Lead discovery of alpha,beta-unsaturated sulfones from a combinatorial library as inhibitors of inducible VCAM-1 expression

alpha,beta-Unsaturated sulfones have been discovered from a combinatorial library as leads for a new series of inhibitors of inducible VCAM-1 expression. Although not essential, further conjugation of the sulfonyl group to another vinyl group or a phenyl group increases the potency dramatically.     

Cell wall reactive proteins in the coat and wall of maize pollen: potential role in pollen tube growth on the stigma and through the style

The surface of a pollen grain consists of an outermost coat and an underlying wall. In maize (Zea mays L.), the pollen coat contains two major proteins derived from the adjacent tapetum cells in the anthers. One of the proteins is a 35-kDa endoxylanase (Wu, S. S. H., Suen, D. F., Chang, H. C., and Huang, A. H. C. (2002) J. Biol. Chem. 277, 49055-49064). The other protein of 70 kDa was purified to homogeneity and shown to be a beta-glucanase. Its gene sequence and the developmental pattern of its mRNA differ from those of the known beta-glucanases that hydrolyze the callose wall of the microspore tetrad. Mature pollen placed in a liquid medium released about nine major proteins. These proteins were partially sequenced and identified via GenBank trade mark data bases, and some had not been previously reported to be in pollen. They appear to have wall-loosening, structural, and enzymatic functions. A novel pollen wall-bound protein of 17 kDa has a unique pattern of cysteine distribution in its sequence (six tandem repeats of CX3CX10-15) that could chelate cations and form signal-receiving finger motifs. These pollen-released proteins were synthesized in the pollen interior, and their mRNA increased during pollen maturation and germination. They were localized mainly in the pollen tube wall. The pollen shell was isolated and found to contain no detectable proteins. We suggest that the pollen-coat beta-glucanase and xylanase hydrolyze the stigma wall for pollen tube entry and that the pollen secrete proteins to loosen or become new wall constituents of the tube and to break the wall of the transmitting track for tube advance.     

Concanavalin A induced apoptosis in murine macrophage PU5-1.8 cells through clustering of mitochondria and release of cytochrome c

Concanavalin A (ConA), normally a mitogen of T-lymphocytes, was found to be a cell cycle-independent apoptosis-inducing agent in cultured murine macrophage PU5-1.8 cells. This assertion is based on the following observations: (1) ConA increased the number of cells with hypo-diploid DNA in a dose dependent manner as revealed by flow cytometry; (2) ConA elicited DNA fragmentation and the cytotoxicity of ConA was suppressed by -D-methylmannoside which blocks the lectin site of ConA; (3) ConA was able to release cytochrome c (cyto c) into the cytosol of PU5-1.8 cells. When isolated mitochondria were incubated with ConA, release of cyto c was observed too. Interestingly, clustering of mitochondria was found in the cytosol under a confocal microscope after ConA treatment. When cells were incubated with ConA-FITC and subsequently with mitotracker red (a probe for mitochondria), co-localization of fluorescence signals was observed. These results suggest that ConA was delivered to the mitochondria, induced mitochondrial clustering and released cyto c. Our results also show that introduction of exogenous cyto c electroporationally into ConA-untreated cells elicited DNA fragmentation. On the other hand, introduction of specific antibody against cyto c into PU5-1.8 cells suppressed the ConA-mediated cell death. Taken together, our results indicate that ConA induced apoptosis in PU5-1.8 cells through mitochondrial clustering and release of cyto c and the release of cyto c was sufficient to elicit apoptosis in PU5-1.8 cells.     

Expression of GABA Receptor ρ Subunits in Rat Brain

Abstract: The GABA receptor ρ1, ρ2, and ρ3 subunits are expressed in the retina where they form bicuculline-insensitive GABA_C receptors. We used northern blot, in situ hybridization, and RT-PCR analysis to study the expression of ρ subunits in rat brains. In situ hybridization allowed us to detect ρ-subunit expression in the superficial gray layer of the superior colliculus and in the cerebellar Purkinje cells. RT-PCR experiments indicated that (a) in retina and in domains that may contain functional GABA_C receptors, ρ2 and ρ1 subunits are expressed at similar levels; and (b) in domains and in tissues that are unlikely to contain GABA_C receptors, ρ2 mRNA is enriched relative to ρ1 mRNA. These results suggest that both ρ1 and ρ2 subunits are necessary to form a functional GABA_C receptor. The use of RT-PCR also showed that, except in the superior colliculus, ρ3 is expressed along with ρ1 and ρ2 subunits. We also raised an antibody against a peptide sequence unique to the ρ1 subunit. The use of this antibody on cerebellum revealed the rat ρ1 subunit in the soma and dendrites of Purkinje neurons. The allocation of GABA_C receptor subunits to identified neurons paves the way for future electrophysiological studies.     

Chemotherapy-Related Amenorrhea and Menopause in Young Chinese Breast Cancer Patients: Analysis on Incidence,Risk Factors and Serum Hormone Profiles

Purpose

In this prospective cross-sectional study on young premenopausal breast cancer patients, the objectives were to: determine the incidences of chemotherapy-related amenorrhea (CRA) and menopause (CRM); identify associated factors; and assess plasma levels of estradiol (E2) and follicular stimulating hormone (FSH) among patients who developed menopause.

Methods

Eligibility criteria include Chinese stage I-III breast cancer patients, premenopausal, age ≤45 at breast cancer diagnosis, having received adjuvant chemotherapy, within 3–10 years after breast cancer diagnosis. Detailed menstrual history prior to and after adjuvant treatment was taken at study entry. Patients’ background demographics, tumor characteristics and anti-cancer treatments were collected. The rates of CRA and CRM were determined. Analysis was conducted to identify factors associated with CRM. For postmenopausal patients, levels of E2 and FSH were analyzed.

Results

286 patients were recruited; the median time from breast cancer diagnosis to study entry was 5.0 years. 255 patients (91.1%) developed CRA. Of these, 66.7% regained menstruation. At the time of study entry, 137 (48.9%) had developed CRM, amongst whom 84 were age ≤45. On multivariate analysis, age was the only associated factor. Among patients with CRM, the median FSH was 41.0 IU/L; this was significantly lower in those who were taking tamoxifen compared to those who were not (20.1 vs. 59.7 IU/L, p<0.0001). The E2 level was <40 pmol/L; there was no difference between those who were still on tamoxifen or not.

Conclusion

After adjuvant chemotherapy, the majority of young Chinese breast cancer patients developed CRA; ~50% developed CRM, with 61% at age ≤45. Age at diagnosis is the only factor associated with CRM. FSH level may be affected by tamoxifen intake.