endogeneous tribosupplementation includes a role for anti - inflammatory agents such as tnf - α blockers such as etanercept or il - 1 inhibitors in the treatment of injured joints or joints that are at risk of degeneration following joint trauma . post - traumatic causes of oa involve catabolic cytokines . il - 1 has been shown to down regulate lubricin , which by itself does not lead to oa but may play a degenerative role since il - 1β has also been shown to result in less lubricin secretion in vitro . the sf levels of il - 1β and tnf - α are elevated following an acute acl - injury , and remain elevated 3 weeks post injury . both il - 1β and tnf - α stimulate the secretion of latent cysteine proteinases , primarily that of cathepsin b , from synovial fibroblasts . cathepsin b has been shown to possess a strong ability to proteolytically degrade lubricin and abolish lubricin &# 39 ; s lubricating ability . inhibition prolongs and augments joint lubrication . acl injury has both immediate and long - term implications on patients &# 39 ; quality of life , long - term disability and risk for oa . many acl - injured subjects suffer a severe functional deficit . although one third of them may improve function with rehabilitation alone , there is substantial evidence that they will manifest articular cartilage degeneration . on average , patients with oa following acl injury are 15 - to 20 - years younger than those with primary oa when they seek medical help for their symptoms . reasons for this profile include the initial inflammatory response , the presence of concomitant injuries , altered kinematics , abnormal contact stresses , and / or the increased incidence of “ giving way ” following injury producing additional insult to the cartilage and menisci . all of these factors may disrupt the homeostasis of the joint and place the knee at risk for early oa . therefore , surgeons advocate reconstruction of the acl to decrease joint laxity , to restore an active lifestyle , and to reduce future knee injuries . the impact of a non - reconstructed acl injury upon the chondroprotective features of the joint has not been established . the inflammatory response at the time of injury decreases the lubricating ability of the joint therefore sets the stage for post - traumatic arthritis . patients who undergo acl reconstruction also exhibit progressive articular cartilage damage in the reconstructed knee . in a recent 14 - year follow - up study of 205 male atheletes , 78 % had degenerative signs in their injured knee compared to 4 % in their uninjured knee ( von porat et al ., 20054 , ann . rheum . dis . 63 : 269 - 273 ). in a 5 - year follow - up , others ( daniel et al ., 1994 , am . j . sports med . 22 : 632 - 644 ) determined that both acute and chronic acl reconstructed knees had significantly great radiographic evidence of oa as compared to those in a conservatively treated ( non - operative ) group . these findings were confirmed by another group ( fithian et al ., 2002 , orthoped . clin . n . america 33 : 621 - 636 ) who found that the incidence of chondropathy was 94 % and 92 % with and without meniscus tears respectively using mri . although radiographic signs of oa were present within five years of surgery , the mechanisms of chondropathy were heretofore unknown . studies were carried out to evaluate the association of dysfunction of joint tribologic properties with acute acl injuries in both an animal model and clinical aspirates . inhibiting inflammation was found to preserve lubricating properties and prevent chondropathy . re - establishing the normal lubricating ability of the diarthrodial joint is important following an injury . catabolism of lubricin eliminates the lubricating ability of synovial fluid . this process occurs both within the synovial fluid as well as the lubricin located on the surface of articular cartilage . introducing lubricin and hyaluronic acid together ( i . e ., artificial synovial fluid ) is a potential therapy but the half life of this therapy may be short . combination therapy in which anti - inflammatory treatment is administered simultaneously or sequentially preserves the introduced lubricant and prevent its digestion by activated proteases . intervention of the inflammatory process is accomplished at multiple stages in the cyclo - oxygenase and lipoxy - oxygenase inflammatory cascades . one method involves treating the injured diarthrodial joint at the same time through the intra - articular administration of il - 1 inhibitors and tnf - beta inhibitors to block the upstream proinflammatory cytokines , which initiate the downward cascade resulting in protease expression . the methods involve the introduction of lubricants intended to protect the articular surface and lengthening of their half life and residence time by the introduction of anti - inflammatory medication and biologics . the data described herein shows that such a treatment regimen preserves and augments lubrication of injured joints . treatment of an inflamed rat joint following an acl injury with a tnf - α inhibitor etanerept / enbrel ™ ( amgen ) reestablishes some of the lubricin layer in the superficial zone . an increase in the appearance of lubricin was observed with enbrel ™ alone . exogenous tribonectin is administered to protect the articular surface from wearing against one another . a combination of anti - inflammatory therapy in traumatized joints with a boundary lubricant ( tribonectin ) to restore chondroprotection re - establishes or increases lubricin concentration and decreases one or more symptoms of joint degeneration ( e . g ., pain , decreased mobility , decreased range of motion ). lubricin is a mucinous glycoprotein , secreted by synovial fibroblasts ( jay et al , j ortho res 2001 , 19 : 677 - 687 ) and the superficial zone articular chondrocyte ( flannery cr et al , biochem biophys res commun 1999 , 254 : 535 - 541 ) and is responsible for lubrication of articular surfaces . sf from patients with an acute acl injury had decreased lubricin at early stage following injury ( elsaid k a et al , trans orthop res soc 2007 ; 32 : 160 ), which has been associated with increased cartilage damage . endogenous lubricin sf levels were significantly lowered following acl injury , and were associated with increased cartilage damage . furthermore , inflammatory cytokines e . g . il - 1β and tnf - α were shown to decrease lubricin synthesis ( jones arc et al , eur cell mater 2007 ; 31 : 40 - 45 ). a tribonectin is an lubricating polypeptide , which contains at least one repeat of an amino acid sequence which is at least 50 % identical to kepaptt ( seq id no : 3 ). for example , a tribonectin comprises a polypeptide , the amino acid sequence of which comprises at least one but less than 76 subunits , with each subunit comprising at least 7 amino acids and the amino acid sequence of each subunit being at least 50 % identical to seq id no : 3 with a non - identical amino acid being a conservative amino acid substitution . a tribonectin contains at least one o - linked lubricating moiety . preferably the lubricating moiety is a β ( 1 - 3 ) gal - galnac moiety . optionally , the β ( 1 - 3 ) gal - galnac is capped with neuac . the polypeptide contains an oligosaccharide , which is moiety is n - linked to an asparagine residue , e . g ., the oligosaccharide is asialo -, digalactosylated bi - antennary , bisecting n - acteylglucosamine , tri - mannosyl core - fucosylated . tribonectins are further described in u . s . pat . nos . 7 , 001 , 881 ; 6 , 960 , 562 ; 6 , 743 , 774 ; u . s . patent application pub . no . 2004 / 0229804 ; and u . s . patent application pub . no . 2004 / 0072741 . the amino acid sequence of the protein backbone of a lubricating polypeptide may differ depending on alternative splicing of exons of the human megakaryocyte stimulating factor ( msf ) gene ( genbank ® accession number u70136 ). tribonectins are purified naturally - occurring polypeptides or synthetically produced or recombinant polypeptides . in one example , the tribonectin has the amino acid sequence of a naturally - occurring full - length msf ; alternatively , the sequence corresponds to an alternative splice variant of the msf gene . optionally , the polypeptide compositions do not contain a lipid . for example , less than 10 %, preferably less than 5 %, and more preferably less than 1 % of the lubricating polypeptide composition is a lipid . the polypeptide compositions are purified from fibronectin . for example , less than 10 %, preferably less than 5 %, and more preferably less than 1 % of the lubricating polypeptide composition is a fibronectin . the amino acid sequence of the backbone of purified , synthetic , or recombinant tribonectins is at least 50 % identical to the amino acid sequence of a naturally - occurring tribonectin and possess at least 50 % of the lubricating activity of a naturally - occurring tribonectin . a tribonectin lubricating polypeptide is a purified protein or polypeptide containing the amino acid sequence of human megakaryocyte stimulating factor ( msf ) or a fragment thereof . for example , a tribonectin lubricating polypeptide contains amino acids 67 - 106 and 200 - 1140 of seq id no : 1 and at least one o - linked oligosaccharide , but lacks amino acids 26 - 66 of seq id no : 1 . in other examples , the polypeptide further lacks amino acids 107 - 156 of seq id no : 1 or amino acids 107 - 199 of seq id no : 1 , or the polypeptide contains amino acids 1 - 25 , 67 - 106 , and 200 - 1404 of seq id no : 1 . alternatively , the polypeptide contains amino acids 67 - 106 and 200 - 1140 of seq id no : 1 and at least one o - linked oligosaccharide , but lacks amino acids 107 - 156 of seq id no : 1 . in another variation , the lubricating polypeptide contains amino acids 67 - 106 and 200 - 1140 of seq id no : 1 and at least one o - linked oligosaccharide , but lacks amino acids 157 - 199 of seq id no : 1 . for example , the polypeptide contains amino acids 1 - 156 and 200 - 1404 of seq id no : 1 ( lacking amino acids 157 - 199 of seq id no : 1 ) or the polypeptide contains amino acids 1 - 106 and 200 - 1404 ( lacking amino acids 107 - 199 of seq id no : 1 ). the amino acid sequences are contiguous to one another or may be separated by intervening unrelated sequences . preferably , the lubricating polypeptide contains residues encoded by exons 1 , 3 , and 6 - 12 of the msf gene . polynucleotides encoding the polypeptide backbone of a lubricating polypeptide include nucleotides 232 - 351 and 631 - 3453 of seq id no : 2 and lacks nucleotides 109 - 231 of seq id no : 2 . in another example , the polynucleotide contains nucleotides 232 - 351 and 631 - 3453 of seq id no : 2 and lacks nucleotides 352 - 501 of seq id no : 2 . in yet another examples , the polynucleotide contains nucleotides 232 - 351 and 631 - 3453 of seq id no : 2 and lacks nucleotides 502 - 630 of seq id no : 2 . a polynucleotide containing nucleotides 232 - 351 and 631 - 3453 of seq id no : 2 and lacking nucleotides 352 - 630 of seq id no : 2 is also within the invention as well as a polynucleotide containing nucleotides 232 - 351 and 631 - 3453 of seq id no : 2 and lacking nucleotides 109 - 231 and 352 - 630 of seq id no : 2 . for example , the polynucleotide contains nucleotides 34 - 501 linked in - frame to nucleotides 631 - 4245 of seq id no : 2 or nucleotides 34 - 501 linked in - frame to nucleotides 631 - 4245 of seq id no : 2 . the polynucleotide contains a first sequence containing nucleotides 34 - 501 of seq id no : 2 , a second sequence containing nucleotides 232 - 351 of seq id no : 2 , and a third sequence containing nucleotides 631 - 4245 of seq id no : 2 . the first , second and third sequences are linked in - frame . preferably , the sequences described above are contiguous . in addition to the tribonectins described above , recombinant lubricin molecules and other compositions described in u . s . patent application pub . no . 2007 / 0191268 are used in combination with tribonectins , ha , and / or inhibitors of proinflammatory mediators to preserve , prolong , or augment joint lubrication . a strong link has been established between the p38 pathway and inflammation . inhibition of inflammation via the p38 pathway leads to enhanced lubricin / tribonectin production . the activation of the p38 pathway plays essential roles in the production of proinflammatory cytokines ( il - 1 , tnf - and il - 6 ); induction of enzymes such as cox - 2 which controls connective tissue remodeling in pathological conditions ; expression of intracellular enzymes such as inos , a regulator of oxidation ; induction of vcam - 1 and other adherent proteins along with other inflammatory related molecules . in addition , a regulatory role for p38 in the proliferation and differentiation of immune system cells such as gm - csf , epo , csf and cd - 40 has been established . inhibition of elements of this pathway together with administration of a tribonectin lead to improved joint lubrication over prolonged periods of time . exemplary functional blockers of tnf - α include , but are not limited to , recombinant and / or soluble tnfα receptors , monoclonal antibodies , and small molecule antagonists and / or inverse agonists . exemplary commercial tnf - α blocking agents include , etanerept / enbrel ™, infliximab / remicade , and adalimumab / humira . etanercept ( enbrel ™, co - marketed by amgen and wyeth ) is a recombinant human soluble tnf - α receptor ( drugbank btd0052 ). it is a small protein ( 75 kda ) that binds tnfα and decreases its role in inflammation . enbrel ™ is a dimeric fusion protein comprised of the extracellular ligand - binding portion of the human 75 kilodalton ( p75 ) tumor necrosis factor receptor ( tnfr ) linked to the fc portion of human igg1 . the fc component of etanercept contains the ch2 domain , the ch3 domain and hinge region , but not the ch1 domain of igg1 . etanercept is produced by recombinant dna technology in a chinese hamster ovary ( cho ) mammalian cell expression system and is comprised of 934 amino acids ( genbank m32315 ). etanercept binds specifically to tumor necrosis factor ( tnf ) and blocks its interaction with cell surface tnf receptors . the biological activity of tnf is dependent upon binding to either cell surface receptor ( p75 or p55 ). etanercept is a dimeric soluble form of the p75 tnf receptor that can bind to two tnf molecules , thereby effectively removing them from circulation . inhibitors or antagonists of proinflammatory cytokine il - 1 include anakinra / kineret ™ ( recombinant human il - 1ra , rhil - 1ra ). il - 1ra is an endogenous receptor antagonist , which is primarily produced by activated monocytes and tissue macrophages and inhibits the activities of the proinflammatory forms of il - 1 by competitively binding to il - 1 receptor . il - 1ra is an inducible gene that is often upregulated in inflammatory conditions . although the binding affinity of natural il - 1ra is similar to that of il - 1 , it lacks il - 1 agonist activity . exemplary il - 1ra compositions include ncbi accession no . nm — 173842 ( human il - 1ra , transcript 1 ), which encodes amino acid sequence ncbi accession no . nm — 173842 ; human il - 1ra , transcript 2 ncbi accession no . nm — 173841 which encodes amino acid sequence ncbi accession no . nm — 173841 ; and human il - 1ra , transcript 3 ncbi accession no . nm — 000577 which encodes amino acid sequence ( ncbi accession no . nm — 000577 ). anakinra / kineret ™ is encoded by transcript sequence ncbi accession no . m55646 , and the amino acid sequence of anakinra / kineret ™ is recorded at drugbank accession no . btd00060 . inhibitory antibodies include anti - il - 1α ( u . s . patent no . 20030026806 ), anti - il - 1β ( u . s . patent no . 20030026806 ) and humanized monoclonal anti - il - 1r ( amgen , u . s . patent no . 2004022718 and roche , u . s . patent no . 2005023872 ). reversible rise in joint ex - vivo μ is a result of decreased synovial lubricin expression in an antigen - induced arthritis model data obtained with an antigen - induced arthritis rat model using limbs studied ex vivo showed that a reversible rise in joint ex - vivo μ was attributable to decreased synoviocyte lubricin expression . the ex - vivo μ of arthritic joints was significantly ( p & lt ; 0 . 001 ) higher than the μ of contra - lateral joints at 7 , 21 and 24 days following the induction of arthritis . lubricin mrna expression in the synovial tissues of the arthritic joints relative to those of the contralateral joints was significantly ( p & lt ; 0 . 001 ) lower at days 4 and 7 compared to control . at day 28 following arthritis induction , there was no significant difference between relative lubricin mrna expression in the arthritic and control joints . decreased lubricin expression in the superficial zone of articular chondrocytes was demonstrated by decreased lubricin staining in the arthritic joints at 7 days following the initiation of arthritis ( fig1 ). acl injury results in loss of joint lubricating ability and damage to the articular surface in rats the method described above was applied to a rat acl injury model . 12 rats underwent acl transection ( aclt ) of the right rear limb knee joints . following 7 and 28 days both the right and left rear limbs from 6 animals at each time point were harvested and underwent pendulum studies to determine ex - vivo μ . following pendulum studies , joints were lavaged and sf lavages were analyzed for sulfated glycosaminoglycan ( sgag ) levels using alcian blue binding assay . immunohistochemical staining for surface damage and presence of lubricin , using a lubricin - specific monoclonal antibody was also performed . the ex - vivo μ values of aclt joints were significantly elevated at 4 weeks following injury compared to either contralateral ( cl ) joints at week 4 or aclt joints at 1 week following the injury ( fig2 ). this time - dependent elevation of friction was associated with increased sgag sf lavage levels ( fig3 ). at 1 week following the injury , sgag levels dramatically increased in the aclt joints compared to the contra - lateral joints . at 4 weeks following the injury , the aclt joints demonstrated elevated sf lavage sgag levels compared to the contralateral joints . however , sgag levels of sf lavages at week 4 were significantly ( p & lt ; 0 . 001 ) lower than sgag levels of sf lavages at week 1 . administration of etanercept blunts the catabolic decrease in synovial fluid lubricin concentration following aclt studies were carried out to investigate the effects of blocking tnf - α at an early stage after injury on sf lubricin levels , joint lubrication and cartilage damage . inhibition of tnf - α was performed using etanercept , a tnf - α soluble receptor that is approved for treatment of rheumatoid arthritis . the following reagents and methods were used to evaluate inhibition of the effects of tnf - α by etanercept and the preservation of joint lubrication and decrease cartilage damage following an acl injury . acl - transection ( aclt ) model and entanercept administration : male lewis rats 7 - 8 weeks were assigned to either an acl - transection group ( n = 5 ), etanercept - treated acl - transection group ( n = 5 ) or a sham - group ( n = 4 ). etanercept was given subcutaneously at 0 . 5 mg / kg on days 1 , 3 , 5 , 7 , 9 , 11 , and 13 following aclt . at 14 days following surgery , aclt , contralateral ( cl ) and sham ( s ) joints were harvested and lavaged . lavaging was performed by injecting 100 μl in the joint capsule , flexing and extending the joint for ten times and aspirating 50 μl of fluid . sf lubricin levels : lubricin levels were determined using sandwich elisa employing a lubricin - specific monoclonal antibody , and peanut agglutinin ( pna ). ex - vivo joint μ : articular joints &# 39 ; μ values were determined using modified stanton pendulum ( elsaid k a et al , arthritis rheum 2007 ; 56 : 108 - 116 ). sgag levels in sf lavages : total sgag levels were determined by alcian blue binding assay . the concentrations of lubricin in the sf lavages were found to be significantly ( p & lt ; 0 . 001 ) higher in the etanercept - treated aclt joints compared to the non - treated joints ( fig4 ). the ex - vivo joints μ valves were significantly ( p = 0 . 021 ) lower in the etanercept - treated aclt compared to the non - treated joints ( fig5 ). sgag levels in sf were significantly ( p & lt ; 0 . 001 ) lower in the etanercept - treated group compared to the non - treated group ( fig6 ). at an early stage following an acute acl injury , inhibition of the effects of tnf - α leads to a significant increase in sf lubricin levels and decrease in joint μ . this effect is associated with decreased cartilage damage as determined by a decrease in sgag turnover . early intervention following acl injury by blocking the effects of tnf - α preserved articular joint &# 39 ; s chondroprotective mechanisms and decreased the extent of cartilage - injury . enbrel ™ administered subcutaneously led to an upregulation of lubricin , leading to effective chondroprotection and prevention / reduction of cartilage wear . the data indicate that a tnf - α inhibitor ( e . g ., enbrel ™) is effective in increasing lubricin levels . a combination of recombinant lubricin and enbrel ™ leads to a greater clinical response in the cartilage preservation endpoint by the inhibition of wear . early intervention is beneficial in retarding long - term cartilage damage and development of secondary osteoarthritis following acl injury . comparison of early and late inhibition of tnf - α in restoring chondroprotection by lubricin in the acl transection injury model etanercept was administered to animals , and condroprotection was evaluated using an acl - transection model . male lewis rats 7 - 8 weeks were assigned to either an acl - transection group ( n = 5 ), 2 etanercept - treated aclt groups ( n = 12 , 6 in each group ) or a sham surgery group ( n = 4 ). etanercept was given subcutaneously at 0 . 5 mg / kg on days 8 , and 15 following transection ( treatment a ) or on days 15 and 22 ( treatment b ). at 28 days following transection , acl - transected ( aclt ), contralateral ( cl ) and sham joints were harvested and lavaged . lavaging was performed by injecting 50 μl of normal saline in the joint capsule , flexing and extending the joint for ten times and then aspirating 30 μl of fluid . sf lubricin levels were determined using a sandwich elisa employing a lubricin - specific monoclonal antibody such as 9g3 , and peanut agglutinin . surface - associated lubricin coverage was calculated from 9g3 - stained histological specimens . quantitiation of lubricin staining intensity was calculated using image pro - plus software ( media cybernetics , md , usa ) with pre - determined threshold parameters and expressed as percentage of lubricin surface coverage . an average of lubricin surface coverage of the medial and lateral regions of femur and tibial cartilage surfaces was calculated . articular joints &# 39 ; μ values were determined ex vivo using modified stanton pendulum ( elsaid k a et al ., arthritis rheum ., 2007 , 56 : 108 - 116 ). the sf lavage lubricin levels in treatment - a aclt joints were found to be significantly ( p & lt ; 0 . 01 ) higher than in control or treatment b joints ( fig7 ). sf lavage lubricin levels in cl joints were comparable across the different groups . lubricin coverage of articular surfaces was significantly ( p & lt ; 0 . 01 ) lower in the aclt joints compared to treatments a , b and sham surgery . lubricin coverage in the cl joints was comparable across the different groups . the joints &# 39 ; μ values were comparable in treatments a , and b and were lower than the μ values of aclt joints , but approximated the μ values of sham surgery joints ( table 3 ). table 3 shows the mean coefficient of friction ( μ )± standard error of the mean ( sem ) of aclt and cl joints of different groups . inhibition of the effects of tnf - α by etanercept treatment re - establishes lubricin coverage on the surface of articular cartilage and is associated with a reduction in joints &# 39 ; coefficient of friction compared to non - treated joints . initiating tnf - α inhibition early ( treatment a ) results in higher sf lavage lubricin levels compared to later intervention ( treatment b ). differences in sf lavage lubricin levels did not correspond to changes in surface - associated lubricin or changes in ex - vivo μ values . articular cartilage surface coverage with lubricin was associated with a lowering of μ values in etanercept - treated joints compared to no treatment . these results indicate that surface - associated lubricin is more important than sf lubricin in modulating articular lubrication ability . two early administrations of etanercept was found to be more effective than later treatment in re - establishing high sf lubricin which may serve as a reservoir of lubricin for articular surfaces . this administration approach is useful as an alternative or adjunct to intra - articular lubricin supplementation . tnf - α inhibitory compositions either alone or in combination with a tribonectin confer a clinical benefit by increasing the amount of surface - associated lubricin and reducing the co - efficient of friction in the joint . while the invention has been described in conjunction with the detailed description thereof , the foregoing description is intended to illustrate and not limit the scope of the invention , which is defined by the scope of the appended claims . other aspects , advantages , and modifications are within the scope of the following claims .
the invention provides compositions and methods for preserving , prolonging , or augmenting joint lubrication by contacting a tissue of a joint such as a knee , elbow , or other articulating joint , with a tribonectin and an inhibitor of a proinflammatory mediator .