The Role Of Lnk Adaptor Protein In Hematopoietic Stem Cell Genome Stability And Self-Renewal

Hematopoietic stem cells (HSCs) are rare cells that reside in bone marrow. HSCs function to give rise to all blood cells through proliferation and differentiation, but also to HSCs in a tightly regulated process known as self-renewal. It is for these abilities that stem cells stand out from progenitors and other short-lived cells and which allows them to last a lifetime. Self-renewal remains mechanistically enigmatic but central to the biology and long lifespan of HSCs. Because HSCs are so long-lived they face numerous genomic insults and therefore mechanisms of genome stability are also central to HSC function throughout life. This thesis examines the role of an adaptor protein known as LNK (SH2B3), which negatively regulates a central cytokine signaling axis in HSCs, in regulating HSC self-renewal and genome stability. HSCs in Lnk-/- mice are expanded, and endowed with enhanced proliferative and self-renewal capabilities. Given this superiority, this thesis first investigates the impact of LNK deficiency in context of a bone marrow failure syndrome, Fanconi Anemia (FA), where HSCs accumulate fatal levels of genomic insults and cannot function. Superimposed on the deletion of a central gene in FA, FANCD2, Lnk deficiency rescues HSC function through restoring genome stability at sites of stress encountered during DNA duplication. Second, using a model that is capable of tracking HSC divisions in vivo, this thesis investigates the in vivo self-renewal dynamics of Lnk deficient HSCs. On a population level, HSCs exist along a continuum of states between fully functional HSCs and progenitors, and LNK deficiency tips the balance towards HSCs. This is a cell-intrinsic process, and may be regulated by gene expression-dependent and –independent functions of LNK. Taken together, the data presented in this thesis describes a novel role for cytokine signaling in HSC genome stability, and deepens our understanding of how LNK influences self-renewal and genome stability. Hopefully, these findings can contribute to the foundation of work that may result in the development of novel therapeutic approaches to treat bone marrow failure and genome instability in HSCs

Fertility education for adolescent cancer patients: Gaps in current clinical practice in Europe

Objective: As adolescent cancer patients may suffer from infertility following treatment, fertility counselling is essential. Our aim was to explore the current situation in four European countries in terms of (I) education about the risk for infertility, (II) counselling on fertility preservation, (III) patients' knowledge on fertility, (IV) sufficiency of information and (V) uptake of cryopreservation. Methods: In total, 113 patients (13–20 years) at 11 study centres completed a self-report questionnaire three and six months after cancer diagnosis. Multivariate logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (CI). Results: As many as 80.2% of participants reported having received education about the risk for infertility prior to treatment, 73.2% recalled counselling on fertility preservation. Only 52.3% stated they felt sufficiently informed to make a decision. Inability to recall counselling on fertility preservation (OR = 0.03, CI: 0.00–0.47) and female gender (OR = 0.11, CI: 0.03–0.48) was associated with lower use of cryopreservation, whereas older age was associated with higher use. Conclusion: Fertility counselling was available to a relatively high proportion of patients, and it did influence the utilisation of cryopreservation. However, many patients did not feel sufficiently informed. Further improvement is needed to enable adolescent cancer patients to make an informed decision on fertility preservation

The Role of Lnk Adaptor Protein in Hematopoietic Stem Cell Genome Stability and Self-Renewal

Hematopoietic stem cells (HSCs) are rare cells that reside in bone marrow. HSCs function to give rise to all blood cells through proliferation and differentiation, but also to HSCs in a tightly regulated process known as self-renewal. It is for these abilities that stem cells stand out from progenitors and other short-lived cells and which allows them to last a lifetime. Self-renewal remains mechanistically enigmatic but central to the biology and long lifespan of HSCs. Because HSCs are so long-lived they face numerous genomic insults and therefore mechanisms of genome stability are also central to HSC function throughout life. This thesis examines the role of an adaptor protein known as LNK (SH2B3), which negatively regulates a central cytokine signaling axis in HSCs, in regulating HSC self-renewal and genome stability. HSCs in Lnk-/- mice are expanded, and endowed with enhanced proliferative and self-renewal capabilities. Given this superiority, this thesis first investigates the impact of LNK deficiency in context of a bone marrow failure syndrome, Fanconi Anemia (FA), where HSCs accumulate fatal levels of genomic insults and cannot function. Superimposed on the deletion of a central gene in FA, FANCD2, Lnk deficiency rescues HSC function through restoring genome stability at sites of stress encountered during DNA duplication. Second, using a model that is capable of tracking HSC divisions in vivo, this thesis investigates the in vivo self-renewal dynamics of Lnk deficient HSCs. On a population level, HSCs exist along a continuum of states between fully functional HSCs and progenitors, and LNK deficiency tips the balance towards HSCs. This is a cell-intrinsic process, and may be regulated by gene expression-dependent and –independent functions of LNK. Taken together, the data presented in this thesis describes a novel role for cytokine signaling in HSC genome stability, and deepens our understanding of how LNK influences self-renewal and genome stability. Hopefully, these findings can contribute to the foundation of work that may result in the development of novel therapeutic approaches to treat bone marrow failure and genome instability in HSCs

Integrated Bioethanol Fermentation/Anaerobic Digestion for Valorization of Sugar Beet Pulp

Large amounts of waste biomass are generated in sugar factories from the processing of sugar beets. After diffusion with hot water to draw the sugar from the beet pieces, a wet material remains called pulp. In this study, waste sugar beet pulp biomass was enzymatically depolymerized, and the obtained hydrolyzates were subjected to fermentation processes. Bioethanol, biomethane, and biohydrogen were produced directly from the substrate or in combined mode. Stillage, a distillery by-product, was used as a feedstock for anaerobic digestion. During biosynthesis of ethanol, most of the carbohydrates released from the sugar beet pulp were utilized by a co-culture of Saccharomyces cerevisiae Ethanol Red, and Scheffersomyces stipitis LOCK0047 giving 12.6 g/L of ethanol. Stillage containing unfermented sugars (mainly arabinose, galactose and raffinose) was found to be a good substrate for methane production (444 dm3 CH4/kg volatile solids (VS)). Better results were achieved with this medium than with enzymatic saccharified biomass. Thermal pre-treatment and adjusting the pH of the inoculum resulted in higher hydrogen production. The largest (p < 0.05) hydrogen yield (252 dm3 H2/kg VS) was achieved with sugar beet stillage (SBS). In contrast, without pre-treatment the same medium yielded 35 dm3 H2/kg VS. However, dark fermentation of biohydrogen was more efficient when sugar beet pulp hydrolyzate was used

Nitric Acid Pretreatment of Jerusalem Artichoke Stalks for Enzymatic Saccharification and Bioethanol Production

This paper evaluated the effectiveness of nitric acid pretreatment on the hydrolysis and subsequent fermentation of Jerusalem artichoke stalks (JAS). Jerusalem artichoke is considered a potential candidate for producing bioethanol due to its low soil and climate requirements, and high biomass yield. However, its stalks have a complexed lignocellulosic structure, so appropriate pretreatment is necessary prior to enzymatic hydrolysis, to enhance the amount of sugar that can be obtained. Nitric acid is a promising catalyst for the pretreatment of lignocellulosic biomass due to the high efficiency with which it removes hemicelluloses. Nitric acid was found to be the most effective catalyst of JAS biomass. A higher concentration of glucose and ethanol was achieved after hydrolysis and fermentation of 5% (w/v) HNO3-pretreated JAS, leading to 38.5 g/L of glucose after saccharification, which corresponds to 89% of theoretical enzymatic hydrolysis yield, and 9.5 g/L of ethanol. However, after fermentation there was still a significant amount of glucose in the medium. In comparison to more commonly used acids (H2SO4 and HCl) and alkalis (NaOH and KOH), glucose yield (% of theoretical yield) was approximately 47–74% higher with HNO3. The fermentation of 5% nitric-acid pretreated hydrolysates with the absence of solid residues, led to an increase in ethanol yield by almost 30%, reaching 77–82% of theoretical yield

The Ethanol Production from Sugar Beet Pulp Supported by Microbial Hydrolysis with <i>Trichoderma viride</i>

Despite the significant progress in the research, the problem of finding an efficient method for producing bioethanol from renewable lignocellulosic waste materials remains unresolved. Our investigation aimed to assess the efficacy of ethanol production from sugar beet pulp (SBP) utilising various approaches, including pretreatment variations, enzymatic processes, and microbial hydrolysis. Our research involved using the post-cultivation concentrate of T. viride LOCK 0588 grown in the SBP-based medium as a source of enzymes. The SBP hydrolysis process was carried out for 48 h at 50 °C. The quantity of sugar released, up to 61 g dm−3, through the utilisation of this extract proved to be on par with the outcomes achieved by the application of the commercial Cellic Ctec2 preparation. The final yields of the ethanol production with the use of the coculture of S. cerevisiae (Ethanol Red) and Scheffersomyces stipitis LOCK 0047 strain were in the range 5.1 ± 0.11 kg 100 kg−1 ÷ 5.38 ± 0.11 kg 100 kg−1. These results provide a solid basis for improving larger-scale industrial procedures that involve converting SBP into bioethanol using a cost-efficient approach of microbial hydrolysis with T. viride and a blend of pentose and hexose fermenting yeast

Udział tkanki tłuszczowej w powstawaniu zaburzeń metabolicznych

Zarówno nadmiarowi, jak i niedoborowi tkanki tłuszczowej w organizmie przypisuje się rolę w etiologii wielu zaburzeń metabolicznych, niemniej częściej spotykaną nieprawidłowością w tym zakresie jest otyłość. Nadmierne otłuszczenie śródsierdzia może skutkować rozwojem choroby wieńcowej, stanami zapalnymi wątroby czy przebudową ścian serca. Stłuszczenia trzustki i wątroby sprzyjają ich dysfunkcjom, rozwojowi cukrzycy typu 2, miejscowym stanom zapalnym oraz zwiększają ryzyko rozwoju nowotworów złośliwych w obrębie tych gruczołów. Klinicznie istotnym zagadnieniem jest także metaboliczna otyłość u osób z prawidłową masą ciała, u której podstawy leży znaczne zwiększenie objętości wisceralnej tkanki tłuszczowej przy zachowaniu prawidłowej wartości wskaźnika masy ciała. Tym samym pacjenci z tym schorzeniem znajdują się w grupie ryzyka chorób układu sercowo-naczyniowego. Cele niniejszego opracowania obejmują przegląd i analizę danych literaturowych na temat roli tkanki tłuszczowej w powstawaniu zaburzeń metabolicznych

Two-Stage Pretreatment to Improve Saccharification of Oat Straw and Jerusalem Artichoke Biomass

Pretreatment is a necessary step when lignocellulosic biomass is to be converted to simple sugars; however single-stage pretreatment is often insufficient to guarantee full availability of polymeric sugars from raw material to hydrolyzing enzymes. In this work, the two-stage pretreatment with use of acid (H2SO4, HNO3) and alkali (NaOH) was applied in order to increase the susceptibility of Jerusalem artichoke stalks (JAS) and oat straw (OS) biomass on the enzymatic attack. The effect of the concentration of reagents (2% and 5% w/v) and the order of acid and alkali sequence on the composition of remaining solids and the efficiency of enzymatic hydrolysis was evaluated. It was found that after combined pretreatment process, due to the removal of hemicellulose and lignin, the content of cellulose in pretreated biomass increased to a large extent, reaching almost 90% d.m. and 95% d.m., in the case of JAS and OS, respectively. The enzymatic hydrolysis of solids remaining after pretreatment resulted in the formation of up to 45 g/L of glucose, for both JAS and OS. The highest glucose yield was achieved after pretreatment with 5% nitric acid followed by NaOH, and 90.6% and 97.6% of efficiency were obtained, respectively for JAS and OS

Conversion of Potato Industry Waste into Fodder Yeast Biomass

In this study, we evaluate potato pulp waste as a potential raw material for obtaining yeast biomass. A portion of the carbohydrates in the potato pulp waste can thereby be converted into more valuable protein. The potato pulp waste was analyzed in terms of protein and ash content, dry mass, simple sugars, and starch content. Two kinds of hydrolysis were performed (thermo-acidic and enzymatic) to produce media for cultivating Candida guilliermondii and Pichia stipitis. The hydrolysates and post-cultivation leachates were analyzed by High Performance Liquid Chromatography (HPLC). The highest biomass yield after 48 h (39.3%) was noted for Candida guilliermondii yeast grown on enzymatic hydrolysate-based medium. Our results prove that potato waste pulp is a promising raw material for the production of yeast single-cell protein (SCP)