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Regeneration has long been known to occur in the cnidarian Hydractinia. This process refers to its ability to regrow structures, i.e a head, lost by injury, a phenomenon that depends on the migration of proliferative cells to the site of injury, and the formation of a blastema, a mass of undifferentiated cells that will restore the missing head tissues. In our study, we showed that members of SoxB transcription factors and HDACs are involved in the regulation of Hydractinia neurogenesis in tissue homeostasis and regeneration. Particularly, we revealed that knockdown of SoxB2 or Hdac2 (a class I HDAC) knockdown, or inhibition of HDAC activity, suppress head regeneration. Here, we show that SoxB2 knockdown, or the inhibition of HDACs activity by TSA, a HDAC Class I and II inhibitor, interfere with head regeneration by affecting the migration of proliferative cells and the formation of a proliferative blastema.

Alchajmerova bolest je progresivno neurodegenerativno oboljenje i najčešći uzrok demencije kod starijih osoba, sa prevalencom dva puta većom u ženskoj populaciji. Jedna od struktura koje najranije bivaju zahvaćene patohistološkim promenama u AB je hipokampus, deo limbičkog sistema koji ima važnu ulogu u procesima učenja i formiranja memorije. Nova istraživanja potvrdila su da se i kod ljudi u subgranularnoj zoni hipokampusa aktivno odvija proces neurogeneze u adultnom periodu. Imajući u vidu činjenicu da novostvoreni neuroni imaju ulogu u procesima učenja i pamćenja, odnosno da utiču na oblikovanje kognicije i ponašanje individue, smatra se da se kognitivni deficit i gubitak pamćenja kod neurodegenerativnih oboljenja može delom pripisati poremećenoj neurogenezi na nivou subgranularne zone hipokampusa. Istraživanja procesa i dinamike adultne neurogeneze u hipokampusu životinja ili osoba obolelih od Alchajmerove bolesti su dala kontradiktorne rezultate. U zavisnosti od eksperimentalnih uslova, kao što su životinjski model Alchajmerove bolesti, starost i pol životinje, kao i markeri kojima se analiziraju ćelijski procesi, rezultati su ukazali kako na smanjenje, tako i na nepromenjen ili čak povećan obim neurogeneze kod animalnih modela i kod pacijenata obolelih od Alchajmerove bolesti. Dosadašnja istraživanja ukazuju na važnu ulogu članova SOXB grupe transkripcionih faktora u brojnim ćelijskim procesima uključenim u neurogenezu tokom embrionalnog i adultnog perioda razvoja, kao što su održavanje multipotentnosti, proliferacije i diferencijacije neuralnih matičnih/prekursornih ćelija. Pored SOXB transkripcionih faktora određeni neurotrofički faktori, kao što je neurotrofički faktor poreklom iz mozga (BDNF), utiču na procese proliferacije i diferencijacije neuralnih matičnih/prekursornih ćelija. Međutim, tačna uloga ovih faktora u nastanku različitih neurorazvojnih i neurodegenerativnih poremećaja nije dovoljno razjašnjena. Imajući u vidu navedeno, cilj ove studije bio je da se utvrdi obrazac uzrasno-zavisnih promena u ekspresiji SOXB transkripcionih faktora u okviru procesa adultne neurogeneze kod jedinki muškog i ženskog pola, kao i da se ispitaju promene u ekspresiji SOXB transkripcionih faktora kod 5xFAD mišjeg modela Alchajmerove bolesti oba pola i različite starosti... Alzheimer's disease is a progressive neurodegenerative disease and the most common cause of dementia in the elderly, with a prevalence of two times higher in the female population. One of the earliest affected structures by pathohistological changes in AB is the hippocampus, a part of the limbic system that plays an important role in the processes of learning and memory formation. New research has confirmed that even in humans the neurogenesis process actively occurs through the adult period in the subgranular zone of the hippocampus. Bearing in mind the fact that newly created neurons play a role in the processes of learning and memory, affecting the cognition and behavior of an individual, cognitive deficit and memory loss in neurodegenerative diseases can be partly attributed to altered neurogenesis at the level of the hippocampal subgranular zone. Analysis of the adult neurogenesis processes in the hippocampus of animals or persons suffering from Alzheimer's disease have resulted in contradictory data. Depending on experimental conditions, such as the Alzheimer's animal model, age and sex, as well as the markers used to analyze the neurogenesis, the results indicated both a decrease, unchanged or even increased levels of neurogenesis both in animal models, and even in patients suffering from Alzheimer's disease in smaller number of studies. Previous results indicate the important role of members of the SOXB group of transcription factors in numerous cellular processes involved in neurogenesis during embryonic and adult developmental periods, such as the maintenance of multipotency, proliferation and differentiation of neural stem/precursor cells. In addition to SOXB transcription factors, certain neurotrophic factors, such as the brain derived neurotrophic factor (BDNF), affect the processes of proliferation and differentiation of neural stem/precursor cells. However, the exact role of these factors in the patogenesis of various neurodevelopmental and neurodegenerative disorders is not sufficiently clarified. Bearing in mind the above, the aim of this study was to determine the pattern of age-dependent changes in the expression of SOXB transcription factors within the adult neurogenesis process in male and female individuals and to examine the changes in the expression of SOXB transcription factors in the 5xFAD mouse model of Alzheimer's disease of both sexes and different ages...