Keratinocyte growth factor causes proliferation of urothelium in vivo.

PURPOSE: To determine the effect of keratinocyte growth factor (KGF), a mesenchymally derived epithelial growth factor that can cause proliferation of pulmonary, gastrointestinal and mammary epithelia, on urothelium. MATERIALS AND METHODS: Recombinant human KGF was systemically administered to rats and Rhesus monkeys, and the proliferative effects on the bladder were evaluated. RESULTS: Keratinocyte growth factor causes proliferation of transitional epithelial cells. Proliferating cell nuclear antigen (PCNA) expression in rat bladder is dramatically increased along the basal layer of urothelium 1, 3, 7 and 14 days after daily injections of KGF. Incorporation of 5-bromodeoxyuridine (BrdU) at 7 and 14 days in the urothelium of KGF-treated rats parallels PCNA immunoreactivity and confirms that KGF increases DNA synthesis in urothelial cells. Urothelial cell proliferation is accompanied histologically by an increase in mitotic activity. Keratinocyte growth factor-induced PCNA expression is reversible upon cessation of KGF administration. Keratinocyte growth factor mRNA and receptor mRNA are detected by whole organ RNAase protection assays of the urinary bladder and the kidney of normal rats. Rhesus monkeys receiving KGF for 7 days demonstrate a dramatic incorporation of BrdU in the urothelium of the bladder and renal pelvis as well as in the collecting ducts of the kidney. CONCLUSION: Systemic administration of KGF causes rapid and striking proliferation of urothelium.

Keratinocyte growth factor causes cystic dilation of the mammary glands of mice. Interactions of keratinocyte growth factor, estrogen, and progesterone in vivo.

Keratinocyte growth factor (KGF) is a paracrine mediator of epithelial cell proliferation that has been reported to induce marked proliferation of mammary epithelium in rats. In this study, systemic administration of KGF into naive and oophorectomized mice causes mammary gland proliferation, as evidenced histologically by the appearance of cysts lined by a single layer of epithelium and by hyperplastic epithelium. Whole mount preparations of the mammary glands reveal that the histologically noted cysts are actually ducts that are dilated along much of their length. The histology of the mammary glands of KGF-treated mice is similar to the histology of fibrocystic disease in the human female breast. The response in mice differs significantly from the appearance of the mammary glands in KGF-treated rats in which ductal epithelial proliferation is most prominent. Estrogen and progesterone when administered in combination but not alone cause the development of numerous endbuds in the mouse mammary gland. KGF in estrogen- and progesterone-pretreated mice causes the growth of dilated ducts, hyperplastic epithelium within ducts and endbuds, and a fibrous metamorphosis of periductal adipose tissue. The mammary epithelial hyperplasia caused by KGF is rapidly reversible in both mice and rats after cessation of KGF treatment. The spectrum of KGF-, estrogen-, and progesterone-induced mammary histopathology in mice provides a model for the study of fibrocystic and hyperplastic breast disease.

Keratinocyte growth factor induces proliferation of hepatocytes and epithelial cells throughout the rat gastrointestinal tract.

Keratinocyte growth factor (KGF), a member of the fibroblast growth factor (FGF) family, was identified as a specific keratinocyte mitogen after isolation from a lung fibroblast line. Recently, recombinant (r)KGF was found to influence proliferation and differentiation patterns of multiple epithelial cell lineages within skin, lung, and the reproductive tract. In the present study, we designed experiments to identify additional target tissues, and focused on the rat gastrointestinal (GI) system, since a putative receptor, K-sam, was originally identified in a gastric carcinoma. Expression of KGF receptor and KGF mRNA was detected within the entire GI tract, suggesting the gut both synthesized and responded to KGF. Therefore, rKGF was administered to adult rats and was found to induce markedly increased proliferation of epithelial cells from the foregut to the colon, and of hepatocytes, one day after systemic treatment. Daily treatment resulted in the marked selective induction of mucin-producing cell lineages throughout the GI tract in a dose-dependent fashion. Other cell lineages were either unaffected (e.g., Paneth cells), or relatively decreased (e.g., parietal cells, enterocytes) in rKGF-treated rats. The direct effect of rKGF was confirmed by demonstrating markedly increased carcinoembryonic antigen production in a human colon carcinoma cell line, LIM1899. Serum levels of albumin were specifically and significantly elevated after daily treatment. These results demonstrate rKGF can induce epithelial cell activation throughout the GI tract and liver. Further, endogenous KGF may be a normal paracrine mediator of growth within the gut.

Keratinocyte growth factor induces pancreatic ductal epithelial proliferation.

Keratinocyte growth factor (KGF) causes a proliferation of pancreatic ductal epithelial cells in adult rats after daily systemic administration for 1 to 2 weeks. Even before the proliferation of intralobular ducts is histologically evident, KGF also induces proliferating cell nuclear antigen expression within the ductal epithelium of intercalated, intralobular, and interlobular ducts. KGF also causes incorporation of 5-bromodeoxyuridine in ductal epithelial cells. Epithelial cell proliferation is histologically most prominent at the level of the intralobular ducts adjacent to and within the islets of Langerhans. Pancreatic ductal proliferation is not histologically apparent in rats sacrificed 7 to 10 days after the cessation of KGF administration. The pancreatic hormones insulin, glucagon, somatostatin, and pancreatic polypeptide are normally distributed within islets that demonstrate intrainsular ductal proliferation. The proliferating ductal epithelium does not show endocrine differentiation as evidenced by the lack of immunoreactivity for pancreatic hormones. KGF is a potent in vivo mitogen for pancreatic ductal epithelial cells.

Keratinocyte growth factor is a growth factor for type II pneumocytes in vivo.

Keratinocyte growth factor (KGF) administered as a single intratracheal injection causes a prominent dose-dependent proliferation of type II alveolar epithelial cells in the lungs of adult rats. The increase in mitotically active alveolar cells histologically appears as a micropapillary epithelial cell hyperplasia after 2 d and peaks after 3 d in the form of monolayers of cuboidal epithelial cells lining alveolar septae. Proliferating cell nuclear antigen immunohistochemistry confirmed the profound proliferative response induced by KGF. The hyperplastic alveolar lining cells contain immunoreactive surfactant protein B and are ultrastructurally noted to contain lamellar inclusions characteristic of surfactant-producing type II pneumocytes. Mild focal bronchiolar epithelial hyperplasia is noted but is much less striking than the proliferation of type II pneumocytes. Large airways are unaffected by KGF. Daily intravenous injection of KGF is also able to cause pneumocyte proliferation. The normal adult rat lung constitutively expresses both KGF and KGF receptor mRNA, suggesting that endogenous KGF may be implicated in the paracrine regulation of the growth of pneumocytes. In conclusion, KGF rapidly and specifically induces proliferation and differentiation of type II pneumocytes in the normal adult lung.

Crystallization studies of lunar igneous rocks: crystal structure of synthetic armalcolite.

Crystals of armalcolite, Mg(0.5)Fe(0.5)Ti(2)O(5), up to several millimeters in length have been grown from a glass initially having the composition of lunar rock 10017. A single-crystal x-ray study has confirmed that the crystals are isomorphous with pseudobrookite and has shown that the cations are strongly ordered, with the Ti(4+) ions occupying the 8f sites and the Fe(2+) and Mg(2+) ions randomly distributed over the 4c sites. An examination of karrooite, MgTi(2)O(5), has revealed a similar distribution of Mg(2+) and Ti(4+) ions. A reexamination of earlier x-ray and Mössbauer data for pseudobrookite, Fe(2)TiO(5), has shown that it is more consistent with this type of ordering than with the inverse structure that has been generally assumed.

Mossbauer spectroscopy of moon samples.

Lunar bulk sample 10084,85 (< 1 mm size dust), and samples from rocks 10017,17 (fine grained, vesicular), 10046,17 (breccia), 10057,59 (fine grained, vesicular, top surface), 10057,60 (fine grained, vesicular, interior), and 10058,24 (medium grained, not vesicular) have been investigated by (57)Fe Mössbauer spectroscopy. Iron metal and the Fe(2+) minerals ilmenite, pyroxene, troilite, and iron containing glass have been identified. An iron line of sample 10084,85 (originally sealed in nitrogen) showed no significant intensity change when the sample was exposed to air. The antiferromagnetic transition in several lunar ilmenites at 57(0) +/- 2 degrees K corresponds to stoichiometric FeTiO,. Magneticallv separated 10057 showed troilite and somne metallic iron.