Temporal tracking of mineralization and transcriptional developments of shell formation during the early life history of pearl oyster Pinctada maxima

Molluscan larval ontogeny is a highly conserved process comprising three principal developmental stages. A characteristic unique to each of these stages is shell design, termed prodissoconch I, prodissoconch II and dissoconch. These shells vary in morphology, mineralogy and microstructure. The discrete temporal transitions in shell biomineralization between these larval stages are utilized in this study to investigate transcriptional involvement in several distinct biomineralization events. Scanning electron microscopy and X-ray diffraction analysis of P. maxima larvae and juveniles collected throughout post-embryonic ontogenesis, document the mineralogy and microstructure of each shelled stage as well as establishing a timeline for transitions in biomineralization. P. maxima larval samples most representative of these biomineralization distinctions and transitions were analyzed for differential gene expression on the microarray platform PmaxArray 1.0. A number of transcripts are reported as differentially expressed in correlation to the mineralization events of P. maxima larval ontogeny. Some of those isolated are known shell matrix genes while others are novel; these are discussed in relation to potential shell formation roles. This interdisciplinary investigation has linked the shell developments of P. maxima larval ontogeny with corresponding gene expression profiles, furthering the elucidation of shell biomineralization

Differential Expression of Keratinocyte-Derived Extracellular Vesicle Mirnas Discriminate Exosomes From Apoptotic Bodies and Microvesicles

Extracellular vesicles (EVs) are mammalian cell-derived nano-scale structures enclosed by a lipid bilayer that were previously considered to be cell debris with little biological value. However, EVs are now recognized to possess biological function, acting as a packaging, transport and delivery mechanisms by which functional molecules (i.e., miRNAs) can be transferred to target cells over some distance. To examine the miRNA from keratinocyte-derived EVs, we isolated three distinct populations of EVs from both HaCaT and primary human keratinocytes (PKCs) and characterized their biophysical, biochemical and functional features by using microscopy, immunoblotting, nanoparticle tracking, and next generation sequencing. We identified 1,048; 906; and 704 miRNAs, respectively, in apoptotic bodies (APs), microvesicles (MVs) and exosomes (EXs) released from HaCaT, and 608; 506; and 622 miRNAs in APs, MVs and EXs released from PKCs. In which, there were 623 and 437 identified miRNAs common to three HaCaT-derived EVs and PKC-derived EVs, respectively. In addition, we found hundreds of exosomal miRNAs that were previously un-reported. Differences in the abundance levels of the identified EV miRNAs could discriminate between the three EV populations. These data contribute substantially to knowledge within the EV-identified miRNA database, especially with regard to keratinocyte-derived EV miRNA content

Integrated Modelling Frameworks for Environmental Assessment and Decision Support

As argued in Chapter 1, modern management of environmental resources defines problems from a holistic and integrated perspective, thereby imposing strong requirements on Environmental Decision Support Systems (EDSSs) and Integrated Assessment Tools (IATs). These systems and tools tend to be increasingly complex in terms of software architecture and computational power in order to cope with the type of problems they must solve. For instance, the discipline of Integrated Assessment (IA) needs tools that arc able to span a wide range of disciplines, from socio-economics to ecology to hydrology. Such tools must support a wide range of methodologies and techniques like agent-based modeling, Bayesian decision networks, optimization, multicriteria analyses and visualization tools, to name a few

A Fragment of the LG3 Peptide of Endorepellin Is Present in the Urine of Physically Active Mining Workers: A Potential Marker of Physical Activity

Biomarker analysis has been implemented in sports research in an attempt to monitor the effects of exertion and fatigue in athletes. This study proposed that while such biomarkers may be useful for monitoring injury risk in workers, proteomic approaches might also be utilised to identify novel exertion or injury markers. We found that urinary urea and cortisol levels were significantly elevated in mining workers following a 12 hour overnight shift. These levels failed to return to baseline over 24 h in the more active maintenance crew compared to truck drivers (operators) suggesting a lack of recovery between shifts. Use of a SELDI-TOF MS approach to detect novel exertion or injury markers revealed a spectral feature which was associated with workers in both work categories who were engaged in higher levels of physical activity. This feature was identified as the LG3 peptide, a C-terminal fragment of the anti-angiogenic/anti-tumourigenic protein endorepellin. This finding suggests that urinary LG3 peptide may be a biomarker of physical activity. It is also possible that the activity mediated release of LG3/endorepellin into the circulation may represent a biological mechanism for the known inverse association between physical activity and cancer risk/survival

Application of Mesenchymal Stem Cells for repair and regeneration of cartilage and bone

Australian efforts to provide orthopaedic surgeons with living, load-bearing scaffolds suitable for current joint (knee and hip) replacement surgery, non-union fracture repair, and miniscal and growth plate cartilage regeneration are being lead by teams at the Institute for Medical and Veterinary Science and Women's and Children's Hospital in Adelaide; the Peter MacCallum and St Vincent's Medical Research Institutes in Melbourne; and the Mater Medical Research Institute and new Institute for Health and Biomedical Innovation at QUT, Brisbane. In each case multidisciplinary teams are attempting to develop autologous living tissue constructs, utilising mesenchymal stem cells (MSC), with the intention of effecting seamless repair and regeneration of skeletal trauma and defects. In this article we will briefly review current knowledge of the phenotypic properties of MSC and discuss the potential therapeutic applications of these cells as exemplified by their use in cartilage repair and tissue engineering based approaches to the treatment of skeletal defects

A brief history of haemotopoietic stem cell Ex vivo expansion

*This article is free to read on the publisher's website* Haematopoiesis is the process by which a hierarchy of mature and progenitor blood cells are formed. These cell populations are all derived from multipotent haematopoietic stem cells (HSC), which reside in the bone marrow ‘niche’ of adult humans. Over the lifetime of a healthy individual, this HSC population replenishes between 1010-1011 blood cells on a daily basis. Dysregulation of this system can lead to a number of haematopoietic diseases, including aplastic anaemias and leukaemias, which result in, or require for disease resolution, bone marrow cell depletion. In 1956, E. Donnall Thomas demonstrated that haematopoiesis could be restored by transplanting bone marrow-derived cells from one man into his identical twin brother, who was suffering from advanced leukaemia. His success drew significant interest in academic research and medicine communities, and 12 years later, the first successful allogeneic transplant was performed. To this day, HSCs remain the most studied and characterised stem cell population. In fact, HSCs are the only stem cell population routinely utilised in the clinic. As such, HSCs function as a model system both for the biological investigation of stem cells, as well as for their clinical application. Herein, we briefly review HSC transplantation, strategies for the ex vivo cultivation of HSCs, recent clinical outcomes, and their impact on the future direction of HSC transplantation therapy

QUT seeks to heal wounds without scars

Treatment of wounds represents a significant challenge at all levels of our society, in terms of cost (physical, emotional and financial) to patients, the economy and to the wider Australian and global communities. Despite this, relatively little research is directed at this hidden health problem. The Tissue Repair & Regeneration team at QUT is addressing this challenge using advanced biotechnological, biomaterials and bioengineering strategies. Our interdisciplinary team is focussed on delivering practical innovations in wound healing, with an emphasis on diabetic and venous ulcers, as well as burns. This 'snapshot' of our research briefly describes some of the research projects we are pursuing at QUT: interactions of growth factors with other components of the extracellular milieu in tissues; cellular mechanisms associated with wound healing and scar remediation; diagnostic and prognostic markers of healing; novel, relevant, ex vivo 3D skin equivalent models for pre-clinical evaluation of new wound therapeutics; and the design and production of "smart" bioactive wound dressings. The overall goal of our research is to generate new technologies and wound management interventions that keep patients healthy and obviate their need to depend upon the cost-intensive hospital-based health care sector

Mechanical And Electrical Environments To Stimulate Bone Cell Development

Oral Presentation - no full written paper:\ud The aim of this project was to evaluate the effects of mechanical strain and indirect electrical stimulation upon the development of bone forming osteoblast cells and any possible synergistic effects of the two stimulants. This aim was achieved by using a novel device, designed and developed with the capability of creating a cell substrate surface strain along with an exogenous electrical stimulant individually or at the same time. Proliferation and differentiation was determined as a measure of cellular development. The indirect electrical stimulation was achieved through the use of pulsed electromagnetic field (PEMF) stimulation while the mechanical strain was produced from the dynamic stretching of a deformable cell substrate. The PEMF signal mimicked a clinically available bone growth stimulator signal. Results showed reduced proliferation and increased differentiation (alkaline phosphatase activity) with SaOS-2 osteoblast-like cell cultures, which were exposed to indirect electrical stimulation. MG-63 osteoblast-like cell cultures also showed reduced proliferation, however they did not show an increase in their differentiation with PEMF exposure. Mechanical stimulation alone did not have a significant effect over either proliferation or differentiation, while a dual mechanical and electrical stimulation resulted in cellular differentiation significantly increasing. It is possible a synergistic interaction between the two stimulants is occurring on a biological level

Regulation of epithelial-mesenchymal transition by micrornas

Cells at the wound margin during reepithelialization share phenotypic and genotypic similarities with cancer metastasis. In both scenarios, effected cells increase their epithelial characteristics. A sedentary, epithelial phenotype converts to a more motile, mesenchymal state in a process known as epithelial‐to‐mesenchymal transition (EMT). The extensive evidence that microRNAs induce EMT during cancer cell metastasis and migration is lacking in wound healing. Using an in vitro model of re‐epithelialization, primary keratinocytes at the wound edge were visualized migrating and undergoing dynamic morphological changes as they extended and retract lamellipodia at the leading edge of a collective sheet. Furthermore, expression of mesenchymal proteins vimentin and cytokeratin‐14 increased only at the leading edge suggesting a localized and partial EMT had occurred. Next, RNA was extracted from cells at the leading edge and from cells distal to the edge. Next generation sequencing revealed a number of microRNA species are differentially expressed in the cells at the migrating leading edge including miR‐501‐3p, miR‐4972 and miR‐181a‐5p (padj<0.001). MiR‐501‐3p and miR‐181a‐5p are known to be up‐regulated in tumor cells and microRNA‐4792 has been shown to target and repress an important EMT transcription factor, FOXC1. These results suggest that these miRNAs may play a similar role in EMT during wound healing. MiR‐4792 overexpression and knock down experiments are now underway in keratinocytes to investigate functional effects and mechanisms of action