Head of department:

Buchtová Marcela, prof. RNDr., Ph.D.

E-mail: buchtova@iach.cz Phone: +420 532 290 157 Department: Laboratoř molekulární morfogeneze Building: Brno/

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Knowledge of developmental processes is a key to understand causes of developmental abnormalities or to uncover the origin and diversification of lineage-specific structures during vertebrate evolution. Our laboratory focuses on fundamental morphogenetic processes in organogenesis with special interest in formation of craniofacial structures and limb patterning. Novel molecules and unique roles for known molecules are investigated during cell proliferation, adhesion, migration, differentiation and cell death. Particular attention is paid to hard tissues development, including teeth (odontogenesis) and bones (osteogenesis). Physiological aspects at molecular and cellular levels are investigated and related developmental disorders are examined. Along with increasing longevity of human population, complications related to bone and dental tissues become a significant medical and scientific issue. We use in vivo, ex vivo and in vitro approaches in several experimental models including mice, pig, chicken and chameleon embryos to reveal underlying developmental mechanisms. The effort of LMM is also to contribute to recent knowledge in basic and biomedical research with links to practical applications in tissue repair and regeneration.

Carcinomas of the oral cavity and oropharynx are among the ten most frequently occurring malignancies in the human population. Our project is focused on squamous cell carcinoma, which is the most frequent type of malignant disease in this area. The prognosis of these malignancies is determined by the degree of invasiveness of the primary tumor and by the extent of metastatic spread into regional and distant lymph nodes. The intensity of perineural invasion correlates with tumor localization, its extent, and the presence of nodal metastases. In our project, we focus on the detection of clinically relevant somatic mutations in patients with perineural invasion and the evaluation of early molecular markers during perineural invasion, which are expressed on the interface between tumor and surrounding tissues. Moreover, we analyze role of primary cilia and Sonic hedgehog paracrine signaling in tumorous cells and the effect of altered Shh signaling on perineural invasion. We also focus on the study of PLK1 (Polo-like kinase 1) and NEK2 (Never in mitosis A (NimA)-related kinase), which play a key role in the regulation of the cell cycle and primary cilia, and their expression is significantly increased in this tumor type. Our aim is to introduce new protocols into routine histopathological diagnostics aiming to predict future cell behavior, which will improve planning and management of the subsequent therapies in patients.

Tooth ankyloses are pathological conditions in human, which arise by direct fusion of the tooth with surrounding tissues as a result of trauma or inflammation around teeth. Failure of interaction between these tissues lead to the disruption of tooth function as an organ and the resorption of alveolar bone. This state is followed by loss of teeth and by the initiation of conditions inappropriate for following teeth reconstruction. Aim of the project is to uncover cellular and molecular processes contributing to morphological and functional changes during tooth ankyloses initiation in human. Project will use new methodical approaches such as LIBS, micro CT examination or gene expression analyses of osteogenic factors in periodontal area with aim to expand our understanding about causes of teeth ankyloses commencement as well as possibilities of new approaches for their prevention during teeth traumas.

Infections affecting the root canal of the tooth are the most common cause of apical periodontitis (AP). Chronic inflammation in the periodontium may lead to the development of a radicular cyst (RC), a type of inflammatory odontogenic cyst (OC). OC of developmental origin also includes dentigerous cysts (DC) and odontogenic keratocysts (OKC). Correct classification of OCs reflecting their etiopathogenesis including genetic factors is crucial for choosing an optimum therapy and patient management. The aim of the project is to identify risk factors of OC development and improve their diagnosis. The project includes study of microbiome present in the root canal, genetic association studies focused on patients' immune profiling and influence of genes envolved in odontogenesis, comparative studies of gene expression profiles in various types of odontogenic cysts, and study of selected molecular pathways in OC pathogenesis in an animal model. Based on the obtained results we will propose a panel of markers for prediction of OC development and differential diagnosis of OC types.

Inhalation is the main route for exposure of organism to nanoparticles. Inhaled nanoparticles penetrate into the lung, translocate across the alveolar-capillary barrier into blood and they are transported to the secondary target organs. This project focuses on the influence of inhaled water-soluble and semi-soluble compounds of lead and cadmium nanoparticles found in the urban aerosol on target organs of mice and mechanisms of the metal nanoparticle clearance from different exposed tissues. Mice are exposed to nanoparticles in inhalation chambers to provide physiological exposure similar to real air conditions in urban areas. The results will deepen the knowledge of the effects of inhaled metal nanoparticles with different physicochemical properties on individual target organs and will contribute to uncover possible tissue-specific responses to nanoparticles exposure. Determined molecular and cellular mechanisms of nanoparticle clearance from exposed organs will help to find new approaches how to enhance the nanoparticle clearance in polluted industrial areas

Cyclin-dependent kinase 13 (CDK13) in complex with the cyclin K influence activity of the RNA polymerase II and together regulate transcription of target genes. Its crucial role was observed in processes of neurogenesis, haematopoiesis and regulation of cell stemness. In human patients, mutations in CDK13 gene have been associated with the congenital heart defects, facial dysmorphic features and intellectual developmental disorder. To study functions of the Cdk13, we developed Cdk13-deficient mouse strains via which we observed its necessity for mouse development when the homozygous mutations in Cdk13 result in embryonic lethality. Moreover, mouse embryos show developmental defects of brain, heart, kidney, liver, facial structures and limbs. The follow-up in vivo studies of this kinase should reveal important facts regarding its effect on development of facial structures and limbs and could thus bring useful knowledge in molecular background of developmental defects found in patients bearing the CDK13 mutations.

SATB2 is a regulator of gene expression, it is involved in chromatin remodeling, playing a key role in neurogenesis, craniofacial patterning, and bone development. Complete or partial loss of the Satb2 gene results in varying degrees of craniofacial abnormalities, including a shorter mandible and cleft palate. However, its role in dental tissue development is not yet fully understood. In humans, haploinsufficiency in Satb2, known as Glass syndrome, leads to intellectual disabilities, reduced bone density, craniofacial deformities, cleft palate, and dental anomalies. Our research uses a SATB2 deficient mouse model, which mirrors the human condition. In Satb2^-/- mice, we observe a loss of otherwise continuously growing incisors and, on the other hand, ectopic tooth formation in the molar area. This opposite effect on tooth formation raises interest in further characterizing this phenomenon. We are trying to uncover a mechanism responsible for tooth patterning during the embryonic period as well as to target the role of SATB2 in hard dental tissue repair and periodontal tissue regeneration following the injury. Our goal is to develop treatments that address dental pathologies, enhancing both functional and social aspects of a patient's life.

Protein TMEM107 is crucial for primary cilia formation and function in various developmental processes. In Tmem107 knockout mice, we observed significant eye defects, including anophthalmia and microphthalmia, and decreased ciliogenesis with downregulated Sox2 expression. TMEM107's role in retinal development was confirmed using 3D retinal organoids, where its absence led to impaired retinal structure formation. In craniofacial development, Tmem107 deficiency caused anomalies in the rostral jaw area, such as malformed or absent incisors. We also focused on TMEM107's involvement in Wnt signaling using NIH3T3 cells and zebrafish models, revealing a reduction in ciliogenesis and downregulation of Wnt pathway genes. Zebrafish mutants displayed ciliopathy traits and craniofacial abnormalities. Our findings underscore TMEM107's essential role in cilia function, influencing ocular and craniofacial development and Wnt signaling. This research enhances our understanding of ciliopathies and mechanisms behind these defects.

Polycystic kidney disease is one of the most common kidney diseases. It is characterized by the formation of numerous cysts in the kidneys, which reduce their function and cause a range of secondary problems, such as infections or blood pressure issues. There are two forms of this genetic disease: one (AR PKD) appears before birth, and the other manifests in adulthood (AD PKD). Currently, there is no targeted treatment; patients are treated with dialysis, transplantation, or lifestyle modifications. In our project, we use a mouse model of polycystic kidney disease with a mutation in Nek8 gene. We aim to closely examine the processes that initiate cyst formation. This will allow us to propose directions for future drug development.

Nanodiamonds are carbon particles of extremely small dimensions. Due to their size, they possess a range of interesting properties, and their potential use as nanosensors or in drug delivery is currently being explored. In our project, we use nanodiamonds prepared by colleagues from Petr Cígler’s group (IOCB CAS), which are capable of specifically binding the FGF (Fibroblast Growth Factor) molecule. We are testing the use of these biocompatible nanodiamonds on various animal models, such as chickens and mice, and in the future, we aim to test their application in mice with polycystic kidney disease.