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Global Medicinal Plants and Phyto-Derived Compounds in Wound Healing
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Samantha R. Loggenberg, Namrita Lall
Angiogenesis is a process that involves the regeneration and revascularization of blood vessels within newly formed tissue following tissue repair (Morgan and Nigam, 2013). The reformation of blood vessels plays a pivotal role in the wound recovery process, as well as the maturation of nascent tissue for normal cellular functions to occur. Angiogenesis is an intricate process that overlaps with the degradation of granulation tissue and cell proliferative stages of wound healing. Angiogenesis is regulated by various factors secreted by numerous cells involved in wound healing, such as PDGF-AA, PDGF-BB and vascular endothelial growth factor (VEGF), which are secreted by activated leukocytes (Lynch, Colvin, and Antoniades, 1989). These growth factors act as potent endothelial and fibroblast cell mitogens which ultimately facilitate the maturation of blood capillaries and surrounding connective tissue to re-establish the blood vessels and restore the blood supply to cells in nascent tissues (Aldridge, 2015).
Platelet-Derived Growth Factor
Published in Jason Kelley, Cytokines of the Lung, 2022
James P. Fabisiak, Jason Kelley
Most of the PDGF present in human platelets (70–80%) has been identified as the AB heterodimer, but both the BB and AA homodimers are also present (Hammacher et al., 1988a; Hart et al., 1990). In contrast, PDGF from porcine platelets exists almost entirely as the BB isoform (Stroobant and Waterfield, 1984). The small amounts of PDGF detectable in plasma (Bowen-Pope et al., 1989) vary considerably among species, both in amount and types (Table 1). In most nonhuman species tested, serum and platelets contain a predominance of PDGF BB. Human serum stands out because it is relatively richer in total PDGF levels, and also, it is composed almost entirely of PDGF-A–containing isoforms, with little PDGF BB homodimer. On the other hand, PDGF-like activity in the conditioned medium of various cells, such as those derived from malignant osteosarcomas (Graves et al., 1984; Heldin et al., 1986), glioma (Hammacher et al., 1988b), and smooth muscle (Sejersen et al., 1986) consists largely of PDGF-AA homodimer. There are striking differences in the amounts and types of PDGF isoforms secreted by normal vascular cells and transformed cells. Medium conditioned by cultured PDGF-secreting cells, other than vascular endothelial cells, generally contains no detectable PDGF-BB (Bowen-Pope et al., 1989).
Dermatofibrosarcoma Protuberans
Published in Debjani Sahni, Adam Lerner, Bilal Fawaz, Advanced Skin Cancer, 2022
Constitutive over-expression of the platelet-derived growth factor B (PDGFB) gene on chromosome 22 is believed to play a key role in the development of DFSP. The uncontrolled production PDGFB occurs due to a translocation resulting in the fusion of two genes; the COL1A1 gene located on chromosome 17q22, which encodes the α1 chain of type 1 collagen, and the PDGFB gene located on chromosome 22q13, which encodes the β chain of the PDGF ligand. The PDGF receptor, PDGF-R, is a transmembrane tyrosine kinase that is normally expressed by fibroblasts, which upon binding the cytokine PDGFB induces fibroblast cellular proliferation and connective tissue growth. The translocation places the PDGFB gene under direct control of the COL1A1 gene, resulting in its deregulation. The fusion gene product is cleaved intracellularly into mature PDGFB, followed by secretion of this cytokine and autocrine stimulation of tumor growth. A (17;22)(q22;q13) translocation resulting in a collagen1α1 (COL1A1)/PDGFB fusion gene and resultant growth factor has been identified in up to 90% of DFSP cases, with various other combinations of genetic alterations found in rare cases.7
Determination of cytokine profile and associated genes of the signaling pathway in HNSCC
Published in Journal of Receptors and Signal Transduction, 2022
Aysel Kalayci Yigin, Ali Azzawri, Kayhan Ozturk, Tulin Cora, Mehmet Seven
PDGFRB, a homodimer of PDGFB, is associated with a poor prognosis of many common malignancies especially fibroblast-rich stroma [20], and it is also a crucial factor for tumor growth, angiogenesis and tumor survival. PDGFRB has been found to interact with members of several different RTK families, including EGFR [21]. PTEN is an important tumor suppressor gene, which functions in many cellular processes such as cell proliferation, survival, growth, metabolism, cell migration by inactivating PI3-kinase-dependent signaling. In the literature, associations between PTEN and PDGF isoforms were reported in human prostate cancer cell lines [22]. Lin et al. reported that the expressions of PDGFA and PDGFB mRNAs were higher in oral squamose cell carcinoma tissue than in the adjacent normal tissues [23]. Taken together, our results suggest a mechanism by which loss of PTEN may promote HNSCC progression via PDGFR signal transduction in HNSCC.
The Efficacy of Recombinant Platelet-Derived Growth Factor on Beta-Tricalcium Phosphate to Regenerate Femoral Critical Sized Segmental Defects: Longitudinal In Vivo Micro-CT Study in a Rat Model
Published in Journal of Investigative Surgery, 2020
Mohammed Badwelan, Mohammed Alkindi, Sundar Ramalingam, Nasser Nooh, Khalid Al Hezaimi
Platelet derived growth factor (PDGF) is a potent mitogen and chemoattractant for mesenchymal and osteogenic cells and stimulates angiogenic molecules which play an essential role in bone regeneration [11]. Although several isoforms of recombinant PDGF (AA, AB, BB, CC, and DD) have been reported to be released from platelets following tissue injury, PDGF-BB is considered capable of binding with all known receptor isotypes and possesses profound physiological functions [12, 13]. Preclinical studies in animals have reported the ability of PDGF, when used alone, to increase the rate of fracture repair [14] and induce new bone formation when injected subperiosteally [15]. Similarly, PDGF used in combination with mineralized bone allografts and xenografts, within calvarial and dental alveolar ridge bone defects, has been reported to form significant volumes of new bone both in animal and clinical studies [16, 17]. Based on a clinical study, Nevins and Reynolds [18] reported better bone augmentation around dental implant sites when using a combination of PDGF with beta-TCP. Nevertheless, new bone formation around dental implant sites at best mimics intramembranous ossification and is not comparable to bone regeneration within segmental defects, which occurs through endochondral ossification [19, 20].
Efficacy of Sunitinib, Sunitinib-Hesperetin, and Sunitinib-Doxycycline Combinations on Experimentally-Induced Corneal Neovascularization
Published in Current Eye Research, 2019
Yeliz Ekim, Selcuk Kara, Baran Gencer, Turan Karaca
The formation of CNV is linked to the balance between local pro-angiogenic and anti-angiogenic factors.5 CNV commonly develops due to increased secretion of angiogenic cytokines (including vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), tumor necrosis factor (TNF), prostaglandins (PG), and interleukins (IL)) as a result of an inflammatory or hypoxic process.2 VEGF is an angiogenic stimulating factor with a critical role in controlling the stages of pathological angiogenesis.6–8 Thus, most investigations into treatment options have focused on anti-VEGF drugs. VEGFR1, VEGFR2 and VEGF-A are the primary factor inducing neovascularization. Also, PDGF-B plays a vital role in angiogenesis, vascular maturation, and pericyte stabilization.9 PDGF-B signaling may contribute to anti-VEGF therapy resistance. Thus, a dual-block treatment inhibiting both factor PDGF-B and VEGF has been shown to be more effective in ocular neovascularization models.10