About
83
Publications
8,680
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
5,267
Citations
Introduction
Skills and Expertise
Current institution
Additional affiliations
January 1988 - June 2022
October 1980 - October 1988
Publications
Publications (83)
Objectives
Neurotrophin‐3 (NT3) plays a key role in the development and function of locomotor circuits including descending serotonergic and corticospinal tract (CST) axons and afferents from muscle and skin. We have previously shown that gene therapy delivery of human NT3 into affected forelimb muscles improves sensorimotor recovery after stroke i...
Stroke often leads to arm disability and reduced responsiveness to stimuli on the other side of the body. Neurotrophin-3 (NT3) is made by skeletal muscle during infancy but levels drop postnatally and into adulthood. It is essential for the survival and wiring-up of sensory afferents from muscle. We have previously shown that gene therapy delivery...
There is an urgent need for a therapy that reverses disability after stroke when initiated in a time frame suitable for the majority of new victims. We show here that intramuscular delivery of neurotrophin-3 (NT3, encoded by NTF3) can induce sensorimotor recovery when treatment is initiated 24 h after stroke. Specifically, in two randomized, blinde...
The corticospinal tract (CST) can be completely severed unilaterally in the medullary pyramids of the rodent brainstem. The CST is a motor tract that has great importance for distal muscle control in humans and, to a lesser extent, in rodents. A unilateral cut of one pyramid results in loss of CST innervation of the spinal cord mainly on the contra...
Lesions of the spinal cord cause two distinctive types of neuroimmune responses, a response at the lesion site that leads to additional tissue destruction and a more subtle response, termed Wallerian degeneration (WD), that occurs distal to the lesion site. We have evidence that the neuroimmune response associated with WD may support tissue repair....
The assembly of neuronal circuits during development requires the precise navigation of axons, which is controlled by attractive and repulsive guidance cues. In the developing spinal cord, ephrinB3 functions as a short-range repulsive cue that prevents EphA4 receptor-expressing corticospinal tract and spinal interneuron axons from crossing the midl...
Normal gait in control mouse. Control mice use alternate limb movements during walking. (WMV)
RhoA expression in P4 mouse brain and spinal cord. In situ hybridization was used to detect RhoA message in (A) sagittal sections of P4 mouse brain and (B) transverse sections of P4 mouse spinal cord. These images, couresy of the Allen Developing Mouse Brain Atlas (http://developingmouse.brain-map.org) and the Allen Spinal Cord Atlas (http://mouses...
Hopping gait in RhoA cKO mouse. RhoA cKO mice use their forelimbs and hindlimbs sychronously during walking. (WMV)
The molecular mechanisms by which extracellular guidance cues regulate axonal morphology are not fully understood. Recent findings suggest that increased activity of the protein kinase Akt promotes dendritic branching and elongation in hippocampal neurons. We tested whether expression of constitutively active Akt (CA-Akt) in primary sensory neurons...
Perineural invasion is the only interaction between cancer cells and nerves studied to date. It is a symbiotic relationship between cancer and nerves that results in growth advantage for both. In this article, we present data on a novel biological phenomenon, cancer-related axonogenesis and neurogenesis.
We identify spatial and temporal association...
This paper evaluates the effects of adenoviral vector-mediated glial cell-derived neurotrophic factor (GDNF) gene delivery on survival of primary human corneal epithelial cells (PHCEC) established from limbal explants in vitro and the overexpression of GDNF gene in bioengineered human corneal constructs on substrate of corneal stromal discs followe...
A successful treatment for spinal cord injury (SCI) must include means to induce axonal regeneration and synaptogenesis. Though much research has demonstrated the effectiveness of neurotrophic factors (NFs) in supporting axonal regeneration, systemic delivery of doses sufficient to reach therapeutic concentrations and overcome their short half-live...
Neurotrophins support neuronal survival and axonal regeneration after injury. To test whether local expression of Neurotrophin-3 (NT-3) would elicit axonal regeneration we lesioned the corticospinal tract (CST) at the level of the hindbrain and measured the number of axons that would grow from the unlesioned CST to the contralateral side where NT-3...
After an unilateral lesion of the corticospinal tract (CST) at the level of the medulla over-expression of Neurotrophin-3 (NT-3) in lumbar spinal cord motoneurons induced axonal sprouting of the intact CST in the acutely injured but not uninjured or chronically injured spinal cord in rats. This suggested that processes associated with immune-mediat...
Nerve growth factor (NGF), a member of the neurotrophin family, has been identified as an essential growth factor supporting stem cell self-renewal outside the nervous system and was previously shown to stimulate corneal epithelial proliferation both in vivo and in vitro. In this study, we evaluated the expression of NGF and its corresponding recep...
Medulloblastoma is a common malignant brain tumor of childhood. Human epidermal growth factor receptor 2 (HER2) is expressed by 40% of medulloblastomas and is a risk factor for poor outcome with current aggressive multimodal therapy. In contrast to breast cancer, HER2 is expressed only at low levels in medulloblastomas, rendering monoclonal antibod...
To evaluate the expression patterns of neurotrophic factors (NTFs) and their receptors in the human cornea with the intention of exploring the role of NTFs in maintaining corneal epithelial stem cells in the limbus.
Fresh human corneoscleral tissues were prepared for frozen sections. Immunofluorescent staining was performed with primary antibodies...
Current techniques used to quantify axons often rely upon manual quantification or potentially expensive commercially available programs for automated quantification. We describe a computerized method for the detection and quantification of axons in the rat CNS using readily available free software. Feature J, a java-based plug-in to the imaging so...
Previously, we reported that over-expression of neurotrophin-3 (NT-3) promoted sprouting of axons in the injured but not uninjured spinal cord, suggesting that processes associated with the injury such as Wallerian degeneration (WD) participated to induce the neuroplasticity. To determine whether NT-3-induced axonal sprouting depends upon processes...
Background: The long-term objective of this project is to develop an innovative HER2-targeted immunotherapeutic approach for medulloblastoma. HER2 is expressed in 40% of medulloblastomas and at present less than one third of patients with HER2-positive tumors are cured by conventional therapies. The aim of this study was to determine if T cells gra...
Neurotrophins promote sprouting and elongation of central nervous system (CNS) axons following injury. Consequently, it has been suggested that neurotrophins could be used to repair the CNS by inducing axonal sprouting from nearby intact axons, thereby compensating for the loss of recently injured axons. We tested whether long-term overexpression o...
We tested whether adenoviral-mediated expression of the neurotrophins Brain-Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT-3), or Nerve Growth Factor (NGF) is sufficient to induce regeneration of lesioned serotonergic axons in the cerebral cortex. A single, subcutaneous injection of the neurotoxin p-chloroamphetamine (PCA, 9mg/kg) selective...
Neurotrophins (NTs) play an important role in the modulation of synaptic transmission and in morphological changes in synaptic structures. Although there is agreement that brain-derived neurotrophic factor (BDNF) is sorted to large dense-core vesicles (LDCVs) and released via the regulated secretory pathway, there has been some dispute regarding th...
Osteoblasts are continually recruited from stem cell pools to maintain bone. Although their immediate precursor is a plastic-adherent mesenchymal stem cell able to generate tissues other than bone, increasing evidence suggests the existence of a more primitive cell that can differentiate to both hematopoietic and mesenchymal cells. We show here tha...
We reported recently that overexpression of neurotrophin-3 (NT-3) by motoneurons in the spinal cord of rats will induce sprouting of corticospinal tract (CST) axons (Zhou et al. [2003] J. Neurosci. 23:1424-1431). We now report that overexpression of brain-derived neurotrophic factor (BDNF) or glial cell-derived neurotrophic factor (GDNF) in the rat...
The mammalian CNS lacks the ability to effectively compensate for injury by the regeneration of damaged axons or axonal plasticity of intact axons. However, reports suggest that molecular or cellular manipulations can induce compensatory processes that could support regeneration or plasticity after trauma. We tested whether local, sustained release...
Adenovirus-mediated transfer of the nerve growth factor gene promotes significant recovery of age-related cholinergic neuronal deficits in aged rats, but the effects of such treatment on cognitive dysfunction remain unclear. Herein we report a beneficial effect of first-generation adenovirus-mediated nerve growth factor gene transfer (AdNGF) on the...
Reports have suggested that adult mouse bone marrow cells (BMCs) are capable of transdifferentiating into cells with neural characteristics in the central nervous system (CNS) ([1][1],[2][2]). Because side-population (SP) cells within whole bone marrow are hematopoietic stem cells that can
Proliferating cells within the terminal end buds of the virgin female rat mammary gland are the most susceptible to chemical carcinogen induced tumorigenesis. We hypothesized that selective ablation of proliferating cells in the mammary gland would reduce mammary tumor incidence upon carcinogen challenge. Selective ablation of proliferating cells w...
Little is understood regarding mechanisms of perineural invasion in prostate cancer progression. We present a novel model system and data that indicate perineural invasion is an active, specific, and reciprocal interaction between nerves and prostate cancer cells.
Mouse dorsal root ganglia (DRG) and human prostate cancer cells (Du-145, LNCaP, PC3)...
Altered axon-Schwann cell interactions in PNS myelin-deficient Trembler mice result in changed axonal transport rates, neurofilament and microtubule-associated protein phosphorylation, neurofilament density, and microtubule stability. To determine whether PNS and CNS myelination have equivalent effects on axons, neurofilaments, and microtubules in...
Between December 1996 and September 1998, 13 patients with advanced recurrent malignant brain tumors (9 with glioblastoma multiforme, 1 with gliosarcoma, and 3 with anaplastic astrocytoma) were treated with a single intratumoral injection of 2 109, 2 1010, 2 1011, or 2 1012 vector particles (VP) of a replication-defective adenoviral vector bearing...
Axotomy of peripheral nerves in neonatal rats induces motoneuron death that can be delayed but not arrested by the application of several neurotrophic factors (NFs) or adenoviral vectors carrying genes for NFs. We tested whether an adenoviral vector carrying the gene for glial cell-line-derived neurotrophic factor (Adv.RSV-GDNF) would prevent neona...
Application of neurotrophic factors (NFs) to the cut stump of peripheral nerves confers transient (1- to 2-week) neuroprotection of motoneurons from axotomy-induced death in neonates. We tested whether lumbar spinal motoneurons would be protected from axotomy-induced death when they were genetically modified to produce NFs in situ. Adenoviral (Adv)...
The current treatment concept of ovarian cancer consists of radical surgery with subsequent chemotherapy. We have shown that adenovirus (ADV) mediated thymidine kinase (TK) gene transduction of cisplatin-resistant human ovarian cancer xenotransplanted into nude mice followed by ganciclovir (GCV) administration leads to prolongation of survival or c...
Application of neurotrophic factors (NFs) to the cut stump of motor nerves of neonatal rats confers neuroprotection from trauma-induced neuronal death. To test whether motoneurons are capable of responding to endogenously produced NFs, facial motoneurons were genetically modified in vivo to express several NFs and then tested for their response to...
The neurotoxicity of an adenoviral vector (Adv.RSVtk) carrying the gene for herpes simplex virus thymidine kinase (HSVtk) was tested in the cotton rat, a semipermissive host. Adv.RSVtk was injected intracerebrally in cotton rats at a dose of 5.0 x 10(6) or 7.5 x 10(7) p.f.u. No signs of illness were observed. Histological inspection at 12 and 28 da...
Axon caliber may be influenced by intrinsic neuronal factors and extrinsic factors related to myelination. To understand these extrinsic influences, we studied how axon-caliber expansion is related to changes in neurofilament and microtubule organization as axons of retinal ganglion cells interact with oligodendroglia and become myelinated during n...
Transduction of experimental gliomas with the herpes simplex virus thymidine kinase gene (HSV-tk) using a replication-defective adenoviral vector (ADV/RSV-tk) confers sensitivity to ganciclovir (GCV) leading to tumor destruction and prolonged host survival in rodents. To determine treatment tolerance prior to clinical trials, we conducted toxicity...
Wild-type adenoviruses (ADV) do not have neurotoxic effects and are therefore good vectors for gene therapy in the nervous system. Adenoviral vectors have been used in a variety of in vitro and in vivo studies and clinical applications of gene therapy. The high transduction efficiency characteristic of adenovirus vectors suggests that they may have...
We investigated the therapeutic efficacy of adenovirus-mediated gene therapy to treat malignant mammary tumors in vitro and in vivo in the brain. A mammary adenocarcinoma cell line derived from Fischer rats (13762 MAT B III; MAT-B) was used. In vitro studies demonstrated that the MAT-B cells could be efficiently transduced with a replication-defect...
We evaluated the efficacy of adenoviral-mediated gene therapy of experimental spinal cord tumors and the functional outcome after this treatment. Spinal cord tumors were generated in the thoracic region of the spinal cord in Fischer 344 rats by stereotaxic intramedullary injection of 1 x 10(4) 9L gliosarcoma cells. Seven days after tumor cell injec...
The efficacy of adenovirus (ADV)-mediated gene therapy to treat brain tumors was tested in a syngeneic glioma model. Tumor cells were transduced in situ with a replication-defective ADV carrying the herpes simplex virus thymidine kinase (HSV-tk) gene controlled by the Rous sarcoma virus promoter. Expression of the HSV-tk gene enables the transduced...
The therapeutic efficacy of adenovirus-mediated herpes simplex virus thymidine kinase (HSV-tk) gene transduction of rat C6 glioma cells followed by ganciclovir (GCV) administration was studied in tumors generated in the brains of nude mice. C6 glioma cells were efficiently transduced in vitro by a replicative-defective recombinant adenovirus carryi...
Schwann cells in the intact sciatic nerve express high amounts of ciliary neurotrophic factor (CNTF), but 7 days after injury to the nerve expression dramatically decreases. To determine whether this change occurs only in the region of the injury or throughout the whole nerve we examined the spatial and temporal expression of CNTF after a crush inj...
We investigated the effects of increasing the concentration of intracellular cyclic adenosine monophosphate (cAMP) on genes associated with oligodendrocyte differentiation in an immortalized glial cell line, 6E12, derived from the spinal cord of an MBP-SV40 large T-antigen transgenic mouse. Raising intracellular levels of cAMP induced expression of...
To study the effect of SV40 large T-antigen expression in myelin-forming cells of both the central and peripheral nervous system, a series of transgenic mice were generated expressing the SV40 large T-antigen under control of the myelin basic protein (MBP) promoter. Two neurologic phenotypes, designated A and B, appeared among individual transgenic...
Tight junctions may play an important role in maintaining the integrity of the blood-brain barrier. These junctions can be individually visualized using electron microscopy but no current technique is able to provide a more global picture of the presence and density of tight junctions in central nervous system tissue. We used an antibody that recog...
The neurological mutant mice shiverer (shi) and myelin deficient (shimld) lack a functional gene for the myelin basic proteins (MBP), have virtually no myelin in their CNS, shiver, seize, and die early. Mutant mice homozygous for an MBP transgene have MBP mRNA and MBP in net amounts approximately 25% of normal, have compact myelin, do not shiver or...
Ciliary neurotrophic factor (CNTF) is a 200-amino acid protein expressed in high concentrations by peripheral nerves and is thought to be important for the survival and regeneration of injured motoneurons (Lin et al., J Biol Chem 265:8942-8947, 1990). To better understand CNTF's role in nerve injury we have characterized the effects of crush injury...
The peripheral nervous system (PNS), unlike the central nervous system (CNS), has the ability for axonal regeneration after injury. As demonstrated by the grafting experiments of Aguayo and colleagues, PNS tissue supports regeneration of both PNS and CNS axons and provides evidence that the regenerative capacity of the PNS is a property of its envi...
Mice homozygous for the autosomal recessive mutation shiverer (shi) lack myelin basic protein (MBP) and exhibit a distinct behavioral pattern including tremors (shivering), convulsions, and early death. We have previously demonstrated that shiverer mice have a partial deletion in the gene encoding MBP. We now have introduced the wild-type MBP gene...
Mice homozygous for the mutation myelin deficient (mld), an allele of shiverer, exhibit decreased CNS myelination, tremors, and convulsions of progressively increasing severity leading to an early death. In this report we demonstrate in mld mice that the gene encoding myelin basic protein (MBP) is expressed at decreased levels and on an abnormal te...
A new type of collagen surface for use with cultures of peripheral nervous system cells is described. Collagen is derivatized to plastic culture dishes by a cross-linking reagent, l-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide-metho-p-toluene sulfonate (carbodiimide), to form a uniform and durable surface for cell attachment and growth that allows...
A new type of collagen surface for use with cultures of peripheral nervous system cells is described. Collagen is derivatized
to plastic culture dishes by a cross-linking reagent, 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide-metho-p-toluenesulfonate (carbodiimide), to form a uniform and durable surface for cell attachment and growth that allows...
Axons of a cut peripheral nerve will grow across a gap (less than or equal to 10 mm in adult rodents) formed when the proximal and distal stumps are placed at opposite ends of an impermeable, inert tube, but will not grow to the end of a blind-ended tube in the absence of the distal stump [Williams et al, 1984]. Work reported here demonstrates that...
Shiverer (shi) is an autosomal recessive mutation in mice that results in hypomyelination in the central nervous system (CNS) but normal myelination in the peripheral nervous system (PNS). Myelin basic proteins (MBPs) are virtually absent in both PNS and CNS. It is not known whether the cellular target in the PNS is the myelin-forming Schwann cell...
In order to determine the cellular localization of gamma-glutamyl transpeptidase (gamma-GTP) in the nervous system the enzyme was purified to homogeneity and used to prepare an antiserum in rabbits. The anti-gamma-GTP serum cross-reacted with rodent tissues, but not those of human, monkey, calf, sheep or chicken. Monospecificity of the antibody was...
A new fluorometric assay was developed for the measurement of gamma-glutamyl transpeptidase (gamma-GTP). The assay utilizes as a substrate the synthetic compound 7-gamma-glutamylamido-4-methyl coumarin which is cleaved by gamma-GTP to yield the highly fluorescent product 7-amino-4-methyl coumarin. Optimal excitation and emission wavelengths for the...
Levels of 7S nerve growth factor in various tissues of the Golden Hamster were measured using a new assay procedure. The assay consisted of labelling native 7S nerve growth factor by allowing an 125Ilabelled subunit ([125I] α) of 7S nerve growth factor to compete with the native α subunit. The presence of 7S nerve growth factor was noted in a wide...
— The 7S Nerve Growth Factor (NGF) found in mouse is a protein composed of three dissimilar subunits designated α, γ, and β. Mouse NGF reversibly dissociates into its component subunits at pH values lower than 5 or greater than 8. The 7S protein complex is in fast equilibrium wiih the free subunits. A quantitative determination of 7S NGF based on t...
Shiverer(shi)isan autosomal recessivemutation inmice thatresultsinhypomye- linationinthecentralnervous system (CNS) but normal myelinationinthe peripheralnervous system (PNS).Myelin basicproteins(MBPs) arevirtually absentinboth PNS and CNS .Itisnot known whether the cellulartargetinthe PNS isthe myelin-formingSchwann cellor another celltype which s...