The molecular cloning of platelet-derived growth factor-C (PDGF-C) gene of Gekko japonicus and its expression change in the spinal cord after tail amputation

Ovarian recovery via autologous platelet-rich plasma: New benchmarks for condensed cytokine applications to reverse reproductive aging

Health and life expectancy gains have pushed the overall number of menopausal patients to record levels. Because maternal age at first pregnancy also continues to rise, it is unsurprising that reduced birth rates are consistently reported across many populations. Both trends severely strain national demographics and present a socioeconomic challenge for which no satisfactory solution currently exists. Symptomatic menopause and infertility/miscarriage are met with standard therapies like hormone replacement therapy (HRT) and in vitro fertilization, respectively. Although these accepted interventions do supply some cover, both are expensive, low yield, and not without controversy. Meanwhile, ovarian steroid output and competent oocyte availability approach unrecoverable loss beyond age ~35 years, irrespective of treatment. Received wisdom holds that postnatal oogenesis in humans is impossible, a tenet which until recently encountered little serious confrontation. Reassessing this paradigm is overdue given proof‐of‐concept work on native sex steroid rejuvenation, de novo euploid oogenesis, ovulation, blastocyst development, fetal growth, and healthy term livebirths—all apparently possible with intraovarian insertion of platelet‐rich plasma (PRP). Discrete functional analysis of the full platelet‐derived cytokine array carried with PRP unfortunately for now, is incomplete. Here, selected platelet releasate constituents and measured effects are framed to address advances in wellness and women’s health. Emphasis is on cytokines best positioned to enable recovery of senescent ovarian function sufficient to suspend synthetic HRT dependency and/or permit egg retrieval and pregnancy. Whereas the chronicle of progress in other clinical fields does invite generalization of fresh platelet applications to reproductive endocrinology, basic mechanistic questions remain open.

PDGF/PDGFR axis in the neural systems

Platelet-derived growth factors (PDGFs) and their receptors (PDGFRs) are expressed in several cell types including the brain cells such as neuronal progenitors, neurons, astrocytes, and oligodendrocytes. Emerging evidence shows that PDGF-mediated signaling regulates diverse functions in the central nervous system (CNS) such as neurogenesis, cell survival, synaptogenesis, modulation of ligand-gated ion channels, and development of specific types of neurons. Interestingly, PDGF/PDFGR signaling can elicit paradoxical roles in the CNS, depending on the cell type and the activation stimuli and is implicated in the pathogenesis of various neurodegenerative diseases. This review summarizes the role of PDGFs/PDGFRs in several neurodegenerative diseases such as Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, brain cancer, cerebral ischemia, HIV-1 and drug abuse. Understanding PDGF/PDGFR signaling may lead to novel approaches for the future development of therapeutic strategies for combating CNS pathologies.

Platelet-derived growth factor-C and -D in the cardiovascular system and diseases

The cardiovascular system is among the first organs formed during development and is pivotal for the formation and function of the rest of the organs and tissues. Therefore, the function and homeostasis of the cardiovascular system are finely regulated by many important molecules. Extensive studies have shown that platelet-derived growth factors (PDGFs) and their receptors are critical regulators of the cardiovascular system. Even though PDGF-C and PDGF-D are relatively new members of the PDGF family, their critical roles in the cardiovascular system as angiogenic and survival factors have been amply demonstrated. Understanding the functions of PDGF-C and PDGF-D and the signaling pathways involved may provide novel insights into both basic biomedical research and new therapeutic possibilities for the treatment of cardiovascular diseases.

Assessment of platelet-derived growth factor using A splinted full thickness dermal wound model in bearded dragons (Pogona vitticeps)

Wounds in reptiles are a common reason for presentation to a veterinarian. At this time there is limited information on effective topical medications to aid in wound closure. The objectives of this study were to translate the splinted, full-thickness dermal wound model, validated in mice, to the bearded dragon (Pogona vitticeps) and to determine the effect of topical becaplermin (BP), a platelet-derived growth factor (0.01%), on the rate of wound closure. Ten bearded dragons were anesthetized and two full-thickness cutaneous wounds were made on the dorsum of each lizard. Encircling splints were applied surrounding each wound and subsequently covered by a semi-occlusive dressing. Five lizards had one wound treated with BP and the adjacent wound treated with a vehicle control. Five additional lizards had one wound treated with saline and the second wound treated with a vehicle control. Wounds were imaged daily, and the wound area was measured using digital image analysis. The change in percentage wound closure over 17 days and the time to 50% wound closure was compared among the four treatment groups. There was no significant difference in wound closure rates between BP-treated and saline-treated wounds or in the time to 50% wound closure between any treatments. Vehicle-treated wounds adjacent to saline-treated wounds closed significantly slower than did BP (P < 0.010), saline (P < 0.001), and vehicle-treated wounds adjacent to BP-treated wounds (P < 0.013). Our preliminary study indicates that the splinted wound model, with modifications, may be used to determine wound closure rates in bearded dragons. When compared with saline, BP did not have a significant effect on wound closure rates, while the vehicle alone delayed wound closure. Histologic analysis of experimentally created wounds throughout the wound healing process is needed to further evaluate the effects of these treatments on reptile dermal wound healing.

PDGF-C: a new performer in the neurovascular interplay

The importance of neurovascular crosstalk in development, normal physiology, and pathologies is increasingly being recognized. Although vascular endothelial growth factor (VEGF), a prototypic regulator of neurovascular interaction, has been studied intensively, defining other important regulators in this process is warranted. Recent studies have shown that platelet-derived growth factor C (PDGF-C) is both angiogenic and a neuronal survival factor, and it appears to be an important component of neurovascular crosstalk. Importantly, the expression pattern and functional properties of PDGF-C and its receptors differ from those of VEGF, and thus the PDGF-C-mediated neurovascular interaction may represent a new paradigm of neurovascular crosstalk.

The cloning and characterization of the enolase2 gene of Gekko japonicus and its polyclonal antibody preparation

The enolase2 gene is usually expressed in mature neurons and also named neuron specific enolase (NSE). In the present study, we first obtained the NSE gene cDNA sequence by using the RACE method based on the expressed sequence tag (EST) fragment from the cDNA library of Gekko japonicus and identified one transcript of about 2.2 kb in central nervous system of Gekko japonicus by Northern blotting. The open reading frame of NSE is 1305 bp, which encodes a 435 amino-acid protein. We further investigated the multi-tissue expression pattern of NSE by RT-PCR and found that the expression of NSE mRNA was very high in brain, spinal cord and low in heart, while it was not detectable in other tissues. The real-time quantitative PCR was used to investigate the time-dependent change in the expression of the NSE mRNA level after gecko spinal cord transection and found it significantly increased at one day, reaching its highest level three days post-injury and then decreasing at the seventh day of the experiment. The recombinant plasmid of pET-32a-NSE was constructed and induced to express His fused NSE protein. The purified NSE protein was used to immunize rabbits to generate polyclonal antisera. The titer of the antiserum was more than 1:65536 determined by ELISA. Western blotting showed that the prepared antibody could specifically recognize the recombinant and endogenous NSE protein. The result of immunohistochemistry revealed that positive signals were present in neurons of the brain and the spinal cord. This study provided the tools of cDNA and polyclonal antibody for studying NSE function in Gekko japonicus.

[Molecular cloning of tubulin beta 3 (TUBB3) in Gekko japonicus and preparation of its polyclonal antibody]

The tubulin beta III (TUBB3) gene encodes a class III member of the beta tubulin protein family that is primarily expressed in neurons and is considered to play a critical role in proper axon guidance and maintenance. This protein is generally used as a specific marker of neurons in the central nervous system. We obtained the full length cDNA sequence of TUBB3 by using the RACE method based on the EST fragment from the brain and spinal cord cDNA library of Gekko japonicus. We further investigated the multi-tissue expression pattern by RT-PCR and identified one transcript of TUBB3 about 1.8 kb in the central nervous system of Gekko japonicus by Northern blotting. The completed cDNA of gecko TUBB3 is 1 790 bp with an open reading frame of 1 350 bp, encoding a 450 amino-acid protein. The recombinant plasmid of pET-32a-TUBB3 was constructed and induced to express His-tagged TUBB3 protein in prokaryotic BL21 cells. The purified TUBB3 protein was then used to immunize rabbits to generate polyclonal antisera. The titer of the antiserum was more than 1:65 536 determined by ELISA. The result of western blotting showed that the TUBB3 antibody could specifically recognize the recombinant TUBB3 protein and endogenous TUBB3 protein. Our findings provide the tools to further understand the TUBB3 gene and investigate the regeneration of the central nervous system in Gekko japonicas.

Establishment and characterization of two cell lines derived from primary cultures of Gekko japonicus cerebral cortex

Adult Gekko japonicus is one of those vertebrates that are able to regenerate their missing or amputated tail. The most interesting feature of this animal lies in the ability of its spinal cord to regrow a functional tail. A fundamental question is whether the neuroglial cells play a different role compared with high vertebrates. Since in vitro studies using primary neuroglial cells are hampered by the limited lifespan and miscellaneous genetic background of these cells, we generated neuroglial cell lines from primary cell cultures of cerebral cortex of G. japonicus. The SV40 (simian-virus-40) T antigen gene was introduced into primary cell cultures. Cell cycle analysis, cell growth and proliferation, cell colony formation and contact inhibition, as well as karyotype assays were investigated. Two cell colonies, Gsn-1 and Gsn-3, were immunochemically characterized as glial fibrillary acidic protein and galactocerebroside-positive respectively. Compared with parental primary cells, the Gsn cells displayed shorter population doubling time, decreased percentage of cells in the G0/G1 phase, higher cell proliferation index, and increased cell activity. In assays of colony characteristics, Gsn cells showed increased cell activity at the lower cell densities or FBS (fetal bovine serum) supplement. The karyotype of immortalized Gsn cells exhibited transformational characteristics with hyperdiploid and polyploid chromosomes. The cell lines will provide a useful in vitro model for gecko neuroglial cells and facilitate systematic studies investigating the biological functions of specific gene products related to regeneration of the central nervous system.