Os objetivos deste estudo foram avaliar o efeito da aplicação subcutânea do cloridrato de papaverina no processo de reparação de feridas cirúrgicas abertas no dorso de ratos e avaliar pelos métodos histomorfológico, histomorfométrico e imunoistoquímico eventos biológicos do processo de reparação. Foram realizadas feridas dérmicas padronizadas com punch, 5mm de diâmetro e 2mm de profundidade, no dorso de ratos. Os animais foram divididos em dois grupos conforme o tratamento realizado: no grupo controle, 25 ratos foram tratados através da injeção de cloreto de sódio 0,9% e no grupo teste, 25 ratos foram tratados através da injeção da solução de cloridrato de papaverina a 50mg/mL de cloreto de sódio a 0,9%. Em ambos os grupos foi aplicado subcutâneo (por quadrante da ferida), 0,25mL da solução correspondente aos frascos do grupo teste ou grupo controle totalizando 1 mL da solução. Os 50 espécimes foram processados para as análises macro e microscópica. Para análise do cálculo do edema, foram utilizados 10 ratos (5 animais do grupo teste e 5 animais do grupo controle). Fragmentos de pele padronizados (3cm2) foram removidos da área da ferida e pesados no período de 6 horas. Para análise morfométrica do fechamento da ferida/formação de cicatriz, 10 ratos foram utilizados (5 animais do grupo teste e 5 do grupo controle). As feridas cirúrgicas padronizadas foram fotografadas nos períodos de 0h, 3,7,14 e 21 dias pós-cirúrgico e as imagens foram analisadas por software de morfometria (ImageLab2000®) quanto a área, perímetro e fator de forma. Pela técnica de coloração da hematoxilina e eosina, a análise histomorfológica (análise qualitativa descritiva) e histomorfométrica (análise quantitativa em relação à reepitelização, formação do tecido de granulação, edema, celularidade e matriz colagênica) foram realizadas nos períodos de 6h, 3,7,14 e 21 dias e analisadas sob microscopia de luz. Reações de imunoistoquímica com o anticorpo anti-actina de músculo liso foi realizada para identificação e contagem do número de miofibroblastos nos períodos de 3, 7, 14 e 21 dias. A partir do modelo experimental avaliado, comprovou-se a ação vasodilatadora da papaverina. Os fragmentos padronizados do grupo teste apresentaram maior peso em relação ao grupo controle (p= 0,047). As feridas do grupo teste mostraram um fechamento maior e menor formação de cicatriz quando comparado ao grupo controle no período de 21 dias. No grupo teste, uma maior quantidade de edema (p = 0,028) e uma menor quantidade de matriz colagênica (colágeno) (p = 0,028) foram encontradas no período de 6 horas. Houve maior reepitelização no grupo teste no período de 7 dias e menor formação de tecido de granulação nos períodos de 14 e 21 dias para o mesmo grupo. No grupo controle, um maior número de miofibroblastos foi encontrado quando comparado ao grupo teste nos períodos de 14 e 21 dias (p=0, 016). Dentro dos limites deste estudo, a aplicação subcutânea do cloridrato de papaverina parece acelerar o processo de reparação de feridas cirúrgicas abertas no dorso de ratos. Sua aplicação promove vasodilatação e um maior exsudato inflamatório no início do processo de reparação. Tal efeito parece estar relacionado com a maior velocidade de reparação observada macro e microscopicamente. / The objectives of this study were to evaluate the effect of subcutaneous administration of papaverine hydrochloride in the process of open surgical repair of wounds in the back of rats and evaluate the methods histomorphological, immunohistochemical and histomorphometric biological events of the repair process. Standardized wounds were inflicted by dermal punch, 5mm in diameter and 2mm deep, in the backs of rats. Animals were divided into two groups according to treatment: control group, 25 rats were treated by injection of sodium chloride 0.9%) and test group (25 rats treated by the injection of papaverine hydrochloride 50 mg / mL sodium chloride 0.9%). In both groups was administered subcutaneously (by quadrant of the wound), 0.25 mL of the solution corresponding to bottles of the test group or control group, totaling 1 mL of the solution. The 50 specimens were processed for macro and microscopic analysis. For analysis of the calculation of edema, we used 10 rats (5 animals in the test group and 5 control animals). Standardized skin fragments (3cm2) were removed from the wound area and heavy during the 6 hours. For morphometric analysis of the closure of the wound / scar formation, 10 rats were used (five animals in the test group and 5 in the control group). Surgical wounds were photographed in standardized periods of 0h, 3,7,14 and 21 days after surgery and the images were analyzed by morphometry software (ImageLab2000 ®) as area, perimeter and form factor. By staining with hematoxylin and eosin, the histomorphologic analysis (descriptive qualitative analysis) and histomorphometric (quantitative analysis in relation to reepithelialization, formation of granulation tissue, edema, cellularity and collagen matrix) were recorded at 6h, 3.7 , 14 and 21 days and analyzed under light microscopy. Immunohistochemical reactions with anti-smooth muscle actin was performed to identify and count the number of myofibroblasts at 3, 7, 14 and 21 days. From the experimental model evaluated, proved the vasodilator papaverine. The fragments of the standardized test group had a higher weight in the control group (p = 0.047). The wounds of the test group showed a greater closing and less scarring compared to control group within 21 days. In the test group, a greater amount of edema (p = 0.028) and a smaller amount of collagen matrix (collagen) (p = 0.028) were found within 6 h. A greater reepithelialization in the test group after 7 days and less formation of granulation tissue during periods of 14 and 21 days for the same group. In the control group, a greater number of myofibroblasts was found when compared to the test group during the periods of 14 and 21 days (p = 0, 016). Within the limits of this study, subcutaneous administration of papaverine hydrochloride appears to accelerate the repair of surgical wounds opened in the back of rats. Its application promotes vasodilation and a greater inflammatory exudate in the early repair process. This effect appears to be related to a faster repair observed macroscopically and microscopically.

Tendonopathy, resulting in the loss of mechanical strength of a tendon, is a serious health problem affecting many people. The common symptom of tendonopathy is pain – patients' daily activities, their participation in sport and exercise, and their ability to work are greatly compromised. Tendonopathy is considered to be a degenerative disorder caused by repetitive injury of the tendon. The most common tendon lesions are Achilles tendon rupture, lateral epicondylitis (tennis elbow) and rotator cuff tear. However, in spite of its clinical significance, our knowledge about tendonopathy is still very poor. This research was undertaken to investigate the pathology of tendonopathy. It is proposed that apoptosis, autophagic cell death and myofibroblasts play a role in the progression of tendonopathy in the rotator cuff; the aim of this study was therefore to determine if this was indeed the case. Tendon tissues were collected from 30 patients suffering from rotator cuff tears. A terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL assay) was performed to detect apoptosis. Autophagic cell death of the tenocytes in the ruptured rotator cuff tendon was detected by immunohistochemical staining for ubiquitin. Myofibroblasts were identified immunohistochemically with anti-alpha-smooth muscle actin (anti--SMA) antibody. The distribution of apoptosis, autophagic cell death and myofibroblasts, as well as the total cell density, were assessed respectively and were correlated using a four-category (i.e. graded from 0-3) degeneration of collagen matrix. – 6 – The results showed that apoptosis, autophagic cell death and myofibroblasts were observed in all of the samples. The highest percentage of autophagic cell death was evidenced in the Grade 2 matrix, while the percentage of apoptosis increased significantly with the increase of matrix degeneration from Grade 0-3; a similar pattern was found for myofibroblasts. The total cell numbers varied among the matrix grades, with the maximum and minimum percentages occurring in Grades 1 and 3, respectively. It can be concluded that apoptosis, autophagic cell death and myofibroblasts might be closely related to the damage of the extracellular matrix (ECM) structure.

La Fibrose Pulmonaire idiopathique (FPI) est une maladie fibroproliférative pour laquelle il n’existe aucun traitement efficace. Les mécanismes à l’origine de cette pathologie sont méconnus et impliquent plusieurs types cellulaires et facteurs de croissance, comme le TGF-β responsable de la différenciation de fibroblastes en myofibroblastes. Pour mieux comprendre ces mécanismes physiopathologiques, nous nous sommes intéressés à l’implication des miARN dans ce processus. Une analyse par puces à ADN de l’ensemble des miARN modulés dans des échantillons pulmonaires de souris, résistantes ou sensibles à la fibrose pulmonaire induite par la bléomycine, nous a permis d’identifier miR-199a-5p comme le meilleur candidat associé à la fibrose pulmonaire mais aussi fibrose rénale et hépatique. J’ai ensuite démontré que l’expression de miR-199a-5p était induite par le TGF-β in vitro, et que sa surexpression ectopique induisait la différenciation des fibroblastes. Une combinaison d’approche in silico et expérimentale, m’a permis d’identifier la Cavéoline-1 (CAV-1) comme cible de ce miARN. La CAV-1 est impliquée dans la dégradation du récepteur TGF-β. Ainsi, l’inhibition de CAV-1 par miR-199a-5p constitue une boucle de rétrocontrôle positif exacerbant la voie TGF-β. De manière intéressante, l’inhibition de miR-199a-5p in vitro régule la différenciation, la prolifération et la migration des fibroblastes pulmonaires par le TGF-β. Par ailleurs, nos résultats précliniques indiquent que l’inhibition de ce miARN diminue les marqueurs de fibrose, permettant d’envisager le développement de nouvelles approches thérapeutiques dans le traitement de la FPI et d’autres maladies fibroprolifératives. / Idiopathic Pulmonary Fibrosis (IPF) is a fibroproliferative disease with poor prognosis and for which no effective treatment exists. The mechanisms of this disease remain poorly understood and involve numerous cell types and growth factors such as TGF-β, which leads to the activation of lung fibroblasts into myofibroblasts; the key cell type driving the fibrogenic process. In this context, we focused the involvement of miRNAs in fibrosis process. To identify miRNAs with potential roles in lung fibrogenesis, we performed a genome-wide assessment of miRNA expression in lungs from two different mouse strains known for their distinct susceptibility to lung fibrosis after bleomycin exposure. We identified miR- 199a-5p as the best candidate associated with lung fibrosis but also kidney and liver fibrosis. I observed that miR-199a-5p expression was induced upon TGF-β exposure, and that its ectopic expression was sufficient to promote the pathogenic activation of pulmonary fibroblasts. Using combination of targets miRNA prediction tools and a transcriptomic approach we identified the Caveolin-1 (CAV-1), a critical mediator of pulmonary fibrosis, as a specific target of miR-199a-5p. Thus, we shown that miR-199a-5p is a key effector of TGF-β signaling in lung fibroblasts by regulating CAV1. Interestingly, inhibition of miR-199a-5p in vitro prevents the differentiation, proliferation and migration of fibroblasts after TGF-β stimulation. Finally, our preclinical results indicate that inhibition of this miRNA decreases fibrosis markers. Thus, miR-199a-5p behaves as a major regulator of tissue fibrosis with therapeutic potency for the treatment of IPF and fibroproliferative diseases.

Lors de la fibrose pulmonaire idiopathique (FPI), la différenciation fibroblastique s’accompagne d’une accumulation excessive des composants de la matrice extracellulaire ainsi qu’à un dérèglement de la balance protéases / antiprotéases. Nous avons étudié le rôle des cathepsines à cystéine dans la myofibrogenèse et leur contribution potentielle à la physiopathologie de la fibrose pulmonaire chez l’Homme. Pour cela, le profil d’expression des cathepsines ainsi que de leurs inhibiteurs naturels a été évalué dans un modèle cellulaire expérimental, puis dans des myofibroblastes primaires et enfin dans des liquides de lavage broncho-Alvéolaires (LBA) de patients atteints de FPI. Nos résultats montrent que lors de la FPI la cystatine C (inhibiteur naturel des protéases à cystéine) régule les activités protéolytiques des cathepsines extracellulaires et pourrait ainsi contribuer à l’accumulation de collagènes. Elle serait un biomarqueur potentiel de la FPI. D’autre part la cathepsine B participe à la différentiation fibroblastique et son inhibition retarde la myofibrogenèse. / During idiopathic pulmonary fibrosis (IPF), fibroblast differentiation is accompanied by an excessive accumulation of extracellular matrix components as well as an imbalance between proteases and theirs inhibitors. We evaluated the role of human cysteine cathepsins in myofibrogenesis and their potential contribution to the pathogenesis of IPF. Expression of cathepsins and their natural inhibitors have been studied in an experimental cell model, but also in primary myofibroblasts and in bronchoalveolar lavage fluids (BALF) of patients suffering from IPF. Our results show that cystatin C (a natural inhibitor of cysteine proteases) regulates the extracellular proteolytic activities of cathepsins and could contribute to the accumulation of collagens. Cystatin C could also be a potential biomarker of IPF. On the other hand, cathepsin B participates in fibroblast differentiation and its inhibition delays myofibrogenesis.

Harnblase. Weiterhin bestärkt die beobachtete Kopplung die Hypothese, dass das Myofibroblastennetzwerk afferente Signale Verstärken und modulieren kann. Die Verbesserung des Verständnisses der Harnblasenfunktion ist von grundlegendem Interesse für die Behandlung von Miktionsstörungen. Eine Störung von mechanischer Stimulierbarkeit und Kopplung der suburothelialen Myofibroblasten kann eine Störung der Sensorik der Harnblase plausibel erklären und stellt einen neuen Therapieansatz dar.:1 Abkürzungsverzeichnis 2 Einführung 2.1 Hintergrund 2.2 Anatomische und physiologische Grundlagen der Harnblasenfunktion 2.2.1 Aufbau der Harnblasenwand 2.2.2 Terminologie und Klassifikation interstitieller Zellen der Harnblase 2.2.3 Phänotypisierung der suburothelialen Myofibroblasten 2.2.4 Funktionsweise der Myofibroblasten 2.2.5 Innervation des unteren Harntraktes und neuronale Kontrolle der Harnblasenfunktion 2.2.6 Lokale sensorische Netzwerke der Harnblase 3 Aufgabenstellung 4 Material und Methoden 4.1 Gewinnung und Zellkultur suburothelialer Myofibroblasten 4.2 Lösungen und Chemikalien 4.3 Calcium imaging 4.4 Datenanalyse 4.4.1 Erzeugung der FI-Ratio Datensätze 4.4.2 Automatische Fluoreszenz-Signal-Analyse 4.5 Aufbau und Anordnung der Experimente 4.5.1 Spontanaktivität 4.5.2 Mechanische Stimulation mittels Glasmikropipette 4.5.3 Mechanische Stimulation durch Scherstress 4.5.4 Hypoosmolare Stimulation 5 Ergebnisse 5.1 Spontane Kalziumaktivität humaner suburothelialer Myofibroblasten 5.2 Mechanische Stimulierbarkeit durch Druck mittels Glasmikropipette 5.2.1 Intrazelluläre Ausbreitung mechanisch induzierter Kalziumsignale 5.2.2 Interzelluläre Ausbreitung mechanisch induzierter Kalziumsignale in kultivierten humanen suburothelialen Myofibroblasten 5.3 Mechanische Stimulierbarkeit durch Scherstress 5.4 Mechanische Stimulierbarkeit durch osmotischen Stress 6 Diskussion 6.1 Beobachtete Kalziumsignale suburothelialer Myofibroblasten 6.2 Bedeutung der mechanischen Stimulierbarkeit 6.3 Identifikation der stretch-activated channels 6.4 Bedeutung der interzellulären Kopplung 6.5 Konzept zur Rolle der suburothelialen Myofibroblasten 6.6 Methodischer und experimenteller Ansatz 6.6.1 Selbst entwickelte Fluoresence Analysis Software 6.6.2 Methoden der mechanischen Stimulierbarkeit 6.7 Pathophysiologische Aspekte 7 Zusammenfassung der Arbeit 8 Literaturverzeichnis 9 Anlagen 9.1 Selbstständigkeitserklärung 9.2 Lebenslauf 9.3 Publikationen 9.4 Danksagung

Theoretical part of the thesis is a scientific research of latest articles about frozen shoulder syndrome with accent to immunohistochemical level. At the same time, based on scientific literature it aims to clarify and statistically prove multifactorial causes of this syndrome especially in women going through hormonal changes. Psychosocial factors are also taken into account in this study and examined by unique questionnaire that was made expressly for this thesis. The questionnaire originates from internationally accepted clinimetrics such as VAS, SPADI, DASH score and most importantly SF-36. The theoretical research part also consists of "Therapy" chapter which describes latest trending treatment method for this condition. Experimental part, which consists of few case reports, focuses on a group of female patients who underwent range of motion measurement including functional testing of the affected limb. Next step followed was consecutive twelve minutes exercise on bicycle. They were controlled not to cross over anaerobic threshold. Level of exercise was controlled by predicted heart rate and estimation of the threshold by basic calculation and also by subjective Borg's scale of effort determined by the patient. After the bicycle exercise the range of motion was measured again and compared to the...

Bronchiolitis obliterans syndrome (BOS), a form of chronic lung allograft dysfunction, represents a major cause of mortality after lung transplantation. This disease is associated with a progressive fibro-obliteration of small airways (known as obliterative bronchiolitis) which leads to respiratory impairment and graft failure. The mechanisms behind airway occlusion remain unclear, and no curative treatment is available at the moment. Myofibroblasts are considered central effectors in this fibrotic process, but their origin is controversial. They can arise either from donor cells (resident fibroblasts and epithelial cells) or recipient cells (bone marrow-derived cells).The purpose of this project was to identify the precursors of mesenchymal cells responsible for post-transplant airway fibro-obliteration. Lineage-tracing tools were used to track or deplete potential sources of myofibroblasts in the heterotopic tracheal transplantation model, which produces a surrogate of obliterans bronchiolitis. Confocal analysis showed that myofibroblasts in the allografts were mostly recipient-derived, even though immunosuppression with tacrolimus induced a mild increase of donor-derived myofibroblasts. Occasional epithelial-to-mesenchymal transition was detected, but only in tacrolimus-treated recipients. On the other hand, fate-mapping techniques demonstrated that myeloid cells gave rise to the majority of mesenchymal cells in occluded airways. Accordingly, specific ablation of Cx3cR1+ mononuclear phagocytes significantly decreased allografts fibrosis. In parallel, single-cell RNA-sequencing unveiled surprising similarities between myeloid-derived cells (i.e. fibrocytes and macrophages) from the allografts and both murine and human samples of pulmonary fibrosis. Finally, analysis of BOS lesions from transplanted patients allowed us to translate our results to a clinical level. Indeed, confocal microscopy revealed that myofibroblasts expressing the macrophage marker CD68 were increased in BOS explants when compared to controls, and their numbers seemed correlated with the intensity of fibrosis.Collectively, these findings indicate that recipient mononuclear phagocyte system constitutes a clinically relevant source of mesenchymal cells infiltrating the airways after allogeneic transplantation. Therefore, therapies targeting migration and differentiation of mononuclear phagocytes and fibrocytes could prevent fibrotic remodelling of small airways and improve long-term outcomes after lung transplantation. / La bronchiolite oblitérante (bronchiolitis obliterans syndrome, BOS), une forme de dysfonction chronique du greffon, représente une des majeures causes de mortalité après transplantation pulmonaire. Cette pathologie est associée à une oblitération progressive et irréversible des petites voies aériennes par de la fibrose, qui mène à une perte de fonction respiratoire jusqu’à la défaillance du greffon. Les mécanismes impliqués dans la fibroproliferation ne sont pas encore bien compris, et il n’existe pas de traitement efficace de la BOS à l’heure actuelle. Les myofibroblastes joueraient un rôle majeur dans le développement de la fibrose, mais leur origine reste controversée. Ils pourraient dériver des cellules du donneur (fibroblastes in situ ou cellules épithéliales) ou bien du receveur (à partir de la moelle osseuse). L’objectif de cette étude était d’identifier les précurseurs des cellules mésenchymateuses responsables de l’obstruction des voies aériennes après transplantation allogénique. Nous avons utilisé des techniques de lineage tracing pour identifier les sources potentielles de myofibroblastes dans un modèle de transplantation hétérotopique de trachée, lequel permet d’obtenir une maladie fibro-oblitérante du greffon qui simule histologiquement la bronchiolite oblitérante. Les analyses par microscopie confocale ont montré que les cellules du receveur constituent la source principale de myofibroblastes dans les allogreffons, malgré une faible augmentation de la proportion de cellules mésenchymateuses dérivées du donneur lors du traitement immunosuppresseur. En plus, une minime fraction de myofibroblastes d’origine épithéliales a également été détectée, mais seulement dans les greffons traités par tacrolimus. D’autre part, nous avons établi que la lignée myéloïde produit la plupart des cellules mésenchymateuses détectés dans les voies aériennes oblitérées. Par ailleurs, la délétion spécifique de phagocytes mononucléaires Cx3cR1+ était associée avec une diminution significative du nombre de myofibroblastes et de la fibrose endoluminale dans les allogreffons. En parallèle, l’utilisation des techniques de séquençage en single cell a permis de révéler des ressemblances inattendues entre des populations de cellules d’origine myéloïdes (macrophages et fibrocytes) retrouvés dans les greffons et celles impliqués dans le développement de la fibrose pulmonaire chez l’homme et la souris. In fine, l’analyse par microscopie confocale des lésions pulmonaires de patients atteints de BOS nous a permis de transposer en clinique nos résultats expérimentaux. En effet, nous avons observé que la fraction de myofibroblastes positifs pour le CD68, un marqueur typiquement exprimé par les macrophages, était significativement augmentée dans les greffons avec bronchiolite oblitérante par rapport aux contrôles. De plus, leur nombre était corrélé avec la sévérité de la fibrose. L’ensemble de ces résultats indique que le système phagocytaire mononuclée constitue une source significative de cellules mésenchymateuses et contribue à la fibro-oblitération des voies aériennes après transplantation. L’utilisation de thérapies ciblant la migration et la différenciation des phagocytes mononuclées et des fibrocytes pourrait bloquer la destruction du greffon pulmonaire et améliorer la survie à long terme des patients transplantés. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

Type II diabetes mellitus is associated with many detrimental health situations including heart complications. The purpose of this study was to identify a role for PKA-dependent Rap1a signaling in the AGE-RAGE cascade. My hypothesis was Rap1a GTPase increased the downstream effects of AGE-RAGE signaling in diabetes via a PKA-dependent pathway leading to elevated ECM remodeling in the heart. Cardiac fibroblasts were isolated from heterozygous (Het) and diabetic (db/db) mice. To test the hypothesis, gain-ofunction and loss-ofunction treatments were used. PKC-Zeta is known as a major signaling hub that potentially links PKA-dependent and AGE-RAGE signaling cascades so PKC-Zeta inhibition to downregulate PKA-dependent cascade at PKC-Zeta was also used. Results showed a downregulation of signaling markers in the AGE-RAGE cascade when disrupting Rap1a crosstalk at PKC-Zeta. By understanding where the PKA-dependent and AGE-RAGE signaling cascades crosstalk, a new molecular mechanism is understood possibly leading to decreasing remodeling in a diabetic heart.

OBJETIVOS: Determinar a correlação entre a completa regeneração da membrana basal epitelial (MBE) e o desaparecimento de miofibroblastos do estroma anterior e consequente restauração da transparência corneana após diferentes mecanismos de trauma em coelhos. MÉTODOS: Foram utilizados 32 coelhos que tiveram um de seus olhos incluídos em um dos três grupos de estudo: (1) -9 dioptrias (D) ceratectomia fotorrefrativa (PRK), (2) Incisões corneanas verticais de espessura parcial (350 um), ou (3) Ceratite bacteriana, enquanto os olhos contralaterais compuseram o grupo controle. Os animais foram examinados, sacrificados, e tiveram suas córneas analisadas em diferentes momentos afim de investigar com detalhes o processo de cicatrização corneano usando técnicas de imunohistoquímica (IHQ) e microscopia de transmissão eletrônica (MTE). RESULTADOS: No grupo \"-9D PRK\", as córneas apresentavam opacidade corneana densa e nenhuma evidência de regeneração da MBE 1 mês após a cirurgia. Dois meses após a cirurgia, no entanto, pequenas áreas de córnea transparente começaram a surgir em meio à opacidade difusa, correspondendo a pequenas ilhas de MBE completamente regenerada. Após 4 meses da cirurgia a MBE estava completamente regenerada e a transparência corneana havia sido reestabelecida na região ablada pelo laser. No grupo \"incisões corneanas\", o par de densas opacidades corneanas lineares observadas após 1 mês do procedimento tornou-se progressivamente mais tênue ao longo dos próximos 2 meses. A ultraestrutura da MBE estava completamente regenerada e não houve formação de miofibroblastos no local das incisões 1 mês após o procedimento, inclusive ao redor dos plugs epiteliais que se estendiam até o estroma. No grupo \"ceratite bacteriana\", as córneas que haviam sido infectadas apresentaram opacidade densa, vascularização, miofibroblastos em toda a sua espessura, e nenhuma evidência de regeneração da MBE 1 mês após a infecção. Observou-se ao longo dos próximos 3 meses substancial redução da opacidade, evidências ultraestruturais de regeneração da MBE, e desaparecimento de miofibroblastos das porções mais anteriores do estroma, persistindo apenas nas regiões do estroma mais posterior nas quais o endotélio e a membrana de Descemet encontravam-se lesadas. CONCLUSÃO: No modelo animal apresentado, a resolução espontânea da opacidade corneana tardia mediada por miofibroblastos após a ablação com excimer laser ou ceratites infeciosas graves é desencadeada pela completa regeneração da estrutura e função da MBE. As incisões corneanas de espessura parcial em coelhos, no entanto, cicatrizam sem geração de miofibroblastos devido à completa regeneração da MBE após 1 mês do procedimento. Determinou-se, portanto, a correlação entre a reparação da membrana basal epitelial e a consequente redução da opacidade e restauração da transparência corneana / PURPOSE: To determine the correlation between epithelial basement membrane (EBM) regeneration and the disappearance of myofibroblasts from anterior stroma and consequent restoration of corneal transparency after different types of injury in rabbits. METHODS: Thirty-two rabbits had one of their eyes included in one of the 3 study groups: (1) -9 diopters (D) photorefractive keratectomy (PRK), (2) Two vertical partial-thickness (350 um) corneal incisions, or (3) Bacterial keratitis, whereas the opposite eyes served as unwounded control group. The animals were examined, sacrificed, and had their corneas analysed in different time points in order to investigate the corneal wound healing process using immunohistochemistry and transmission electron microscopy. RESULTS: In the \"-9D PRK\" group, corneas at 1 month after surgery had dense corneal opacity and no evidence of regenerated EBM. However, by 2 months after surgery small areas of stromal clearing began to appear within the confluent opacity, and these corresponded to small islands of normally regenerated EBM. By 4 months after surgery, the EBM was fully regenerated and the corneal transparency was completely restored in the ablated zone. In the \"corneal incisions\" group, the two dense, linear corneal opacities observed at 1 month after the procedure progressively faded during the next 2 months. The EBM ultrastructure was fully regenerated and there were no myofibroblasts at the site of the incisions by 1 month after the procedure, including around the epithelial plugs that extended into the stroma. In the \"bacterial keratitis\" group, all the corneas that have been infected presented dense stromal scarring, vascularization, myofibroblasts in the full stromal thickness and no evidence of EBM regeneration by 1 month after the infection. There was a definite decrease in opacity during the next 3 months, besides ultrastructural evidence of EBM regeneration and disappearance of myofibroblasts in the most anterior part of the stroma, which persisted only in the most posterior stroma where the endothelium and Descemet\'s membrane were damaged. CONCLUSION: In the rabbit model, spontaneous resolution of myofibroblast-mediated corneal opacity (fibrosis) after high correction PRK or infectious keratitis is triggered by regeneration of normal EBM structure and function. Conversely, incisional wounds heal in rabbit corneas without the development of myofibroblasts because the EBM regenerates normally by 1 month after the injury. Therefore, it has been determined the correlation between the EBM regeneration and the restoration of corneal transparency after different types of corneal injury

OBJETIVOS: Determinar a correlação entre a completa regeneração da membrana basal epitelial (MBE) e o desaparecimento de miofibroblastos do estroma anterior e consequente restauração da transparência corneana após diferentes mecanismos de trauma em coelhos. MÉTODOS: Foram utilizados 32 coelhos que tiveram um de seus olhos incluídos em um dos três grupos de estudo: (1) -9 dioptrias (D) ceratectomia fotorrefrativa (PRK), (2) Incisões corneanas verticais de espessura parcial (350 um), ou (3) Ceratite bacteriana, enquanto os olhos contralaterais compuseram o grupo controle. Os animais foram examinados, sacrificados, e tiveram suas córneas analisadas em diferentes momentos afim de investigar com detalhes o processo de cicatrização corneano usando técnicas de imunohistoquímica (IHQ) e microscopia de transmissão eletrônica (MTE). RESULTADOS: No grupo \"-9D PRK\", as córneas apresentavam opacidade corneana densa e nenhuma evidência de regeneração da MBE 1 mês após a cirurgia. Dois meses após a cirurgia, no entanto, pequenas áreas de córnea transparente começaram a surgir em meio à opacidade difusa, correspondendo a pequenas ilhas de MBE completamente regenerada. Após 4 meses da cirurgia a MBE estava completamente regenerada e a transparência corneana havia sido reestabelecida na região ablada pelo laser. No grupo \"incisões corneanas\", o par de densas opacidades corneanas lineares observadas após 1 mês do procedimento tornou-se progressivamente mais tênue ao longo dos próximos 2 meses. A ultraestrutura da MBE estava completamente regenerada e não houve formação de miofibroblastos no local das incisões 1 mês após o procedimento, inclusive ao redor dos plugs epiteliais que se estendiam até o estroma. No grupo \"ceratite bacteriana\", as córneas que haviam sido infectadas apresentaram opacidade densa, vascularização, miofibroblastos em toda a sua espessura, e nenhuma evidência de regeneração da MBE 1 mês após a infecção. Observou-se ao longo dos próximos 3 meses substancial redução da opacidade, evidências ultraestruturais de regeneração da MBE, e desaparecimento de miofibroblastos das porções mais anteriores do estroma, persistindo apenas nas regiões do estroma mais posterior nas quais o endotélio e a membrana de Descemet encontravam-se lesadas. CONCLUSÃO: No modelo animal apresentado, a resolução espontânea da opacidade corneana tardia mediada por miofibroblastos após a ablação com excimer laser ou ceratites infeciosas graves é desencadeada pela completa regeneração da estrutura e função da MBE. As incisões corneanas de espessura parcial em coelhos, no entanto, cicatrizam sem geração de miofibroblastos devido à completa regeneração da MBE após 1 mês do procedimento. Determinou-se, portanto, a correlação entre a reparação da membrana basal epitelial e a consequente redução da opacidade e restauração da transparência corneana / PURPOSE: To determine the correlation between epithelial basement membrane (EBM) regeneration and the disappearance of myofibroblasts from anterior stroma and consequent restoration of corneal transparency after different types of injury in rabbits. METHODS: Thirty-two rabbits had one of their eyes included in one of the 3 study groups: (1) -9 diopters (D) photorefractive keratectomy (PRK), (2) Two vertical partial-thickness (350 um) corneal incisions, or (3) Bacterial keratitis, whereas the opposite eyes served as unwounded control group. The animals were examined, sacrificed, and had their corneas analysed in different time points in order to investigate the corneal wound healing process using immunohistochemistry and transmission electron microscopy. RESULTS: In the \"-9D PRK\" group, corneas at 1 month after surgery had dense corneal opacity and no evidence of regenerated EBM. However, by 2 months after surgery small areas of stromal clearing began to appear within the confluent opacity, and these corresponded to small islands of normally regenerated EBM. By 4 months after surgery, the EBM was fully regenerated and the corneal transparency was completely restored in the ablated zone. In the \"corneal incisions\" group, the two dense, linear corneal opacities observed at 1 month after the procedure progressively faded during the next 2 months. The EBM ultrastructure was fully regenerated and there were no myofibroblasts at the site of the incisions by 1 month after the procedure, including around the epithelial plugs that extended into the stroma. In the \"bacterial keratitis\" group, all the corneas that have been infected presented dense stromal scarring, vascularization, myofibroblasts in the full stromal thickness and no evidence of EBM regeneration by 1 month after the infection. There was a definite decrease in opacity during the next 3 months, besides ultrastructural evidence of EBM regeneration and disappearance of myofibroblasts in the most anterior part of the stroma, which persisted only in the most posterior stroma where the endothelium and Descemet\'s membrane were damaged. CONCLUSION: In the rabbit model, spontaneous resolution of myofibroblast-mediated corneal opacity (fibrosis) after high correction PRK or infectious keratitis is triggered by regeneration of normal EBM structure and function. Conversely, incisional wounds heal in rabbit corneas without the development of myofibroblasts because the EBM regenerates normally by 1 month after the injury. Therefore, it has been determined the correlation between the EBM regeneration and the restoration of corneal transparency after different types of corneal injury