Biomedical subjects

David J Fink

Publications and source records attributed to David J Fink.

At least 37 records · Page 2Linked to original sources

PubMed2004

Delivery of herpes simplex virus-based vectors to stem cells.

In contrast to traditional drugs that generally act by altering existing gene product function, gene therapy aims to target the root cause of the disease by altering the genetic makeup of the cell to treat the disease. Researchers have adapted several classes of viruses as gene-transfer vectors, taking advantage of natural viral mechanisms designed to efficiently and effectively deliver DNA to the host-cell nucleus. Among these, the human herpesviruses are excellent candidate vectors for a variety of applications. Herpes simplex virus type 1 (HSV-1) is a particularly attractive gene-transfer vehicle because natural infection in humans includes a latent state in which the viral genome persists in a nonintegrated form without causing disease in an immune-competent host. HSV-1 is a large DNA virus with a broad host range that can be engineered to accommodate multiple or large therapeutic transgenes (4). HSV vectors may be generally useful for gene transfer to a variety of tissues in which short-term or extended transgene expression of therapeutic transgenes achieve a therapeutic effect. We have used therapeutic vectors to successfully treat human disease models in animals, including cancer, Parkinson's disease, and nerve damage (5-10).

Animals↗

PubMed2003

Stem cell therapy in a caprine model of osteoarthritis.

OBJECTIVE: To explore the role that implanted mesenchymal stem cells may play in tissue repair or regeneration of the injured joint, by delivery of an autologous preparation of stem cells to caprine knee joints following induction of osteoarthritis (OA). METHODS: Adult stem cells were isolated from caprine bone marrow, expanded in culture, and transduced to express green fluorescent protein. OA was induced unilaterally in the knee joint of donor animals by complete excision of the medial meniscus and resection of the anterior cruciate ligament. After 6 weeks, a single dose of 10 million autologous cells suspended in a dilute solution of sodium hyaluronan was delivered to the injured knee by direct intraarticular injection. Control animals received sodium hyaluronan alone. RESULTS: In cell-treated joints, there was evidence of marked regeneration of the medial meniscus, and implanted cells were detected in the newly formed tissue. Degeneration of the articular cartilage, osteophytic remodeling, and subchondral sclerosis were reduced in cell-treated joints compared with joints treated with vehicle alone without cells. There was no evidence of repair of the ligament in any of the joints. CONCLUSION: Local delivery of adult mesenchymal stem cells to injured joints stimulates regeneration of meniscal tissue and retards the progressive destruction normally seen in this model of OA.

Animals↗

PubMed2003

Enhanced functional recovery after proximal nerve root injury by vector-mediated gene transfer.

In order to test the functional implication of herpes simplex virus (HSV) vector-mediated gene transfer after axonal injury, we injected replication-incompetent HSV vectors coding for the anti-apoptotic peptide Bcl-2 and the glial cell-derived neurotrophic factor (GDNF), separately or in combination into ventral spinal cord 30 min after a crush injury to the proximal spinal root that was combined with moderate mechanical traction. HSV-mediated expression of Bcl-2 or GDNF enhanced functional recovery assessed by histologic, electrophysiologic, and behavioral parameters up to 5 months after injury. The most sensitive measure of distal motor function, the sciatic function index, was significantly improved in animals injected with the two vectors together. These results suggest an approach to root trauma that might be used to enhance functional recovery after injury.

Animals↗

PubMed2003

Development of HSV-mediated gene transfer for the treatment of chronic pain.

Chronic pain is often difficult to treat effectively. We have exploited the high affinity of herpes simplex virus (HSV) for peripheral sensory neurons to create HSV-based vectors for the treatment of chronic pain. We have demonstrated that an HSV-based vector expressing proenkephalin reduces pain-related responses in rodent models of inflammatory pain, neuropathic pain, and pain resulting from cancer in bone. A human trial has been proposed.

Animals↗

PubMed2003

Therapeutic gene transfer with herpes-based vectors: studies in Parkinson's disease and motor nerve regeneration.

We have examined the possibility of using herpes simplex virus (HSV)-based vectors to prevent neuronal cell death and enhance functional recovery after injury. In the 6-hydroxydopamine (6-OHDA) model of Parkinson's disease (PD) and after proximal spinal root injury, direct stereotactic injection of HSV-based vectors constructed to express the glial cell derived neurotrophic factor (GDNF) or the anti-apoptotic peptide Bcl-2 prevented neuronal death and enhanced recovery. Gene transfer may be useful in the treatment of neurologic disorders in which neuronal cell death occurs in a restricted anatomic distribution.

Animals↗

PubMed2003

Transgene-mediated enkephalin release enhances the effect of morphine and evades tolerance to produce a sustained antiallodynic effect in neuropathic pain.

We examined the pharmacologic characteristics of herpes simplex virus (HSV) vector-mediated expression of proenkephalin in the dorsal root ganglion in a rodent model of neuropathic pain. We found that: (i). vector-mediated enkephalin produced an antiallodynic effect that was reversed by naloxone; (ii). vector-mediated enkephalin production in animals with spinal nerve ligation prevented the induction of c-fos expression in second order sensory neurons in the dorsal horn of spinal cord; (iii). the effect of vector-mediated enkephalin enhanced the effect of morphine, reducing the ED(50) of morphine 10-fold; (iv). animals did not develop tolerance to the continued production of vector-mediated enkephalin over a period of several weeks; and, (v). vector transduction continued to provide an analgesic effect despite the induction of tolerance to morphine. This is the first demonstration of gene transfer to provide an analgesic effect in neuropathic pain. The pharmacologic analysis demonstrates that transgene-mediated expression and local release of opioid peptides produce some effects that are distinct from peptide analogues delivered pharmacologically.

Animals↗

PubMed2003

HSV-mediated gene transfer of the glial cell-derived neurotrophic factor provides an antiallodynic effect on neuropathic pain.

Neuropathic pain is a difficult clinical problem that is often refractory to medical management. Glial-derived neurotrophic factor (GDNF) administered intrathecally has been shown to prevent or reduce pain in an animal model of neuropathic pain, but cannot be delivered in the required doses to treat human pain. We have previously demonstrated that peripheral subcutaneous inoculation of a replication-incompetent herpes simplex virus (HSV)-based vector can be used to transduce neurons of the dorsal root ganglion. To examine whether HSV-mediated expression of GDNF could be used to ameliorate neuropathic pain, we constructed a replication-incompetent HSV vector expressing GDNF. Subcutaneous inoculation of the vector 1 week after spinal nerve ligation resulted in a continuous antiallodynic effect that was maintained for 3-4 weeks. Reinoculation of the vector reestablished the antiallodynic effect with a magnitude that was at least equivalent to the initial effect. Vector-mediated GDNF expression blocked the nonnoxious touch-induced increase in c-fos expression in dorsal horn characteristic of the painful state. Gene transfer to produce a trophic factor offers a novel approach to the treatment of neuropathic pain that may be appropriate for human therapy.

Animals↗

PubMed2003

Protective effect of HSV-mediated gene transfer of nerve growth factor in pyridoxine neuropathy demonstrates functional activity of trkA receptors in large sensory neurons of adult animals.

The distinct distribution of trkA receptors on small neurons and trkC receptors on large neurons in the dorsal root ganglion correlates with the dependence of these two classes of neurons on nerve growth factor and neurotrophin-3, respectively, for survival during development. In adult animals, the distribution of high affinity neurotrophin (trk) is complex and overlapping; neurotrophins are not required for cell survival, but may influence cell phenotype and the response to injury. In order to test the functional activity of trkA receptors in the sensory ganglia of adult animals in vivo, we examined the ability of a nerve growth factor-expressing recombinant replication-defective herpes simplex virus-based vector to prevent the selective degeneration of large sensory fibres caused by intoxication with pyridoxine. Transduction of dorsal root ganglion neurons in vivo by subcutaneous inoculation of the nerve growth factor-expressing vector prevented the development of pyridoxine-induced neuropathy measured by electrophysiological, morphological and behavioural measures. These results demonstrate a functional activity of trkA receptors expressed on large neurons in the dorsal root ganglion in mature animals; this observation has important implications for the choice of neurotrophic factors for treatment of peripheral nerve disease.

Animals↗

PubMed2003

Therapeutic gene transfer to the nervous system using viral vectors.

The past few years have been marked by substantial progress in preclinical studies of therapeutic gene transfer for neurologic disease using viral-based vectors. In this article, the authors review the data regarding (1). treatment of focal neuronal degeneration, exemplified by Parkinson disease, ischemia, and trauma models; (2). treatment of global neurologic dysfunction, exemplified by the mucopolysaccharidoses and other storage diseases; (3). peripheral nervous system diseases including motor neuron disease and sensory neuropathies; and (4). the use of vectors expressing neurotransmitters to modulate functional neural activity in the treatment of pain. The results suggest that a number of different viral vectors may be appropriate for gene transfer to the central nervous system for specific disease processes, and that for the peripheral nervous system herpes simplex virus-based vectors appear to have special utility. The results of the first human gene therapy trials for neurologic disease, which are just now beginning, will be crucial in defining the next step in the development of this therapy.

Animals↗

PubMed2003

Gene transfer to the nervous system: prospects for novel treatments directed at diseases of the aging nervous system.

In the past 3 decades, gene therapy has moved from a theoretical construct to an active field of basic research, animal studies, and clinical trials. In this article, we describe the conceptual basis underlying the use of gene therapy for diseases of the aging nervous system, the principal techniques used for gene delivery, and review preclinical animal studies in 4 different classes of neurologic dysfunction: 1) focal neuronal degeneration in the central nervous system; 2) global neuronal dysfunction in the central nervous system; 3) degenerative disease affecting components of the peripheral nervous system; and 4) intractable focal pain. The full potential of this approach will not be established until the human trials are completed.

Aging↗

PubMed2003

Nifedipine potentiates the antinociceptive effect of endomorphin-1 microinjected into the periaqueductal gray in rats.

UNLABELLED: Endomorphin-1 is a novel endogenous mu-opioid ligand. We investigated the antinociceptive interaction between endomorphin-1 and nifedipine, an L-type calcium channel blocker, microinjected into the midbrain ventrolateral periaqueductal gray (vPAG), using the spinally-organized tail-flick test and the supraspinally-organized tail-pressure test in rats. Sprague-Dawley rats were stereotaxically implanted with a guide cannula lowered into the vPAG. Microinjection of endomorphin-1 into the vPAG led to dose-related increases in antinociceptive responses in the tail-flick test and tail-pressure test. Pretreatment with the mu-opioid receptor-selective antagonist beta-funaltrexamine blocked the antinociceptive effect of endomorphin-1. Pretreatment with beta-funaltrexamine alone had no effect on the tail-flick latency and tail-pressure threshold. Microinjection of nifedipine alone into the vPAG did not produce an antinociceptive response in the tail-flick test and tail-pressure test. However, injection of nifedipine into the vPAG potentiated the antinociceptive effect of endomorphin-1, producing a significant leftward shift in the dose-response curve of endomorphin-1 in both the tail-flick and tail-pressure tests. This result shows that the potent antinociceptive effect of endomorphin-1 microinjected into the vPAG is mediated through the mu-opioid receptor and is potentiated by concomitant administration of nifedipine. IMPLICATIONS: This study shows that the potent antinociceptive effect of endomorphin-1 microinjected into the ventrolateral periaqueductal gray is potentiated by concomitant administration of nifedipine. This suggests that calcium channel blockers may enhance the analgesia of opioids in patients with calcium channel blocker treatment.

Analgesics, Opioid↗

PubMed2003

Exploiting the neurotherapeutic potential of peptides: targeted delivery using HSV vectors.

Neurotrophic factors and peptide neurotransmitters represent two classes of potent macromolecules whose therapeutic use in the treatment of neurologic disease is limited by unwanted effects that result from the widespread distribution of cognate receptors within and beyond the neuraxis. Targeted gene delivery to sensory neurons of the dorsal root ganglion (DRG) by subcutaneous inoculation of herpes simplex virus (HSV)-based gene transfer vectors may be used to achieve local expression and release of these pleiotropic, short-lived molecules in a restricted area. Recent studies demonstrate that HSV-mediated transfer of genes coding for neurotrophic factors prevents the progression of disease in animal models of drug-induced or diabetic polyneuropathy and that HSV-mediated transfer of genes coding for inhibitory neurotransmitters provides a regional analgesic effect in animal models of chronic pain. The first human trial of HSV-mediated gene transfer to DRG is about to commence. HSV-mediated gene transfer may allow the therapeutic potential of these peptides for the treatment of neurologic disease to be realised.

Enkephalins↗

PubMed2003

Gene therapy for chronic pain.

The dorsal horn of the spinal cord represents an attractive site for interventions designed to treat chronic pain, but it has been difficult to identify small molecules that act selectively on pain transmission at the spinal level. One approach is the use of viral vector-mediated gene transfer to achieve focal production and release of short-lived analgesic peptides. Herpes simplex virusbased vectors, expressing proenkephalin delivered by subcutaneous inoculation, transduce neurons of the dorsal root ganglion, leading to release of enkephalin from nerve terminals in dorsal horn to produce an analgesic effect in several models of chronic pain. A clinical trial is set to commence.

Adenoviridae↗

PubMed2002

In vivo gene therapy for pyridoxine-induced neuropathy by herpes simplex virus-mediated gene transfer of neurotrophin-3.

Neurotrophic factors have been demonstrated to prevent the development of peripheral neuropathy in animal models, but the therapeutic use of these factors in human disease has been limited by the short serum half-life and dose-limiting side effects of these potent peptides. We used peripheral subcutaneous inoculation with a replication-incompetent, genomic herpes simplex virus-based vector containing the coding sequence for neurotrophin-3 to transduce sensory neurons of the rat dorsal root ganglion in vivo, and found that expression of neurotrophin-3 from the vector protected peripheral sensory axons from neuropathy induced by intoxication with pyridoxine assessed by electrophysiological (foot sensory response amplitude, and conduction velocity, and H-wave), histological (nerve morphology and morphometry), and behavioral measures of proprioceptive function. In vivo gene transfer using herpes simplex virus vectors provides a unique option for treatment of diseases of the sensory peripheral nervous system.

Animals↗

PubMed2002

Herpes vector-mediated expression of proenkephalin reduces bone cancer pain.

We examined whether a herpes simplex virus vector that expresses human proenkephalin could be used to attenuate nociception in a model of bone cancer pain in mice. Osteolytic sarcoma cells were implanted into the medullary space of the right femur, followed by a subcutaneous inoculation of a replication-defective herpes simplex virus vector expressing human proenkephalin (vector SHPE) or a lacZ-expressing control vector (vector SHZ). SHPE-inoculated mice demonstrated a significant, naltrexone-reversible decrease in pain-related behavior assessed during open-field motor activity. These results suggest that gene transfer with an enkephalin-expressing vector may be used to treat pain resulting from cancer in bone.

Animals↗

PubMed2002

Targeted gene delivery to the nervous system using herpes simplex virus vectors.

Neurotrophic factors are highly potent macromolecules with protean effects. Although they are highly effective in vitro and in animal models in vivo, they have not been successfully applied to the treatment of human disease. Our laboratories have developed recombinant herpes simplex virus (HSV)-based vectors, that we have demonstrated may be used to deliver and express neurotrophic factor genes in dorsal root ganglion neurons to protect against the development of neuropathy in animal models, without causing systemic side effects. In a similar fashion, we have demonstrated that a vector expressing proenkephalin to mediate the release of opioid peptides from afferent nerve terminals in the spinal cord can be used to produce a localized antinociceptive effect in animal models of pain. Targeted gene delivery using HSV-based vectors offers a means to utilize short-lived peptides to produce specific effects in the nervous system.

Animals↗

PubMed2002

The relationship of herpes simplex virus latency associated transcript expression to genome copy number: a quantitative study using laser capture microdissection.

To investigate the quantitative relationship of latent herpes simplex virus (HSV) genomes to the expression of latency associated transcripts (LATs) we used a combination of laser capture microdissection (LCM), polymerase chain reaction (PCR), and quantitative real-time PCR to determine the number of HSV genomes in individual neurons of the mouse trigeminal ganglion (TG) during viral latency. Both LAT-positive and LAT-negative neurons detected by in situ hybridization (ISH) and lifted by LCM contained HSV genomes detected by PCR for HSV ICP47. The number of genomes/cell determined by real-time PCR with probes for HSV UL44 following LCM demonstrated a Poisson distribution with a predicted mean count of 178 genomes/LAT-positive neuron, and 68 genomes/LAT-negative neuron. The range was similar between the LAT-positive and LAT-negative neurons, and there was a substantial overlap in the distributions. These results suggest that the expression of LATs in an amount that is detectable by ISH does not depend only on the number of HSV genomes in the cell, and by implication suggests that neuron-specific factors play a role in the regulation of LAT expression during latency.

Animals↗

PubMed2002

Bcl-2 and GDNF delivered by HSV-mediated gene transfer after spinal root avulsion provide a synergistic effect.

Proximal spinal nerve injury results in the death of motor neurons in ventral horn. We have previously demonstrated this cell death can be prevented by HSV-mediated transfer of the gene coding for the antiapoptotic peptide Bcl-2 7 days prior to injury, but that expression of Bcl-2 does not preserve ChAT expression in the lesioned cells. In the current study, we examined two related issues: whether Bcl-2 delivered by HSV-mediated gene transfer 30 min after injury could similarly protect motor neurons from cell death, and whether the additional HSV-mediated expression of the glial cell derived neurotrophic factor (GDNF) could improve the result. At 30 min after avulsion of the L4, L5, and L6 spinal nerves, replication defective genomic HSV-based vectors coding for Bcl-2, GDNF, a reporter transgene (lacZ), or the Bcl-2 and GDNF vectors together were injected into spinal cord. Transduction of motor neurons with either the Bcl-2-expressing vector or the GDNF-expressing vector resulted in a substantial increase in the number of surviving motor neurons, and coinjection of the two vectors together resulted in cell survival that was similar to the result obtained with either vector alone. Neither the Bcl-2-expressing vector nor the GDNF-expressing vector delivered alone protected choline acetyltransferase (ChAT) expression in lesioned neurons. However, simultaneous injection of the Bcl-2- and the GDNF-expressing vectors together resulted in a substantial increase in the number of ChAT in cells in the lesioned ventral horn. Together, these findings suggest an approach to improving cell survival and regeneration following proximal root injury.

Animals↗