HARNESSING MESENCHYMAL STEM CELL EXOSOMES AS THERAPY FOR FIBROTIC LUNG DISEASE-INDUCED RIGHT VENTRICULAR DYSFUNCTION

Idiopathic pulmonary fibrosis (IPF) is a fatal disease of unknown etiology with no effective treatment except for lung transplantation. It is characterized by progressive lung fibrosis leading to respiratory failure. Outcomes are worse with comorbidities such as right ventricular systolic dysfunction (RVSD) and pulmonary hypertension (PH). Consequently, there is an urgent need for novel treatment approaches for IPF. This dissertation aims to (1) determine the strength of the association between hemodynamic indices of right ventricular function and survival in IPF, (2) evaluate the therapeutic potential of human bone marrow-derived mesenchymal stem cells (hMSCs) and their derived exosomes in regulating the right ventricular function in a mouse model of IPF, and (3) categorize the protein cargo of hMSCs. The analysis of the data from an IPF registry showed that the risk of death was significantly higher among subjects with PH in IPF compared to IPF alone (HR: 1.406; 95% CI: 1.026-1.928). Similarly, the risk of mortality was significantly higher in subjects with RVSD compared to those without (HR: 2.523; 95% CI: 1.599-3.979). We concluded that PH and RVSD were strongly associated with survival and that right heart catheterization hemodynamic assessments in IPF is crucial to identify patients at risk of worse outcomes who may be considered for clinical trials. In evaluating the potential beneficial effects of hMSC and their exosomes in fibrotic lung injuries, we found that the mean pulmonary arterial pressure was significantly increased in the BLM group when compared with controls (20.0±0.45 vs 16.1±0.43, mmHg). Also, there was a significant increase in right ventricular dysfunction (dP/dtmx-EDV) when comparing the BLM group with controls (45.5±2.52 vs 32.8±2.87, mmHg.s-1. ul-1) with an improvement in the RVD after administering hMSCs and exosomes. We concluded that hMSCs and their exosomes have the therapeutic potential to regulate the RV contractile function. Lastly, we performed a descriptive proteomic analysis to identify and categorize the protein components of the hMSC exosomes. We identified 845 proteins, 166 of them had enzymatic activities involved in proteolysis and oxidative stress regulation. Our conclusion was that the proteome of hMSC exosomes carry enzymatic proteins that could mediate their therapeutic effects

A Commemorative Issue in Honor of Professor Nick Hadjiliadis: Metal Complex Interactions with Nucleic Acids and/or DNA

This Special Issue of the International Journal of Molecular Science comprises a comprehensive study on “Metal Complex Interactions with Nucleic Acids and/or DNA”. This Special Issue has been inspired by the important contribution of Prof. Nick Hadjiliadis to the field of palladium or/and platinum/nucleic acid interactions. It covers a selection of recent research and review articles in the field of metal complex interactions with nucleic acids and/or DNA. Moreover, this Special Issue on "Metal Complexes Interactions with Nucleic Acids and/or DNA" provides an overview of this increasingly diverse field, presenting recent developments and the latest research with particular emphasis on metal-based drugs and metal ion toxicity

Gene profiling of lung toxicity

Bleomycin is a potent anti-tumour compound used in the treatment of squamous cell carcinomas. An unfortunate side effect of this drug is pulmonary toxicity. The onset of this damage manifests as mild oedema and inflammation which eventually develops into pulmonary fibrosis. The ability to correctly identify patients showing early signs of lung injury could significantly reduce the morbidity associated with bleomycin treatment. As such, this study was undertaken to identify genetic markers of early oedema and inflammation. A model of mild pulmonary injury was induced by bleomycin. Conventional quantitative analysis of broncho-alveolar lavage was used to indicate the severity of the oedematous response, whilst morphological changes were identified by histology and electron microscopy. Macroarrays were used to measure the expression of multiple genes during mild, progressive and severe oedema. Following normalisation and statistical analysis, gene expression patterns were compared from saline- and bleomycin-treated rats. A variety of genes were differentially expressed during each model, with the number increasing with the severity of the oedema. A cluster and two individual genes were consistently expressed across two of the models of oedema. The magnitude of the changes in gene expression were quantified and confirmed by quantitative PCR. In summary, complete toxicological and histological characterisation of the bleomycin-induced model of pulmonary injury successfully identified specific endpoints of injury. This model proved to be ideal for studying differential gene expression in response to drug-induced pulmonary oedema. A cluster of ion channels and trafficking genes has the potential to act as a biomarker. Two specific genetic markers (Na+/CI- betaine/GABA transporter, glucocorticoid receptor), and a protein marker (cocoacrisp) have been identified for the oedema. In addition to these genes and protein being potential biomarkers of injury, they are also prospective targets for clinical treatment.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Gene profiling of lung toxicity

Bleomycin is a potent anti-tumour compound used in the treatment of squamous cell carcinomas. An unfortunate side effect of this drug is pulmonary toxicity. The onset of this damage manifests as mild oedema and inflammation which eventually develops into pulmonary fibrosis. The ability to correctly identify patients showing early signs of lung injury could significantly reduce the morbidity associated with bleomycin treatment. As such, this study was undertaken to identify genetic markers of early oedema and inflammation. A model of mild pulmonary injury was induced by bleomycin. Conventional quantitative analysis of broncho-alveolar lavage was used to indicate the severity of the oedematous response, whilst morphological changes were identified by histology and electron microscopy. Macroarrays were used to measure the expression of multiple genes during mild, progressive and severe oedema. Following normalisation and statistical analysis, gene expression patterns were compared from saline- and bleomycin-treated rats. A variety of genes were differentially expressed during each model, with the number increasing with the severity of the oedema. A cluster and two individual genes were consistently expressed across two of the models of oedema. The magnitude of the changes in gene expression were quantified and confirmed by quantitative PCR. In summary, complete toxicological and histological characterisation of the bleomycin-induced model of pulmonary injury successfully identified specific endpoints of injury. This model proved to be ideal for studying differential gene expression in response to drug-induced pulmonary oedema. A cluster of ion channels and trafficking genes has the potential to act as a biomarker. Two specific genetic markers (Na+/CI- betaine/GABA transporter, glucocorticoid receptor), and a protein marker (cocoacrisp) have been identified for the oedema. In addition to these genes and protein being potential biomarkers of injury, they are also prospective targets for clinical treatment.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Gene profiling of lung toxicity

Bleomycin is a potent anti-tumour compound used in the treatment of squamous cell carcinomas. An unfortunate side effect of this drug is pulmonary toxicity. The onset of this damage manifests as mild oedema and inflammation which eventually develops into pulmonary fibrosis. The ability to correctly identify patients showing early signs of lung injury could significantly reduce the morbidity associated with bleomycin treatment. As such, this study was undertaken to identify genetic markers of early oedema and inflammation. A model of mild pulmonary injury was induced by bleomycin. Conventional quantitative analysis of broncho-alveolar lavage was used to indicate the severity of the oedematous response, whilst morphological changes were identified by histology and electron microscopy. Macroarrays were used to measure the expression of multiple genes during mild, progressive and severe oedema. Following normalisation and statistical analysis, gene expression patterns were compared from saline- and bleomycin-treated rats. A variety of genes were differentially expressed during each model, with the number increasing with the severity of the oedema. A cluster and two individual genes were consistently expressed across two of the models of oedema. The magnitude of the changes in gene expression were quantified and confirmed by quantitative PCR. In summary, complete toxicological and histological characterisation of the bleomycin-induced model of pulmonary injury successfully identified specific endpoints of injury. This model proved to be ideal for studying differential gene expression in response to drug-induced pulmonary oedema. A cluster of ion channels and trafficking genes has the potential to act as a biomarker. Two specific genetic markers (Na+/CI- betaine/GABA transporter, glucocorticoid receptor), and a protein marker (cocoacrisp) have been identified for the oedema. In addition to these genes and protein being potential biomarkers of injury, they are also prospective targets for clinical treatment

Characterisation of a novel STAT3 inhibitor, VS-43, and the role of STAT3 in the repair of DNA-interstrand crosslinks

Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor constitutively activated in cancer, leading to survival, proliferation, angiogenesis and metastasis. STAT3 inhibitors possess anti-cancer properties, however, the selectivity and potency of current inhibitors must be improved. This thesis characterises a novel STAT3 inhibitor, VS-43. VS-43 is a potent and selective STAT3 inhibitor, able to inhibit cancer cell growth and induce apoptosis in cancer cell lines. VS-43 is shown to inhibit STAT3 DNA binding and downstream target expression. VS-43 is also able to synergise with cisplatin, and this combination is more synergistic than the combination of cisplatin with other STAT3 inhibitors. Cisplatin acts via the formation of adducts with the cellular DNA, and the interstrand crosslink (ICL) is the most toxic of the cisplatin lesions. Resistance to cisplatin can occur via enhanced repair of ICLs. Therefore, the effect of STAT3 inhibition on ICL repair was investigated. STAT3 nhibitors are shown to block the unhooking of cisplatin-induced ICLs and down-regulate the expression of the ICL repair factors EME1, MUS81, BRCA1 and FANCD2. Binding of STAT3 to the MUS81 and EME1 promoters was demonstrated using ChIP assays, suggesting direct transcriptional regulation of the MUS81-EME1 nuclease by STAT3. In contrast, STAT3 inhibitors did not synergise with melphalan and did not block melphalan-ICL unhooking. siRNA knockdown of MUS81 or EME1 demonstrated that the MUS81-EME1 nuclease is selectively involved in cisplatin-ICL repair. This thesis presents VS-43 as a promising novel STAT3 inhibitor, and provides mechanistic insight into how STAT3 inhibitors synergise with cisplatin through the regulation of ICL unhooking. Understanding the differences in the repair of different ICLs will be essential for the design of future chemotherapy combinations