Hypertrophic signalling in human skeletal muscle

Ý-lactoglobulin enriched whey protein isolate, but not carbohydrate, increased growth signalling in human skeletal muscle when consumed in conjunction with resistance exercise. Ageing did not impair the anabolic signalling response; however this response was attenuated after training. These findings help identify strategies to prevent, or delay the onset of sarcopenia.

AHI1 and NDRG2 function in skeletal muscle and the development of type 2 diabetes

In this study, AHI1 and NDRG2 gene function in the insulin signalling pathways regulating skeletal muscle homeostasis was investigated. Findings implicate AHI1 in the regulation of insulin-stimulated glucose transport and the development of insulin resistance, whilst associating NDRG2 with the regulation of myoblast proliferation and differentiation; possible via interactions with PICK1 and arfaptin2.

Evaluation of novel dairy fatty acids in inflammatory muscle-wasting conditions

This work examined the effects of a novel dairy fatty acid conjugated linoleic acid (CLA) and its effects on muscle wasting in advanced cancer. Results showed a positive anti-inflammatory role of CLA on the supression of tumour growth and established a model for studying the action of CLA in human muscle-wasting conditions.

Enhanced proliferation of human skeletal muscle precursor cells derived from elderly donors cultured in estimated physiological (5%) oxygen

Human skeletal muscle precursor cells (myoblasts) have significant therapeutic potential and are a valuable research tool to study muscle cell biology. Oxygen is a critical factor in the successful culture of myoblasts with low (1–6%) oxygen culture conditions enhancing the proliferation, differentiation, and/or viability of mouse, rat, and bovine myoblasts. The specific effects of low oxygen depend on the myoblast source and oxygen concentration; however, variable oxygen conditions have not been tested in the culture of human myoblasts. In this study, muscle precursor cells were isolated from vastus lateralis muscle biopsies and myoblast cultures were established in 5% oxygen, before being divided into physiological (5%) or standard (20%) oxygen conditions for experimental analysis. Five percent oxygen increased proliferating myoblast numbers, and since low oxygen had no significant effect on myoblast viability, this increase in cell number was attributed to enhanced proliferation. The proportion of cells in the S (DNA synthesis) phase of the cell cycle was increased by 50%, and p21^Cip1 gene and protein expression was decreased in 5 versus 20% oxygen. Unlike in rodent and bovine myoblasts, the increase in myoD, myogenin, creatine kinase, and myosin heavy chain IIa gene expression during differentiation was similar in 5 and 20% oxygen; as was myotube hypertrophy. These data indicate for the first time that low oxygen culture conditions stimulate proliferation, whilst maintaining (but not enhancing) the viability and the differentiation potential of human primary myoblasts and should be considered as optimum conditions for exvivo expansion of these cells.

Nucleic acid expressed in the hypothalamus or muscle tissue in obese animals

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a sequence encoding a molecule or derivative or homologue thereof wherein said nucleic acid molecule is expressed in a larger amount in one or both hypothalamus tissue or muscle tissue of obese animals compared to lean animals or in fed animals compared to fasted animals. Nucleic acid sequences are disclosed. It is proposed to use the expression products of such nucleic acids as modulators and/or monitors of physiological processes associated with obesity, anorexia, weight maintenance, impaired muscle development, diabetes and/or metabolic energy levels.

Nucleic acid expressed in the hypothalamus or muscle tissue in obese animals

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a sequence encoding a molecule or derivative or homologue thereof wherein said nucleic acid molecule is expressed in a larger amount in one or both hypothalamus tissue or muscle tissue of obese animals compared to lean animals or in fed animals compared to fasted animals. Nucleic acid sequences are disclosed. It is proposed to use the expression products of such nucleic acids as modulators and/or monitors of physiological processes associated with obesity, anorexia, weight maintenance, impaired muscle development, diabetes and/or metabolic energy levels.

Nucleic acid expressed in the hypothalamus or muscle tissue in obese animals

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a sequence encoding a molecule or derivative or homologue thereof wherein said nucleic acid molecule is expressed in a larger amount in one or both hypothalamus tissue or muscle tissue of obese animals compared to lean animals or in fed animals compared to fasted animals. Nucleic acid sequences are disclosed. It is proposed to use the expression products of such nucleic acids as modulators and/or monitors of physiological processes associated with obesity, anorexia, weight maintenance, impaired muscle development, diabetes and/or metabolic energy levels.

Nucleic acid expressed in the hypothalamus or muscle tissue in obese animals

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a sequence encoding a molecule or derivative or homologue thereof wherein said nucleic acid molecule is expressed in a larger amount in one or both hypothalamus tissue or muscle tissue of obese animals compared to lean animals or in fed animals compared to fasted animals. Nucleic acid sequences are disclosed. It is proposed to use the expression products of such nucleic acids as modulators and/or monitors of physiological processes associated with obesity, anorexia, weight maintenance, impaired muscle development, diabetes and/or metabolic energy levels.

Nucleic acid expressed in the hypothalamus or muscle tissue in obese animals

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a sequence encoding a molecule or derivative or homologue thereof wherein said nucleic acid molecule is expressed in a larger amount in one or both hypothalamus tissue or muscle tissue of obese animals compared to lean animals or in fed animals compared to fasted animals. Nucleic acid sequences are disclosed. It is proposed to use the expression products of such nucleic acids as modulators and/or monitors of physiological processes associated with obesity, anorexia, weight maintenance, impaired muscle development, diabetes and/or metabolic energy levels.

Mitrochondrial target discovery in diabetic skeletal muscle

This study identified the protein PARL (Presenilin-associated rhomboid like) as a potential mediator of the mitochondrial abnormalities that are observed in diabetic skeletal muscle. This was demonstrated by analysing PARL expression in an animal model of type 2 diabetes and by investigating the biological effects of genetic variation in the human PARL gene.

Investigation of JAK/STAT signaling in human skeletal muscle

Understanding muscle adaptation and repair is vital for preserving muscle loss with aging. Analysis of the inflammatory-responsive signalling pathway, JAK/STAT was performed. After intense exercise, the STAT3 pathway is highly activated, potentially by the pro-inflammatory regulator IL-6. This pathway is suppressed in older individuals, possible leading to altered inflammatory regulation.

Glycogen-protein associations in human skeletal muscle

The collective findings of this dissertation demonstrated little effect of exercise on the absolute or relative expression of glycogen regulatory proteins associated with a glycogen enriched fraction in human skeletal muscle. However the findings of this thesis help inform methodological approaches to future investigations into glycogen-protein associations.