Endocrine Abstracts

Trans-differentiation of osteoblasts to adipocytes may in part be responsible for diseases such as osteoporosis and arthritis. The processes involved are however complex and largely unknown. Our previous data showed that the adenosine A2b receptor (A2bR) is important for human osteoprogenitor cell function. In this study, we investigated the expression of adenosine receptors in an osteoblast cell line (7F2) and during its differentiation into adipocytes (7F2A).<p class="ab...

Osteoblasts and adipocytes are derived from mesenchymal stem cells (MSC), although the mechanisms involved are not fully understood. Our previous findings showed that MSCs express functional adenosine receptors (ARs) and that adenosine stimulates osteoblastogenesis. Here we describe changes in AR expression as MSCs differentiate into osteoblasts and adipocytes, and provide evidence that ARs are involved in these differentiation pathways.Rat MSCs were dif...

Neuroendocrine tumours of the GI tract originate from enterochromaffin cells. Somatostatin analogues are the mainstay drugs for therapy in these cancers as they ameliorate symptoms and lower hormone secretion, but only in 30–70% of patients. Such tumours are also associated with angiogenesis which has been used as a prognostic indicator; adenosine, the major regulator of angiogenesis, is released by enhanced degradation of ATP, during cellular stress, damage and hypoxia.<...

Introduction: Neuroendocrine tumors of GI tract are a heterogeneous group of rare neoplasms that secrete peptides and amines. These tumors are highly vascular and their vascularity reflects increased tumour related angiogenesis. Adenosine, a major regulator of angiogenesis, is released by enhanced degradation of ATP, during cellular stress, damage and hypoxia.Material and methods: The expression of adenosine receptors (AR) was investigated in two human n...

Obesity (excess adipose tissue generated by hypertrophy and hyperplasia) predisposes to poor health. Adipogenesis (hyperplasia) involves the differentiation of adherent preadipocytes into non-adherent adipocytes and is accompanied by alterations to the extracellular matrix of which hyaluronan (HA) is a component. Used in vitro to promote lineage specific differentiation, little is known of HA’s role in adipogenesis. We hypothesise that HA modifications must occur d...

Pluripotent mesenchymal stem cells (MSCs) have the capacity to differentiate into osteoblasts, adipocytes and chondrocytes and are characterised by expression of CD105, CD90 and CD73. CD73 is the enzyme that dephosphorylates AMP to adenosine. The role of adenosine in MSCs is unknown and we have thus investigated whether it plays a role in the differentiation process to osteoblasts.MSCs, obtained from the bone marrow of 10 week old male rats, were expande...

Folliculostellate (FS) cells within the anterior pituitary gland produce cytokines and growth factors which are regulated by molecules produced by neighbouring endocrine cells. There are many factors that could potentially be responsible for this intercellular communication that is mediated via connexins (Cx) and gap-junctions. We thus investigated the effect of co-culturing lactotrophs (MMQ) and FS cells (TtT/GF) on Cx43 expression. Our in vitro model system consists o...

Bone marrow stem cells (BMSCs) are able to differentiate along multiple lineages including adipogenic and osteogenic lineages. The adenosine A1 receptor (A1R) modulates adipose tissue function causing an inhibition of lipolysis. We therefore studied A1R expression in BMSCs induced to differentiate along the adipogenic lineage.BMSCs were isolated from rat femur (10 wk male Wistar), cultured in control medium (alphaMEM 10% FCS) and then plated into adipocy...