Calcitonin induces connective tissue growth factor through ERK1/2 signaling in renal tubular cells.

Calcitonin (CT), a polypeptide hormone, plays important roles in a variety of physiological processes. CT has been used clinically to treat osteoporosis and humoral hypercalcemia of malignancy. In order to clarify the pharmacological effects of CT in the kidney, we identified potential downstream genes induced by CT in the renal cells. Using a cDNA subtraction hybridization method, we identified connective tissue growth factor (CTGF) as a CT-induced gene in the porcine renal cell line, LLC-PK1. Furthermore, we found that CT-mediated induction of the gene was not inhibited by cycloheximide, which suggests that CTGF gene was not induced by an increased synthesis of regulating proteins. Therefore, CTGF is an immediate early gene. We further demonstrated that the regulation of CTGF gene expression by CT involved the ERK1/2 pathway, because PD98059, a MEK1 inhibitor, partially inhibited the mRNA expression of CTGF induced by CT. CT-induced CTGF protein expression was also observed in vivo. Our present findings suggest that CT induces the transcription of CTGF through ERK1/2 phosphorylation. We also identified twelve other genes induced by CT that, like CTGF, were related to wound healing. These results suggest that CT may have an effect on renal differentiation and wound healing in the kidney.

A case of pulmonary intravascular lymphomatosis diagnosed by thoracoscopic lung biopsy.

Intravascular lymphomatosis with primary pulmonary lesion is an extremely rare disease. Although the major clinical symptoms include fever, cough, dyspnea and loss of body weight, these are not diagnostic. Chest radiograph findings are also nonspecific and include bilateral reticular shadow, reticulonodular shadow, ground-glass opacity or wedge-shaped subpleural opacities. Therefore, the antemortem diagnosis is relatively difficult. It is considered that intravascular lymphomatosis is a high-grade malignant lymphoma. However, it has been shown recently that a good response and long-term survival may possibly be obtained through systemic combination chemotherapy. We report a case of intravascular lymphomatosis with primary pulmonary lesion where an early diagnosis was obtained through thoracoscopic lung biopsy and subsequent systemic chemotherapy proved to be quite effective. Because the clinical symptoms or chest radiograph findings are usually nonspecific, it was thought that thoracoscopic lung biopsy could be a useful procedure for early and reliable diagnosis of primary pulmonary intravascular lymphomatosis and that it might contribute to an improved prognosis.