Transforming Growth Factor-beta 1 (TGF-beta 1) expression in normal healthy pulps and in those with irreversible pulpitis A. Piattelli 1 , C. Rubini 2 , M. Fioroni 2 , D. Tripodi 1 & R. Strocchi 1 1 DentalSchool,UniversityofChieti,Chieti;and 2 Departmentof PathologicAnatomyandHistopathology,UniversityofAncona, Ancona,Italy Abstract Piattelli A, Rubini C, Fioroni M, Tripodi D, Strocchi R. Transforming Growth Factor-beta 1 (TGF-beta 1) expression in normal healthy pulps and in those with irreversible pulpitits. Interna- tional Endodontic Journal , 37, 114^119, 2004. Aim ToevaluatetheTransformingGrowthFactor-beta 1 (TGF-beta1) expression in normal healthy pulps and inthosewithirreversiblepulpitis. Methodology Twenty-three normal, healthy pulps were removed from mandibular third molars, and 20 pulpswereretrievedfromteethwithirreversiblepulpitis. TGF-beta1wasevaluatedintheodontoblasticandsubo- dontoblastic layers, in the stromal cells (¢broblasts), andinthebloodvessels.TGF-beta1expressionwasdeter- mined byevaluating 500 cells inthe odontoblastic and subodontoblastic layers and 500 ¢broblasts in the stromaforeachspecimen,andcountingthenumberof positive cells. The number of the positive vessels was evaluated in 10 high power ¢elds (HPF). In almost all cases,thecellularpositivitywascytoplasmatic.Statisti- cal analysis was performed using Mann^Whitney U- andStudent's t-tests. Results A higher expression of TGF-beta 1 was found in the odontoblastic^subodontoblastic layer of the irreversible pulpitis specimens; this di¡erence was statistically signi¢cant ( P  0.0002). No statisti- cally signi¢cant di¡erence was observed between the two groups in TGF-beta 1 expression in the stro- mal cells ( P  0.54) or in the vascular component ( P  0.94). Conclusions The higher and statistically signi¢cant expressionofTGF-beta1foundintheodontoblastic^sub- odontoblastic layer of irreversible pulpitis specimens mayindicatearoleforTGF-beta1inthedentinalrepair processesafterpulpin£ammation. Keywords: in£ammation, irreversible pulpitis,Trans- forming Growth Factor-beta. Received19February2002;accepted10September2003 Introduction Members of the Transforming Growth Factor-beta 1 (TGF-beta1)superfamilyhavebeenimplicatedinmany aspects of the regulation of cell growth, di¡erentiation andfunction(Smith et al .1998,Tziafas&Papadimitriou 1998).Thesemoleculeshavemitogenice¡ectsandareg- ulatoryroleinmatrixbiosynthesis,andtheyarechemo- tactic for ¢broblasts, neutrophils and monocytes (Tziafas&Papadimitriou1998).Coordinatedexpression ofTGF-betamembersinpulpmaybeimportantintooth developmentandrepair(Toyono et al .1997a,Smith et al. 1998, Nakashima et al . 1998). It has been shown that TGF-beta 1 as a pulp-capping medicament enhances reparative dentine formation in rat molars (Hu et al . 1998, Tziafas et al. 1998), and exerts dentine-speci¢c e¡ects inducing di¡erentiationof odontoblast-like cells andstimulatingprimaryodontoblasts(Tziafas etal .1998). TGF-beta1plays a role in the di¡erentiation of pulp cellsintoodontoblastsduringreparativedentinogenesis (Toyono et al .1997b).TGF-beta1issigni¢cantlyup-regu- latedinfullydi¡erentiatedodontoblastsduringprimary dentine formation (D'Souza et al .1998). It is a mitogen for human pulp cells (Shirakawa et al . 1994), and is expressed in the developing tooth from the initiation stagethroughadulthood(Thyagarajan et al.2001). Correspondence: Professor DrAdrianoPiattelli,ViaF. Sciucchi 63,66100Chieti,Italy(Fax: 3908713554076;e-mail:apiattelli@ unich.it). 114 International Endodontic Journal, 37, 114^119, 2004 ß 2004 Blackwell Publishing Ltd