In vitro analysis of transport and metabolism of 4'-thiothymidine in human tumor cells.

Introduction: The use of thymidine (TdR) and thymidine analogs such as 3'-fluoro-3'-deoxythymidine (FLT) as positron emission tomography (PET)-based proliferation markers can provide information on tumor response to treatment. Studies on another TdR analog, 4'-thiothymidine (4DST), suggest that it might be a better PET-based proliferation tracer than either TdR or FLT. 4DST is resistant to the catabolism that complicates analysis of TdR in PET studies, but unlike FLT, 4DST is incorporated into DNA.

Role of lung pericytes and resident fibroblasts in the pathogenesis of pulmonary fibrosis.

Rationale: The origin of cells that make pathologic fibrillar collagen matrix in lung disease has been controversial. Recent studies suggest mesenchymal cells may contribute directly to fibrosis.

Objectives: To characterize discrete populations of mesenchymal cells in the normal mouse lung and to map their fate after bleomycin-induced lung injury.

Transforming growth factor β-1 stimulates profibrotic epithelial signaling to activate pericyte-myofibroblast transition in obstructive kidney fibrosis.

Pericytes have been identified as the major source of precursors of scar-producing myofibroblasts during kidney fibrosis. The underlying mechanisms triggering pericyte-myofibroblast transition are poorly understood. Transforming growth factor β-1 (TGF-β1) is well recognized as a pluripotent cytokine that drives organ fibrosis.

MicroRNA-21 promotes fibrosis of the kidney by silencing metabolic pathways.

Scarring of the kidney is a major public health concern, directly promoting loss of kidney function. To understand the role of microRNA (miRNA) in the progression of kidney scarring in response to injury, we investigated changes in miRNA expression in two kidney fibrosis models and identified 24 commonly up-regulated miRNAs. Among them, miR-21 was highly elevated in both animal models and in human transplanted kidneys with nephropathy.