Search PubMed⌕ Search

Biomedical subjects

David J Fink

Publications and source records attributed to David J Fink.

At least 19 recordsLinked to original sources
PubMed2006

HSV-mediated delivery of erythropoietin restores dopaminergic function in MPTP-treated mice.

To investigate the neuroprotective effects of erythropoietin (EPO) in a rodent model of Parkinson disease, we inoculated a nonreplicating herpes simplex virus-based vector expressing EPO (vector DHEPO) into the striatum of mice 1 week prior to, or 2 weeks after, the start of continual administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (4 mg/kg intraperitoneally, 5 of 7 days) for 6 weeks. Inoculation with DHEPO prior to MPTP intoxication preserved behavioral function measured by pellet retrieval and the histological markers of tyrosine hydroxylase-immunoreactive (TH-IR) neuronal cell bodies in the substantia nigra (SN) and TH-IR and dopamine transporter-immunoreactive (DAT-IR) terminals in striatum. Inoculation of DHEPO 2 weeks into a 6-week course of MPTP resulted in improvement of behavioral function and restoration of TH-IR cells in SN and TH- and DAT-IR in the striatum. The effects of vector-produced EPO were similar in magnitude to the effects of vector-mediated expression of glial-derived neurotrophic factor in the same model. These results demonstrate that vector-mediated EPO production may be used to reverse dopaminergic neurodegeneration in the face of continued toxic insult.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2006

Vector-mediated gene transfer to express inhibitory neurotransmitters in dorsal root ganglion reduces pain in a rodent model of lumbar radiculopathy.

STUDY DESIGN: A prospective in vivo animal study. OBJECTIVES: To examine the effect of the proenkephalin and glutamic acid decarboxylase (GAD)-expressing herpes simplex virus (HSV)-based vectors in a rodent model of lumbar radiculopathy. SUMMARY OF BACKGROUND DATA: We have previously shown that nonreplicating HSV-based vectors coding for proenkephalin or GAD can be used to transduce dorsal root ganglion (DRG) neurons in vivo to produce enkephalin or gamma-aminobutyric acid. HSV-mediated gene transfer of proenkephalin or GAD to DRG reduces pain-related behavior in rodent models of peripheral neuropathic pain. METHODS: We created a model of lumbar radiculopathy by ligation of the dorsal and ventral lumbar roots proximal to the DRG. Three days later, we inoculated nonreplicating HSV-based vectors coding for proenkephalin or GAD subcutaneously in the foot. RESULTS: Subcutaneous inoculation of either vector 3 days after ligation of the dorsal and ventral L5 lumbar roots resulted in a substantial and significant reduction in pain-related behavior (mechanical allodynia). Vector-mediated reduction in pain-related behavior was higher in magnitude and longer in duration after inoculation of the GAD-expressing vector than that achieved by the inoculation of the proenkephalin-expressing vector. CONCLUSIONS: HSV-mediated gene transfer provides a novel method for treating chronic neuropathic pain related to lumbar root injury in rodents.

Animals↗
PubMed2006

HSV-mediated expression of interleukin-4 in dorsal root ganglion neurons reduces neuropathic pain.

BACKGROUND: To examine the role of inflammatory mediators in neuropathic pain, we used a replication-defective genomic herpes simplex virus (HSV)-based vector containing the coding sequence for the anti-inflammatory peptide interleukin (IL)-4 under the transcriptional control of the HSV ICP4 immediate early promoter, vector S4IL4, to express IL-4 in dorsal root ganglion (DRG) neurons in vivo. RESULTS: Subcutaneous inoculation of S4IL4 in the foot transduced lumbar DRG to produce IL-4. Transgene-mediated expression of IL-4 did not alter thermal latency or tactile threshold in normal animals, but inoculation of S4IL4 1 week after spinal nerve ligation (SNL) reduced mechanical allodynia and reversed thermal hyperalgesia resulting from SNL. Inoculation of S4IL4 1 week before SNL delayed the development of thermal hyperalgesia and tactile allodynia, but did not prevent the ultimate development of these manifestations of neuropathic pain. S4IL4 inoculation suppressed non-noxious-induced expression of c-Fos immunoreactivity in dorsal horn of spinal cord and reversed the upregulation of spinal IL-1beta, PGE2, and phosphorylated-p38 MAP kinase, characteristic of neuropathic pain. CONCLUSION: HSV-mediated expression of IL-4 effectively reduces the behavioral manifestations of neuropathic pain, and reverses some of the biochemical and histologic correlates of neuropathic pain at the spinal level.

Animals↗
PubMed2006

Release of GABA from sensory neurons transduced with a GAD67-expressing vector occurs by non-vesicular mechanisms.

We have demonstrated that dorsal root ganglion neurons transduced with a recombinant replication-defective herpes simplex virus vector coding for glutamic acid decarboxylase (QHGAD67) release GABA to produce an analgesic effect in rodent models of pain. In this study, we examined the mechanism of transgene-mediated GABA release from dorsal root ganglion neurons in vitro and in vivo. Release of GABA from dorsal root ganglion neurons transduced with QHGAD67 was not increased by membrane depolarization induced by 60 mM extracellular K+ nor reduced by the removal of Ca2+ from the medium. Release of GABA from transduced dorsal root ganglion neurons was, however, blocked in a dose-dependent manner by NO-711, a selective inhibitor of the GABA transporter-1. The amount of GABA released from a spinal cord slice preparation, prepared from animals transduced by subcutaneous inoculation of QHGAD67 in the hind paws, was substantially increased compared to animals transduced with control vector Q0ZHG or normal animals, but the amount of GABA released was not changed by stimulation of the dorsal roots at either low (0.1 mA, 0.5-ms duration) or high (10 mA, 0.5-ms duration) intensity. We conclude that QHGAD67-mediated GABA release from dorsal root ganglion neurons is non-vesicular, independent of electrical depolarization, and that this efflux is mediated through reversal of the GABA transporter.

Analysis of Variance↗
PubMed2006

Tumor necrosis factor-alpha contributes to below-level neuropathic pain after spinal cord injury.

OBJECTIVE: Our objective was to elucidate the mechanisms responsible for below-level pain after partial spinal cord injury (SCI). METHODS: We used lateral hemisection to model central neuropathic pain and herpes simplex viral (HSV) vector-mediated transfer of the cleaved soluble receptor for tumor necrosis factor-alpha (TNF-alpha) to evaluate the role of TNF-alpha in the pathogenesis of below-level pain. RESULTS: We found activation of microglia and increased expression of TNF-alpha below the level of the lesion in the lumbar spinal cord after T13 lateral hemisection that correlated with emergence of mechanical allodynia in the hind limbs of rats. Lumbar TNF-alpha had an apparent molecular weight of 27 kDa, consistent with the full-length transmembrane form of the protein (mTNF-alpha). Expression of the p55 TNF soluble receptor (sTNFRs) by HSV-mediated gene transfer resulted in reduced pain behavior and a decreased number of ED1-positive cells, as well as decreased phosphorylation of the p38 MAP kinase (p-p38) and diminished expression of mTNF-alpha in the dorsal horn. INTERPRETATION: These results suggest that expression of mTNF-alpha after injury is related to development of pain, and that reverse signaling through mTNF-alpha by sTNFR at that level reduces cellular markers of inflammatory response and pain-related behavior.

Animals↗
PubMed2006

Gene therapy for the treatment of sensory neuropathy.

Sensory polyneuropathy can be a serious problem, but for the majority of clinically important neuropathies there are no available therapies. Neurotrophic and neuroprotective peptide factors have been identified that prevent or reverse neuropathy in rodent models of disease, but delivery of these highly pleiotropic peptides has posed an obstacle for translation into effective human therapies. Gene transfer into muscle using viral or non-viral vectors, or into neurons of the dorsal root ganglion using herpes simplex virus-based vectors, provides an alternative means to achieve this end. Studies in animal models have been promising, and the first human trial, using a plasmid to transfer the gene coding for vascular endothelial growth factor into muscle for the treatment of diabetic neuropathy, is now underway. Evidence supporting the trial and the challenges facing this therapy are reviewed.

Animals↗
PubMed2005

Gene transfer of glutamic acid decarboxylase reduces neuropathic pain.

We tested whether transfer of the gene coding for glutamic acid decarboxylase to dorsal root ganglion using a herpes simplex virus vector to achieve release of GABA in dorsal horn would attenuate nociception in this condition. Subcutaneous inoculation of a replication-defective herpes simplex virus vector expressing glutamic acid decarboxylase (vector QHGAD67) 7 days after selective L5 spinal nerve ligation reversed mechanical allodynia and thermal hyperalgesia; the antiallodynic effect lasted 6 weeks and was reestablished by reinoculation. QHGAD67 inoculation also suppressed induction of c-Fos and phosphorylated extracellular signal-regulated kinase 1 and 2 in the spinal cord.

Animals↗
PubMed2005

Long-term neuroprotection achieved with latency-associated promoter-driven herpes simplex virus gene transfer to the peripheral nervous system.

We examined the ability of the herpes simplex virus (HSV) latency-associated promoter (LAP2) to drive biologically relevant prolonged transgene expression in the peripheral nervous system. Rat dorsal root ganglia were transduced in vivo by subcutaneous inoculation of replication-incompetent HSV-based vectors containing nerve growth factor (NGF) or neurotrophin-3 (NT-3) under the control of LAP2 (vectors SLN and QLNT3, respectively) and vector SHN expressing NGF under the control of the human cytomegalovirus immediate early promoter. Twenty-four weeks later a pure sensory neuropathy was induced by overdose of pyridoxine (PDX), and the animals were assessed 6 months after inoculation. Inoculation of SLN, but not SHN, attenuated the nerve damage caused by PDX and protected foot sensory amplitude, H-wave amplitude, and behavioral measures of proprioceptive function. QLNT3 was more effective than SLN in preserving the largest myelinated fibers from degeneration. These results indicate that expression of NGF or NT-3 driven by LAP2 is sufficient to prevent the development of neuropathy 6 months after vector inoculation in rats.

Animals↗
PubMed2005

Use of laser capture microdissection together with in situ hybridization and real-time PCR to study distribution of latent herpes simplex virus genomes in mouse trigeminal ganglia.

The herpes simplex virus (HSV) frequently establishes a latent state in neurons, which can then be reactivated from the infected neurons. Quantifying the single-cell viral load is essential for understanding latency and reactivation of this virus. In this chapter the methods of laser capture microdissection and quantitative real-time polymerase chain reaction with in situ hybridization have been combined to determine the HSV copy number per neuron in latently infected trigeminal ganglia. The distribution of latent herpes simplex genomes at the individual cell level has been deteremined and the relationship of the number of latent genomes to the expression of latency-associated transcripts established.

Animals↗
PubMed2005

Replication-defective genomic HSV gene therapy vectors: design, production and CNS applications.

Herpes simplex virus (HSV) is a neurotropic double-stranded DNA virus. In an unmodified form it is a human pathogen, causing recurrent cold sores, keratitis and, rarely, severe encephalitis. Elimination of pathogenic functions results in the generation of a valuable gene transfer vector for neurological applications. Replication-defective genomic HSV-based vectors are highly infectious, and efficiently transduce and express transgenes in a broad range of both dividing and non-dividing cells. Clinically relevant yields of clinical grade vector can be produced by growth in cell lines that complement the viral functions that are deleted in the vectors to eliminate pathogenicity. The viral genome is over 150 kb in length and many of the viral genes may be deleted without compromising viral growth in vitro, and therefore large or multiple transgenes can be accommodated within the vectors. The wild-type virus adopts a lifelong latent state in neurons of sensory ganglia. This property can be exploited in the generation of vectors to allow long-term transgene expression in neurons. In this review, we summarize recent progress in the areas of vector development and vector production, and in developing gene transfer therapeutics to treat malignant glioma.

Animals↗
PubMed2004

Protective effect of herpes simplex virus-mediated neurotrophin gene transfer in cisplatin neuropathy.

Attempts to develop clinical treatments for neuropathy using neurotrophins have not been successful. We tested whether neurotrophin gene delivery to dorsal root ganglia (DRGs) using non-replicating herpes simplex virus (HSV)-based vectors could prevent the development of neuropathy caused by administration of cisplatin. Following subcutaneous inoculation of HSV vectors expressing nerve growth factor (NGF) or neurotrophin-3 (NT-3), neurons in the DRG were transduced to produce NGF or NT-3 in vivo. Inoculation of either the NGF- or the NT-3-expressing vectors 3 days before the start of a 6-week course of cisplatin treatment protected against cisplatin-induced neuropathy assessed by electrophysiological, histological and behavioural measures 2 months later. Iatrogenic neuropathy caused by administration of chemotherapeutic drugs represents an excellent target for a human trial to assess the potential of gene therapy to prevent neuropathy.

Animals↗
PubMed2004

Prolonged biologically active transgene expression driven by HSV LAP2 in brain in vivo.

Herpes simplex virus (HSV) naturally establishes a life-long latent state in neurons, characterized by the expression of latency-associated transcripts (LATs) in the absence of viral lytic functions, and the latency-associated promoter (LAP2) has been identified as a moveable element responsible for the expression of LATs from latent HSV genomes. Prolonged transgene expression will be required for the treatment of chronic diseases of the CNS using HSV vectors. We therefore examined the ability of LAP2 to drive prolonged expression of a biologically active transgene from latent HSV vector genomes in brain in vivo using the 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) models of Parkinson disease. A replication-incompetent HSV vector containing the glial cell-derived neurotrophic factor (GDNF) under the control of LAP2 was injected into the substantia nigra and 5 and a half months later 6-OHDA was injected into the striatum. GDNF expression from the vector preserved dopaminergic function measured by histology and behavior 6 months after vector inoculation. Mice inoculated with the LAP2-GDNF replication-incompetent HSV vector followed by 3 months of daily low-dose MPTP injections were substantially protected against the consequences of that treatment measured by weekly behavioral testing and histologic measures at the conclusion of the experiment. These studies using subacute and chronic models of neurodegeneration demonstrate that the HSV LAP2 promoter element provides prolonged expression of relevant amounts of a transgene to produce significant biological effects in brain in vivo over the course of many months.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2004

Peripherally delivered glutamic acid decarboxylase gene therapy for spinal cord injury pain.

Neuropathic pain after spinal cord injury (SCI) represents a difficult problem that is commonly refractory to conventional medical management. To determine if spinal release of gamma-amino butyric acid (GABA) could reduce below-level central neuropathic pain after SCI, we constructed a replication-incompetent herpes simplex virus (HSV)-based vector encoding one isoform of human glutamic acid decarboxylase (GAD67). Dorsal root ganglion (DRG) neurons transduced in vitro or in vivo by subcutaneous inoculation produced GAD and released GABA constitutively. T13 spinal cord hemisection resulted in central neuropathic pain manifested by mechanical allodynia and thermal hyperalgesia. Subcutaneous inoculation of the vector into both feet reduced both manifestations of below-level SCI pain; the vector-mediated effect was partially reversed by intrathecal bicuculline or phaclofen at doses that did not affect thresholds in normal or injured uninoculated animals. Vector-mediated GABA release attenuated the increase in spinal calcitonin gene-related peptide immunoreactivity caused by cord hemisection. These results suggest that HSV-mediated gene transfer to DRG could be used to treat below-level central neuropathic pain after incomplete SCI.

Animals↗
PubMed2004

Central sprouting of uninjured small fiber afferents in the adult rat spinal cord following spinal nerve ligation.

Partial nerve injury results in chronic pain that is difficult to treat effectively. To investigate the anatomic basis of this phenomenon we used wheat germ agglutinin-horseradish peroxidase (WGA-HRP) to label the central projections of uninjured small fibers (Adelta and C) in a well-established model of neuropathic pain created by selective spinal nerve ligation in the adult. We found extensive sprouting of uninjured WGA-HRP-labeled afferents into the central termination field in lamina II of dorsal horn normally occupied by L5 afferents whose peripheral axons had been ligated distal to the dorsal root ganglion. The formation of new projections by uninjured fibers into a functionally but not anatomically deafferented field in the adult may play a role in the development of chronic pain.

Afferent Pathways↗
PubMed2004

Herpes vector-mediated gene transfer in treatment of diseases of the nervous system.

Vectors constructed from recombinant herpes simplex virus (HSV) have special utility for gene transfer to the nervous system. Nonreplicating vectors created by deletion of essential immediate early genes can be propagated to high titers on complementing cell lines that provide the missing gene product(s) in trans. Direct inoculation of these vectors into neural parenchyma is effective in rodent models of brain tumor, Parkinson disease, spinal cord injury, and spinal root trauma. Subcutaneous inoculation of the HSV vectors can be used to transduce neurons of the dorsal root ganglion to provide a therapeutic effect in models of polyneuropathy and chronic regional pain. In human trials, direct injection of replication-competent HSV into brain tumors has proven safe. Human trials of nonreplicating HSV gene transfer by direct inoculation for treatment of glioblastoma and HSV gene transfer by subcutaneous inoculation for the treatment of chronic intractable pain should commence soon.

Animals↗
PubMed2004

Delivery using herpes simplex virus: an overview.

The human herpesviruses represent excellent candidate viruses for several types of gene vector applications. As a class, they are large DNA viruses with the potential to accommodate large or multiple transgene cassettes, and they have evolved to persist in a lifelong nonintegrated latent state without causing disease in the immune-competent host. Among the herpesviruses, herpes simplex virus type 1 (HSV-1) is an attractive vehicle because in natural infection, the virus establishes latency in neurons, a state in which viral genomes may persist for the life of the host as intranuclear episomal elements. The natural lifelong persistence of latent genomes in trigeminal ganglia (TG) without the development of sensory loss or histologic damage to the ganglion attests to the effectiveness of these natural latency mechanisms. Although the wild-type virus may be reactivated from latency under the influence of a variety of stresses, completely replication defective viruses can be constructed that retain the ability to establish persistent quiescent genomes in neurons, but that are unable to subsequently reactivate in the nervous system. These persistent genomes are devoid of lytic gene expression, but retain the ability to express latency-associated transcripts (LATs).

Animals↗
PubMed2004

Delivery of herpes simplex virus-based vectors to the nervous system.

Gene transfer to the nervous system is an attractive option to treat a wide variety of neurological insults. The expression of trophic factor and/or antiapoptotic genes may be beneficial in halting the slow neurodegeneration in such conditions as Parkinson's disease (4,5), the rapid neuronal cell death following trauma to the brain or spinal cord (6,7), or in treating peripheral neuropathies associated with diabetes or use of chemotherapeutic agents (8,9). Introduction of dominant-negative mutant genes or antisense RNA to treat diseases such as Huntington's disease, or transfer of genes to replace lost or mutated endogenous proteins to treat disorders such as lysosomal storage diseases, may prove useful. In addition, gene transfer to overexpress endogenous antinociceptive proteins has great potential in pain management. The problem faced by all of these applications is finding a suitable methodology that will facilitate the transfer of exogenous genes to the appropriate nerve cells; virusbased vectors have proven quite efficient in transferring genes to many different cell types.

Animals↗