Serdecznie zapraszamy na Seminarium Doktorantów, które odbędzie się 28 marca, 2025 r. o godz. 10.30 w Sali Konorskiego (II piętro).

W programie przewidziane są 3 prezentacje:
1. Mgr Paulina Kamińska
2. Mgr Klaudia Krystecka
3. Mgr inż. Patrycja Rosa

Informacje dotyczące prelegentów wraz z abstraktami znajdują się poniżej.

MSc Paulina Kamińska
Laboratory of Molecular Neurobiology Nencki Institute of Experimental Biology
& Cellular Neurobiology Research Group University of Warsaw
Supervisor: Dr. Anna Malik, PhD, DSc

Title: The role of SorLA sorting receptor in shaping pro-tumorigenic properties of microglia during glioma progression

Abstract:
SorLA (SORL1 gene) is an intracellular sorting receptor which transports protein cargos between subcellular compartments and therefore defines their final localization. While SorLA was initially thought to be limited to neurons in the brain, it was later discovered to be expressed in glial cells as well, including microglia. During glioblastoma progression, both brain-resident microglia and blood-derived macrophages are reprogrammed, and promote tumor growth instead of fighting it. These cells are collectively called glioma associated microglia and macrophages (GAMs). Finding a mechanism responsible for the phenotypic polarization of GAMs is crucial for the development of glioblastoma new therapeutic strategies. In doing so, I focus on SorLA as a potential factor driving pro-tumorigenic properties of GAMs. Studies on primary mouse microglia revealed that the level of Sorl1 transcript depends on the activation mode of the cells. I also observed that microglia depleted of SorLA (SorLA-KO) release higher amounts of pro-inflammatory factors when compared to wild-type cells (WT) and that their response to co-culture with glioma cells (GL261) is different. These findings raised the hypothesis that the lack of SorLA may unlock the pro- inflammatory potential of microglia and thereby influence glioma growth. Indeed, SorLA-KO mice develop smaller brain tumors than WTs, which coincides with increased inflammatory state of tumor microenvironment, manifested by changes in microglia properties, infiltration of immune cells from the periphery and enhanced necroptosis. Results of my research indicate SorLA as a key player in shaping the properties of GAMs, which depletion unlocks anti- tumor response, leading to prevention of tumor growth.

MSc Klaudia Krystecka
Laboratory of Neurophysiology of Mind, Nencki Institute of Experimental Biology
Supervisor: Dr. Aneta Szymaszek, PhD, DSc

Title: Individual Differences in Temporal Information Processing: Electrophysiological Indicators

Abstract:
Temporal Information Processing (TIP) is a crucial aspect of human cognition, influencing efficiency of functions such as language, attention, memory, motor control, and planning.
This study aimed to assess TIP efficiency in healthy young individuals and identify related electrophysiological markers.
Eighty-four participants (M = 25 years) completed a behavioural auditory Temporal- Order Judgment task measuring TIP efficiency. Based on their performance, they were divided into two subgroups characterised by (1) High Temporal Efficiency (HTE; N = 34) or (2) Low Temporal Efficiency (LTE; N = 33). Then, both HTE and LTE groups followed electrophysiological assessment: resting state EEG, a passive oddball task, and a Go/No-Go task.
The results revealed between-group differences in spectral slope, suggesting that higher TIP efficiency may be associated with reduced neuronal noise. Moreover, the HTE group displayed a late MMN offset and longer duration, which indicated better temporal stimulus integration. More efficient TIP was also associated with better cognitive functioning, as evidenced by faster reaction times, better stimulus discrimination, as well as stronger and earlier P300 responses during Go/No-Go task.
Such new knowledge may provide more insights into the dynamic processing of
information in our brains, as well as to the relationship between time and cognition.
Supported by National Science Centre, Poland, grant no. 2018/29/B/HS6/02038

MSc Patrycja Rosa
Laboratory of Molecular Neurobiology
Supervisor: Prof. Bożena Kamińska-Kaczmarek, PhD, DSc
Auxiliary supervisor: Dr. Aleksander Jankowski

Title: Applications of single-cell sequencing to better understand transcriptomics changes underlying microglia repopulation and human brain organoid development

Abstract:
Single-cell RNA sequencing (scRNAseq) offers valuable insights into biological processes and functional diversity of cells.
Microglia, the myeloid cells of the central nervous system, maintain its homeostasis, renew throughout an organism’s lifetime. We investigated the origin and functionality of microglia in young and old mice following pharmacological depletion. By performing scRNAseq on immunosorted CD11b+ cells, we identified distinct microglial subpopulations emerging during the repopulation. Our results indicate that repopulated microglia exhibit a shift in gene expression toward a progenitor-like state, with an increased expression of inflammatory genes. Interestingly, while transcriptomic profiles in microglia from young and old mice did
not differ, repopulated microglia from older mice showed different profiles: increased proliferation and deficits of mature microglial states. A comparative analysis of repopulated microglia and subpopulations of glioma-associated microglia revealed striking similarities in their transcriptomic programs related to proliferation, motility, and extracellular matrix degradation activity. The findings suggest that microglial repopulation shares mechanistic features with other pathological states. Human brain organoids provide a valuable model for studying brain diseases. ScRNAseq was employed to characterize dynamic transcriptomic changes in human wild type and TSC2-mutant cerebral organoids. The analysis highlighted developmental differences in transcriptional programs, particularly in the expression of PAX6.