APOTEX ET AL. - EXHIBIT 1054
`Apotex Inc. et al. v. Novartis AG
`IPR2017-00854
`
`

`

`Keller et al
`282
`rllPJnrirurrvfllirT; trial. no. No r
`
`down-regulation of the receptor subtypes SiP. on thy-
`mocytes and lymphocytes. depriving them from the
`obligatory SlP—rnediated signal to egress from lymphoid
`organs.7 Besides the action on lymphocyte recirculation.
`FI'Y720 maintains vascular integrity of endothelial cells
`by enhancing adherens junction assembly.”
`Although sequestration of lymphocytes is solely me-
`diated by SlP.. unspecific Sit?I receptor agonists elicit
`a variety of physiological and pathological responses.g
`it has been shown that high plasma levels of StP lead
`to adverse cardiovascular effects. including hypoten-
`sioh. bredycardia. and coronary artery vasospasm.
`which are mediated after activation of the receptor
`subtype SlP3.1° Thus.
`it is not astonishing that high
`concentrations of FTY?20 may also induce SlPa-medi-
`ated bradycardia.‘
`Most recently. we have shown that there also exists a
`crosstalk betlrveen SlP receptors and the signaling cas-
`cade of transforming growth factor (TGFt-p in a variety of
`cells.“‘13 in general. TGF-B signals through transmern—
`brane receptor serinerthreonine kinases to activate sig-
`naling intermediates, called Smad proteins. which then
`translocate into the nucleus and act as transcription fac—
`tors.” In different cell types. it has been shown that SlP
`augments Smada phosphorylation. one of the two homol-
`ogous proteins. which signals from TGF-Bl'activin. and
`that the abrogation of Smad3 prevents S1P—mediated ef-
`fects. indicating a surprising but essential role of Smad3 in
`the signaling cascade of the lysophospholipid."'-12
`Besides its immunomodulatory effect. TGF-fl pos—
`sesses multiple biological actions. which contribute to the
`capacity that it plays in many fibrotic diseases.” A key
`role is the HERB—mediated differentiation of fibroblasts
`into myofibroblasts because these cells are primarily re-
`sponsible for excessive matrix protein formation.1E Be-
`cause ot a crosstalk between 81 P and TGF-B signaling. it
`was theretore of interest whether FTY720 may also influ-
`ence nlyotibroolasi differentiation. Indeed. here we show
`that FTY720 strongly rncreases myofibroblast differentia-
`tion as a result of interaction of the phosphorylated ana—
`logue with the SlF'5 receptor subtype and the subse-
`quent activation of Smad3.
`
`Materials and Methods
`
`Materials
`
`N.N-Dimethy|sphingoeine (UNIS). pertussis toxin (PTX).
`and protein (3 agarose were purchased from Calblochem
`{Bad Soden. Germany). FuGene was from Roche Diag—
`nostics {Mannheim Germany). Mouse monoclonal anti-
`Smad1.2.3. rabbit polyclcnal anti—SlF‘.. goat polyclcnal
`anti-StPa. goat polyolortal anti-SlP... goat polyclcnal anti—
`SlP5 antibodies. goat polyclcnal anti—TGF-fi antibodies.
`normal goat lgG. and anti—goat lgG-horseradish peroxi-
`dase were purchased from Santa Cruz Biotechnology
`{Santa Cruz. CA). LumiGlo reagent. peroxide. and anti—
`rabbit and anti-mouse IgG horseradish peroxidase were
`obtained from New England Biolabs (Beverly. MA).
`FI'WED was purchased from Calbiochem. Bovine serum
`
`albumin. fetal bovine serum (HES). 4—(2—hydroxyethylt-l—
`piperazineethanesultonic acid (HEPES) buffer, and L-glu-
`lamina solution were from Sercmed Biochrom (Berlin.
`Germany). Aprotinin. 3—[4.5-dimethyllhiazol—E-yI]-2.5-dl-
`phenyl
`tetrazolium bromide (MW). dimethyl sulfcxide.
`Dulbecco's modified Eagle‘s medium lDMEM). ethyl-
`enediaminetetraacetic acid tBDTA).
`leupeptin. Mowiol.
`murine monoclonal anti—a-smooth muscle actin (e—SMA)
`antibodies. lluorescein isothiocyanate (FITCJ-linkad anti~
`mouse antibodies. penicillin. pepstatin. sodium dodecyl
`sulfate (EDS). TGF~51. sodium fluoride.
`sodium or-
`thovanadate. streptomycin, Tris. Triton x—roo.
`trypsin.
`and Tween 20 were purchased from Sigma (Deisen—
`hoien. Germany). OptiMEM was
`from lnvitrogen
`{Karlsruhe Germany). Oligonucleotides were synthe-
`sized at Tib Molbiol
`(Berlin. Germany). Polyvinylidene
`difluoride membranes were purchased from Millipore
`(Schwalbach. Germany).
`
`Synthesis of WHO-P
`
`FFY72o—F' {phosphoric acid monoflH/Sl—Z-amino-E-hy-
`droxymethyi—4—{4-octylphenyl)buryliester) was synthe-
`sized from FTY72C- l2—amino—2-t2-[4-octylphenyl]ethyl)-
`1.3-propanedioll as recently described.” In brief.
`FTYYED was protected as an oxazolidlnone by the ad—
`dition of benzyl chloroformate. Then. phosphorylation
`of the free hydroxyl group was performed by the addi-
`tion of 3stdiethylaminol-t.5-dihydro-2.4.3-benzodiox—
`aphosphepintrlphenyl phosphlte and a subsequent ox-
`idation to obtain tR/St-4-[2-{4-octylphenyl)ethyl]-4-{3-
`oxo-l .5-dlhydro—3A5-bsnzo[e][‘l .3.2]dioxaphosphepin-
`3-yio>tymethyltoxazolidin-Q-one. The phosphate-pro-
`tecting group was removed by hydrogenation. and the
`oxazolidincne was cleaved with lithium hydroxide
`yielding to FTY720-P. identity was checked by electro—
`spray ionization time-of-flight mass spectrometry using
`an Agilent 6210 TOF LCZMS {Waldbronn Germany).
`Electrospray ionization-mass spectrometry. mlz: 386
`{M — Hi’. Moreover. purity of FTY'r’ZO—P was measured
`by-high-periormance liquid chromatography r‘.HF’LC).1B
`Therefore. synthesized F‘W'r'EO—P or standard FFY'IEO
`was dissolved in 275 pl of methanollom' mollL
`KEHPO4 (9:1). A derivatizatlon mixture of 10 mg of
`o-phthaldialdehyde. 200 pl of ethanol. 10 pl of 2-mer-
`captoethanol. and 10 ml of 3% boric acid was pre—
`pared and adjusted to pH 10.5 with KOH. Twenty-five
`pl of the derivatlzation mixture was added to the re—
`solved FTY72U or FTY720—P for 15 minutes at room
`temperature. The derivatives were analyzed by a
`Merck Hitachi LaChrom HPLC system (Merck Hitachi.
`Darmstadt. Germany) using a RP 18 Kromasil oolumn
`(Chromatographic Service. Langerwehe. Germany).
`Separation was done with a gradient of methanol and
`0.07 moIlL KEHPO... Resulting profiles were evaluated
`using the Merck system manager software. indicating
`no detectable amount of Fl’Y'r’ZtJ in the synthesized
`FTY720-P.
`
`

`

`Preparation of Human Fibroblasts
`
`To isolate human fibroblasts. juvenile foreskin from sur-
`gery was incubated at 3?°C for 2.5 hours in a solution of
`0.25% trypsin and 0.2% EDTA. Trypsinizaticn was termi-
`nated by the addition of DMEM containing 10% FBS.
`Cells were washed with phosphate-buffered saline (PBS)
`and centrifuged at 250 X g for 5 minutes. The pellet was
`resuspended in DMEM containing 7.5% PBS. 2 mmcliL
`L—glutamlne. 100 Uiml penicillin. and 0.1 mgrml strepto-
`mycin. Fibroblasts were pooled from several donors and
`cultured at 137°C in 5% C02. Only cells of the third to sixth
`passage were used for the experiments
`
`Preparation of Wild-Type and Smack?“H
`Fibroblasts
`
`Murine fibroblasts. isolated from polymerase chain reac-
`tion-genotyped wild—type and SmadB knockout newborn
`mice. were kindly provided from Dr. Anita Roberts (Na—
`tional Institutes of Health. National Cancer Institute. Be-
`thesda. MD).1g Cells were cultured in DMEM supple—
`mented with 10% PBS. 2 mmoliL t-glutamine. 100 Uiml
`penicillin. and 0.1 mgi'rnl streptomycin. For detection of
`wild—type and Smad3“"i
`fibroblasts the primer
`se—
`quences 5'-CCACTTCATTGCGATATGCCCTG—B‘
`(lo-
`cated 5' to the deletion) and 5’-CCCGAACAGT‘TGGAT-
`TCACACA-S' {located within the deletion) were used.
`Smad3‘"‘i fibroblasts were identified using the primer
`located to the 5' deletion and a primer specific for the
`pLoxpneo cassette
`{5'-CCAGACTGCCTTGGGAAAA—
`GC-a').
`
`Preparation of Wiid- Type and 314103“H
`Fibroblasts
`
`Wild-type and SinJ knockout mice were generated by
`Dr. Jerold Chun as recently described?0 To isolate mu-
`rine fibroblasts. skin was incubated at 3?“C for 2.5 hours
`in a solution of 0.25% trypsin and 0.2% EDTA. Trypsiniza—
`tion was completed by the addition of DMEM containing
`10% FBS. Isolated fibroblasts were washed with PBS and
`centrifuged at 250 x g for 5 minutes. The pellet was
`resuspended in DMEM containing 10% PBS. 2 mmoliL
`L~giutamine. 100 Ulml penicillin. and 0.1 mgiml strepto-
`mycin and cultured at 137°C in 5% (302. Cells were geno-
`typed by polymerase chain reaction. The following prim-
`ers were used: 5'-CACAGCAAGCAGACCTCCAGA—S'.
`5'-TGGTGTGCGGCTGTCTAGTCAA-S‘, and 5’-ATCG-
`ATACCGTCGATCGACCT~3’.
`
`Real-Time Polymerase Chain Reaction (PCB)
`
`Heal-time PCFl assays Were performed using the SYBR
`Green PCR Master Mix on ABI Prism ?900HT sequence
`detection system according to the manufacturer's proto—
`col (Applied Bicsystems. Foster City. CA). Amplification
`was performed in 10-pl reactions (primer concentration.
`250 nmoliL. 1x SYBR Green Master Mix] containing 2 pl
`
`283
`l—‘l'Y‘rECr and Myofibroblast Differentiation
`AJP format}- 2r‘11'37.
`I’m“. ”'0. No.
`i
`
`of cDNA {equivalent to 10 ng of total RNA) in 40 cycles of
`95°C. 15 seconds. 50%].
`1 minute. Primers were pur—
`chased at SuperArray Bioscience Corporation (Freder—
`lck. MD). Total RNA of three different sets of fibroblasts
`were used to analyze receptor expression. Data normal-
`ization was performed using GADPH as reference gene.
`Relative mRNA expression was quantified using the com-
`parative CT method according to the ABI manual.
`
`Cell Viability Assay
`
`Cell viability was measured by the MTT dye reduction
`assay. Cells. seeded into 24~weil plates for 24 hours.
`were incubated with FTY720 or l—‘TY720-P for 24 hours at
`37°C in 5% (30?. After the addition of 100 ,u.| ol MTT
`solution (5 mgiml} per well. the plates were incubated for
`another 4 hours. The supernatants were removed. and
`the formazan crystals were solubilized in 1 ml of dimethyl
`sulfcxide. The optical density was determined at 540 nm
`using a scanning microplate spectrophotometer (Multi-
`scan Pius; Labsystems. Helsinki. Finland).
`
`immunoflucrescence Microscopy of a-SMA
`
`Fibroblasts were seeded into 12-well plates. each con—
`taining a glass coverslip. and cultured for 24 hours in
`DMEM containing 2 nmoll'L L-glutamine. 100 Uit'nl peni~
`ciliin. 0.1 mgiml streptomycin. and 7.5% FBS. Then they
`were serum-deprived for 48 hours in DMEM supple-
`mented with 2 nmcIiL L-glutamine. 100 Uimt penicillin.
`and 0.1 mgr’ml streptomycin. Quiescent fibroblasts were
`stimulated with the indicated substances for 72 hours.
`Cells were washed with ice-cold PBS and fixed in meth-
`anol at 4°C for 2 minutes. Cells were treated with blocking
`buffer (1% boyine serum albumin in PBS] for 30 minutes
`followed by incubation with murine anti—a~SMA antibodies
`(1 :50 diluted in blocking buffer). Coverslips were washed
`three times with blocking buffer and incubated with FITC-
`Iinked anti-mouse antibodies (1:125 diluted in blocking
`butter). After 30 minutes. fibroblasts were washed three
`times with blocking buffer and fixed by a Mowiol mount—
`ing medium. Staining was examined using the Olympus
`BX41 fluorescence microscope (Hamburg. Germany)
`and documented by the digital camera Nikon DXM1200
`iDLisseldorf. Germany). Appropriate emission filter set-
`tings and controls were included for bleed-through
`effects.
`
`imm un oprecipitaficn
`
`Human fibroblasts were seeded in six-well plates and
`cultured for 24 hours in DMEM containing 7.5% FBS. 2
`mmolrL L-glutamine. 100 Uiml penicillin. and 0.1 mgr‘t‘nl
`streptomycin. and then medium was replaced by HEPES
`buffer {1 molr'L} for 2 hours. Cells were treated with TGF-p
`(2 ngiml) or FTY720 (1 pmoliL) for 30 minutes. Fibroblasts
`were rinsed twice with ice-cold PBS and harvested in
`radiolmmunoprecipitation assay tFliPA) buffer [50 mmollL
`Trisr‘HCl. pH 7.5. 150 mmoliL NaCl. 1% Nonidet P-40.
`0.5% deoxycholic acid. and 0.1% 808). containing pro—
`
`

`

`Keller et a!
`284
`.-l_{Pjrrrtrwrj|'3tirJ?.
`
`i’oi'. FWD. No i
`
`tease inhibitors (1 mmoIrL phenylmethyl sulfonyl fluoride.
`1 mmoli’L EDTA. 1 pgrmlleupeptin. t pgrmlaprotinin. and
`‘ hgiml pepstatint and phosphatase inhibitors (1 mmoliL
`sodium orthovanadate. 50 mmot/L sodium fluoride. and
`40 mmoliL p—glycerophosphate). Lysates were centri-
`fuged at 14.000 x g for 30 minutes. One hundred pg of
`lysate protein was immunopreclpiteted overnight at 4"(3
`with 0.2 pg of anti-Smad1.2.3 antibodies or 0.2 pg of
`normal goat lgG (196 control). followed by a precipitation
`with 10 pl of protein G plus agarose at 4‘0 for 90 minutes.
`After four washes with complete RIPA buffer. the immu-
`noprecipitates were eluted by boiling for 5 minutes in 80
`pl of SDS sample buffer (100 mmcliL TrisiHCI. pH 8.8, 4%
`SDS. 0.2% bromphenot blue. 20% glycerol. and 200
`mmoliL dithiothreitol).
`
`immunobioitr'ng
`
`For Western blot analysis. immunoprecipitates (20 pit or
`cell lysates {10 to 20 pg of protein) were separated by
`SDSipolyecrylamide gel electrophoresis. Gels were blot-
`ted overnight onto pclyvinylidene difluoride membranes.
`After blocking with 5% nonfat dry milk in Tris—buffered
`saline (TBS-Tween 20 (0.1%) overnight at 4°C. mem—
`branes were incubated with the indicated specific pri-
`mary antibodies for 0.5 or 2 hours at room temperature.
`The blots were washed three times in TBS—Tween 20
`followed by incubation with the secondary horseradish
`peroxidase-conjugated antibodies for
`1 hour at room
`temperature. Immunooomplexes were detected using an
`enhanced chemiluminescence detection method. Den-
`sitometry of films was performed using the Syngene
`GeneGenius (Cambridge. UK).
`
`Anti—Sense Oiigonucteotr’des
`
`Anti-sense oligonucleotides (A805) were designed to
`surround the translational
`initiation site. a place emplri-
`cally known to be most effective for inhibition of gene
`expression. The following specific ASOs as well as same-
`Iength control oligonuclsotides (with the same nucleo-
`tides but randomly scrambled sequence) were synthe—
`sized: SmadS ASO: 5'-GCAGGATGGACGACAT-3‘. con-
`trol oligcnucleotldes 5'-GTGGACAGCTAGAGAC-3';
`Sth2 A50: 5“—CAGGGGAAGAGGCAGGTCAGACA-B'.
`control oligonucleotldes; 5'—TGCAAGCTCACCAACCCC—
`AGATA—3'; S1P1: ASO 5'-GACGCTGGTGGGCCCCAT-
`3‘. control otlgonucleotides: 5'—ATGGGGCCCACCAGC-
`GTE-3‘: SiPa: A30 5'-CGGGAGGGCAGTTGCCAT-3'.
`control oligonucleotides: 5’—ATGGCAACTGCCCTCCCG~
`3'; SiF‘d: ASD 5‘-GAAGGCCAGCAGGATCATCAGCAC-
`3’. control oligonucleotides: 5'—ACCTAGCCAACCCTCC-
`ATGAAGGC-S’; StPfi; A50 5'-CAACATGCCACAAAGG-
`CCAGGAGS'. control oligonucleotides: 5'-GCAACAAC—
`ATAACGGGCCAGCAG-S'. Cells were seeded in six-well
`plates and cultured in DMEM supplemented with 10%
`FBS. 2 mmoli’L L-glutamine. 100 Ufml penicillin. and 0.1
`mgiml streptomycin for 12 hours. Control oligonucleo-
`tides and #603 were solubilized in OpthEM and Fu-
`GENE (1 pg of DNArQ at) to achieve a final concentration
`
`of 500 nmoliL of oligonucleotides. Then the solution was
`added to fibroblasts for 72 hours. Abrogation of protein
`expression was verified by immunoblotting.
`
`Measurement of TGF—fi Secretion
`
`Fibroblasts [t x 105 ceiisrml} were stimulated with
`FI'Y720 (1 pmolrL) throughout a time period of 24 hours.
`Then levels of TGF-fi in the supernatant were quantified
`by selective enzyme-linked immunosorbent assay kits
`following the instructions of the manufacturer (Amersham
`Pharmacia Biotech. Freiburg. Germany). For measure—
`ment of latent complexes of TGF—p. activation was ac—
`complished by acid treatment. Therefore. 0.5 ml of cell
`culture supernatants were treated with 0.1 ml of ‘l moliL
`HCI. incubated for 10 minutes. and than neutralized with
`0.1 ml of 1.2 molrL NaOHr0.5 molrl. HEPES. Samples
`were analyzed by a Fluostar Optima ELISA reader from
`BMG Labtech (Offenburg. Germany}. The detection limit
`was 4 pgr’ml.
`
`Results
`
`Fir W20 induces Transformation of fibroblasts
`
`into Myot‘ibrobiasi‘s
`
`The expression of a—SMA is one of the most prominent
`features of myoffbroblasts. which have a phenotype
`intermediate between smooth muscle cells and fibro-
`biasts. TGF-fi has been indicated as the crucial cyto-
`kine to induce transformation of fibroblasts into myofi—
`broblasts.‘5 Most recently. we figured out that there
`exists a crosstalk between TGF—p and 81? receptors
`and that StP mimics biological effects of TGF—p in
`dendritic cells.“ Based on the structural similarity be-
`tween SiP and the phosphorylated l-‘lYT20. we inves-
`tigated whether the immunomodulator FTY720 might
`also influence myofibrobtast differentiation. Therefore.
`cx-SMA expression in response to FTY720 was mea—
`sured by Western blotting and immunofluorescence
`microscopy in primary human fibroblasts. For positive
`control experiments.
`fibroblasts were treated with
`TSP-,0. and immunofluorescence indicated a pro-
`nounced o-SMA formation confirming that TGF-B stim-
`ulates the fibroblasts to differentiate into myofibro—
`blasts (Figure 1). Most
`interestingly.
`treatment of
`primary cells with FTY720 also resulted in a distinct
`expression of a-SMA (Figure 1). Immunofluorescence
`of e-SMA in response to FTYTEO showed a distinct
`appearance of numerous bundles of actin microfila-
`merits comparable with TGF-B. whereas the cell shape
`was slightly elongated. The number of fibroblasts ex-
`pressing cr-SMA was drastically increased in a dose—
`dependent manner (Figure 1}. A significant increase
`was detected at a concentration of 0.1 pmoliL W720.
`whereas a maximal effect occurred at 1 pmoIIL induc-
`ing a similarly strong expression of a-SMA as the most
`effective dose of TGF-fl f2 ngfml) {Figure 1).
`It should
`be noted that higher concentrations of l-‘FY‘r’EO did not
`further increase a-SMA formation attributable to a toxic
`
`

`

`285
`FTrrzu and Myofibroblast Differentiation
`Aijmrtrij 2007,
`ir’of.
`)‘ 70. No. i
`
`t'nttl :‘ol
`
`
`
`rm
`
`10
`gazes;
`gases“
`HYWsfimrflatinn
`TGF—fi-Ifimdatlan
`period (It)
`Wind (1:)
`IJIGF‘JB find FIIYTEU induce myol'il'imhlztst differentiation. A: Human Fibroblasts were stimulated with 'J'Gti-fi f2 nefttil} lJl' Fl'YTZO t1 untold.) for T2
`“El-IN I.
`hours Followed by an irt‘imunolluorcst‘enee analysis of tx-SMA. fl ttttd C: Cells were treated with the indicated mneemratiuns of 'l't'ili-B or |'”l“r"?2[] for 72 hours
`(B: or with 2 ngr'ml ‘l'GF-B or 1 untolr‘l. J’I'Yizil for different stitttulation perindstJ. Then a-SMA was measured by Western blot analysis tts described in Materials
`and Methods. All results were confirmed in three independent experiments. Densilnn'ieirie analysis of a-SMA formation wits performed after Western blot analysis.
`Values :ll‘L‘ normalized to B-aet'tn levels and are expressed as am X-Folid increase of u-SMA formation compared with untreated L‘ells : 51$.“ From at least three
`experilttunts. ‘P < 0.05 and "P < 0.00] indicate a statistically significant difference Versus unstimulaled control cells. Original magnifications. K400
`
`'5
`
`g
`3
`3
`IGF—fiwml)
`
`lEl
`E
`3
`3
`3'
`Function
`
`the immunosuppressive agent {data not
`effect of
`shown). Furthermore. in analogy to TGFvB, a significant
`increase of a-SMA was first detected after a 24~hour
`treatment of fibroblasts with Fi'Y'i’20. whereas a maxi—
`mal response was visible after ?2 hours (Figure 1).
`
`Phosphoryfation of F i 5720 is Required for
`Myofibrobiast Differentiation
`
`Although FTY720 induces myofibroblast differentiation.
`a variety of studies indicate that phosphorylation of
`i—‘fY720 by sphingosine kinase is necessary for
`its
`biological effects?“5 Therefore, we measured whether
`FfY720—P is also able to differentiate fibroblasts into
`myoiibroblasts. indeed. in Figure 2 it is presented that
`the phosphorylated product entranced a—SMA forma-
`tion comparable with FTY720.
`it
`is of interest that the
`kinetic of or-SMA formation induced by FTY720-P was
`very similar to FTY720 showing a maximal effect after
`an incubation period of 72 to 96 hours {Figure 2).
`These results suggest that fibroblasts induce a rapid
`
`phosphorylation of FTYTED. Because FfY720—P shares
`structural homology to the natural biological mediator
`SiP. we examined whether the lysophospholipid S‘iP
`also induces myofibrobiast differentiation. Actually.
`in
`Figure 2 it is shown that treatment of primary cells with
`StP also resulted in the formation of o-SMA. A maximal
`effect occurred after an in—cubation period of 72 hours
`with 10 umoiiL sre (Figure 2).
`To examine whether the action of FTY720 is mediated
`by the phosphorylated product. conversion of FTY?2O to
`Fl'Y720-P was blocked by the sphingosine kinase inhib-
`itor DMS. Indeed. when fibroblasts were treated with 5
`pmoiil. DMS. the ability of FTY720 to enhance a—SMA was
`almost completely diminished. whereas TGF-B-induced
`a—SMA formation was not affected in the presence of
`DM8 (Figure 3. A and 8). Moreover. several studies indi-
`cate that Sth2 is mainly responsible for the phosphor—
`ylation of FTY720. Therefore. we measured the ability of
`l-‘fY72O to induce or—SMA expression after treatment with
`Sth2—ASO. In Figure SC. it is shown that control Oligo—
`nucieotides did not reduce a-SMA formation in response
`to FTY720. But when cells were treated with Sthz-ASO.
`
`

`

`286 Kelleretal
`Aijmrtrani2007. Vof.
`
`i390, No.
`
`i'
`
`A
`
`
` r‘ m it t'ol
`Elma-unionofmm
`Exprlninnofmm
`
`Harm-Pm
`
`SIP- stimulation
`FIYmP—nimulction
`period (In)
`Wind (I!)
`Figure 2. Thu: phosphorylulcd compound FTYT’ZG-P and 511‘ induce myofibroblasl diffumnlialion. A: Human fibroblasts wen: slltmilalcd \|'ll]‘. HTTZtl-P f1
`antral-"Li or SII‘ [10 mural-51,) for T2 hours followed by an immunofluorcsccncc :inttiysis of a—SMA. B and C: Ceils were treated with the indicated concentrations
`of l.‘]'\’j20_|! or 51p for 72 hours: (B) or with 1 pinch]. 1-”[1'72041 or 10 gmulrL S] P for different time periods (C). or-SMA was measured by Western blot analysis.
`and its quantitative determination by dcnsilomcin' normalized to ,B-riclin levels. All results were confirmed in t'an-L' indcpcndcnl experiments. ‘P d {1.05, "P 4
`0.00] Original magnifications. xrno.
`
`51PM
`
`FTY72O but not TGF—ta lost the capability to induce ex-
`pression of a—SMA. These results clearly indicate that
`FTYT’20—P is the active metabolite to induce transforma-
`tion of fibroblasts.
`
`Fit/7204D Mediates Myofibrobiast
`Differentiation through Activation of the S 1' P3
`Receptor
`
`Because FTY?20-P is a potent agonist of four of the five G
`protein-coupled SlP receptors. we performed real-time
`PCR to quantify mRNA of 81 P receptors in primary fibro—
`blasts. In agreement with further studies. mRNA of all five
`SiP receptor subtypes were expressed in fibroblasts.21
`The relative amount of StP receptor mRNA was 8th3 >>
`SiP. > 8in > S‘iP5 > SlPd [Figure 4B}. To prove the
`involvement of Cue—sensitive SIP receptors
`in
`the
`l—‘TYT20—mediated myofibroblast differentiation. we mea—
`sured the FTY720-induced cr—SMA formation in the pres-
`ence of PTX. Preincubation of fibroblasts with PTX almost
`completely abolished the ability of FI'YT20 to induce
`a-SMA expression. indicating that it is mainly dependent
`
`on SlP receptors interacting with Go. (Figure 4). it should
`be stated that PTX did not influence the aptitude of TGF—fi
`to induce a-SMA expression (Figure 4). To further eluci-
`date which of the 81 P receptor subtypes are essential for
`myofibroblast formation in response to F'TY720. expres—
`sion of 81 P receptors were abrogated by the use of A50.
`Treatment of cells with StP.-. 81P3—. StP..-. and 81%-
`A80 resulted in a serious reduction of protein levels
`(Figure 5A). Most interestingly. measurement of e-SMA
`expression revealed that StF’3 is critical for the FTY720—
`mediated myotibroblast differentiation. Thus. abrogation
`of 81 P3 significantly inhibited the capability of FI'Y72O to
`increase levels of a—SMA. whereas abrogation of 81P..
`StP... and StP5 did not significantly decrease aASMA
`expression in response to FTY720 (Figure SB). To more
`rigorously confirm that StPa is essential for FTY720—me—
`dialed myofibroblast differentiation. we used primary fi—
`broblasts isolated from wild—type or StP3 knockout mice.
`In analogy to our results in primary human fibroblasts.
`FTY720 was able to enhance the expression of a-SMA in
`control fibroblasts derived from wild—type mice. On the
`contrary. SiPa—deficient fibroblasts did not augment lev—
`
`

`

`28?
`FTY?20 and Myofibroblast Differentiation
`Aijwttimjv 200?.
`l-bi. 1‘70. No.
`i
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`control
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`l-‘JT'J‘ZO-mudiatcd myofihml'llast differentiation. A anti B: Iiuntan fibrniilttsls were
`is. responsible For
`“8‘1“: 3. Ti“: phosphorylatcd metabolite l-‘I‘Yizu-l’
`stiitttiialctl with I-“l'YTZU (i pmolr‘i.) nr '|'G|"-B f2 ngr’ml) for "F2 hours In the presence of DMS {5 unmifi.) followed by an intmunofluorcst‘cnco analysis [A] or
`
`Western blot analysis and dcnsitnmetric quantification of a-SMA normalized to ,B-actin {B}. Cells Wt'rc transit-crud with SpitK2-ASO {500 nntoile or control
`
`()ligonucicmidcs (500 nrnolt'i.) for 72 hours.
`Western blot analysis confirmed the relative abundance of the SpltKZ pl‘UiL‘ln expressed after SthZ-ASO
`pretreatment.
`'l‘hcn coils \A'crc treated \"ilil
`l-‘l‘I’TZO (i ulnuli’LJ or 'J'Ciii-fi (2 ngrml) for 72 hours. and n-SMA was measured by Western blot anal
`and
`X400.
`densitrmtctric quantification of u-SMA nonnalizcd tn B-ut‘tin All results were c'onl'irrttt'd in three independent experiments. “P< 0.0m. Original magnifications.
`
`nxm
`
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`
`sis of a—SMA in response to FTY?2U. whereas TGF—a was
`able to induce a‘SMA expression in both wild—type and
`S‘iPs-deficient fibroblasts (Figure 6).
`
`FW720 Mediates Myofibrooiast Differentiation
`through Activation of Smad8 Protein
`
`In several studies it has been demonstrated that activa-
`tion of Smad3 is critical for TGF-fi-induoed transformation
`of fibroblasts into myofibroblasts. Because we found that
`TGF—B and SiP activated Smad3 in X852 dendritic
`cells.11 it was of
`fundamental
`interest
`to determine
`whether FTY720 is also able to activate Smad signaling in
`primary fibroblasts. To address this. FTY720— or TGF-fi-
`stimulated cells were immunoprecipitated with anti-
`Smadi .2.3 and immunoblotted with anti—Smad4 antibod—
`ies.
`Indeed. Smad4 was oo—immunoprecipitated after
`treatment with both. FTY720 and TGF—fi.
`indicating an
`activation of the Smad cascade in response to both stim-
`uli (Figure 7B). To further explore a role of Smad3 in
`FTY?20—mediated differentiation of fibroblasts. u—SMA ex-
`pression was measured after treatment with Smad3-ASO.
`which significantly reduced levels of Smad3 proteins
`
`(Figure 70). Most interestingly. FTY720—mediated a—SMA
`formation was significantly diminished in the presence of
`SmadS—ASO compared with a treatment with control oli-
`gonucleotides (Figure 7D}. To more rigorously substanti-
`ate that these effects of FTY720 were dependent on
`SmadS. we used Smads knockout and wild—type fibro—
`blasts. Similar to Our ASO experiments. a strong a-SMA
`expression was only visible in wild—type fibroblasts after
`treatment with l—‘iY72O or TGF—fi as positive control. On
`the contrary. SmadS-deficient
`fibroblasts did not
`in—
`duce formation of a—SMA in response to both stimulants
`(Figure F’E).
`To examine whether FI'Y720-mediated differentiation
`into myofibrobiast is a consequence of TGF-ts secretion.
`we measured TGF—fi levels after treatment with F'Y720.
`Indeed. basal levels of TGF-B (5.3 pgimi) or latent cem-
`plexes of TGF-fi (83.5 pgimli were not increased through-
`out a 24-hour stimulation period with l-‘iY720 (4.5 or 78.7
`pgiml, respectively). To further substantiate that F'Y720-
`induced myolibroblast differentiation is independent of
`TGF-fi release. a—SMA formation was visualized under
`immunoneutralized conditions, As presented in Figure
`7A. FTY72O induced a-SMA expression in the presence
`
`
`
`

`

`Keller et al
`288
`Aijmmrrljr 2007, Vor'. 170, No.
`
`I
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`Involvement of Go, protein-L'tm}'lled receptors in I’l'YTZU-nttrtiiatud mynt‘throhlast differentiation. B: Real-time I’CR was performed as (leat‘riirlcd in
`Figure 4.
`Materials and Methods. indicating the presence of milk“ ut‘nli five .‘ill’ receptor sul'lt_\-'pt::t. Human fibroblasts Were pretreated with PT}: {200 ngr’ntli for 3 hours
`and than .‘llirnulatcd With 'E'Gli-fi {2 ngr’ml} or FITTED {1 proof-"U for 1’. hours. A and C: «film was dctcmtinud by inununol‘luorcsccncc LA] or Western blot
`itnttiysrs and its densitomem‘c quantification normalized to fi-nt'lin (C). All results were crinfirrticti in three independent experiments “P < Until. Original
`magnifications. X200.
`
`of anti—TGF-fi antibodies. whereas the effect in response
`to TGF—fi was completely diminished. These results
`clearly indicate that FTY720 induces differentiation of
`fibroblasts into myolibroblasts via activation of 81 P3. Al—
`though FI'Y720 does not induce TGF-B secretion, Smads
`is crucial for the differentiation-inducing effect.
`
`Discussion
`
`FTY720 has been discovered as an immunomodulator
`with a novel mode of action that is not similar to that of
`classical immunosuppressive drugs.2 It has been shown
`that FTY?2O is rapidly phosphorylated in vivo and that
`FI'Y720-P is the biologically active principle. This com-
`pound shares striking structural homology with StP. thus
`acting as a high—affinity agonlst at four of the live SlP
`receptor SUbinES.3'5'6'22 9“
`It is of interest that FTY720-P does not only influence
`immunomodulation by internalization of StP1 on thymo-
`cytes and lymphocytes. but also possesses a variety of
`further biological actions via stimulation of different SlP
`
`receptor subtypes. Both SW and FTY72U-P have been
`indicated to interact with the endothelium resulting in the
`regulation of the vascular permeability?‘25 Moreover.
`SIP and FTY?2O stimulate endothellal nitric oxide syn-
`thase [eNOS] inducing a nitric oxide (NOJ-dependent
`vasOrelaxatlon of precontracted isolated arteries via the
`receptor subtype 51 P3?” Because eNOS stimulation is
`associated with a cytoprotective role in the development
`of several cardiovascular diseases. FTY720 may also
`possess additional therapeutic effects that are indepen-
`dent of an immunomodulating role.” But a reduction of
`the heart rate has also been reported in response to
`FfY720.
`limiting its therapeutic feasibility.”I .Thls effect
`seems to be mediated by an activation of 8ng because
`this receptor subtype is dominantly expressed in the
`heart and moreover FFY72O loses its ability to reduce the
`heart rate in StPs-deficient mice.‘°-29 It is of interest that
`the FTY720-mediated bradycardia could be reversed in
`the presence of :32 receptor agonists or atropine indicat-
`ing a cross—communication between StP and muscarinic
`receptors.“ This is
`in agreement with several studies
`
`

`

`289
`FTYI’EO and Myofibroblast Differentiation
`Aijwmmft- 200?. Vol.
`i' 3’0. No. I
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`Figure 5.
`otides (500 nrnolr'l.) or SiP.-, SiP,-_. Site-5 or SlPfi—ASO (each 500 nrnolr'l.) for 72 hours. A: Western blot analysis confirmed the relative abundance of the SIP
`receptor proteins expressed after A80 pretreatment. 3: Then cells were treated with l’i'Y‘i‘20 (1 pmolfi.) for ?2 hours. and a-SMA was measured by Western blot
`analysis and densitomctric quantification normalized to B—actin. All results were confirmed in three independent experiments. “P < 0.001.
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`Figure 6. Myofibrobirtst differentiation of wild-type and bill’s-deficient fi-
`broblasts in response to f-TY'FZO anti 'I'GF—B. I’ibrtiblasLs isolated from wild-
`type (A) and s I P,‘ "' ‘ mice (B) were stimulated with FI'Y?20 (I Irutrrtoirl.) or
`‘l'Gl-Zfi (2 ngx'ml) for 43 hours. Then nASMA formation and its quantification
`normalized to fl—aetin Were measured. All results were confirmed in three
`independent experiments. "P c 0.001.
`
`showing that diverse pharmacological actions of 31 P are
`the result of a cross-communication between S1Precep-
`tors and other plasma membrane receptors?0 33 Such
`an interaction has also been indicated for TGF~B and StP
`receptors in different cell types, which is accompanied
`by an activation of intracellular Smad proteins not only in
`response to TGIF-.3 but also to 81R“—13 Thus. SiP mim-
`ics the anti—inflammatory effect of TGF-e on mesangial
`cells because both mediators inhibit cytokine~induced
`secretion of phospholipase A2, release of NO. and ex-
`pression of matrix metalloproteinase 9 {Milli—9).“i Be-
`sides its role as an anti-inflammatory cytokine. TGF—B has
`also been identified as an important mediator in a number
`of fibrotic diseases. and increased levels of TGF-B are
`often present in tissues such as s