Epidermal growth factor induces phosphorylation of extracellular signal-regulated kinase 2 via multiple pathways.

Expression of p21rasAsn-17, a dominant negative mutant of p21ras that blocks p21ras activation by growth factors, inhibits activation of extracellular signal-regulated kinase 2 (ERK2) by insulin and platelet-derived growth factor in rat-1 cells [A. M. M. de Vries-Smits, B. M. T. Burgering, S. J. Leevers, C. J. Marshall, and J. L. Bos, Nature (London) 357:602-604, 1992]. Here we report that expression of p21rasAsn-17 does not abolish epidermal growth factor (EGF)-induced phosphorylation of ERK2 in fibroblasts. Since EGF activates p21ras in these cells, this indicates that EGF induces a p21ras-independent pathway for the phosphorylation of ERK2 as well. We investigated whether activation of protein kinase C (PKC) or increase in intracellular calcium could be involved in p21ras-independent signaling. In rat-1 cells, inhibition of either PKC, by prolonged 12-O-tetradecanoylphorbol-13-acetate (TPA) pretreatment, or calcium influx, by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) pretreatment, did not abolish EGF-induced ERK2 phosphorylation. However, a combined inhibition of both p21ras and calcium influx, but not PKC, resulted in a complete inhibition of EGF-induced ERK2 phosphorylation. In contrast, in Swiss 3T3 cells, inhibition of both p21ras activation and TPA-sensitive PKC, but not calcium influx, inhibited EGF-induced ERK2 phosphorylation. These results demonstrate that in fibroblasts, EGF induces alternative pathways of ERK2 phosphorylation in a cell-type-specific manner.     

Localisation of the Vacuolar Proton Pump (V-H+-ATPase) and Carbonic Anhydrase II in the Human Eccrine Sweat Gland

The localisation of the vacuolar proton pump (V-H+ -ATPase) and the enzyme carbonic anhydrase II (CAII) was investigated in the human eccrine sweat gland employing standard immunohistochemical techniques after antigen retrieval using microwave heat treatment and high pressure. The high-pressure antigen retrieval unmasked the presence of V-H+ -ATPase in the clear cells of the secretory coil, with a distribution similar to that previously observed for CAII. However, the dark cells were unreactive to both antibodies. In addition, heat and high-pressure antigen retrieval demonstrated the presence of CAII in the apical zone of luminal cells of the reabsorptive duct, a location not previously reported. The localisation of V-H+ -ATPase and CAII in the secretory coil clear cells suggests that the formation of HCO3- and H+ by carbonic anhydrase II and the transport of H+ by V-H+ -ATPase may play an role in sweat fluid secretion. Their presence at the apex of the duct cells indicates involvement in ductal ion reabsorption.     

Molecular nuclear therapies for thyroid carcinoma

Thyroid cancer, divided in the subvarieties of papillary and follicular carcinoma, together also called differentiated thyroid carcinoma (DTC), medullary thyroid carcinoma (MTC) and anaplastic thyroid carcinoma (ATC), is the most common endocrine malignancy. Over the course of the last seven decades multiple molecular nuclear therapies have been tried to treat the various varieties of thyroid cancer. The sodium iodine symporter (NIS) substrate I-131 is a well known and extremely successful agent to treat DTC, but is not successful in treating other thyroid cancer varieties and some de-differentiated DTC tumors. An alternative to I-131 are radioactively labeled somatostatin analogues, which have predominantly been used to target MTC, but may also be effective in some DTC cases. In experimental preclinical studies the re-induction of NIS expression or transfection with recombinant NIS shows some promise for the treatment of ATC and dedifferentiated DTC. Furthermore, several other potential radioactive NIS substrates are developed. In this review, we will extensively discuss the aforementioned established therapeutic modalities and promising new concepts in molecular nuclear therapy of thyroid carcinoma.     

Differential expression and function of breast regression protein 39 (BRP-39) in murine models of subacute cigarette smoke exposure and allergic airway inflammation

Background

While the presence of the chitinase-like molecule YKL40 has been reported in COPD and asthma, its relevance to inflammatory processes elicited by cigarette smoke and common environmental allergens, such as house dust mite (HDM), is not well understood. The objective of the current study was to assess expression and function of BRP-39, the murine equivalent of YKL40 in a murine model of cigarette smoke-induced inflammation and contrast expression and function to a model of HDM-induced allergic airway inflammation.

Methods

CD1, C57BL/6, and BALB/c mice were room air- or cigarette smoke-exposed for 4 days in a whole-body exposure system. In separate experiments, BALB/c mice were challenged with HDM extract once a day for 10 days. BRP-39 was assessed by ELISA and immunohistochemistry. IL-13, IL-1R1, IL-18, and BRP-39 knock out (KO) mice were utilized to assess the mechanism and relevance of BRP-39 in cigarette smoke- and HDM-induced airway inflammation.

Results

Cigarette smoke exposure elicited a robust induction of BRP-39 but not the catalytically active chitinase, AMCase, in lung epithelial cells and alveolar macrophages of all mouse strains tested. Both BRP-39 and AMCase were increased in lung tissue after HDM exposure. Examining smoke-exposed IL-1R1, IL-18, and IL-13 deficient mice, BRP-39 induction was found to be IL-1 and not IL-18 or IL-13 dependent, while induction of BRP-39 by HDM was independent of IL-1 and IL-13. Despite the importance of BRP-39 in cellular inflammation in HDM-induced airway inflammation, BRP-39 was found to be redundant for cigarette smoke-induced airway inflammation and the adjuvant properties of cigarette smoke.

Conclusions

These data highlight the contrast between the importance of BRP-39 in HDM- and cigarette smoke-induced inflammation. While functionally important in HDM-induced inflammation, BRP-39 is a biomarker of cigarette smoke induced inflammation which is the byproduct of an IL-1 inflammatory pathway.     

Increase in prevalence of overweight in Dutch children and adolescents: a comparison of nationwide growth studies in 1980, 1997 and 2009

Objective

To assess the prevalence of overweight and obesity among Dutch children and adolescents, to examine the 30-years trend, and to create new body mass index reference charts.

Design

Nationwide cross-sectional data collection by trained health care professionals.Participants: 10,129 children of Dutch origin aged 0–21 years.

Main Outcome Measures

Overweight (including obesity) and obesity prevalences for Dutch children, defined by the cut-off values on body mass index references according to the International Obesity Task Force.

Results

In 2009, 12.8% of the Dutch boys and 14.8% of the Dutch girls aged 2–21 years were overweight and 1.8% of the boys and 2.2% of the girls were classified as obese. This is a two to three fold higher prevalence in overweight and four to six fold increase in obesity since 1980. Since 1997, a substantial rise took place, especially in obesity, which increased 1.4 times in girls and doubled in boys. There was no increase in mean BMI SDS in the major cities since 1997.

Conclusions

Overweight and obesity prevalences in 2009 were substantially higher than in 1980 and 1997. However, the overweight prevalence stabilized in the major cities. This might be an indication that the rising trend in overweight in the Netherlands is starting to turn.