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Pediatric Research Center

The Pediatric Research Center currently represents almost 30 research groups carrying out clinical, translational and basic research in pediatrics in the University of Helsinki, Finland. Our mission is to promote research, to communicate the latest research results to physicians, patients and the general public, and to serve as a reference guide for researchers and companies seeking academic collaboration.  We warmly invite students and young physician-scientists to join our growing team!

Heart defects on a dish

About 1% of all newborns have structural cardiac malformations called congenital heart defects (CHD), which are the most common congenital malformations. CHD is an illustrative example of a complex disease, where both genes and adverse environmental stimuli can contribute to the pathogenesis. Around 10% of CHDs are estimated to be monogenic, however, in many cases the cause is thought to be oligogenic with two or more predisposing genetic variants. CHD has reduced penetrance, meaning that not all individuals with predisposing genetic variants develop disease. In addition, the genetic variants result in variable expressivity, where the same variant can cause different types of cardiac malformations in different individuals. Due to the complex inheritance pattern, identifying gene variants associated with CHD has been challenging. Further complicating the research field is the knowledge that certain environmental exposures, such as maternal diabetes, are known to be additional risks for CHD in the offspring.

Recent advances in stem cell biology and genome editing techniques have brought patient derived induced pluripotent stem cells (iPSC) as appealing disease modelling tools, which are especially attractive in complex disease. iPSCs can be reprogrammed from patients' skin or blood cells. The iPSCs can then further be differentiated into cells of interest, such as heart muscle cells (cardiomyocytes) or to cells lining blood vessels (endothelial cells). The properties of these patient derived cells can be studied to explore possible functional abnormalities.

Modern gene editing techniques allow us to do arts and crafts with genes. For example, the CRISPR/Cas9 technology is a useful tool in determining the pathogenicity of specific genetic variants. If patient derived cells are found to possess functional or phenotypic abnormalities, correcting the genetic variant suspected to cause disease should also correct these abnormalities. In practice this happens by 1) correcting the candidate variant in the patient’s iPSCs and 2) differentiating iPSCs containing the candidate variant and iPSCs in which the variant has been corrected to cells of interest and comparing the properties of these two cell lines.

The Finnish population is ideal for genetic studies and we have been able to collect a unique patient material from patients with congenital heart defects. We have identified potential disease causing variants in some of these individuals. During the last year, we have established iPS-cardiomyocyte (iPS-CM) and iPS-endothelial cell (iPS-EC) differentiation protocols in the Kivelä lab, and we are currently studying the pathogenicity and disease mechanisms of the candidate variants in patient derived iPSCs. Cardiac development is a complex interplay between multiple cell types, signaling pathways, and their response to mechanical forces of early blood flow. Co-cultures of iPS-CM and iPS-ECs and culturing the cells in flow are techniques we are using to mimic this complex system.

Our study will shed light on the origins of heart defects and model these defects on a dish. In addition to finding disease-associated genes, our study contributes to developing new methods to use patient derived iPSCs for disease modelling in complex cardiovascular disease. These methods can be applied to other forms of research involving the interplay between iPS-ECs and iPS-CMs, such as the cardiotoxicity of certain pharmaceuticals, and the role of endothelial cells in cardiomyocyte wellbeing in adult disease. In addition, our study results will shed light on the pathogenic mechanisms in diseases with a complex inheritance pattern in general.

Single T cells under scrutiny

Hematological stem cell transplantation (HSCT) is a life-saving treatment of choice in many pediatric malignancies showing an inadequate response to standard chemotherapeutic approaches. In addition, HSCT is increasingly utilized as a curative option in non-malignant primary immunodeficiencies and hemoglobinopathies. (Read more)

NEW INSIGHTS INTO RSV DISEASE

In developed countries respiratory syncytial virus (RSV) causes busy epidemics during winter seasons but fortunately with very low levels of mortality in children. However, in developing countries the situation is different. In a recent meta-analysis it was estimated that globally RSV causes more than 100 000 deaths in children <5 years of age every year (Shi et al. Lancet 2017) and RSV is considered the second most important pathogen causing mortality in children only after malaria (Lozano et al. 2012 Lancet). This is something that we pediatricians in Finland and other developing countries often forget when we worry about crowded emergency departments, overfilled wards and busy on call shifts every winter during RSV epidemics. (Read more)

A NOVEL THERAPY TRIAL FOR AGU DISEASE AT HUCH

We have recently started a novel investigator initiated therapy trial for AGU (aspartylglucosaminuria) with betaine in HUCH child neurology clinic. It is performed in collaboration with Prof. Ritva Tikkanen, University of Giessen. AGU is a progressive disease leading to mental retardation due to the accumulation of aspartylglucosamine in all tissues and also in the brain. It belongs to the Finnish disease heritage, and most of the patients are from Finland (about 160 alive patients). AGU disease is diagnosed by urine oligosaccharides at the average age of five, when global developmental delay is noticed. (Read more)

Monogenic primary immunodeficiencies reveal new concepts of immune regulation

Rapid development of next generation sequencing (NGS) technologies and decreased costs of the whole exome and genome sequencing coupled with modern biochemistry and cellular biology methodology, have made identification of novel disease-causing gene mutations routine. Primary immunodeficiency diseases (PIDDs) are a clinically heterogeneous group of clinical entities caused by mutations in the genes which control the immune responses. Most of the PIDDs are monogenic rare disorders that follow Mendelian inheritance. (Read more)