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The SOX genes encode a group of transcription factors showing diverse expression patterns during de- velopment and acting as key regulators of diverse cellular processes. SOX transcription factors are in- volved in multiple events from the maintaining of stem cells pluripotency and cell fate decision to driving terminal differentiation of cells into specialized cell types. During adulthood SOX transcription factors control various physiological processes. Mutations in SOX genes have been associated with severe clin- ical disorders, while deregulation of their expressions cause a broad range of pathological condition. Ac- cumulating evidence suggests that SOX proteins act as oncogenes and recent evidence points toward pro-proliferative, pro-survival and/or anti-differentiation roles of the SOX proteins. The results of long-term research of the structure, regulation of expression and the function of selected SOX genes will be presented. It will include data obtained by studying the roles of SOX genes in in vitro neural differentiation of pluripotent embryonal carcinoma cells, as well as interaction of SOX transcrip- tion factors with signalling pathways active during neurogenesis and oncogenesis. Special focus will be made on ongoing research focused on the roles of SOX genes in promotion of malignant phenotype of cancer cells and maintaining of cancer stem cells. The interplay of SOX transcription factors and mi- croRNAs in the brain under physiological and pathological conditions, along with crosstalk between SOX genes and long non-coding RNAs in glioblastoma will be discussed. The role of SOX transcription factors in ageing and age-related diseases will be outlined.

More than 50 years have passed since Nobel laureate Cristian de Duve described for the first time the presence of tiny subcellular compartments filled with hydrolytic enzymes: the lysosome. For a long time, lysosomes were deemed simple waste bags exerting a plethora of hydrolytic activities involved in the recycling of biopolymers, and lysosomal genes were considered to just be simple housekeeping genes, transcribed in a constitutive fashion. However, lysosomes are emerging as multifunctional signalling hubs involved in multiple aspects of cell biology, both under homeostatic and pathological conditions. Lysosomes are involved in the regulation of cell metabolism through the mTOR/TFEB axis. They are also key players in the regulation and onset of the immune response. Furthermore, it is becoming clear that lysosomal hydrolases can regulate several biological processes outside of the lysosome. They are also implicated in a complex communication network among subcellular compartments that involves intimate organelle‐to‐organelle contacts. Furthermore, lysosomal dysfunction is nowadays accepted as the causative event behind several human pathologies: low frequency inherited diseases, cancer, or neurodegenerative, metabolic, inflammatory, and autoimmune diseases. Recent advances in our knowledge of the complex biology of lysosomes have established them as promising therapeutic targets for the treatment of different pathologies. Although recent discoveries have started to highlight that lysosomes are controlled by a complex web of regulatory networks, which in some cases seem to be cell‐ and stimuli‐dependent, to harness the full potential of lysosomes as therapeutic targets, we need a deeper understanding of the little‐known signalling pathways regulating this subcellular compartment and its functions. Keywords: lysosomes, mTORC1, signalling pathways, STATs, TFEB, transcriptional regulation

More than 50 years have passed since Nobel laureate Cristian de Duve described for the first time the presence of tiny subcellular compartments filled with hydrolytic enzymes: the lysosome. For a long time, lysosomes were deemed simple waste bags exerting a plethora of hydrolytic activities involved in the recycling of biopolymers, and lysosomal genes were considered to just be simple housekeeping genes, transcribed in a constitutive fashion. However, lysosomes are emerging as multifunctional signalling hubs involved in multiple aspects of cell biology, both under homeostatic and pathological conditions. Lysosomes are involved in the regulation of cell metabolism through the mTOR/TFEB axis. They are also key players in the regulation and onset of the immune response. Furthermore, it is becoming clear that lysosomal hydrolases can regulate several biological processes outside of the lysosome. They are also implicated in a complex communication network among subcellular compartments that involves intimate organelle‐to‐organelle contacts. Furthermore, lysosomal dysfunction is nowadays accepted as the causative event behind several human pathologies: low frequency inherited diseases, cancer, or neurodegenerative, metabolic, inflammatory, and autoimmune diseases. Recent advances in our knowledge of the complex biology of lysosomes have established them as promising therapeutic targets for the treatment of different pathologies. Although recent discoveries have started to highlight that lysosomes are controlled by a complex web of regulatory networks, which in some cases seem to be cell‐ and stimuli‐dependent, to harness the full potential of lysosomes as therapeutic targets, we need a deeper understanding of the little‐known signalling pathways regulating this subcellular compartment and its functions. Keywords: lysosomes, mTORC1, signalling pathways, STATs, TFEB, transcriptional regulation

More than 50 years have passed since Nobel laureate Cristian de Duve described for the first time the presence of tiny subcellular compartments filled with hydrolytic enzymes: the lysosome. For a long time, lysosomes were deemed simple waste bags exerting a plethora of hydrolytic activities involved in the recycling of biopolymers, and lysosomal genes were considered to just be simple housekeeping genes, transcribed in a constitutive fashion. However, lysosomes are emerging as multifunctional signalling hubs involved in multiple aspects of cell biology, both under homeostatic and pathological conditions. Lysosomes are involved in the regulation of cell metabolism through the mTOR/TFEB axis. They are also key players in the regulation and onset of the immune response. Furthermore, it is becoming clear that lysosomal hydrolases can regulate several biological processes outside of the lysosome. They are also implicated in a complex communication network among subcellular compartments that involves intimate organelle‐to‐organelle contacts. Furthermore, lysosomal dysfunction is nowadays accepted as the causative event behind several human pathologies: low frequency inherited diseases, cancer, or neurodegenerative, metabolic, inflammatory, and autoimmune diseases. Recent advances in our knowledge of the complex biology of lysosomes have established them as promising therapeutic targets for the treatment of different pathologies. Although recent discoveries have started to highlight that lysosomes are controlled by a complex web of regulatory networks, which in some cases seem to be cell‐ and stimuli‐dependent, to harness the full potential of lysosomes as therapeutic targets, we need a deeper understanding of the little‐known signalling pathways regulating this subcellular compartment and its functions. Keywords: lysosomes, mTORC1, signalling pathways, STATs, TFEB, transcriptional regulation

More than 50 years have passed since Nobel laureate Cristian de Duve described for the first time the presence of tiny subcellular compartments filled with hydrolytic enzymes: the lysosome. For a long time, lysosomes were deemed simple waste bags exerting a plethora of hydrolytic activities involved in the recycling of biopolymers, and lysosomal genes were considered to just be simple housekeeping genes, transcribed in a constitutive fashion. However, lysosomes are emerging as multifunctional signalling hubs involved in multiple aspects of cell biology, both under homeostatic and pathological conditions. Lysosomes are involved in the regulation of cell metabolism through the mTOR/TFEB axis. They are also key players in the regulation and onset of the immune response. Furthermore, it is becoming clear that lysosomal hydrolases can regulate several biological processes outside of the lysosome. They are also implicated in a complex communication network among subcellular compartments that involves intimate organelle‐to‐organelle contacts. Furthermore, lysosomal dysfunction is nowadays accepted as the causative event behind several human pathologies: low frequency inherited diseases, cancer, or neurodegenerative, metabolic, inflammatory, and autoimmune diseases. Recent advances in our knowledge of the complex biology of lysosomes have established them as promising therapeutic targets for the treatment of different pathologies. Although recent discoveries have started to highlight that lysosomes are controlled by a complex web of regulatory networks, which in some cases seem to be cell‐ and stimuli‐dependent, to harness the full potential of lysosomes as therapeutic targets, we need a deeper understanding of the little‐known signalling pathways regulating this subcellular compartment and its functions. Keywords: lysosomes, mTORC1, signalling pathways, STATs, TFEB, transcriptional regulation

More than 50 years have passed since Nobel laureate Cristian de Duve described for the first time the presence of tiny subcellular compartments filled with hydrolytic enzymes: the lysosome. For a long time, lysosomes were deemed simple waste bags exerting a plethora of hydrolytic activities involved in the recycling of biopolymers, and lysosomal genes were considered to just be simple housekeeping genes, transcribed in a constitutive fashion. However, lysosomes are emerging as multifunctional signalling hubs involved in multiple aspects of cell biology, both under homeostatic and pathological conditions. Lysosomes are involved in the regulation of cell metabolism through the mTOR/TFEB axis. They are also key players in the regulation and onset of the immune response. Furthermore, it is becoming clear that lysosomal hydrolases can regulate several biological processes outside of the lysosome. They are also implicated in a complex communication network among subcellular compartments that involves intimate organelle-to-organelle contacts. Furthermore, lysosomal dysfunction is nowadays accepted as the causative event behind several human pathologies: low frequency inherited diseases, cancer, or neurodegenerative, metabolic, inflammatory, and autoimmune diseases. Recent advances in our knowledge of the complex biology of lysosomes have established them as promising therapeutic targets for the treatment of different pathologies. Although recent discoveries have started to highlight that lysosomes are controlled by a complex web of regulatory networks, which in some cases seem to be cell- and stimuli-dependent, to harness the full potential of lysosomes as therapeutic targets, we need a deeper understanding of the little-known signalling pathways regulating this subcellular compartment and its functions.

Cool season grain legumes occupy an important place among the agricultural crops and essentially provide multiple benefits including food supply, nutrition security, soil fertility improvement and revenue for farmers all over the world. However, owing to climate change, the average temperature is steadily rising, which negatively affects crop performance and limits their yield. Terminal heat stress that mainly occurred during grain development phases severely harms grain quality and weight in legumes adapted to the cool season, such as lentils, faba beans, chickpeas, field peas, etc. Although, traditional breeding approaches with advanced screening procedures have been employed to identify heat tolerant legume cultivars. Unfortunately, traditional breeding pipelines alone are no longer enough to meet global demands. Genomics-assisted interventions including new-generation sequencing technologies and genotyping platforms have facilitated the development of high-resolution molecular maps, QTL/gene discovery and marker-assisted introgression, thereby improving the efficiency in legumes breeding to develop stress-resilient varieties. Based on the current scenario, we attempted to review the intervention of genomics to decipher different components of tolerance to heat stress and future possibilities of using newly developed genomics-based interventions in cool season adapted grain legumes.

Skeletal muscle differentiation is triggered by a unique family of myogenic basic helix-loop-helix transcription factors, including MyoD, MRF-4, Myf-5, and Myogenin. These transcription factors bind promoters and distant regulatory regions, including E-box elements, of genes whose expression is restricted to muscle cells. Other E-box binding zinc finger proteins target the same DNA response elements, however, their function in muscle development and regeneration is still unknown. Here, we show that the transcription factor zinc finger E-box-binding homeobox 2 (Zeb2, Sip-1, Zfhx1b) is present in skeletal muscle tissues. We investigate the role of Zeb2 in skeletal muscle differentiation using genetic tools and transgenic mouse embryonic stem cells, together with single-cell RNA-sequencing and in vivo muscle engraftment capability. We show that Zeb2 over-expression has a positive impact on skeletal muscle differentiation in pluripotent stem cells and adult myogenic progenitors. We therefore propose that Zeb2 is a novel myogenic regulator and a possible target for improving skeletal muscle regeneration. The non-neural roles of Zeb2 are poorly understood.

Ultraviolet B radiation (UVBR) induces the formation of photolesions in epidermal keratinocytes, potentially affecting cellular function and contributing towards malignant transformation. Insulin-like growth factor-I (IGF-I) contributes to protection of keratinocytes against UVBR-induced damage. Studies have shown that exogenous IGF-I or dermal fibroblast conditioned media pre-UVBR contributes to protection in primary keratinocytes by preventing apoptosis, modulating cell cycle progression and affecting photolesion removal through its damage preventative effects, however, the efficacy of IGF-I post-UVBR has not been sufficiently addressed. Using 2D and 3D photobiology skin models, the ability of IGF-I post-UVBR to rescue primary keratinocytes from photodamage was investigated. The photoprotective effect of IGF-I, both pre- and post-UVBR on cellular functions of irradiated keratinocytes was examined. IGF-I application, either pre- or post-UVBR, was found to alter keratinocyte survival, apoptosis, cell cycle progression and damage removal responses to UVBR. In particular, IGF-I application post-UVBR was found to promote increased keratinocyte survival, prevent apoptosis, shift cell cycle progression and reduce photodamage in all the skin models. Furthermore, marked differences were observed in activation of signalling cascades upon IGF-I treatment post-UVBR. Taken together, these findings indicate that in addition to a previously known photodamage preventative effect, IGF-I treatment post-UVBR has a photoreparative role suggesting it may hold potential in the development of effective remedial strategies against sunburns and photodamage.

Introduction: Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with ovulatory dysfunction, hyperandrogenism, obesity, and insulin resistance, that leads to subfertility. Sam68 is an RNA-binding protein with signaling functions that is ubiquitously expressed, including gonads. Sam68 is recruited to leptin signaling, mediating different leptin actions. Objective: We aimed to investigate the role of Sam68 in leptin signaling, mediating the effect on aromatase expression in granulosa cells and the posible implication of Sam68 in the leptin resistance in PCOS. Materials and methods: Granulosa cells were from healthy donors (n = 25) and women with PCOS (n = 25), within the age range of 20 to 40 years, from Valencian Infertility Institute (IVI), Seville, Spain. Sam68 expression was inhibited by siRNA method and overexpressed by expression vector. Expression level was analysed by qPCR and immunoblot. Statistical significance was assessed by ANOVA followed by different post- hoc tests. A P value of <0.05 was considered statistically significant. Results: We have found that leptin stimulation increases phosphorylation and expression level of Sam68 and aromatase in granulosa cells from normal donors. Downregulation of Sam68 expression resulted in a lower activation of MAPK and PI3K pathways in response to leptin, whereas overexpression of Sam68 increased leptin stimulation of signaling, enhancing aromatase expression. Granulosa cells from women with PCOS presented lower expression of Sam68 and were resistant to the leptin effect on aromatase expression. Conclusions: These results suggest the participation of Sam68 in leptin receptor signaling, mediating the leptin effect on aromatase expression in granulosa cells, and point to a new target in leptin resistance in PCOS.

Introduction: Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with ovulatory dysfunction, hyperandrogenism, obesity, and insulin resistance, that leads to subfertility. Sam68 is an RNA-binding protein with signaling functions that is ubiquitously expressed, including gonads. Sam68 is recruited to leptin signaling, mediating different leptin actions. Objective: We aimed to investigate the role of Sam68 in leptin signaling, mediating the effect on aromatase expression in granulosa cells and the posible implication of Sam68 in the leptin resistance in PCOS. Materials and methods: Granulosa cells were from healthy donors (n = 25) and women with PCOS (n = 25), within the age range of 20 to 40 years, from Valencian Infertility Institute (IVI), Seville, Spain. Sam68 expression was inhibited by siRNA method and overexpressed by expression vector. Expression level was analysed by qPCR and immunoblot. Statistical significance was assessed by ANOVA followed by different post- hoc tests. A P value of <0.05 was considered statistically significant. Results: We have found that leptin stimulation increases phosphorylation and expression level of Sam68 and aromatase in granulosa cells from normal donors. Downregulation of Sam68 expression resulted in a lower activation of MAPK and PI3K pathways in response to leptin, whereas overexpression of Sam68 increased leptin stimulation of signaling, enhancing aromatase expression. Granulosa cells from women with PCOS presented lower expression of Sam68 and were resistant to the leptin effect on aromatase expression. Conclusions: These results suggest the participation of Sam68 in leptin receptor signaling, mediating the leptin effect on aromatase expression in granulosa cells, and point to a new target in leptin resistance in PCOS.

With an increase in the number of annual craniomaxillofacial orthopaedic procedures being performed, and an understanding of the drawbacks of autologous bone grafting, the bone graft substitute market is burgeoning. Several bone graft alternatives, including, FDA-approved osteogenic molecule, Bone Morphogenetic Protein-2 have shown promise in promoting large volumes of de novo bone formation, however are ladened with several adverse effects, hampering their clinical application. Perivascular Stem Cells (PSC) are a prospectively purified mesenchymal stem cell population isolated from adipose tissue by fluorescent-activated cell sorting (FACS), and have previously been shown to induce robust bone formation in small and large animal models. Herein, by utilizing species-specific MHC immunohistochemistry, we demonstrated that PSC elicit their osteogenic effect primarily via a paracrine-mediate mechanism. Subsequently, after resolving that PSC mediate host mesenchymal stem cells, via the secretion of pro-osteogenic molecules, RNA sequencing was performed to compare PSC with their unpurified predecessor, stromal vascular fraction (SVF). It was observed that Wnt-related secretory molecules, WISP-1 and Wnt16 were upregulated in PSC by 72- and 21- fold, respectively, when compared to SVF. Gain-of-function assays for these two secretory molecules revealed a significant increase in osteogenic markers, whereby a significant decrease in osteogenic markers was observed when WISP-1 or Wnt16 were knocked-down in PSC. Wnt16 was observed to indeed be a mixed ligand and demonstrate activation of both the canonical and noncanonical Wnt pathways. In aggregate, these data demonstrate that PSC promote osteogenesis via a primarily paracrine-mediate secretion of pro-osteogenic molecules, of which WISP-1 and Wnt16 are highly upregulated and play a functional and necessary role in PSC osteogenesis.

With an increase in the number of annual craniomaxillofacial orthopaedic procedures being performed, and an understanding of the drawbacks of autologous bone grafting, the bone graft substitute market is burgeoning. Several bone graft alternatives, including, FDA-approved osteogenic molecule, Bone Morphogenetic Protein-2 have shown promise in promoting large volumes of de novo bone formation, however are ladened with several adverse effects, hampering their clinical application. Perivascular Stem Cells (PSC) are a prospectively purified mesenchymal stem cell population isolated from adipose tissue by fluorescent-activated cell sorting (FACS), and have previously been shown to induce robust bone formation in small and large animal models. Herein, by utilizing species-specific MHC immunohistochemistry, we demonstrated that PSC elicit their osteogenic effect primarily via a paracrine-mediate mechanism. Subsequently, after resolving that PSC mediate host mesenchymal stem cells, via the secretion of pro-osteogenic molecules, RNA sequencing was performed to compare PSC with their unpurified predecessor, stromal vascular fraction (SVF). It was observed that Wnt-related secretory molecules, WISP-1 and Wnt16 were upregulated in PSC by 72- and 21- fold, respectively, when compared to SVF. Gain-of-function assays for these two secretory molecules revealed a significant increase in osteogenic markers, whereby a significant decrease in osteogenic markers was observed when WISP-1 or Wnt16 were knocked-down in PSC. Wnt16 was observed to indeed be a mixed ligand and demonstrate activation of both the canonical and noncanonical Wnt pathways. In aggregate, these data demonstrate that PSC promote osteogenesis via a primarily paracrine-mediate secretion of pro-osteogenic molecules, of which WISP-1 and Wnt16 are highly upregulated and play a functional and necessary role in PSC osteogenesis.

Trichoderma species are widely known for their antagonistic properties, but plant growth promotion and abiotic stress tolerance have also been reported. Mechanisms of abiotic stress tolerance, such as drought in plants in interaction with Trichoderma spp., remain unclear. In this work, the results about the influence of Trichoderma brevicompactum on the physiological parameters and abscisic acid (ABA) content in leaves and roots of tomato, as well as the Trichodermamodulated plant response to drought are presented. Both in optimally watered plants and droughted plants treated with Trichoderma, the relative water content (RWC) was 17% higher than in untreated plants. Drought lowered RWC by 25% in both Trichoderma-untreated and -treated plants. Under drought conditions, the better water status of plants treated with Trichoderma is connected with lower stomatal conductance and closure of stomata. The lower increase of root ABA content in Trichoderma-treated plants that we observed could be an adaptive advantage in sense of smaller inhibition of plant growth induced by drought. Trichoderma modulation of the salicylic acid (SA) marker genes response to drought was observed in leaves. Our results suggest that signalling pathways of jasmonic acid (JA), SA and ABA are involved in response to both drought and Trichoderma. The mutual effect of the tested treatments leads to the modification of gene expression in comparison to the reaction to a single stress. The upregulation of SA marker genes in leaves and JA marker genes in the roots 2 weeks after the interaction with T. brevicompactum indicates that it could be promising biocontrol agent.

Trichoderma species are widely known for their antagonistic properties, but plant growth promotion and abiotic stress tolerance have also been reported. Mechanisms of abiotic stress tolerance, such as drought in plants in interaction with Trichoderma spp., remain unclear. In this work, the results about the influence of Trichoderma brevicompactum on the physiological parameters and abscisic acid (ABA) content in leaves and roots of tomato, as well as the Trichodermamodulated plant response to drought are presented. Both in optimally watered plants and droughted plants treated with Trichoderma, the relative water content (RWC) was 17% higher than in untreated plants. Drought lowered RWC by 25% in both Trichoderma-untreated and -treated plants. Under drought conditions, the better water status of plants treated with Trichoderma is connected with lower stomatal conductance and closure of stomata. The lower increase of root ABA content in Trichoderma-treated plants that we observed could be an adaptive advantage in sense of smaller inhibition of plant growth induced by drought. Trichoderma modulation of the salicylic acid (SA) marker genes response to drought was observed in leaves. Our results suggest that signalling pathways of jasmonic acid (JA), SA and ABA are involved in response to both drought and Trichoderma. The mutual effect of the tested treatments leads to the modification of gene expression in comparison to the reaction to a single stress. The upregulation of SA marker genes in leaves and JA marker genes in the roots 2 weeks after the interaction with T. brevicompactum indicates that it could be promising biocontrol agent.

Oxidative stress plays a main role in the pathogenesis of the diabetic nephropathy. The present study investigated the effect of (−)-epicatechin (EC) and the colonic-derived flavonoid metabolites 2,3-dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid (DHPAA), and 3-hydroxyphenylpropionic acid on the redox status in high-glucose-exposed renal proximal tubular NRK-52E cells. EC and DHPAA (10 µM) alleviated the redox imbalance induced in high-glucose-challenged cells, as both compounds reverted to control levels reactive oxygen species (ROS) values. EC and DHPAA pre-treatment prevented the decrease of antioxidant defences and silent information regulator protein-1 (SIRT-1), and the increase of phosphorylated mitogen-activated-protein-kinases and NADPH-oxidase-4 (NOX-4) values under high-glucose-conditions. The presence of selective NOX-4 and SIRT-1 inhibitors in EC- and DHPAA-pre-treated cells showed the involvement of both proteins in EC- and DHPAA-mediated protection. These findings suggest that EC and DHPAA protected NRK-52E cells against a high-glucose-challenge by improving the cellular redox status through multiple signalling pathways, playing NOX-4/SIRT-1 a relevant role.

Hydroxytyrosol (HT) and its derivatives represent the minor components of Virgin Olive Oil (VOO) that are of great interest for their pharmacological properties and among the most widely researched natural antioxidant compounds. In this review, the occurrence and metabolic fate of HT and its precursors are presented prior to discussing its beneficial effects on health. Bioavailability studies show that the metabolites detected in plasma depend on the model used (animal or human), the HT source (simple molecule or complex precursors) and the dose administered. However, in all cases HT sulphate appears to be the most ubiquitous metabolite in biofluids and it seems probable that it is responsible to a great extent for HT biological effects. Epidemiological evidence of HT and its derivatives against such lifestyle-associated pathologies as cancer, cardiovascular and neurodegenerative diseases is reviewed together with the newest perspectives on the mechanisms of action based on in-vitro and animal studies. According to the reviewed data, HT and its precursors could have the potential clinical use in cardiovascular diseases; more epidemiological data is needed to demonstrate their neurodegenerative diseases and cancer prevention.

Oxidative stress plays a main role in the pathogenesis of the diabetic nephropathy. The present study investigated the effect of (−)-epicatechin (EC) and the colonic-derived flavonoid metabolites 2,3-dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid (DHPAA), and 3-hydroxyphenylpropionic acid on the redox status in high-glucose-exposed renal proximal tubular NRK-52E cells. EC and DHPAA (10 µM) alleviated the redox imbalance induced in high-glucose-challenged cells, as both compounds reverted to control levels reactive oxygen species (ROS) values. EC and DHPAA pre-treatment prevented the decrease of antioxidant defences and silent information regulator protein-1 (SIRT-1), and the increase of phosphorylated mitogen-activated-protein-kinases and NADPH-oxidase-4 (NOX-4) values under high-glucose-conditions. The presence of selective NOX-4 and SIRT-1 inhibitors in EC- and DHPAA-pre-treated cells showed the involvement of both proteins in EC- and DHPAA-mediated protection. These findings suggest that EC and DHPAA protected NRK-52E cells against a high-glucose-challenge by improving the cellular redox status through multiple signalling pathways, playing NOX-4/SIRT-1 a relevant role.

Trichoderma species are widely known for their antagonistic properties, but plant growth promotion and abiotic stress tolerance have also been reported. Mechanisms of abiotic stress tolerance, such as drought in plants in interaction with Trichoderma spp., remain unclear. In this work, the results about the influence of Trichoderma brevicompactum on the physiological parameters and abscisic acid (ABA) content in leaves and roots of tomato, as well as the Trichodermamodulated plant response to drought are presented. Both in optimally watered plants and droughted plants treated with Trichoderma, the relative water content (RWC) was 17% higher than in untreated plants. Drought lowered RWC by 25% in both Trichoderma-untreated and -treated plants. Under drought conditions, the better water status of plants treated with Trichoderma is connected with lower stomatal conductance and closure of stomata. The lower increase of root ABA content in Trichoderma-treated plants that we observed could be an adaptive advantage in sense of smaller inhibition of plant growth induced by drought. Trichoderma modulation of the salicylic acid (SA) marker genes response to drought was observed in leaves. Our results suggest that signalling pathways of jasmonic acid (JA), SA and ABA are involved in response to both drought and Trichoderma. The mutual effect of the tested treatments leads to the modification of gene expression in comparison to the reaction to a single stress. The upregulation of SA marker genes in leaves and JA marker genes in the roots 2 weeks after the interaction with T. brevicompactum indicates that it could be promising biocontrol agent.

Deregulated activity of the c-Myc protooncogene is a frequent molecular event underlying mouse and human hepatocarcinogenesis. Nonetheless, the mechanisms sustaining c-Myc oncogenic activity in liver cancer remain scarcely delineated. Recently, we showed that the mammalian target of rapamycin complex 1 (mTORC1) cascade is induced and necessary for c-Myc dependent liver tumor development and progression. Since the heat shock factor 1 (HSF1) transcription factor is a major positive regulator of mTORC1 in the cell, we investigated the functional interaction between HSF1 and c-Myc using in vitro and in vivo approaches. We found that ablation of HSF1 restrains the growth of c-Myc-derived mouse hepatocellular carcinoma (HCC) cell lines, where it induces downregulation of c-Myc levels. Conversely, silencing of c-Myc gene in human and mouse HCC cells led to downregulation of HSF1 expression. Most importantly, overexpression of a dominant negative form of HSF1 (HSF1dn) in the mouse liver via hydrodynamic gene delivery resulted in the complete inhibition of mouse hepatocarcinogenesis driven by overexpression of c-Myc. Altogether, the present results indicate that a functional HSF1 is necessary for c-Myc-driven hepatocarcinogenesis. Consequently, targeting HSF1 might represent a novel and effective therapeutic strategy for the treatment of HCC subsets with activated c-Myc signaling.

The current study explored the in vitro anticancer properties of Mesua ferrea stem bark (SB) extract towards human colon carcinoma HCT116 cells. SB was successively extracted with different solvents using soxhlet apparatus. MTT assay was employed to test toxicity against different cancer and normal cell lines. Active extract (n-Hexane) was fractionated by column chromatography (CC) to get the most active fraction (F-3). Series of in vitro assays were employed to characterize cytotoxic nature of F-3. Antioxidant properties of F-3 were assessed using DPPH, ABTS and FRAP assays followed by GC-MS analysis. Intracellular ROS levels were measured by DCFH-DA fluorescent assay. Finally, cell signalling pathways and their downstream proteins targeted by F-3 were studied using 10-cancer pathway and human apoptosis protein profilers and in silico docking studies. n-Hexane extract and its fraction (F-3) showed potent anti-proliferative effect against HCT 116. Programmed cell death (PCD) studies showed that F-3 modulated the expression of multiple proteins in HCT 116. F-3 showed weak antioxidant activity in all the models, while significant increase in ROS was observed in HCT 116. GC-MS analysis revealed that F-3 was majorly comprised of terpenes. Data of pathway profiler and in silico studies revealed that F-3 downregulated the expression of NF-kB and HIF-1 alpha pathways. Overall these results demonstrate that anticancer effects of M. ferrea stem bark towards human colon carcinoma are mainly due to its terpenes contents.

Deregulated activity of the c-Myc protooncogene is a frequent molecular event underlying mouse and human hepatocarcinogenesis. Nonetheless, the mechanisms sustaining c-Myc oncogenic activity in liver cancer remain scarcely delineated. Recently, we showed that the mammalian target of rapamycin complex 1 (mTORC1) cascade is induced and necessary for c-Myc dependent liver tumor development and progression. Since the heat shock factor 1 (HSF1) transcription factor is a major positive regulator of mTORC1 in the cell, we investigated the functional interaction between HSF1 and c-Myc using in vitro and in vivo approaches. We found that ablation of HSF1 restrains the growth of c-Myc-derived mouse hepatocellular carcinoma (HCC) cell lines, where it induces downregulation of c-Myc levels. Conversely, silencing of c-Myc gene in human and mouse HCC cells led to downregulation of HSF1 expression. Most importantly, overexpression of a dominant negative form of HSF1 (HSF1dn) in the mouse liver via hydrodynamic gene delivery resulted in the complete inhibition of mouse hepatocarcinogenesis driven by overexpression of c-Myc. Altogether, the present results indicate that a functional HSF1 is necessary for c-Myc-driven hepatocarcinogenesis. Consequently, targeting HSF1 might represent a novel and effective therapeutic strategy for the treatment of HCC subsets with activated c-Myc signaling.

The acrosome reaction occurs in vivo following sperm capacitation and is essential for the acquisition of sperm fertilization ability. However, little is known about the molecular identity of the physiological acrosome reaction regulators. In addition to progesterone, which is produced by cumulus oophorus cells and known to regulate acrosome reaction by activating the specific calcium channel CatSper, endogenous opioid peptides such as beta-endorphin and met-enkephalin are present at high concentrations in the follicular fluid suggesting that the opioid system may be involved in the mechanisms regulating the acrosome reaction in humans. By using Reverse Transcription-PCR, western blot and immunofluorescence approaches, we described the presence and localization of the beta-endorphin precursor, pro-opiomelanocortinin the middle section and in flagellum of human spermatozoa, and inside the seminiferous tubules of human testis. Flow cytometry and intracellular calcium analyses showed that beta-endorphin causes an inversely dose-dependent increase in the percentage of acrosome-reacted sperm cells by a calcium-independent protein kinase C pathway. These findings are important for future studies of sperm physiology and provide new insight into the function of the opioid system as a target of fertility management.

The acrosome reaction occurs in vivo following sperm capacitation and is essential for the acquisition of sperm fertilization ability. However, little is known about the molecular identity of the physiological acrosome reaction regulators. In addition to progesterone, which is produced by cumulus oophorus cells and known to regulate acrosome reaction by activating the specific calcium channel CatSper, endogenous opioid peptides such as beta-endorphin and met-enkephalin are present at high concentrations in the follicular fluid suggesting that the opioid system may be involved in the mechanisms regulating the acrosome reaction in humans. By using Reverse Transcription-PCR, western blot and immunofluorescence approaches, we described the presence and localization of the beta-endorphin precursor, pro-opiomelanocortinin the middle section and in flagellum of human spermatozoa, and inside the seminiferous tubules of human testis. Flow cytometry and intracellular calcium analyses showed that beta-endorphin causes an inversely dose-dependent increase in the percentage of acrosome-reacted sperm cells by a calcium-independent protein kinase C pathway. These findings are important for future studies of sperm physiology and provide new insight into the function of the opioid system as a target of fertility management.

Das Leben und Überleben einer Zelle wird auf verschiedenen Ebenen streng reguliert. Diese Ebenen sind eng miteinander verknüpft: (i) Signalwege leiten extrazelluläre Signale in den Zellkern, wo (ii) Genregulation sie zu Proteinen übersetzt, und (iii) Proteine kontrollieren metabolische Funktionen, die Nährstoffe zu Energie und zellulären Bausteinen konvertieren. Diese Systeme sind hochkomplex und werden oft nur einzeln betrachtet. Systembiologie ist ein interdisziplinäres Forschungsgebiet, das Methoden anbietet, um Informationen aus heutigen Hochdurchsatz-Experimenttechnologien zu extrahieren. Diese Methoden können effektiv sein, um die vorgenannten Systeme einzeln oder im Ganzen zu untersuchen. In dieser Doktorarbeit wende ich Methoden an, um Signalwege und Zellmetabolismus zu erforschen, und ich präsentiere neue Arbeitsabläufe für das Modellieren und Analysieren dieser Systeme. Beide Methoden sind auf großskalige Netzwerkrekonstruktionen fokussiert. Da die Erhältlichkeit von xperimentellen Daten eines der größten Probleme der Systembiologie darstellt, befassen sich die Methoden explizit mit dem Umgang mit Wissenslücken. Sie werden auf den Snf1 Signalweg und den Metabolismus von Hefezellen angewendet und vermitteln neue Erkenntnisse über diesen Modellorganismus. Des Weiteren präsentiert diese Arbeit eine eingehende Analyse vom metabolischen Reprogrammieren in Darmkrebszellen, welche bisher unbekannte Zusammenhänge von metabolischer Funktionalität und Onkogenen beinhaltet. Zum Abschluss stelle ich unseren Vorschlag für ein standardisiertes Datenaustauschformat vor, welches seinen Schwerpunkt auf Datentabellen der Systembiologie legt. Zusammenfassend behandelt diese Doktorarbeit die Signalwege und den Metabolismus von Zellen, inklusive neuer Modellierabläufe und biologischer Erkenntnisse. Diese Erkenntnisse werden in den Kontext unseres aktuellen Wissensstandes gesetzt und darauf aufbauend werden neue potentielle Ansatzpunkte für Experimente vorgeschlagen., Cellular life is governed on different layers of regulation, which are tightly interconnected: (i) Signalling pathways transmit extracellular signals to the cells’ nucleus, where (ii) gene regulation translates these signals into proteins, and (iii) proteins control metabolic functions, which convert nutrients to energy and cell building blocks. Due to the complexity of each of these systems, they are often analysed individually or only partially. Systems Biology is an interdisciplinary field of research that offers techniques to harvest the information of todays high-throughput experiments. These techniques can be powerful approaches to investigate the aforementioned regulatory layers of a cell either individually or as a whole. In this thesis, I am employing means of Systems Biology to explore signalling pathways and metabolism, and I provide novel workflows for modelling and exploring these systems. Both workflows are focussed on accurate large-scale network reconstructions of the target system. Since one of the major problems in Systems Biology is the availability of experimental data, the workflows put emphasis on the handling of knowledge gaps. They are applied on the Snf1 pathway and metabolism in yeast and provide new findings about this model organism. Furthermore, this thesis presents an in-depth analysis of metabolic reprogramming in colorectal cancer cells, which yields previously unknown coherences of metabolic function and oncogenes. Finally, I am presenting a proposal for a standardised data format in Systems Biology, which is based on data tables. In summary, this thesis comprises works on signalling pathways and cell metabolism, which includes novel modelling workflows and new biological findings, analyses their impact on the scientific state of the art, and proposes directions for new experimental targets.

The acrosome reaction occurs in vivo following sperm capacitation and is essential for the acquisition of sperm fertilization ability. However, little is known about the molecular identity of the physiological acrosome reaction regulators. In addition to progesterone, which is produced by cumulus oophorus cells and known to regulate acrosome reaction by activating the specific calcium channel CatSper, endogenous opioid peptides such as beta-endorphin and met-enkephalin are present at high concentrations in the follicular fluid suggesting that the opioid system may be involved in the mechanisms regulating the acrosome reaction in humans. By using Reverse Transcription-PCR, western blot and immunofluorescence approaches, we described the presence and localization of the beta-endorphin precursor, pro-opiomelanocortinin the middle section and in flagellum of human spermatozoa, and inside the seminiferous tubules of human testis. Flow cytometry and intracellular calcium analyses showed that beta-endorphin causes an inversely dose-dependent increase in the percentage of acrosome-reacted sperm cells by a calcium-independent protein kinase C pathway. These findings are important for future studies of sperm physiology and provide new insight into the function of the opioid system as a target of fertility management.

The acrosome reaction occurs in vivo following sperm capacitation and is essential for the acquisition of sperm fertilization ability. However, little is known about the molecular identity of the physiological acrosome reaction regulators. In addition to progesterone, which is produced by cumulus oophorus cells and known to regulate acrosome reaction by activating the specific calcium channel CatSper, endogenous opioid peptides such as beta-endorphin and met-enkephalin are present at high concentrations in the follicular fluid suggesting that the opioid system may be involved in the mechanisms regulating the acrosome reaction in humans. By using Reverse Transcription-PCR, western blot and immunofluorescence approaches, we described the presence and localization of the beta-endorphin precursor, pro-opiomelanocortinin the middle section and in flagellum of human spermatozoa, and inside the seminiferous tubules of human testis. Flow cytometry and intracellular calcium analyses showed that beta-endorphin causes an inversely dose-dependent increase in the percentage of acrosome-reacted sperm cells by a calcium-independent protein kinase C pathway. These findings are important for future studies of sperm physiology and provide new insight into the function of the opioid system as a target of fertility management.

The acrosome reaction occurs in vivo following sperm capacitation and is essential for the acquisition of sperm fertilization ability. However, little is known about the molecular identity of the physiological acrosome reaction regulators. In addition to progesterone, which is produced by cumulus oophorus cells and known to regulate acrosome reaction by activating the specific calcium channel CatSper, endogenous opioid peptides such as beta-endorphin and met-enkephalin are present at high concentrations in the follicular fluid suggesting that the opioid system may be involved in the mechanisms regulating the acrosome reaction in humans. By using Reverse Transcription-PCR, western blot and immunofluorescence approaches, we described the presence and localization of the beta-endorphin precursor, pro-opiomelanocortinin the middle section and in flagellum of human spermatozoa, and inside the seminiferous tubules of human testis. Flow cytometry and intracellular calcium analyses showed that beta-endorphin causes an inversely dose-dependent increase in the percentage of acrosome-reacted sperm cells by a calcium-independent protein kinase C pathway. These findings are important for future studies of sperm physiology and provide new insight into the function of the opioid system as a target of fertility management.

Das Leben und Überleben einer Zelle wird auf verschiedenen Ebenen streng reguliert. Diese Ebenen sind eng miteinander verknüpft: (i) Signalwege leiten extrazelluläre Signale in den Zellkern, wo (ii) Genregulation sie zu Proteinen übersetzt, und (iii) Proteine kontrollieren metabolische Funktionen, die Nährstoffe zu Energie und zellulären Bausteinen konvertieren. Diese Systeme sind hochkomplex und werden oft nur einzeln betrachtet. Systembiologie ist ein interdisziplinäres Forschungsgebiet, das Methoden anbietet, um Informationen aus heutigen Hochdurchsatz-Experimenttechnologien zu extrahieren. Diese Methoden können effektiv sein, um die vorgenannten Systeme einzeln oder im Ganzen zu untersuchen. In dieser Doktorarbeit wende ich Methoden an, um Signalwege und Zellmetabolismus zu erforschen, und ich präsentiere neue Arbeitsabläufe für das Modellieren und Analysieren dieser Systeme. Beide Methoden sind auf großskalige Netzwerkrekonstruktionen fokussiert. Da die Erhältlichkeit von xperimentellen Daten eines der größten Probleme der Systembiologie darstellt, befassen sich die Methoden explizit mit dem Umgang mit Wissenslücken. Sie werden auf den Snf1 Signalweg und den Metabolismus von Hefezellen angewendet und vermitteln neue Erkenntnisse über diesen Modellorganismus. Des Weiteren präsentiert diese Arbeit eine eingehende Analyse vom metabolischen Reprogrammieren in Darmkrebszellen, welche bisher unbekannte Zusammenhänge von metabolischer Funktionalität und Onkogenen beinhaltet. Zum Abschluss stelle ich unseren Vorschlag für ein standardisiertes Datenaustauschformat vor, welches seinen Schwerpunkt auf Datentabellen der Systembiologie legt. Zusammenfassend behandelt diese Doktorarbeit die Signalwege und den Metabolismus von Zellen, inklusive neuer Modellierabläufe und biologischer Erkenntnisse. Diese Erkenntnisse werden in den Kontext unseres aktuellen Wissensstandes gesetzt und darauf aufbauend werden neue potentielle Ansatzpunkte für Experimente vorgeschlagen., Cellular life is governed on different layers of regulation, which are tightly interconnected: (i) Signalling pathways transmit extracellular signals to the cells’ nucleus, where (ii) gene regulation translates these signals into proteins, and (iii) proteins control metabolic functions, which convert nutrients to energy and cell building blocks. Due to the complexity of each of these systems, they are often analysed individually or only partially. Systems Biology is an interdisciplinary field of research that offers techniques to harvest the information of todays high-throughput experiments. These techniques can be powerful approaches to investigate the aforementioned regulatory layers of a cell either individually or as a whole. In this thesis, I am employing means of Systems Biology to explore signalling pathways and metabolism, and I provide novel workflows for modelling and exploring these systems. Both workflows are focussed on accurate large-scale network reconstructions of the target system. Since one of the major problems in Systems Biology is the availability of experimental data, the workflows put emphasis on the handling of knowledge gaps. They are applied on the Snf1 pathway and metabolism in yeast and provide new findings about this model organism. Furthermore, this thesis presents an in-depth analysis of metabolic reprogramming in colorectal cancer cells, which yields previously unknown coherences of metabolic function and oncogenes. Finally, I am presenting a proposal for a standardised data format in Systems Biology, which is based on data tables. In summary, this thesis comprises works on signalling pathways and cell metabolism, which includes novel modelling workflows and new biological findings, analyses their impact on the scientific state of the art, and proposes directions for new experimental targets.

The acrosome reaction occurs in vivo following sperm capacitation and is essential for the acquisition of sperm fertilization ability. However, little is known about the molecular identity of the physiological acrosome reaction regulators. In addition to progesterone, which is produced by cumulus oophorus cells and known to regulate acrosome reaction by activating the specific calcium channel CatSper, endogenous opioid peptides such as beta-endorphin and met-enkephalin are present at high concentrations in the follicular fluid suggesting that the opioid system may be involved in the mechanisms regulating the acrosome reaction in humans. By using Reverse Transcription-PCR, western blot and immunofluorescence approaches, we described the presence and localization of the beta-endorphin precursor, pro-opiomelanocortinin the middle section and in flagellum of human spermatozoa, and inside the seminiferous tubules of human testis. Flow cytometry and intracellular calcium analyses showed that beta-endorphin causes an inversely dose-dependent increase in the percentage of acrosome-reacted sperm cells by a calcium-independent protein kinase C pathway. These findings are important for future studies of sperm physiology and provide new insight into the function of the opioid system as a target of fertility management.

There is considerable evidence supporting an association between enterovirus (EV), infection, particularly Coxsackievirus B (CVB), and the development of type 1 diabetes. However, the mechanisms for viral induced destruction of pancreatic β-cells are not well understood and it remains unclear whether the effects are strain specific. The central hypothesis of this PhD is that EV infection induces the production of pro-inflammatory cytokine and chemokine in β-cells, causing activation of apoptotic signalling pathways and leading to immune-mediated destruction of β-cells. The major aims of the project were to determine the effect of EV infection in β-cells on (i) production of pro-inflammatory cytokine and chemokine and (ii) activation of apoptotic and anti-apoptotic pathway.The first investigation examined the effects of multiple EVs (CVB1-6; ECHO4, 6, 9, 11 and 18; and two EV71 strains) on the expression of cytokine IFN-γ, IL-1α, IL-1β, IL-5, IL-6, IL-10, IL-18, MIP-1α, EOTAXIN and GCSF) and chemokine CCL-2 and CCL5 in the rat β-cell line INS-1 and RINm5F. The second investigation examined the effects of CVB4 and CVB5 at MOI 1 and MOI 10 on the activation of apoptotic signalling factors such as p38 MAPK, ERK1/2, JNK, NF-κB, and c-Jun and the anti-apoptotic signalling factors, Akt. The third investigation examined cytokine regulation of signalling pathways in INS-1 cells transfected with either IFN-γ or IL-1β and infected with either CVB4 or CVB5. The same signalling factors were investigated in the previous study along with STAT-1. The fourth investigation examined the effects of IFN-γ and IL-1β on CVB4 and CVB5 replication in INS-1.In the first investigation, the levels of CCL-2 and CCL-5 increased in β-cells infected with CVB2, CVB4-5, CVB6, ECHO4, 6, 9 and 11 and not with two strains of EV71. The levels of IFN-γ, IL-1α, IL-1β, IL-5, IL-6, IL-10, IL-18, MIP-1α, EOTAXIN and GCSF, the majority of which are pro-inflammatory cytokines, increased in β-cells infected wit

The 15 members of the kallikrein-related serine peptidase (KLK) family have diverse tissue-specific expression profiles and roles in a range of cellular processes, including proliferation, migration, invasion, differentiation, inflammation and angiogenesis that are required in both normal physiology as well as pathological conditions. These roles require cleavage of a range of substrates, including extracellular matrix proteins, growth factors, cytokines as well as other proteinases. In addition, it has been clear since the earliest days of KLK research that cleavage of cell surface substrates is also essential in a range of KLK-mediated cellular processes where these peptidases are essentially acting as agonists and antagonists. In this review we focus on these KLK-regulated cell surface receptor systems including bradykinin receptors, proteinase-activated receptors, as well as the plasminogen activator, ephrins and their receptors, and hepatocyte growth factor/Met receptor systems and other plasma membrane proteins. From this analysis it is clear that in many physiological and pathological settings KLKs have the potential to regulate multiple receptor systems simultaneously; an important issue when these peptidases and substrates are targeted in disease.

Blood platelets have a central role in the process of haemostasis (the process of making the bleeding stop in a damaged blood vessel wall) and thrombosis (clotting of a blood vessel). The latter can lead to blood vessel obstruction causing a heart infarct or a stroke. The current antithrombotic, anti-blood vessel medication is only partly effective, and an increased risk of bleeding often creates a considerable complication. For the development of personalized target-specific medication with fewer side-effects a more exact knowledge of the complex process of thrombus formation and mainly the involved blood vessel signalling pathways is essential. The insight described in this thesis is a contribution to future developments in the treatment of arterial thrombosis.

Blood platelets have a central role in the process of haemostasis (the process of making the bleeding stop in a damaged blood vessel wall) and thrombosis (clotting of a blood vessel). The latter can lead to blood vessel obstruction causing a heart infarct or a stroke. The current antithrombotic, anti-blood vessel medication is only partly effective, and an increased risk of bleeding often creates a considerable complication. For the development of personalized target-specific medication with fewer side-effects a more exact knowledge of the complex process of thrombus formation and mainly the involved blood vessel signalling pathways is essential. The insight described in this thesis is a contribution to future developments in the treatment of arterial thrombosis.

[Purpose] Procyanidin B2 (PB2) is a naturally occurring flavonoid widely found in cocoa, red wine and grape juice. Recent studies have suggested that PB2 could protect against oxidative stress- and chemical-induced injury in colonic cells by modulating the endogenous cellular defence. However, the precise mechanism for this protection is not fully understood. Herein, we examined the effect of PB2 on the expression of one of the major antioxidant/detoxificant enzymes related to intestinal protection, the glutathione S-transferase P1 (GSTP1), and the molecular mechanisms involved. [Methods] Human colonic Caco-2 cells were treated with PB2 at different times and enzymatic activity, and mRNA and protein levels of GSTP1 were evaluated. The nuclear translocation of the transcription factor NF-erythroid 2-related factor (Nrf2) and the phosphorylation states of specific proteins central to intracellular signalling cascades were also investigated. [Results] PB2 induced the expression and activity of GSTP1 and the nuclear translocation of Nrf2. Interestingly, two important signalling proteins involved in Nrf2 translocation, the extracellular signal-regulated protein kinases (ERKs) and the p38 mitogen-activated protein kinase (MAPK) were also activated. Further experiments with specific inhibitors of both pathways confirmed their critical role in the beneficial effects induced by PB2. [Conclusions] The present results show that PB2 protects against oxidative injury in colonic cells and up-regulate the expression of GSTP1 via a mechanism that involves ERK and p38 MAPK activation and Nrf2 translocation. These results provide a molecular basis for the potential contribution of PB2 in the prevention of oxidative stress-related intestinal injury and gut pathologies.

[no abstract]

Malignant pleural mesothelioma (MPM) is an aggressive, treatment-resistant tumour. Cisplatin (cis-diamminedichloroplatinum (II)) is the best single-agent chemotherapy for MPM, but platinum-based combination therapies give the best overall response rates. However, cisplatin use is limited by resistance and severe side effects. This thesis has increased the knowledge concerning cisplatin-induced cell death in MPM by describing a novel potential therapeutic target, and three novel phenotypes of cisplatin-resistance in a human MPM cell line (P31) and its cisplatin-resistant sub-line (P31res1.2). The novel potential therapeutic target, and one of the novel phenotypes, was cisplatin-resistant pro-apoptotic BH3-only proteins. In the P31 cells, cisplatin transiently increased pro-apoptotic BH3-only proteins during 6 h of exposure. This response was almost completely abrogated in the P31res1.2 cells. De-regulated caspase activity and activation was the second novel phenotype identified. The P31res1.2 cells had earlier, possibly mitochondria-independent, caspase-3 activation, increased basal caspase-3 activity and increased basal cleavage of caspase-8 and -9. Despite these differences, 6-h equitoxic cisplatin exposures rendered 50-60% of the cells apoptotic in both cell lines. The third novel phenotype was abrogated Na+K+2Cl--cotransporter (NKCC1) activity. Although NKCC1 activity was dispensable for cisplatin-induced apoptosis, balanced potassium transport activity was essential for P31 cell survival. Finally, the survival signalling protein Protein Kinase B (PKB or Akt) isoforms α and γ were constitutively activated in a PI3K-independent manner in P31 cells. In the P31res1.2 cells, PKBα and γ activities were increased, and there was PI3K-dependent activation of PKBβ. However, this increase in PKB isoform activity was not strongly associated to the cisplatin-resistance of the P31res1.2 cells.

Malignant pleural mesothelioma (MPM) is an aggressive, treatment-resistant tumour. Cisplatin (cis-diamminedichloroplatinum (II)) is the best single-agent chemotherapy for MPM, but platinum-based combination therapies give the best overall response rates. However, cisplatin use is limited by resistance and severe side effects. This thesis has increased the knowledge concerning cisplatin-induced cell death in MPM by describing a novel potential therapeutic target, and three novel phenotypes of cisplatin-resistance in a human MPM cell line (P31) and its cisplatin-resistant sub-line (P31res1.2). The novel potential therapeutic target, and one of the novel phenotypes, was cisplatin-resistant pro-apoptotic BH3-only proteins. In the P31 cells, cisplatin transiently increased pro-apoptotic BH3-only proteins during 6 h of exposure. This response was almost completely abrogated in the P31res1.2 cells. De-regulated caspase activity and activation was the second novel phenotype identified. The P31res1.2 cells had earlier, possibly mitochondria-independent, caspase-3 activation, increased basal caspase-3 activity and increased basal cleavage of caspase-8 and -9. Despite these differences, 6-h equitoxic cisplatin exposures rendered 50-60% of the cells apoptotic in both cell lines. The third novel phenotype was abrogated Na+K+2Cl--cotransporter (NKCC1) activity. Although NKCC1 activity was dispensable for cisplatin-induced apoptosis, balanced potassium transport activity was essential for P31 cell survival. Finally, the survival signalling protein Protein Kinase B (PKB or Akt) isoforms α and γ were constitutively activated in a PI3K-independent manner in P31 cells. In the P31res1.2 cells, PKBα and γ activities were increased, and there was PI3K-dependent activation of PKBβ. However, this increase in PKB isoform activity was not strongly associated to the cisplatin-resistance of the P31res1.2 cells.

Malignant pleural mesothelioma (MPM) is an aggressive, treatment-resistant tumour. Cisplatin (cis-diamminedichloroplatinum (II)) is the best single-agent chemotherapy for MPM, but platinum-based combination therapies give the best overall response rates. However, cisplatin use is limited by resistance and severe side effects. This thesis has increased the knowledge concerning cisplatin-induced cell death in MPM by describing a novel potential therapeutic target, and three novel phenotypes of cisplatin-resistance in a human MPM cell line (P31) and its cisplatin-resistant sub-line (P31res1.2). The novel potential therapeutic target, and one of the novel phenotypes, was cisplatin-resistant pro-apoptotic BH3-only proteins. In the P31 cells, cisplatin transiently increased pro-apoptotic BH3-only proteins during 6 h of exposure. This response was almost completely abrogated in the P31res1.2 cells. De-regulated caspase activity and activation was the second novel phenotype identified. The P31res1.2 cells had earlier, possibly mitochondria-independent, caspase-3 activation, increased basal caspase-3 activity and increased basal cleavage of caspase-8 and -9. Despite these differences, 6-h equitoxic cisplatin exposures rendered 50-60% of the cells apoptotic in both cell lines. The third novel phenotype was abrogated Na+K+2Cl--cotransporter (NKCC1) activity. Although NKCC1 activity was dispensable for cisplatin-induced apoptosis, balanced potassium transport activity was essential for P31 cell survival. Finally, the survival signalling protein Protein Kinase B (PKB or Akt) isoforms α and γ were constitutively activated in a PI3K-independent manner in P31 cells. In the P31res1.2 cells, PKBα and γ activities were increased, and there was PI3K-dependent activation of PKBβ. However, this increase in PKB isoform activity was not strongly associated to the cisplatin-resistance of the P31res1.2 cells.

The potential lipotoxic effect of intramyocellular triglyceride (IMTG) accumulation has been suggested to be a major component in the development of insulin resistance. Increased levels of IMTGs correlate with insulin resistance in both obese and diabetic patients, but this relationship does not exist in endurance trained (ETr) subjects. This may be, in part, related to differences in the gene expression and activities of key enzymes involved in fatty acid transport and oxidation as well as in the perodixation status of the IMTGs in obese/diabetic patients as compared with ETr subjects. Disruptions in fat and lipid homeostasis in skeletal muscle have been shown to activate protein kinase C (PKC), which acts on several downstream signalling pathways, including the insulin and the IB kinase (IKK)/NFB signalling pathways. Additionally, an increased peroxidation of IMTGs may reduce insulin sensitivity by increasing TNF, which is known to increase the expression of suppressor of cytokine signalling proteins (SOCS). A common characteristic observed when activating both PKC and TNF/SOCS3 is the inhibition of tyrosine phosphorylation of IRS-1 and subsequently an inhibition of its activation of downstream signalling molecules. These may be important players in the development of insulin resistance and understanding their activation and expression in both obese and ETr humans should assist in understanding how and why IMTGs become lipotoxic.

The cloning of the opioid-receptor-like 1 (ORL1) receptor and the identification of nociceptin as its endogenous agonist have revealed a new G-protein-coupled receptor signalling system. The structural and functional homology of ORL1 to the opioid receptor systems has posed a number of challenges in understanding the often competing physiological responses elicited by these G-protein-coupled receptors. Thus, this review will attempt to summarize recent research by many groups that has revealed numerous subtleties of the ORL1 receptor and its signalling pathways, as well as document the efforts to produce high-affinity selective ligands for the ORL1 receptor that may be of value as research and therapeutic tools. Copyright © 2002 S. Karger AG, Basel.

The cloning of the opioid-receptor-like 1 (ORL1) receptor and the identification of nociceptin as its endogenous agonist have revealed a new G-protein-coupled receptor signalling system. The structural and functional homology of ORL1 to the opioid receptor systems has posed a number of challenges in understanding the often competing physiological responses elicited by these G-protein-coupled receptors. Thus, this review will attempt to summarize recent research by many groups that has revealed numerous subtleties of the ORL1 receptor and its signalling pathways, as well as document the efforts to produce high-affinity selective ligands for the ORL1 receptor that may be of value as research and therapeutic tools. Copyright © 2002 S. Karger AG, Basel.

The cloning of the opioid-receptor-like 1 (ORL1) receptor and the identification of nociceptin as its endogenous agonist have revealed a new G-protein-coupled receptor signalling system. The structural and functional homology of ORL1 to the opioid receptor systems has posed a number of challenges in understanding the often competing physiological responses elicited by these G-protein-coupled receptors. Thus, this review will attempt to summarize recent research by many groups that has revealed numerous subtleties of the ORL1 receptor and its signalling pathways, as well as document the efforts to produce high-affinity selective ligands for the ORL1 receptor that may be of value as research and therapeutic tools. Copyright © 2002 S. Karger AG, Basel.