the inventors have identified gene expression changes that may mediate neuronal disease progression , in particular , the cell death of retinal ganglion cells . neurodegenerative disorders can be treated and identified using the methods of the present invention . these include disorders of the central nervous system as well as disorders of the peripheral nervous system . neurodegenerative disorders include , but are not limited to , brain injuries , cerebrovascular diseases and their consequences , parkinson &# 39 ; s disease , corticobasal degeneration , motor neuron disease ( including als ), multiple sclerosis , traumatic brain injury , stroke , post - stroke , post - traumatic brain injury , and small - vessel cerebrovascular disease . dementias , such as alzheimer &# 39 ; s disease , vascular dementia , dementia with lewy bodies , frontotemporal dementia and parkinsonism linked to chromosome 17 , frontotemporal dementias ( including pick &# 39 ; s disease ), progressive nuclear palsy , corticobasal degeneration , huntington &# 39 ; s disease , thalamic degeneration , creutzfeld - jakob dementia , hiv dementia , schizophrenia with dementia , and korsakoffs psychosis , also are neurodegenerative disorders . neuronal cell death is a major feature of a variety of human neurological disorders , including the neurodegenerative diseases ( such as alzheimer &# 39 ; s , parkinson &# 39 ; s , huntington &# 39 ; s and amyotrophic lateral sclerosis ), stroke and trauma . alzheimer &# 39 ; s disease afflicts about 4 million people in the united states , primarily the elderly . it is characterized by progressive memory loss , disorientation , depression and eventual loss of bodily functions . amyotrophic lateral sclerosis , afflicts about 30 , 000 americans . it begins after age 40 and results in progressive weakness and paralysis . huntington &# 39 ; s disease , which afflicts an estimated 25 , 000 patients in the united states , usually begins between the ages of 30 and 50 and includes violent , involuntary movements . loss of neurons by a degenerative process is a major pathological feature of many human neurological disorders . neuronal cell death can occur as a result of a variety of conditions including traumatic injury , ischemia , neurodegenerative diseases ( e . g ., parkinson &# 39 ; s disease , huntington &# 39 ; s disease , alzheimer &# 39 ; s disease , amyotrophic lateral sclerosis ( als ), stroke , or trauma ), or as a normal part of tissue development and maintenance . several inherited disorders produce late onset neuron loss , each of which is highly specific for particular neural cell types . the methods of the present invention can be applied to any of the diseases of the optic nerve , the retina , retinal pigment epithelium ( rpe ), and choroid . these include , but are not limited to , glaucoma , ocular neovascularization , ocular inflammation and retinal degenerations . specific examples of these disease states include diabetic retinopathy , chronic glaucoma , retinal detachment , sickle cell retinopathy , senile macular degeneration , retinal neovascularization , subretinal neovascularization ; rubeosis iritis inflammatory diseases , chronic posterior and pan uveitis , neoplasms , retinoblastoma , pseudoglioma , neovascular glaucoma ; neovascularization resulting following a combined vitrectomy and lensectomy , vascular diseases retinal ischemia , choroidal vascular insufficiency , choroidal thrombosis , neovascularization of the optic nerve , diabetic macular edema , cystoid macular edema , retinitis pigmentosa , retinal vein occlusion , proliferative vitreoretinopathy , angioid streak , and retinal artery occlusion , and , neovascularization due to penetration of the eye or ocular injury . additional relevant disease include the neuropathies , such as leber &# 39 ; s , idiopathic , drug - induced , optic , and ischemic neropathies . any type of neuronal cells can be used in the practice of the invention , for example , for screening for candicate drugs for treating neuronal cell death and disease resulting therefrom . such cells include without limitation cells isolated from brain , neuroblastoma , astrocytoma , glioblastoma , medulloblastoma , retinoblastoma , and retina . such cells can be isolated as is known in the art . cell lines of these types are available from the american type culture collection , mannassas , va . cells that can differentiate into neurons , such as nt2 , and pc12 cells can also be used to advantage . isolated and purified nucleic acids , according to the present invention are those which are not linked to those genes to which they are linked in the human genome . moreover , isolated and purified nucleic acids are not present in a mixture , such as a library , containing a multitude of distinct sequences from distinct genes . they may be , however , linked to other genes such as vector sequences or sequences of other genes to which they are not naturally adjacent . the nucleic acids may represent either the sense or the antisense strand . nucleic acids and proteins although disclosed herein with sequence particularity may be derived from a single individual . allelic variants which occur in the population of humans are including within the scope of such nucleic acids and proteins . those of skill in the art are well able to identify allelic variants as being the same gene or protein . isolated and purified proteins are not in a cell , and are separated from the normal cellular constituents , such as nucleic acids , lipids , etc . typically the protein is purified to such an extent that it comprises the predominant species of protein in the composition , such as greater than 50 , 60 70 , 80 , 90 , or even 95 % of the proteins present . using the proteins according to the invention , one of ordinary skill in the art can readily generate or obtain antibodies which specifically bind to the proteins . such antibodies can be monoclonal or polyclonal . they can be chimeric , humanized , or totally human . any functional fragment or derivative of an antibody can be used including fab , fab ′, fab2 , fab ′ 2 , and single chain variable regions . so long as the fragment or derivative retains specificity of binding for the endothelial marker protein it can be used . antibodies can be tested for specificity of binding by comparing binding to appropriate antigen to binding to irrelevant antigen or antigen mixture under a given set of conditions . if the antibody binds to the appropriate antigen at least 2 , 5 , 7 , and preferably 10 times more than to irrelevant antigen or antigen mixture then it is considered to be specific . techniques for making such partially to fully human antibodies are known in the art and any such techniques can be used . according to one such technique , fully human antibody sequences are made in a transgenic mouse which has been engineered to express human heavy and light chain antibody genes . multiple strains of such transgenic mice have been made which can produce different classes of antibodies . b cells from transgenic mice which are producing a desirable antibody can be fused to make hybridoma cell lines for continuous production of the desired antibody . see for example , nina d . russel , jose r . f . corvalan , michael l . gallo , c . geoffrey davis , liise - anne pirofski . production of protective human antipneumococcal antibodies by transgenic mice with human immunoglobulin loci infection and immunity april 2000 , p . 1820 - 1826 ; michael l . gallo , vladimir e . ivanov , aya jakobovits , and c . geoffrey davis . the human immunoglobulin loci introduced into mice : v ( d ) and j gene segment usage similar to that of adult humans european journal of immunology 30 : 534 - 540 , 2000 ; larry l . green . antibody engineering via genetic engineering of the mouse : xenomouse strains are a vehicle for the facile generation of therapeutic human monoclonal antibodies journal of immunological methods 231 11 - 23 , 1999 ; yang x - d , corvalan jrf , wang p , roy cm - n and davis c g . fully human anti - interleukin - 8 monoclonal antibodies : potential therapeutics for the treatment of inflammatory disease states . journal of leukocyte biology vol . 66 , pp401 - 410 ( 1999 ); yang x - d , jia x - c , corvalan j r f , wang p , c g davis and jakobovits a . eradication of established tumors by a fully human monoclonal antibody to the epidermal growth factor receptor without concomitant chemotherapy . cancer research vol . 59 , number 6 , pp1236 - 1243 ( 1999 ); jakobovits a . production and selection of antigen - specific fully human monoclonal antibodies from mice engineered with human ig loci . advanced drug delivery reviews vol . 31 , pp : 33 - 42 ( 1998 ); green l and jakobovits a . regulation of b cell development by variable gene complexity in mice reconstituted with human immunoglobulin yeast artificial chromosomes . j . exp . med . vol . 188 , number 3 , pp : 483 - 495 ( 1998 ); jakobovits a . the long - awaited magic bullets : therapeutic human monoclonal antibodies from transgenic mice . exp . opin . invest . drugs vol . 7 ( 4 ), pp : 607 - 614 ( 1998 ); tsuda h , maynard - currie k , reid l , yoshida t , edamura k , maeda n , smithies o , jakobovits a . inactivation of mouse hprt locus by a 203 - bp retrotransposon insertion and a 55 - kb gene - targeted deletion : establishment of new hprt - deficient mouse embryonic snm cell lines . genomics vol . 42 , pp : 413 - 421 ( 1997 ); sherman - gold , r . monoclonal antibodies : the evolution from &# 39 ; 80s magic bullets to mature , mainstream applications as clinical therapeutics . genetic engineering news vol . 17 , number 14 ( august 1997 ); mendez m , green l , corvalan j , jia x - c , maynard - currie c , yang x - d , gallo m , louie d , lee d , erickson k , luna j , roy c , abderrahim h , kirschenbaum f , noguchi m , smith d , fukushima a , hales j , finer m , davis c , zsebo k , jakobovits a . functional transplant of megabase human immunoglobulin loci recapitulates human antibody response in mice . nature genetics vol . 15 , pp : 146 - 156 ( 1997 ); jakobovits a . mice engineered with human immunoglobulin yacs : a new technology for production of fully human antibodies for autoimmunity therapy . weir &# 39 ; s handbook of experimental immunology , the integrated immune sysnm vol . iv , pp : 194 . 1 - 194 . 7 ( 1996 ); jakobovits a . production of fully human antibodies by transgenic mice . current opinion in biotechnology vol . 6 , no . 5 , pp : 561 - 566 ( 1995 ); mendez m , abderrahim h , noguchi m , david n , hardy m , green l , tsuda h , yoast s , maynard - currie c , garza d , gemmill r , jakobovits a , klapholz s . analysis of the structural integrity of yacs comprising human immunoglobulin genes in yeast and in embryonic snm cells . genomics vol . 26 , pp : 294 - 307 ( 1995 ); jakobovits a . yac vectors : humanizing the mouse genome . current biology vol . 4 , no . 8 , pp : 761 - 763 ( 1994 ); arbones m , ord d , ley k , ratech h , maynard - curry k , otten g , capon d , tedder t . lymphocyte homing and leukocyte rolling and migration are impaired in l - selectin - deficient mice . immunity vol . 1 , no . 4 , pp : 247 - 260 ( 1994 ); green l , hardy m , maynard - curry k , tsuda h , louie d , mendez m , abderrahim h , noguchi m , smith d , zeng y , et . al . antigen - specific human monoclonal antibodies from mice engineered with human ig heavy and light chain yacs . nature genetics vol . 7 , no . 1 , pp : 13 - 21 ( 1994 ); jakobovits a , moore a , green l , vergara g , maynard - curry k , austin h , klapholz s . germ - line transmission and expression of a human - derived yeast artificial chromosome . nature vol . 362 , no . 6417 , pp : 255 - 258 ( 1993 ); jakobovits a , vergara g , kennedy j , hales j , mcguinness r , casentini - borocz d , brenner d , otten g . analysis of homozygous mutant chimeric mice : deletion of the immunoglobulin heavy - chain joining region blocks b - cell development and antibody production . proceedings of the national academy of sciences usa vol . 90 , no . 6 , pp : 2551 - 2555 ( 1993 ); kucherlapati et al ., u . s . pat . no . 6 , 1075 , 181 . antibodies can also be made using phage display techniques . such techniques can be used to isolate an initial antibody or to generate variants with altered specificity or avidity characteristics . single chain fv can also be used as is convenient . they can be made from vaccinated transgenic mice , if desired . antibodies can be produced in cell culture , in phage , or in various animals , including but not limited to cows , rabbits , goats , mice , rats , hamsters , guinea pigs , sheep , dogs , cats , monkeys , chimpanzees , apes . antibodies can be labeled with a detectable moiety such as a radioactive atom , a chromophore , a fluorophore , or the like . such labeled antibodies can be used for diagnostic techniques , either in vivo , or in an isolated test sample . antibodies can also be conjugated , for example , to a pharmaceutical agent , such as chemotherapeutic drug or a toxin . they can be linked to a cytokine , to a ligand , to another antibody . suitable agents for coupling to antibodies to achieve an anti - tumor effect include cytokines , such as interleukin 2 ( il - 2 ) and tumor necrosis factor ( tnf ); photosensitizers , for use in photodynamic therapy , including aluminum ( iii ) phthalocyanine tetrasulfonate , hematoporphyrin , and phthalocyanine ; radionuclides , such as iodine - 131 ( 131 i ), yttrium - 90 ( 90 y ), bismuth - 212 ( 212 bi ), bismuth - 213 ( 213 bi ), technetium - 99m ( 99m tc ), rhenium - 186 ( 186 re ), and rhenium - 188 ( 188 re ); antibiotics , such as doxorubicin , adriamycin , daunorubicin , methotrexate , daunomycin , neocarzinostatin , and carboplatin ; bacterial , plant , and other toxins , such as diphtheria toxin , pseudomonas exotoxin a , staphylococcal enterotoxin a , abrin - a toxin , ricin a ( deglycosylated ricin a and native ricin a ), tgf - alpha toxin , cytotoxin from chinese cobra ( naja naja atra ), and gelonin ( a plant toxin ); ribosome inactivating proteins from plants , bacteria and fingi , such as restrictocin ( a ribosome inactivating protein produced by aspergillus restrictus ), saporin ( a ribosome inactivating protein from saponaria officinalis ), and rnase ; tyrosine kinase inhibitors ; ly207702 ( a difluorinated purine nucleoside ); liposomes containing anti - tumor agents ( e . g ., antisense oligonucleotides , plasmids which encode for toxins , methotrexate , etc . ); and other antibodies or antibody fragments , such as f ( ab ). those of skill in the art will readily understand and be able to make such antibody derivatives , as they are well known in the art . the antibodies may be cytotoxic on their own , or they may be used to deliver cytotoxic agents to particular locations in the body . the antibodies can be administered to individuals in need thereof as a form of passive immunization . drugs can be screened for the ability to modulate expression of the genes , mrna , and protein which are identified herein . cell populations can be contacted with test substances and the expression of neuronal cell death markers determined . test substances which decrease the expression of up - regulated neuronal cell death markers are candidates for inhibiting neuronal cell death . conversely , test substances which increase the expression of down - regulated neuronal cell death markers can be identified as candidate drugs for causing neuronal cell death . in cases where a biological or enzymatic activity of a nm is known , agents can be screened for their ability to decrease or increase the activity or amount of activity present in a cell . expression can be monitored according to any convenient method . protein or mrna can be monitored . any technique known in the art for monitoring specific genes &# 39 ; expression can be used , including but not limited to elisas , sage , custom or commercial microarray hybridization , western blots . changes in expression of a single marker may be used as a criterion for significant effect as a potential pro - neuronal cell death or anticell death agent . however , it also may be desirable to screen for test substances which are able to modulate the expression of groups of such markers , such as modulators of at least 5 , 10 , 15 , or 20 of the relevant markers . inhibition of nm protein activity can also be used as a drug screen . neuronal cell death markers identified herein were identified using available reagents for probes . in some cases these probes are human . in other case they derive from other mammalian species . each gene has an ortholog in humans , and the human ortholog is to be used for treating humans . when cells , cell lines , and whole animal models of other species are used , it is preferred that the corresponding ortholog be used . nonetheless , as demonstrated in the examples below , probes for orthologs of other species can be used . test substances for screening can come from any source . they can be from libraries of natural products , combinatorial chemical libraries , biological products made by recombinant libraries , etc . the source of the test substances is not critical to the invention . the present invention provides means for screening compounds and compositions which may previously have been overlooked in other screening schemes . nucleic acids and the corresponding encoded proteins of the markers of the present invention can be used therapeutically in a variety of modes . the nucleic acids and encoded proteins can be administered by any means known in the art . such methods include , using liposomes , nanospheres , viral vectors , non - viral vectors comprising polycations , etc . suitable viral vectors include adenovirus , retroviruses , and sindbis virus . administration modes can be any known in the art , including parenteral , intravenous , intramuscular , intraperitoneal , topical , intranasal , intrarectal , intrabronchial , etc . such administrations can be used to reduce or eliminate cell death ( down - regulated genes or proteins ) or induce cell death ( up - regulated genes or proteins ). the pathological condition of the patient will determine which type of gene or protein should be used . specific biological antagonists of nms can also be used to therapeutic benefit . for example , antibodies , t cells specific for an nm , antisense to an nm , and ribozymes specific for an nm can be used to restrict , inhibit , reduce , and / or diminish neuronal cell death ( up - regulated genes or proteins ). conversely , antagonists of down - regulated genes or proteins can be used to induce or stimulated neuronal cell death . such antagonists can be administered as is known in the art for these classes of antagonists generally . mouse counterparts to human nms can be used in mouse models or in cell lines or in vitro to evaluate potential anti - neuronal cell death or pro - neuronal cell death compounds or therapies . their expression can be monitored as an indication of effect . the above disclosure generally describes the present invention . all references disclosed herein are expressly incorporated by reference . a more complete understanding can be obtained by reference to the following specific examples which are provided herein for purposes of illustration only , and are not intended to limit the scope of the invention . one optic nerve on each rat was severed . gene expression was assessed using arrays of probes for genes as shown in fig9 . by comparing right to left eye , genes were identified that were either up or down regulated at various times after axotomy . see fig1 - 7 . by comparing expression in treated and non - treated rats genes were identified whose expression was modulated relative to the control animals . these are identified in fig8 . these genes can be used similarly to those identified in fig1 - 7 in any of the methods of the present invention .
the optic nerve axotomy model in mouse exhibits rapid changes in gene expression . genes identified by microarray analysis as differentially expressed or modulated in this model , can be used diagnostically , therapeutically , and in drug discovery . these results provide clues to underlying molecular processes occurring during optic nerve degeneration , and provide direction for future cell - based studies .