoporosis - A Case-Control Study.

BACKGROUND: Chronic low-grade inflammation is involved in the pathogenesis of postmenopausal osteoporosis, but the cytokines implicated remain elusive. OBJECTIVE: This study aimed to compare the difference in cytokine profile between postmenopausal women with and without osteoporosis in Klang Valley, Malaysia. METHODS: Postmenopausal women with (n = 20) and without osteoporosis (n = 20) were recruited for this study. Their bone health status was determined using dual-energy X-ray absorptiometry. Their fasting blood was collected for proteomic analysis. A protein array was performed for four subjects randomly selected from each group to screen the potential cytokines. Three cytokines at least 20% different between groups and consistently expressed by each subject were selected for validation using enzyme-linked immunosorbent assays (ELISA). RESULTS: The protein array screening demonstrated that platelet-derived growth factor-BB, interleukin- 6 receptor (IL-6R), and tissue inhibitor of metallopeptidase-2 were higher in women with osteoporosis than women without osteoporosis (n = 4 per group), and consistently expressed by all women. Only body mass index (BMI)-adjusted logarithmically transformed IL-6R levels were lower among postmenopausal women with osteoporosis compared to women with normal bone health (p = 0.026) (n = 16 per group) in the ELISA test. CONCLUSION: IL-6R was lower among postmenopausal women with osteoporosis compared to women with normal bone health after adjusting for BMI. However, a large-scale epidemiological study with proteomic analysis needs to confirm the findings.

Role and mechanism of platelet-derived growth factor BB in thrombocytosis in Kawasaki disease / 中国当代儿科杂志

OBJECTIVES@#To study the role and mechanism of platelet-derived growth factor BB (PDGF-BB) on platelet production in Kawasaki disease (KD) mice and human megakaryocytic Dami cells through in vitro and invivo experiments.@*METHODS@#ELISA was used to measure the expression of PDGF in the serum of 40 children with KD and 40 healthy children. C57BL/6 mice were used to establish a model of KD and were then randomly divided into a normal group, a KD group, and an imatinib group (30 mice in each group). Routine blood test was performed for each group, and the expression of PDGF-BB, megakaryocyte colony forming unit (CFU-MK), and the megakaryocyte marker CD41 were measured. CCK-8, flow cytometry, quantitative real-time PCR, and Western blot were used to analyze the role and mechanism of PDGF-BB in platelet production in Dami cells.@*RESULTS@#PDGF-BB was highly expressed in the serum of KD children (P<0.001). The KD group had a higher expression level of PDGF-BB in serum (P<0.05) and significant increases in the expression of CFU-MK and CD41 (P<0.001), and the imatinib group had significant reductions in the expression of CFU-MK and CD41 (P<0.001). In vitro experiments showed that PDGF-BB promoted Dami cell proliferation, platelet production, mRNA expression of PDGFR-β, and protein expression of p-Akt (P<0.05). Compared with the PDGF-BB group, the combination group (PDGF-BB 25 ng/mL + imatinib 20 μmol/L) had significantly lower levels of platelet production, mRNA expression of PDGFR-β, and protein expression of p-Akt (P<0.05).@*CONCLUSIONS@#PDGF-BB may promote megakaryocyte proliferation, differentiation, and platelet production by binding to PDGFR-β and activating the PI3K/Akt pathway, and the PDGFR-β inhibitor imatinib can reduce platelet production, which provides a new strategy for the treatment of thrombocytosis in KD.

Effect of platelet-derived growth factor-BB on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension and its mechanism / 中国当代儿科杂志

OBJECTIVES@#To study the effect of platelet-derived growth factor-BB (PDGF-BB) on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension (HPH).@*METHODS@#A total of 128 neonatal rats were randomly divided into four groups: PDGF-BB+HPH, HPH, PDGF-BB+normal oxygen, and normal oxygen (n=32 each). The rats in the PDGF-BB+HPH and PDGF-BB+normal oxygen groups were given an injection of 13 μL 6×1010 PFU/mL adenovirus with PDGF-BB genevia the caudal vein. After 24 hours of adenovirus transfection, the rats in the HPH and PDGF-BB+HPH groups were used to establish a neonatal rat model of HPH. Right ventricular systolic pressure (RVSP) was measured on days 3, 7, 14, and 21 of hypoxia. Hematoxylin-eosin staining was used to observe pulmonary vascular morphological changes under an optical microscope, and vascular remodeling parameters (MA% and MT%) were also measured. Immunohistochemistry was used to measure the expression levels of PDGF-BB and proliferating cell nuclear antigen (PCNA) in lung tissue.@*RESULTS@#The rats in the PDGF-BB+HPH and HPH groups had a significantly higher RVSP than those of the same age in the normal oxygen group at each time point (P<0.05). The rats in the PDGF-BB+HPH group showed vascular remodeling on day 3 of hypoxia, while those in the HPH showed vascular remodeling on day 7 of hypoxia. On day 3 of hypoxia, the PDGF-BB+HPH group had significantly higher MA% and MT% than the HPH, PDGF-BB+normal oxygen, and normal oxygen groups (P<0.05). On days 7, 14, and 21 of hypoxia, the PDGF-BB+HPH and HPH groups had significantly higher MA% and MT% than the PDGF-BB+normal oxygen and normal oxygen groups (P<0.05). The PDGF-BB+HPH and HPH groups had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group at all time points (P<0.05). On days 3, 7, and 14 of hypoxia, the PDGF-BB+HPH group had significantly higher expression levels of PDGF-BB and PCNA than the HPH group (P<0.05), while the PDGF-BB+normal oxygen group had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group (P<0.05).@*CONCLUSIONS@#Exogenous administration of PDGF-BB in neonatal rats with HPH may upregulate the expression of PCNA, promote pulmonary vascular remodeling, and increase pulmonary artery pressure.

[The Hematopoietic Protective Effect of PDGF-BB on Radiation-Induced Myelosuppression Model Mice].

OBJECTIVE: To investigate the hematopoietic protective effect of platelet-derived growth factor (PDGF)-BB on radiation-induced myelosuppression model mice and effect of anti-apoptosis of megakaryocyte line Meg-01 cells, and its possible mechanism. METHODS: Mice were radiated with 4 Gy of 137Csγ ray to establish the model of myelosuppression. Mice were weighed and peripheral blood cell were counted before radiation (day 0) and day 7, 14 and 21 after radiation. On the 21 st day, the mice were killed. The sternal tissues of the mice were taken for morphological observation, and the femoral bone marrow cells were cultured for the assay of colony cell forming units (CFU). Meg-01 cells were cultured without FBS for 24 h to induce apoptosis, and then treated with PDGF-BB for 48 h. The effects of PDGF-BB on the proliferation were investigated by cell counting. Flow cytometry was used to detect early apoptosis (Annexin V), mitochondrial membrane potential (JC-1) and the expression of caspase-3. RESULTS: Peripheral blood cell counts of mice showed that PDGF-BB stimulated the recovery of white blood cells, red blood cells and platelets after radiation (P<0.05), especially for white blood cells. Morphological examination showed bone marrow hyperplasia in PDGF-BB group, the numbers of megakaryocytes and their progenitor cells were higher than those in the control group. PDGF-BB significantly stimulated the formation of CFU-MK, CFU-GM, BFU-E and CFU-F. PDGF-BB showed a strong proliferation effect in the concentration range of 5-50 ng/ml (P<0.001). PDGF-BB (50 ng/ml) significantly reduced the positive expression of Annexin V (P<0.01). The mitochondrial membrane potential in the control group was decreased when compared with PDGF-BB group, which indicated that the number of apoptotic cells was increased (P<0.01). Besides, the expression of caspase-3 in PDGF-BB group was significantly lower than that in control group (P<0.05). CONCLUSION: PDGF-BB has a protective effect on the hematopoietic system of myelosuppression model mice, especially megakaryocytes and their progenitor cells. PDGF-BB has pro-proliferative and anti-apoptotic effects on Meg-01 cells, and the mechanism may be mediated through JC-1 and caspase-3 pathway.

Development of Growth Factor Releasing Hyaluronic Acid-Based Hydrogel for Pulp Regeneration: A Preliminary Study.

Growth factors play essential roles as signaling molecules in pulp regeneration. We investigated the effect of a hyaluronic acid (HA)-collagen hybrid hydrogel with controlled release of fibroblast growth factor (FGF)-2 and platelet-derived growth factor (PDGF)-BB on human pulp regeneration. The cell interaction and cytotoxicity of the HA-collagen hybrid hydrogel, the release kinetics of each growth factor, and the effects of the released growth factors on pulp cell proliferation were examined. The vitality of pulp cells was maintained. The amounts of FGF-2 and PDGF-BB released over 7 days were 68% and 50%, respectively. Groups with a different concentration of growth factor (FGF-2: 100, 200, 500, and 1000 ng/mL; PDGF-BB: 10, 50, 100, 200, and 500 ng/mL) were experimented on days 1, 3, 5, and 7. Considering FGF-2 concentration, significantly increased pulp cell proliferation was observed on days 1, 3, 5, and 7 in the 100 ng/mL group and on days 3, 5, and 7 in the 200 ng/mL group. In the case of PDGF-BB concentration, significantly increased pulp cell proliferation was observed at all four time points in the 100 ng/mL group and on days 3, 5, and 7 in the 50, 200, and 500 ng/mL groups. This indicates that the optimal concentration of FGF-2 and PDGF-BB for pulp cell proliferation was 100 ng/mL and that the HA-collagen hybrid hydrogel has potential as a controlled release delivery system for FGF-2 and PDGF-BB.

Angiogenetic Factors in Chronic Subdural Hematoma Development.

The levels of angiogenic factors were analyzed in eight patients who underwent the embolization of chronic subdural hematoma (CSDH) with non-adhesive liquid embolic agents. Four of these patients had previously undergone surgical treatment for hematoma removal and had recurrences of a similar volume, and four had an increase in hematoma volume due to rebleeding. The levels of vascular endothelial growth factor (VEGF), matrix metallopeptidase 9 (MMP 9), angiopoietin-2 (Ang2), transforming growth factor beta 1 (TGF-ß1) and platelet-derived growth factor BB (PDGF-BB) in the arterial and venous blood were analyzed. The most significant results were obtained from the peripheral venous blood samples. The levels of VEGF in the samples of all the patients were close to normal or slightly decreased. There was an increase in the MMP9 levels (the factor that contributes to the disintegration of the vessel wall components) in all the patients. The Ang2 and especially the PDGF TGF-ß1 (the factor that plays an important role in the growth of the vessel wall from the already existing blood vessel tissue) levels were distinctly low in most of the cases and slightly elevated only in a number of patients who had previously been operated on. The results obtained show that there is an imbalance in the angiogenesis factors in patients with rebleeding CSDH. At the same time, the factors determining the formation of the vessel wall were reduced, and the levels of factors contributing to the degradation of extracellular matrix components were significantly increased. Such factors could help us to anticipate the increased risk of hemorrhages. Highlights: The levels of VEGF, MMP 9, Ang2, TGF-ß1 and PDGF-BB in the arterial and venous blood were analyzed. The most significant results were obtained from the peripheral venous blood samples. The results obtained show that there is an imbalance in the angiogenesis factors in patients with rebleeding CSDH. Such a profile of factors could help us to anticipate the increased risk of hemorrhages.