Gut microbial composition alters in some special situations, such as in ulcerative colits (UC) after total proctocolectomy and ileal pouch-anal anastomosis (IPAA) surgery. The aim of our study was to determine the composition of the intestinal microbiome in UC patients after IPAA surgery, compared with UC patients, familial adenomatous polyposis (FAP) patients after IPAA surgery and healthy controls. Clinical data of patients, blood and faecal samples were collected. Faecal microbiota structure was determined by sequencing the V4 hypervariable region of the 16S rRNA gene. Overall, 56 patients were enrolled. Compared to the Healthy group, both the Pouch active and UC active groups had higher Enterobacteriaceae, Enterococcaceae and Pasteurellaceae abundance. The Pouch and UC groups showed distinct separation based on their alpha and beta bacterial diversities. The UC group had higher Prevotellaceae, Rikenellaceae, Ruminococcaceae abundance compared to the Pouch active group. Pouch and FAP participants showed similar bacterial community composition. There was no significant difference in the bacterial abundance between the active and inactive subgroups of the Pouch or UC groups. Gut microbiome and anatomical status together construct a functional unit that has influence on diversity, in addition to intestinal inflammation that is a part of the pathomechanism in UC.

Ubiquitylation is critical for preventing aberrant DNA repair and for efficient maintenance of genome stability. As deubiquitylases (DUBs) counteract ubiquitylation, they must have a great influence on many biological processes, including DNA damage response. To elucidate the role of DUBs in DNA repair in Drosophila melanogaster, systematic siRNA screening was applied to identify DUBs with a reduced survival rate following exposure to ultraviolet and X-ray radiations. As a secondary validation, we applied the direct repeat (DR)-white reporter system with which we induced site-specific DSBs and affirmed the importance of the DUBs Ovarian tumor domain-containing deubiquitinating enzyme 1 (Otu1), Ubiquitin carboxyl-terminal hydrolase 5 (Usp5), and Ubiquitin carboxyl-terminal hydrolase 34 (Usp34) in DSB repair pathways using Drosophila. Our results indicate that the loss of Otu1 and Usp5 induces strong position effect variegation in Drosophila eye following I-SceI-induced DSB deployment. Otu1 and Usp5 are essential in DNA damage-induced cellular response, and both DUBs are required for the fine-tuned regulation of the non-homologous end joining pathway. Furthermore, the Drosophila DR-white assay demonstrated that homologous recombination does not occur in the absence of Usp34, indicating an indispensable role of Usp34 in this process.

The importance of three-dimensional (3D) models in pharmacological tests and personalized therapies is significant. These models allow us to gain insight into the cell response during drug absorption, distribution, metabolism, and elimination in an organ-like system and are suitable for toxicological testing. In personalized and regenerative medicine, the precise characterization of artificial tissues or drug metabolism processes is more than crucial to gain the safest and the most effective treatment for the patients. Using these 3D cell cultures derived directly from patient, such as spheroids, organoids, and bioprinted structures, allows for testing drugs before administration to the patient. These methods allow us to select the most appropriate drug for the patient. Moreover, they provide chance for better recovery of patients, since time is not wasted during therapy switching. These models could be used in applied and basic research as well, because their response to treatments is quite similar to that of the native tissue. Furthermore, they may replace animal models in the future because these methods are cheaper and can avoid interspecies differences. This review puts a spotlight on this dynamically evolving area and its application in toxicological testing.

Összefoglaló. A bőrpótlóknak mind a klinikumban, mind a gyógyszerkutatásokban kiemelt szerepük van. Ezek a kezdetleges mesterséges bőrszövetek segíthetik a bőr regenerálódását, modellezhetik a főbb funkciókat, de megvannak a korlátaik is, mechanikailag sérülékenyek, és nem tartósak. A legtöbb bőrpótló vagy acelluláris, vagy csak egy-két sejttípust tartalmaz. Az eredeti bőrrel megegyező szerkezetű, teljesen funkcionális mesterséges bőrszövet a mai napig nem létezik. A háromdimenziós szövetnyomtatás megoldást kínálhat erre a problémára is, hiszen a bőrszövet minden sejtes eleme felhasználható, megfelelő hidrogélek és biotinták segítségével pedig olyan komplex struktúrák hozhatók létre, amelyek képesek a bőr teljes funkcionális repertoárját biztosítani. Ez nemcsak klinikai szempontból kiemelt jelentőségű, hanem a preklinikai kísérletek esetében kiválthatja az állatmodelleket és számos toxikológiai vizsgálatot is. Orv Hetil. 2022; 163(10): 375–385. Summary. Skin substitutes have a prominent role in therapeutic applications and drug research. These simple artificial skin tissues can support skin regeneration, in vitro they can model the main functions of the skin but they also have limitations such as being mechanically vulnerable and not durable enough. Most skin substitutes are either acellular or contain only one or two cell types. Fully functional artificial skin substitute with the same structure as the original skin has not been produced to this day. Three-dimensional tissue bioprinting can also offer a solution to this problem, as all cellular elements of skin tissue can be used, and with the help of appropriate hydrogels and bioinks, complex structures can be created that can provide a complete functional repertoire of the skin. It is important not just in the clinical therapeutic use, but it can also trigger the replacement of animal models and a number of toxicological studies in preclinical trials. Orv Hetil. 2022; 163(10): 375–385.