Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 139-156).

Thesis (Ph.D.)--Kent State University, 2006. / Title from PDF t.p. (viewed Jan. 11, 2007 ) Advisor: J Gary Meszaros. Keywords: cardiac fibroblast, angiotensin II, fibrosis, MAPK Includes bibliographical references (p. 150-168).

Thesis (Ph.D.)--Kent State University, 2006. / Title from PDF t.p. (viewed Sept. 20, 2006). Advisor: Gary Meszaros. Keywords: cardiac fibroblasts; myofibroblasts; extracellular matrix; collagen VI; post-myocardial infarction remodeling. Includes bibliographical references (p. 135-152).

Ventral body wall closure (VBW) defects are amongst the most common human congenital anomalies. They represent a wide and heterogeneous group of phenotypic defects that can present in isolation or as a component in a larger syndromic anomaly. In addition, the incidence of associated anomalies is high and reaches 75% of fetuses in some types of VBW closure defects. Nevertheless, the embryonic origin and the underlying cellular and molecular mechanisms between ventral closure defects and their associated congenital anomalies remain poorly characterised. This is in part due to the poor understanding of the physiological mechanisms that regulate the development of ventral organs and the lack of representative transgenic animal models allowing detailed in vivo analysis of defect formation. Transforming growth factor beta (TGF-ÃŽÂ2) signalling is essential for VBW closure and vascular and cardiac development. Yet, its mechanism of action and the responding cell(s) in the body wall remain largely unknown. In addition, in various cells TGF-B can induce the expression of Tagln, encoding for a cytoskeleton associated protein that enhances cell migration. No function has been ascribed to TAGLN in body wall development. I define here a role of TGF-B during a critical time window in embryonic development to fashion the ventral body wall, anterior diaphragm and parts of the circulatory system. I identify a population of TAGLN+ myofibroblasts that respond to a temporally regulated TGF-B signalling originating from the epithelium of the primary body wall. Deletion of TGF-B receptor in TAGLN+ cells leads to failure of ventral body wall closure, anterior diaphragmatic hernia, cardiac and outflow tract anomaly. Nevertheless, the descending aorta and the large aortic branches are spared. By using advanced transgenic methodology, I generated novel transgenic mouse lines that enabled me to fate map the cells that initiate the formation of important mesenchymal tissues. These studies revealed that the origin of aortic vascular smooth muscle cells can be traced back to a group of progenitor cells that reside in the wall of the dorsal aorta before the VBW closure. My studies provide intriguing evidence for spatially restricted role for TGF-B signalling in ascending but not descending aorta morphogenesis. I used a variety of techniques to characterise, analyse and quantify important mechanisms during mesenchymal and vascular development, their response to injury and repair. This thesis has been written in an alternative format, comprising the different areas which have been investigated. Collectively, the results presented here provide new insights into the role of migratory and mechanically stabilising cells in the development and maintenance of critical structures in the body and their common role in the development of concurrent congenital anomalies. A detailed understanding of the molecular signalling pathways and cells that drive VBW closure raises the hope that the related birth defects can in the future be treated by precise gene and cell therapies.

Made available in DSpace on 2014-06-11T19:33:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-10Bitstream added on 2014-06-13T21:06:01Z : No. of bitstreams: 1 mainenti_p_dr_sjc.pdf: 825103 bytes, checksum: cb4ac2ce4ddd387d52a086efa8ec1795 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A carcinogênese química em glândulas salivares animais não se apresenta como um modelo novo de pesquisa. O uso de DMBA em glândulas submandibulares de ratos produz carcinomas e sarcomas, associados ou não. Apesar de bem estudada a histopatologia deste tipo de carcinogênese, pouco se sabe em relação a imunoistoquímica das neoplasias. Este estudo se propõe a revisar pesquisa pregressa realizada por Mainenti (2006), na tentativa de melhor entender a formação de tumores induzidos por DMBA. O estudo original diagnosticou lesões não neoplásicas, principalmente sialadenites, e tumores como carcinomas, carcinossarcomas e um caso de sarcoma. O presente trabalho fez uso de lâminas e material de estoque em formol. Foram comparadas as lâminas originais com novas lâminas coradas em hematoxilina e eosina. Para a pesquisa de fibras colágenas utilizou-se a coloração pelo método do tricrômico de Gomori. A imunoistoquímica foi realizada utilizando os seguintes anticorpos: AE1/AE3, vimentina, α-SMA, calponina, desmina, miogenina, S-100, CerbB-2 e EMA. Certas lesões, previamente diagnosticadas como sialadenites, foram reclassificadas como carcinomas. A imunoistoquímica foi positiva para os seguintes anticorpos: AE1/AE3 para neoplasia epitelial, vimentina para tecido conjuntivo e tumores mesenquimais, α-SMA e calponina para poucas células fusiformes pleomórficas no estroma dos carcinomas e nas neoplasias mesenquimais. Concluiu-se que a imunoistoquímica revelou diferenciação muito sugestiva de miofibroblastos no estroma dos carcinomas e miofibroblastos compondo o fibrossarcoma e os carcinosarcomas. Estas células produziram colágeno revelado pelo tricrômico de Gomori. O componente epitelial neoplásico foi sugerido como derivado de células luminais. / The chemical carcinogenesis, addressed to animal salivary gland, is not a novel research. The use of DMBA in rat’s submandibular salivary gland is known to produce neoplasms like sarcomas and carcinomas either intermingled or not. Despite of the good amount of information regarding DMBA carcinogenesis histopathology in rat’s submandibular parenchyma, little is known about the immunohistochemistry in such tumors. We proposed a revision of a previous research conduced by Mainenti (2006), in attempt to better understand the neoplasm formation after DMBA. The original experiment disclosed non neoplastic lesions, mainly sialadenitis, and tumors like carcinomas, carcinosarcomas and one case of sarcoma. The present work used all the material from the first research like surgical specimens in formol and slides. We compared the previous hematoxylin and eosin slides with new ones. We also used Gomori’s trichrome in order to disclose collagen fibers. The immunohistochemistry was performed using the following antibodies: AE1/AE3, vimentin, α-SMA, calponin, desmin, myogenin, S-100, CerbB-2 and EMA. Some previous lesions, presented as benign ones, were diagnosed as carcinomas. The immunohistochemistry was positive as shown: AE1/AE3 for epithelial neoplasm, vimentin for connective tissue in mesenchymal tumors, α-SMA and calponin for scarce pleomorphic fusiform cells in the stroma of the carcinomas and in the mesenchymal neoplasms. We concluded that the immunohistochemistry strongly suggested myofibroblast differentiation in the stroma of the carcinomas and myofibroblast cells related to the fibrosarcoma and carcinosarcomas. These cells produced collagen shown after Gomori’s trichrome. The epithelial neoplasm component was suggested as derived from luminal cells.

Transforming growth factor-β1 (TGFβ1) is a mediator of the fibrotic response through activation of quiescent cardiac fibroblasts to hypersynthetic myofibroblasts. Scleraxis (Scx) is a pro-fibrotic transcription factor that is induced by TGFβ1-3 and works synergistically with Smads to promote collagen expression. Ski is a negative regulator of TGFβ/Smad signaling through its interactions with Smad proteins at the promoter region of TGFβ regulated genes. To date, no studies have examined the direct DNA:protein transcriptional mechanisms that regulate Scx expression by TGFβ1-3 or Ski, nor the mechanisms that govern Ski expression by Scx. We hypothesize that Ski and Scx regulate one another, and form a negative feedback loop that represses gene expression and is a central regulator of the fibrotic response in cardiac myofibroblasts. Primary adult rat cardiac myofibroblasts were isolated via retrograde Langendorff perfusion. First passage (P1) cells were infected with adenovirus encoding HA-Ski, HA-Scx, or LacZ at the time of plating. Twenty-four hours later, cells were harvested for Western blot, quantitative real-time PCR (qPCR), and electrophoretic gel shift assays (EMSA). NIH-3T3 or Cos7 cells were transfected with equal quantities of plasmid DNA for 24 hours prior to harvesting for luciferase, qPCR, and EMSA analysis. Ski overexpression in P1 myofibroblasts resulted in a reduction in both Scx mRNA and protein levels. Overexpression of Scx had no effect on Ski expression. Luciferase reporter assays demonstrated that Scx was induced by TGFβ1 treatment in a concentration dependent manner. However, ectopic Smad2/3 expression was unable to transactivate the Scx promoter in a luciferase reporter assay. Inhibition of p44/42-MAPK signaling modestly counteracted the effect of TGFβ1 on Scx expression. Scx had no effect on Ski promoter expression, however, both tumor necrosis factor-α (TNFα) and p65 expression repressed the Ski promoter and correlated with reduced Ski mRNA levels. We conclude that Ski is a repressor of Scx and that Scx expression is partially mediated through a Smad-independent, p44/42-MAPK pathway in cardiac myofibroblasts. Furthermore, this study proposes a role for TNFα/p65 NF-κΒ signaling in the regulation of Ski gene expression in the cardiac myofibroblast. / October 2016

Orientador: Julio Lopes Sequeira / Banca: Alessandre Hataka / Banca: Louisiane de Carvalho Nunes / Resumo: A endometrose é uma alteração degenerativa das glândulas uterinas e do estroma circundante, caracterizada pelo arranjo periglandular de miofibroblastos e a deposição de matriz extracelular (ECM). O presente trabalho objetivou avaliar a expressão de colágeno tipo I, III e IV e α-actina de músculo liso (α-SMA) nas endometroses equinas, procurando esclarecer a participação dos miofibroblastos na progressão destes processos. Foram utilizadas 24 biópsias uterinas com diagnóstico de endometrose, recebidas pelo Serviço de Patologia Veterinária e de Reprodução Animal da FMVZ, UNESP, Botucatu, SP. Cortes histológicos foram submetidos às técnicas histoquímicas de Tricrômico de Masson, Picrosirius Red sob luz polarizada e Ácido Periódico de Schiff (PAS) e imuno-histoquímicas para os três tipos de colágeno citados e α-SMA. Ainda, traçou-se um paralelo entre a técnica de Picrosirius Red e a imunomarcação dos colágenos tipos I e III. A análise histológica revelou que as fibras de colágeno denso correspondem ao colágeno tipo I, predominantes nas endometroses inativa e inativa destrutiva. As fibras de colágeno frouxo correspondem ao colágeno tipo III, predominantes nas endometroses ativas e ativas destrutivas. Nestes mesmos processos, a membrana basal revelou espessamento, aparentemente não relacionado ao colágeno tipo IV, e uma maior imunomarcação de miofibroblastos periglandulares em relação às endometroses inativa e inativa destrutiva. Desta forma, nota-se que os miofibroblastos estão relacionados ao aumento na deposição de colágeno tipo III nos ninhos fibróticos ativos / Abstract: Endometrosis is a degenerative change of the uterine glands and surrounding stroma, characterized by periglandular arrangement of myofibroblasts and deposition of extracellular matrix (ECM). The aim of this study was evaluate the expression of collagen type I, III and IV and α-smooth muscle actin (α-SMA) in equine endometroses, and investigate the role of myofibroblasts in the progression of these processes. A parallel was made with histochemical techniques of Masson's trichrome, Picrosirius Red under polarized light and Periodic Acid-Schiff (PAS). Twenty four uterine biopsies received by the Veterinary Pathology Service and Animal Reproduction of FMVZ, UNESP, Botucatu, SP, were diagnosed with endometrosis. Histological analysis revealed that the orange dense collagen fibers correspond to type I collagen, being prevalent in inactive and inactive destructive endometrosis. And the green loose collagen fibers correspond to type III collagen, and are predominant in active and active destructive endometrosis. In the same processes, a greater amount of periglandular myofibroblasts were observed in comparison to inactive and inactive destructive endometrosis. The presence of these cells in active processes are strongly related to an increased deposition of collagen type III in fibrotic nests. Regarding the basement membrane, the active destructive and active endometrosis shows thickening, apparently not related to an increase in expression of type IV collagen. The active destructive and inactive destructive endometrosis exhibited disruption areas in type IV collagen fibers. Thus, it is noted that the myofibroblasts are related to increased deposition of type III collagen in active fibrotic nests / Mestre

A radioterapia é frequentemente utilizada no tratamento de tumores da próstata, porém durante esse procedimento a bexiga sadia usualmente sofre efeitos colaterais. Através do uso de um modelo animal para irradiação pélvica, avaliamos se a suplementação nutricional com L-glutamina poderia prevenir possíveis danos na parede da bexiga, especialmente em suas camadas mais superficiais. Ratos Wistar adultos machos com idade entre 3 e 4 meses foram separados em grupos de 8 animais: grupo controle que não recebeu a irradiação; grupos somente irradiados que foram mortos 7 (R7) e 15 dias (R15) após a irradiação (dose única de 10 Gy na região pélvico-abdominal); grupos irradiados e suplementados com L-glutamina (0,65g/kg de peso por dia), que foram mortos 7 (RG7) ou 15 após a irradiação. Células e vasos sanguíneos da lâmina própria, bem como o urotélio, foram avaliados com métodos histológicos. No urotélio foram feitas análises da altura e densidade nuclear e na lâmina própria densidade celular, densidade vascular e o número de mastócitos. Os resultados mostraram que em R7, a altura e densidade nuclear do urotélio e a densidade celular da lâmina própria não foram alterados significativamente. Entretanto a densidade dos vasos sanguíneos foi reduzida em 48% (p<0,05) e essa alteração foi evitada pela glutamina (p <0,02). No grupo R15, a densidade celular do epitélio aumentou em 35% (p<0,02). A densidade celular da lâmina própria não apresentou diferença estatística entre os grupos. Os mastócitos na lâmina própria foram reduzidos em R7 e R15. Apesar de ainda reduzidos em RG7 em RG15 houve aumento no número desse tipo celular o que sugere uma ação positiva da glutamina. Células &#945;-actina positivas na lâmina própria formam uma camada suburotelial e foram identificadas como miofibroblastos. A espessura dessa camada aumentou em R7, mas foi semelhante ao controle em RG7, enquanto alterações em R15 e RG15 foram menos evidentes. Esses resultados mostraram que a utilização da L-glutamina antes e após a radioterapia deve ser considerada para uso humano na proteção da bexiga contra os efeitos da radiação. / Radiotherapy is often used to treat prostate tumors, but the normal bladder is usually adversely affected. Using an animal model of pelvic radiation, we investigated whether glutamine nutritional supplementation can prevent radiation-induced damage to the bladder, especially in its more superficial layers. Male rats aged 3 to 4 months were divided into groups of 8 animals each: controls, which consisted intact animals; radiated-only rats, which were sacrificed 7 (R7) or 15 (R15) days after a radiation session (10 Gy aimed at the pelvico-abdominal region); and radiated rats receiving L-glutamine supplementation (0.65 g/kg body weight/day), which were sacrificed 7 (RG7) or 15 (RG15) days after the radiation session. Morphological and morphometric analysis of the urothelium were made. Nuclear density, lamina propria cell density and mast cells numbers per area were counted. The results showed that, in R7, epithelial thickness, epithelial cell density, and cell density in the lamina propria were not significantly affected. However, density of blood vessels in R7 was reduced by 48% (p < 0.05) and this alteration was mostly prevented by glutamine (p < 0.02). In R15, density of blood vessels in the lamina propria was not significantly modified. However, epithelial thickness was reduced by 25% (p < 0.05) in R15, and this effect was prevented by glutamine (p < 0.01). In R15, epithelial cell density was increased by 35% (p < 0.02), but glutamine did not protect against this radiation-induced increase. Cell density in the lamina propria was likewise unaffected in R15. Density of mast cells in the lamina propria was markedly reduced in R7 and R15. The density was still reduced in RG7, but a higher density in RG15 suggested a glutamine-mediated recovery. Alpha-actin positive cells in the lamina propria formed a suburothelial layer and were identified as myofibroblasts. Thickness of this layer was increased in R7, but was similar to controls in RG7, while changes in R15 and RG15 were less evident. In conclusion, pelvic radiation leads to significant acute and post-acute alterations in the composition and structural features of the vesical lamina propria and epithelium. Most of these changes, however, can be prevented by glutamine nutritional supplementation. These results emphasize, therefore, the potential use of this aminoacid as a radioprotective drug.

Resumo: A carcinogênese química em glândulas salivares animais não se apresenta como um modelo novo de pesquisa. O uso de DMBA em glândulas submandibulares de ratos produz carcinomas e sarcomas, associados ou não. Apesar de bem estudada a histopatologia deste tipo de carcinogênese, pouco se sabe em relação a imunoistoquímica das neoplasias. Este estudo se propõe a revisar pesquisa pregressa realizada por Mainenti (2006), na tentativa de melhor entender a formação de tumores induzidos por DMBA. O estudo original diagnosticou lesões não neoplásicas, principalmente sialadenites, e tumores como carcinomas, carcinossarcomas e um caso de sarcoma. O presente trabalho fez uso de lâminas e material de estoque em formol. Foram comparadas as lâminas originais com novas lâminas coradas em hematoxilina e eosina. Para a pesquisa de fibras colágenas utilizou-se a coloração pelo método do tricrômico de Gomori. A imunoistoquímica foi realizada utilizando os seguintes anticorpos: AE1/AE3, vimentina, α-SMA, calponina, desmina, miogenina, S-100, CerbB-2 e EMA. Certas lesões, previamente diagnosticadas como sialadenites, foram reclassificadas como carcinomas. A imunoistoquímica foi positiva para os seguintes anticorpos: AE1/AE3 para neoplasia epitelial, vimentina para tecido conjuntivo e tumores mesenquimais, α-SMA e calponina para poucas células fusiformes pleomórficas no estroma dos carcinomas e nas neoplasias mesenquimais. Concluiu-se que a imunoistoquímica revelou diferenciação muito sugestiva de miofibroblastos no estroma dos carcinomas e miofibroblastos compondo o fibrossarcoma e os carcinosarcomas. Estas células produziram colágeno revelado pelo tricrômico de Gomori. O componente epitelial neoplásico foi sugerido como derivado de células luminais. / Abstract: The chemical carcinogenesis, addressed to animal salivary gland, is not a novel research. The use of DMBA in rat's submandibular salivary gland is known to produce neoplasms like sarcomas and carcinomas either intermingled or not. Despite of the good amount of information regarding DMBA carcinogenesis histopathology in rat's submandibular parenchyma, little is known about the immunohistochemistry in such tumors. We proposed a revision of a previous research conduced by Mainenti (2006), in attempt to better understand the neoplasm formation after DMBA. The original experiment disclosed non neoplastic lesions, mainly sialadenitis, and tumors like carcinomas, carcinosarcomas and one case of sarcoma. The present work used all the material from the first research like surgical specimens in formol and slides. We compared the previous hematoxylin and eosin slides with new ones. We also used Gomori's trichrome in order to disclose collagen fibers. The immunohistochemistry was performed using the following antibodies: AE1/AE3, vimentin, α-SMA, calponin, desmin, myogenin, S-100, CerbB-2 and EMA. Some previous lesions, presented as benign ones, were diagnosed as carcinomas. The immunohistochemistry was positive as shown: AE1/AE3 for epithelial neoplasm, vimentin for connective tissue in mesenchymal tumors, α-SMA and calponin for scarce pleomorphic fusiform cells in the stroma of the carcinomas and in the mesenchymal neoplasms. We concluded that the immunohistochemistry strongly suggested myofibroblast differentiation in the stroma of the carcinomas and myofibroblast cells related to the fibrosarcoma and carcinosarcomas. These cells produced collagen shown after Gomori's trichrome. The epithelial neoplasm component was suggested as derived from luminal cells. / Orientador: Luiz Eduardo Blumer Rosa / Coorientador: Yasmin Rodarte Carvalho / Banca: Luiz Eduardo Blumer Rosa / Banca: Rosilene Fernandes da Rocha / Banca: Fábio Daumas Nunes / Banca: Maria das Graças Afonso Miranda Chaves / Banca: Adriana Aigotti Haberbeck Brandão / Doutor

Η πορεία μιας οξείας σπειραματικής νόσου προς τη χρόνια νεφρική ανεπάρκεια χαρακτηρίζεται από φλεγμονώδεις διεργασίες που εντοπίζονται αρχικά στο σπείραμα, εν συνεχεία στον ενδιάμεσο χώρο, στα ουροφόρα σωληνάρια και τέλος στα νεφρικά αγγεία. Το πρωταρχικό αίτιο για την έναρξη των διεργασιών αυτών είναι η εναπόθεση ανοσοσυμπλεγμάτων στην περιοχή του σπειράματος και η ενεργοποίηση αντιδράσεων που οδηγούν τελικά στην εμφάνιση σπειραματικής σκλήρυνσης, ίνωσης του διαμέσου ιστού και ατροφίας των ουροφόρων σωληναρίων. Οι διεργασίες αυτές φαίνεται να πυροδοτούνται από κυτταροκίνες, όπως είναι οι ιντερλευκίνες (IL-1, IL-2, IL-6) και να εξελίσσονται περαιτέρω κάτω από την επίδραση αυξητικών παραγόντων, όπως είναι ο Transforming Growth Factor (TGF-β1), Epidermal Growth Factor (EGF) και Insulin-like Growth Factor (IGF-1). Πέραν των διεργασιών όμως αυτών, σημαντικό ρόλο στην ολοκλήρωση της καταστροφής του νεφρώνα, φαίνεται να διαδραματίζει ο ρυθμός απόπτωσης των κυττάρων των ουροφόρων σωληναρίων. Πράγματι η απόπτωση αποτελεί ένα σημαντικό μηχανισμό αποικοδόμησης των κυττάρων που σε συνεργασία με την αναγέννησή τους συμβάλλει στη σταθερότητα όλων των βιολογικών συστημάτων (ομοιόσταση). Ο ρυθμός της απόπτωσης των κυττάρων βρίσκεται σε μια σταθερή σχέση με τον ρυθμό αναγέννησης, έτσι ώστε κάθε βιολογικό σύστημα να παραμένει δομικά και λειτουργικά σταθερό. Οι πρωτεΐνες bax και bcl-2 έχουν αποδειχθεί αξιόπιστοι δείκτες της αποπτωτικής διαδικασίας. Η παρούσα μελέτη έχει σαν στόχο να εξετάσει ποιοτικά και ποσοτικά τη συμμετοχή των αυξητικών παραγόντων (TGF-β1, EGF, IGF-1) και των δεικτών της κυτταρικής απόπτωσης (πρωτεΐνες bax και bcl-2) σε ασθενείς με σπειραματικές βλάβες, παρουσία ιστολογικών αλλοιώσεων διαφορετικής βαρύτητας και κατ’ επέκταση διαταραχή της λειτουργίας του νεφρού. Συμπεριελήφθησαν 76 ασθενείς (44 άνδρες και 32 γυναίκες) στους οποίους, με βάση τα ιστολογικά ευρήματα στις βιοψίες του νεφρικού ιστού, ετέθησαν οι διαγνώσεις: ιδιοπαθής μεμβρανώδης σπειραματονεφρίτιδα (n=26), IgA νεφροπάθεια (n=15), νόσος ελαχίστων αλλοιώσεων (n=12), ταχέως εξελισσόμενη σπειραματονεφρίτιδα (n=11), εστιακή σπειραματοσκλήρυνση (n=7) και νεφρίτιδα του λύκου (n=5). Η μέση χρονική διάρκεια παρακολούθησης των ασθενών ήταν 4 χρόνια. Το είδος και η βαρύτητα των δομικών αλλοιώσεων του νεφρικού ιστού συσχετίσθηκαν με την πορεία της νεφρικής λειτουργίας, αλλά και με παραμέτρους των φλεγμονωδών διεργασιών που προσδιορίσθηκαν ανοσοϊστοχημικά, όπως είναι οι αυξητικοί παράγοντες TGF-β1, EGF και IGF-1, οι μυοϊνοβλάστες (κύτταρα που συμμετέχουν στη διαδικασία ανάπτυξης της ίνωσης) και οι δείκτες της κυτταρικής απόπτωσης (πρωτεΐνες bax και bcl-2). Διαπιστώθηκε, λοιπόν, ότι σε ασθενείς με σπειραματική βλάβη η παρουσία των αυξητικών παραγόντων, των μυοϊνοβλαστών και των δεικτών κυτταρικής απόπτωσης στα σπειράματα, στο διάμεσο χώρο και στα ουροφόρα σωληνάρια είναι έντονη. Μάλιστα αυτή του αυξητικού παράγοντα TGF-β1 των μυοϊνοβλαστών και των πρωτεϊνών bax και bcl-2 είναι εντονότερη σε ασθενείς με σημαντικού βαθμού σπειραματική σκλήρυνση, ίνωση του διάμεσου ιστού και ατροφία των ουροφόρων σωληναρίων. Διαπιστώθηκε επίσης σημαντική συσχέτιση της έκφρασης των παραμέτρων αυτών με τη βαρύτητα των ιστολογικών αλλοιώσεων (r=0.444, p<0.05) και το βαθμό έκπτωσης της νεφρικής λειτουργίας (r= 0.454, p<0.05) ενώ αντίθετα δεν παρατηρήθηκε συσχέτιση με τον τύπο της σπειραματικής βλάβης. Αυξημένος ρυθμός κυτταρικής απόπτωσης παρατηρήθηκε στο νεφρικό ιστό ασθενών με έκπτωση της νεφρικής λειτουργίας κατά τη διάγνωση της νόσου. Συμπερασματικά διαπιστώθηκε ότι : 1) Σε όλους τους ασθενείς, ανεξάρτητα από τον τύπο της σπειραματονεφρίτιδας, εντοπίζονται ανοσοϊστοχημικά αυξητικοί παράγοντες στο σπείραμα, στο διάμεσο ιστό και στα ουροφόρα σωληνάρια και μυοϊνοβλάστες κυρίως στο διάμεσο χώρο. 2) Η ποσοτική έκφραση των αυξητικών παραγόντων και ιδιαίτερα του TGF-β1 φαίνεται να σχετίζεται άμεσα με το βαθμό έκπτωσης της νεφρικής λειτουργίας και τη βαρύτητα των ιστολογικών αλλοιώσεων. 3) Ο ρυθμός της κυτταρικής απόπτωσης είναι ανάλογος της βαρύτητας των ιστολογικών αλλοιώσεων και του βαθμού έκπτωσης της νεφρικής λειτουργίας. / The evolution of an acute glomerular injury towards chronic renal failure is characterized by an inflammatory process that is initially localized in the glomeruli and then in the tubulointerstitial area and vessels of the kidney. The deposition of immune complexes in the glomeruli is the main cause of this process that leads to the development of glomerular sclerosis, interstitial fibrosis and tubular atrophy. In this process various cytokines [interleukins (IL), (IL-1, IL-2, IL-6)] and growth factors [Transforming Growth Factor-β (TGF-β), Epidermal Growth Factor (EGF) and Insulin Growth Factor (IGF-1)] are involved. The phenomenon of cellular apoptosis is implicated in the development of renal scarring. Apoptosis represents the programmed cellular death that is in balance with the generation of cells. The rate of cellular apoptosis is responsible for the preservation of homeostasis in each organism. Various genes and proteins are involved in the regulation of apoptosis within kidney. Bax and bcl-2 proteins represent markers of the apoptotic process since bax is related to an enhanced apoptotic rate whereas bcl-2 provides a survival advantage to renal cells. The aim of this study is to investigate the expression of growth factors (TGF-β1, EGF, IGF-1) and apoptotic markers (bax and bcl-2 proteins) in the renal tissue of patients with various types of glomerulonephritis and to identify any correlation of this expression with the severity of histological injury and with the course of renal function. Seventy six patients (44 males and 32 females) were included in the study. The histological diagnoses were: idiopathic membranous nephropathy (n=26), IgA nephropathy (n=15), minimal changes disease (n=12), rapidly progressive glomerulonephritis (n=11), focal segmental glomerulosclerosis (n=7) and lupus nephritis (n=5). The mean follow-up period was 4 years. The expression of growth factors, apoptotic markers and myofibroblasts (cells that are involved in the development of scarring) in the renal tissue was investigated by immunohistochemical technique and quantitated by morphometric analysis. In the renal tissue of patients with glomerulonephritis presence of growth factors, myofibroblasts and apoptotic markers was identified in the glomeruli and in the tubulointerstitial area. The expression of TGF-β1, myofibroblasts and bax, bcl-2 proteins was particularly severe in patients with glomerular sclerosis, interstitial fibrosis and tubular atrophy. The severity of this expression was related to the degree of histological damage (r=0.444, p<0.05) and that of renal impairment (r=0.454, p<0.05) whereas it was not related to the type of glomerulonephritis. In conclusion, it was found that: 1. Growth factors and myofibroblasts are localized in the glomeruli and in the tubulointerstitial area of patients with glomerulonephritis. 2. The severity of growth factors and in particular that of TGF-β1 expression is related to the degree of renal function impairment and to the severity of histological involvement. 3. The rate of cellular apoptosis in the kidney of patients with glomerulonephritis is also related to the severity of histological involvement and to the degree of renal function imparment.