Karim Hyder - Academia.edu (original) (raw)

Papers by Karim Hyder

One strategy to circumvent problems with conventional chemotherapy is to develop drugs against mo... more One strategy to circumvent problems with conventional chemotherapy is to develop drugs against more specific cancer targets. Another is to use molecularly targeted agent (MTA) combinations to circumvent tumor resistance and increase the therapeutic index. Such synergistically lethal (SL) MTA combinations, however, are not easily predicted based on our rudimentary knowledge of cancer biology and drug action mechanisms. In the first strategy, our aim was to identify genes modulating proliferation and survival in leukemic cell lines (K562, Jurkat, and Raji) using a pooled lentiviral library expressing 27,500 shRNA targeting 5,043 human pathway-associated genes. Cells were transduced by the viral library and collected at several time points. Bar-codes were amplified from genomic DNA and sequenced (Illumina GAIIx). In the second strategy, we have adapted the same approach to combinatorially screen shRNA sequences targeting 40 DNA Damage and Repair (DDR) genes to discover additive and synergistic combinations that generate a synthetic-lethal phenotype. Human mammary epithelial cancer (HMEC) cells were transduced with a 27K shRNA SL DDR lentiviral library comprised of a redundant set of 16 binary shRNA constructs for each possible gene-gene combination (1,600). The library-transduced HMEC cells were grown for ten days, then bar-codes amplified and sequenced (Illumina HiSeq2000). The viability screen with leukemic cell lines identified more than 250 essential genes for each panel of cells. Subsequent validation using single shRNA-expressing constructs showed that in each screen, about 80% of shRNAs identified did indeed lead to cell death when transduced in cells. Analysis of the identified essential genes for known biological interactions revealed several non-random clusters of interacting proteins that provide some insight into signaling pathways and protein networks specific to these cancers. The SL screen in HMEC cells identified 10 SL shRNA pair candidates including known SL shRNA pair PARP1/BRCA1. Additional analysis of lethal combinations indicated redundant, complementary, and compensatory responses in cancer cells. We believe that newly discovered hematopoietic-specific genes represent potentially novel drug targets. Moreover, they can be used to develop and establish both novel cancer targeted therapies and myeloablative conditioning regimens with decreased toxicity. Based on SL screen results in HMEC cells, we believe that comprehensive experimental annotation of SL gene-gene interactions in a wider range of cancer and normal cells will not only predict the most promising synergistic lethal combinations but also allow the development of a new generation of multi-specific, highly effective anti-cancer therapeutics with unique mechanisms of action. Citation Format: Donato Tedesco, Kyle Bonneau, Mikhail Makhanov, Debbie Deng, Karim Hyder, Paul Diehl, Costas G. Frangou, Alex Chenchik. Viability screens in leukemic and breast cancer cells with pooled lentiviral shRNA libraries identify potential therapeutic targets and synthetic or synergistic lethal interactions. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr A12.

Molecular Cancer Therapeutics, 2013

Biological Psychiatry, 2000

means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sust... more means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sustained manner. A potentially therapeutic substance is nerve growth factor (NGF), a target-derived neurotrophic factor known to influence phenotypic expression in neurons of the basal forebrain cholinergic (BFC) system. Neurons in this region provide essentially all cholinergic innervation to the cortex, have been shown to regulate cortical activity, and are involved in modulation of attention and some aspects of memory. Further, these neurons are known to degenerate as a prominent component of Alzheimer's disease. Delivery of NGF to the cholinergic basal forebrain has been shown to prevent injury-induced degeneration in both rats and primates. However, delivery of NGF to extensive areas of the brain can induce hyperalgesia, hypophagia, weight loss, and sprouting of sensory and sympathetic neurons into the central nervous system. NGF, delivered to the BFC neurons by intraparenchymal ex vivo gene therapy, was previously demonstrated to reverse naturally-occurring age-related memory loss in aged rats, without inducing any of the aforementioned adverse reactions. In this study (D.E. Smith et al, PNAS 1999, Vol. 96:10893-10898), we investigated the effects of NGF on BFC neurons in the aged primate. Basal forebrain cholinergic neurons in the aged primate were found to have reduced expression of phenotype-specific markers and to have undergone cellular atrophy, when compared with younger primates. Primary autologous fibroblasts were transduced to express and secrete NGF and then transplanted into the aged primate cholinergic basal forebrain. NGF restored expression of cholinergic-specific proteins and reversed cellular atrophy in the aged primate brain. The implications of these findings to degenerative disorders in general, and FTD in particular, will be discussed.

Molecular Cancer Therapeutics, 2013

Journal of autism and developmental disorders, 2001

Studies have identified structural abnormalities in areas of the autistic brain, with a pattern s... more Studies have identified structural abnormalities in areas of the autistic brain, with a pattern suggesting that a neurodevelopmental anomaly took place. Neural cell adhesion molecule (NCAM), which is involved in development of the central nervous system, was previously shown to be decreased in the serum of autistic individuals. In the present study, we measured NCAM protein in the sera from controls, patients with autism, siblings of autistic patients, and individuals with other neurologic disorders, but found no significant differences. We also measured NCAM protein in autistic postmortem brain samples and found the longest isoform, NCAM-180, to be significantly decreased. In addition, we investigated the mRNA expression of NCAM in these brain samples using cDNA microarrays and RT-PCR. Results show that NCAM mRNA levels are not altered in autism.

Neuroscience, 2003

To determine whether the synthesis of macromolecules is increased in the cerebral cortex during s... more To determine whether the synthesis of macromolecules is increased in the cerebral cortex during sleep, we subjected C57BL/6 mice to 6 hours of sleep deprivation and then screened the expression of 1176 genes of known function by using cDNA arrays. The expression of the heat shock proteins (HSP), endoplasmic reticulum protein (ERp72) and glucose-regulated protein (GRp78), was among the genes whose expression was significantly elevated in the cortex during sleep deprivation, whereas GRp78 and GRp94 mRNAs were elevated in the cortex during recovery sleep after sleep deprivation, as confirmed by conventional and quantitative realtime polymerase chain reaction and/or Northern analyses. A systematic evaluation of the expression of six heat shock protein family members in seven brain regions revealed in-creased mRNA levels in cortex, basal forebrain, hypothalamus, cerebellum and medulla during sleep deprivation, whereas increased mRNA levels during recovery sleep were limited to the cortex and medulla. Immunohistochemical studies identified increased numbers of GRp78-, GRp94-, and ERp72-immunoreactive cells in the dorsal and lateral cortex during sleep deprivation but, during recovery sleep, elevated numbers of these cells were found only in the lateral cortex. In the medulla, increased numbers of GRp94-immunoreactive cells were observed in nucleus tractus solitarius, dorsal motor nucleus of the vagus and the rostroventrolateral medulla during recovery sleep. The widespread increase of heat shock protein family mRNAs in brain during sleep deprivation may be a neuroprotective response to prolonged wakefulness. In contrast, the relatively limited heat shock protein family mRNA expression during recovery sleep may be related to the role of heat shock proteins in protein biogenesis and thus to the restorative function of sleep.

Toxicologic Pathology, 2002

As the genomes of mammalian species become sequenced and gene functions are ascribed, the use of ... more As the genomes of mammalian species become sequenced and gene functions are ascribed, the use of differential gene expression (DGE) to evaluate organ function will become common in the experimental evaluation of new drug therapies. The ability to translate this technology into useful information for human exposures depends on tissue sampling that is impractical or generally not possible in man. The possibility that the DGE of nucleated cells, reticulocytes, or platelets in blood may present the necessary link with target organ toxicity provides an opportunity to correlate preclinical with clinical outcomes. Adriamycin is highly effective alone and more frequently in combination with other chemotherapeutic agents in the treatment of a variety of susceptible malignancies. Adriamycin-induced cardiomyopathy was examined as an endpoint to measure the utility of DOE on whole blood as a predictor of cardiac toxicity. Statistically significant gene changes were observed between relevant blood and cardiac gene profiles that corroborated the accepted mechanisms of toxicity (oxidative stress, effects on carnitine transport, DNA intercalation). There were, however, clear indications that other target organs (bone marrow and intestinal tract) were affected. The divergent expression of some genes between the blood and the heart on day 7 may also indicate the timing and mechanism of development of the cardiomyopathy and confirm current therapeutic approaches for its prevention. The data demonstrate that whole blood gene expression particularly in relation to oxidative stress, in conjunction with standard hematology and clinical chemistry, may be useful in monitoring and predicting cardiac damage secondary to adriamycin administration. Appendices A & B, referenced in this paper, are not printed in this issue of Toxicologic Pathology. They are available as downloadable text files at http://taylorandfrancis.metapress.com/openurl.asp?genre=journal&issn=0192-6233. To access them, click on the issue link for 30(4), then select this article. A download option appears at the bottom of this abstract. In order to access the full article online, you must either have an individual subscription or a member subscription accessed through www.toxpath.org.

Human and Ecological Risk Assessment: An International Journal, 2008

The estimation of acute dietary intake plays a key role in the safety assessment of pesticide res... more The estimation of acute dietary intake plays a key role in the safety assessment of pesticide residues and needs knowledge of the unit-to-unit variability in residues. There is limited knowledge of contributions of factors to often observed large unit-tounit variability in residues. A stochastic simulation study was conducted to investigate the effects of sample size and heterogeneity in factors driving residue dissipation of non-systemic pesticides on the unit-to-unit variability among individual apples. The heterogeneity in driving factors was expressed in terms of variability in three dissipation parameters. The variability factor (VF), calculated as the ratio of residues in individual fruit at the 97.5th percentile and the mean residue, was used to represent the unit-to-unit variability. As the rate of dissipation increased, the variability in the corresponding parameter led to larger increases in the variability VF of residues over time. Thus, under field conditions, the relative in pesticide residues is expected to increase with time although the absolute level of residues decreases. The coefficient of variation (CV) was used to describe residue variability in samples of small sizes (5, 10, 20, 40, and 80). When sample size was fewer than 40 fruit, the sample CV increased steeply with decreasing sample size. Measuring residues as concentrations, instead of per fruit, also led to an average 4-8% increase in the CV of residues because of variability in fruit expansion.

Biological Psychiatry, 2000

means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sust... more means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sustained manner. A potentially therapeutic substance is nerve growth factor (NGF), a target-derived neurotrophic factor known to influence phenotypic expression in neurons of the basal forebrain cholinergic (BFC) system. Neurons in this region provide essentially all cholinergic innervation to the cortex, have been shown to regulate cortical activity, and are involved in modulation of attention and some aspects of memory. Further, these neurons are known to degenerate as a prominent component of Alzheimer's disease. Delivery of NGF to the cholinergic basal forebrain has been shown to prevent injury-induced degeneration in both rats and primates. However, delivery of NGF to extensive areas of the brain can induce hyperalgesia, hypophagia, weight loss, and sprouting of sensory and sympathetic neurons into the central nervous system. NGF, delivered to the BFC neurons by intraparenchymal ex vivo gene therapy, was previously demonstrated to reverse naturally-occurring age-related memory loss in aged rats, without inducing any of the aforementioned adverse reactions. In this study (D.E. Smith et al, PNAS 1999, Vol. 96:10893-10898), we investigated the effects of NGF on BFC neurons in the aged primate. Basal forebrain cholinergic neurons in the aged primate were found to have reduced expression of phenotype-specific markers and to have undergone cellular atrophy, when compared with younger primates. Primary autologous fibroblasts were transduced to express and secrete NGF and then transplanted into the aged primate cholinergic basal forebrain. NGF restored expression of cholinergic-specific proteins and reversed cellular atrophy in the aged primate brain. The implications of these findings to degenerative disorders in general, and FTD in particular, will be discussed.

Advances in Enzyme Regulation, 2002

... Zubera, Luda Diatchenkoh, Bakhyt Zhumabayevab, Sejal Desaib, Sai Htunh, Karim Hyderh, Kai Wie... more ... Zubera, Luda Diatchenkoh, Bakhyt Zhumabayevab, Sejal Desaib, Sai Htunh, Karim Hyderh, Kai Wiechena, Alexander Agoulnik0, K. Michael ScharfT, Paul D ... C7076 TN Reg-Rl N72N6 T10 RTP-binding protein (rab5a) NF0729N Til Jagl protein tyrosine ginase (jakl) NJ0005N TC ...

Neurobiology of Disease, 2001

The identification of mutations in the transcriptional repressor methyl-CpG-binding protein 2 (ME... more The identification of mutations in the transcriptional repressor methyl-CpG-binding protein 2 (MECP2) gene in Rett Syndrome (RTT) suggests that an inappropriate release of transcriptional silencing may give rise to RTT neuropathology. Despite this progress, the molecular basis of RTT neuropathogenesis remains unclear. Using multiple cDNA microarray technologies, subtractive hybridization, and conventional biochemistry, we generated comprehensive gene expression profiles of postmortem brain tissue from RTT patients and matched controls. Many glial transcripts involved in known neuropathological mechanisms were found to have increased expression in RTT brain, while decreases were observed in the expression of multiple neuron-specific mRNAs. Dramatic and consistent decreases in transcripts encoding presynaptic markers indicated a specific deficit in presynaptic development. Employing multiple clustering algorithms, it was possible to accurately segregate RTT from control brain tissue samples based solely on gene expression profile. Although previously achieved in cancers, our results constitute the first report of human disease classification using gene expression profiling in a complex tissue source such as brain.

One strategy to circumvent problems with conventional chemotherapy is to develop drugs against mo... more One strategy to circumvent problems with conventional chemotherapy is to develop drugs against more specific cancer targets. Another is to use molecularly targeted agent (MTA) combinations to circumvent tumor resistance and increase the therapeutic index. Such synergistically lethal (SL) MTA combinations, however, are not easily predicted based on our rudimentary knowledge of cancer biology and drug action mechanisms. In the first strategy, our aim was to identify genes modulating proliferation and survival in leukemic cell lines (K562, Jurkat, and Raji) using a pooled lentiviral library expressing 27,500 shRNA targeting 5,043 human pathway-associated genes. Cells were transduced by the viral library and collected at several time points. Bar-codes were amplified from genomic DNA and sequenced (Illumina GAIIx). In the second strategy, we have adapted the same approach to combinatorially screen shRNA sequences targeting 40 DNA Damage and Repair (DDR) genes to discover additive and synergistic combinations that generate a synthetic-lethal phenotype. Human mammary epithelial cancer (HMEC) cells were transduced with a 27K shRNA SL DDR lentiviral library comprised of a redundant set of 16 binary shRNA constructs for each possible gene-gene combination (1,600). The library-transduced HMEC cells were grown for ten days, then bar-codes amplified and sequenced (Illumina HiSeq2000). The viability screen with leukemic cell lines identified more than 250 essential genes for each panel of cells. Subsequent validation using single shRNA-expressing constructs showed that in each screen, about 80% of shRNAs identified did indeed lead to cell death when transduced in cells. Analysis of the identified essential genes for known biological interactions revealed several non-random clusters of interacting proteins that provide some insight into signaling pathways and protein networks specific to these cancers. The SL screen in HMEC cells identified 10 SL shRNA pair candidates including known SL shRNA pair PARP1/BRCA1. Additional analysis of lethal combinations indicated redundant, complementary, and compensatory responses in cancer cells. We believe that newly discovered hematopoietic-specific genes represent potentially novel drug targets. Moreover, they can be used to develop and establish both novel cancer targeted therapies and myeloablative conditioning regimens with decreased toxicity. Based on SL screen results in HMEC cells, we believe that comprehensive experimental annotation of SL gene-gene interactions in a wider range of cancer and normal cells will not only predict the most promising synergistic lethal combinations but also allow the development of a new generation of multi-specific, highly effective anti-cancer therapeutics with unique mechanisms of action. Citation Format: Donato Tedesco, Kyle Bonneau, Mikhail Makhanov, Debbie Deng, Karim Hyder, Paul Diehl, Costas G. Frangou, Alex Chenchik. Viability screens in leukemic and breast cancer cells with pooled lentiviral shRNA libraries identify potential therapeutic targets and synthetic or synergistic lethal interactions. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr A12.

Molecular Cancer Therapeutics, 2013

Biological Psychiatry, 2000

means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sust... more means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sustained manner. A potentially therapeutic substance is nerve growth factor (NGF), a target-derived neurotrophic factor known to influence phenotypic expression in neurons of the basal forebrain cholinergic (BFC) system. Neurons in this region provide essentially all cholinergic innervation to the cortex, have been shown to regulate cortical activity, and are involved in modulation of attention and some aspects of memory. Further, these neurons are known to degenerate as a prominent component of Alzheimer's disease. Delivery of NGF to the cholinergic basal forebrain has been shown to prevent injury-induced degeneration in both rats and primates. However, delivery of NGF to extensive areas of the brain can induce hyperalgesia, hypophagia, weight loss, and sprouting of sensory and sympathetic neurons into the central nervous system. NGF, delivered to the BFC neurons by intraparenchymal ex vivo gene therapy, was previously demonstrated to reverse naturally-occurring age-related memory loss in aged rats, without inducing any of the aforementioned adverse reactions. In this study (D.E. Smith et al, PNAS 1999, Vol. 96:10893-10898), we investigated the effects of NGF on BFC neurons in the aged primate. Basal forebrain cholinergic neurons in the aged primate were found to have reduced expression of phenotype-specific markers and to have undergone cellular atrophy, when compared with younger primates. Primary autologous fibroblasts were transduced to express and secrete NGF and then transplanted into the aged primate cholinergic basal forebrain. NGF restored expression of cholinergic-specific proteins and reversed cellular atrophy in the aged primate brain. The implications of these findings to degenerative disorders in general, and FTD in particular, will be discussed.

Molecular Cancer Therapeutics, 2013

Journal of autism and developmental disorders, 2001

Studies have identified structural abnormalities in areas of the autistic brain, with a pattern s... more Studies have identified structural abnormalities in areas of the autistic brain, with a pattern suggesting that a neurodevelopmental anomaly took place. Neural cell adhesion molecule (NCAM), which is involved in development of the central nervous system, was previously shown to be decreased in the serum of autistic individuals. In the present study, we measured NCAM protein in the sera from controls, patients with autism, siblings of autistic patients, and individuals with other neurologic disorders, but found no significant differences. We also measured NCAM protein in autistic postmortem brain samples and found the longest isoform, NCAM-180, to be significantly decreased. In addition, we investigated the mRNA expression of NCAM in these brain samples using cDNA microarrays and RT-PCR. Results show that NCAM mRNA levels are not altered in autism.

Neuroscience, 2003

To determine whether the synthesis of macromolecules is increased in the cerebral cortex during s... more To determine whether the synthesis of macromolecules is increased in the cerebral cortex during sleep, we subjected C57BL/6 mice to 6 hours of sleep deprivation and then screened the expression of 1176 genes of known function by using cDNA arrays. The expression of the heat shock proteins (HSP), endoplasmic reticulum protein (ERp72) and glucose-regulated protein (GRp78), was among the genes whose expression was significantly elevated in the cortex during sleep deprivation, whereas GRp78 and GRp94 mRNAs were elevated in the cortex during recovery sleep after sleep deprivation, as confirmed by conventional and quantitative realtime polymerase chain reaction and/or Northern analyses. A systematic evaluation of the expression of six heat shock protein family members in seven brain regions revealed in-creased mRNA levels in cortex, basal forebrain, hypothalamus, cerebellum and medulla during sleep deprivation, whereas increased mRNA levels during recovery sleep were limited to the cortex and medulla. Immunohistochemical studies identified increased numbers of GRp78-, GRp94-, and ERp72-immunoreactive cells in the dorsal and lateral cortex during sleep deprivation but, during recovery sleep, elevated numbers of these cells were found only in the lateral cortex. In the medulla, increased numbers of GRp94-immunoreactive cells were observed in nucleus tractus solitarius, dorsal motor nucleus of the vagus and the rostroventrolateral medulla during recovery sleep. The widespread increase of heat shock protein family mRNAs in brain during sleep deprivation may be a neuroprotective response to prolonged wakefulness. In contrast, the relatively limited heat shock protein family mRNA expression during recovery sleep may be related to the role of heat shock proteins in protein biogenesis and thus to the restorative function of sleep.

Toxicologic Pathology, 2002

As the genomes of mammalian species become sequenced and gene functions are ascribed, the use of ... more As the genomes of mammalian species become sequenced and gene functions are ascribed, the use of differential gene expression (DGE) to evaluate organ function will become common in the experimental evaluation of new drug therapies. The ability to translate this technology into useful information for human exposures depends on tissue sampling that is impractical or generally not possible in man. The possibility that the DGE of nucleated cells, reticulocytes, or platelets in blood may present the necessary link with target organ toxicity provides an opportunity to correlate preclinical with clinical outcomes. Adriamycin is highly effective alone and more frequently in combination with other chemotherapeutic agents in the treatment of a variety of susceptible malignancies. Adriamycin-induced cardiomyopathy was examined as an endpoint to measure the utility of DOE on whole blood as a predictor of cardiac toxicity. Statistically significant gene changes were observed between relevant blood and cardiac gene profiles that corroborated the accepted mechanisms of toxicity (oxidative stress, effects on carnitine transport, DNA intercalation). There were, however, clear indications that other target organs (bone marrow and intestinal tract) were affected. The divergent expression of some genes between the blood and the heart on day 7 may also indicate the timing and mechanism of development of the cardiomyopathy and confirm current therapeutic approaches for its prevention. The data demonstrate that whole blood gene expression particularly in relation to oxidative stress, in conjunction with standard hematology and clinical chemistry, may be useful in monitoring and predicting cardiac damage secondary to adriamycin administration. Appendices A & B, referenced in this paper, are not printed in this issue of Toxicologic Pathology. They are available as downloadable text files at http://taylorandfrancis.metapress.com/openurl.asp?genre=journal&issn=0192-6233. To access them, click on the issue link for 30(4), then select this article. A download option appears at the bottom of this abstract. In order to access the full article online, you must either have an individual subscription or a member subscription accessed through www.toxpath.org.

Human and Ecological Risk Assessment: An International Journal, 2008

The estimation of acute dietary intake plays a key role in the safety assessment of pesticide res... more The estimation of acute dietary intake plays a key role in the safety assessment of pesticide residues and needs knowledge of the unit-to-unit variability in residues. There is limited knowledge of contributions of factors to often observed large unit-tounit variability in residues. A stochastic simulation study was conducted to investigate the effects of sample size and heterogeneity in factors driving residue dissipation of non-systemic pesticides on the unit-to-unit variability among individual apples. The heterogeneity in driving factors was expressed in terms of variability in three dissipation parameters. The variability factor (VF), calculated as the ratio of residues in individual fruit at the 97.5th percentile and the mean residue, was used to represent the unit-to-unit variability. As the rate of dissipation increased, the variability in the corresponding parameter led to larger increases in the variability VF of residues over time. Thus, under field conditions, the relative in pesticide residues is expected to increase with time although the absolute level of residues decreases. The coefficient of variation (CV) was used to describe residue variability in samples of small sizes (5, 10, 20, 40, and 80). When sample size was fewer than 40 fruit, the sample CV increased steeply with decreasing sample size. Measuring residues as concentrations, instead of per fruit, also led to an average 4-8% increase in the CV of residues because of variability in fruit expansion.

Biological Psychiatry, 2000

means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sust... more means of providing therapeutic substances to brain parenchyma in a regionally-restricted and sustained manner. A potentially therapeutic substance is nerve growth factor (NGF), a target-derived neurotrophic factor known to influence phenotypic expression in neurons of the basal forebrain cholinergic (BFC) system. Neurons in this region provide essentially all cholinergic innervation to the cortex, have been shown to regulate cortical activity, and are involved in modulation of attention and some aspects of memory. Further, these neurons are known to degenerate as a prominent component of Alzheimer's disease. Delivery of NGF to the cholinergic basal forebrain has been shown to prevent injury-induced degeneration in both rats and primates. However, delivery of NGF to extensive areas of the brain can induce hyperalgesia, hypophagia, weight loss, and sprouting of sensory and sympathetic neurons into the central nervous system. NGF, delivered to the BFC neurons by intraparenchymal ex vivo gene therapy, was previously demonstrated to reverse naturally-occurring age-related memory loss in aged rats, without inducing any of the aforementioned adverse reactions. In this study (D.E. Smith et al, PNAS 1999, Vol. 96:10893-10898), we investigated the effects of NGF on BFC neurons in the aged primate. Basal forebrain cholinergic neurons in the aged primate were found to have reduced expression of phenotype-specific markers and to have undergone cellular atrophy, when compared with younger primates. Primary autologous fibroblasts were transduced to express and secrete NGF and then transplanted into the aged primate cholinergic basal forebrain. NGF restored expression of cholinergic-specific proteins and reversed cellular atrophy in the aged primate brain. The implications of these findings to degenerative disorders in general, and FTD in particular, will be discussed.

Advances in Enzyme Regulation, 2002

... Zubera, Luda Diatchenkoh, Bakhyt Zhumabayevab, Sejal Desaib, Sai Htunh, Karim Hyderh, Kai Wie... more ... Zubera, Luda Diatchenkoh, Bakhyt Zhumabayevab, Sejal Desaib, Sai Htunh, Karim Hyderh, Kai Wiechena, Alexander Agoulnik0, K. Michael ScharfT, Paul D ... C7076 TN Reg-Rl N72N6 T10 RTP-binding protein (rab5a) NF0729N Til Jagl protein tyrosine ginase (jakl) NJ0005N TC ...

Neurobiology of Disease, 2001

The identification of mutations in the transcriptional repressor methyl-CpG-binding protein 2 (ME... more The identification of mutations in the transcriptional repressor methyl-CpG-binding protein 2 (MECP2) gene in Rett Syndrome (RTT) suggests that an inappropriate release of transcriptional silencing may give rise to RTT neuropathology. Despite this progress, the molecular basis of RTT neuropathogenesis remains unclear. Using multiple cDNA microarray technologies, subtractive hybridization, and conventional biochemistry, we generated comprehensive gene expression profiles of postmortem brain tissue from RTT patients and matched controls. Many glial transcripts involved in known neuropathological mechanisms were found to have increased expression in RTT brain, while decreases were observed in the expression of multiple neuron-specific mRNAs. Dramatic and consistent decreases in transcripts encoding presynaptic markers indicated a specific deficit in presynaptic development. Employing multiple clustering algorithms, it was possible to accurately segregate RTT from control brain tissue samples based solely on gene expression profile. Although previously achieved in cancers, our results constitute the first report of human disease classification using gene expression profiling in a complex tissue source such as brain.