We investigated the possibility of a direct action of androgens on the expression of the human corticotropin-releasing hormone (CRH), which plays a central role in the hypothalamicpituitary-adrenal (HPA)-axis. Colocalization of CRH and nuclear/cytoplasmic androgen receptor (AR) was found in neurons of the paraventricular nucleus (PVN) in the human hypothalamus. A potential androgen-responsive element (ARE) in the human CRH promoter was subsequently analyzed with bandshifts and cotransfections in neuroblastoma cells. In the presence of testosterone, recombinant human AR bound specifically to the CRH-ARE. Expression of AR in combination with testosterone repressed CRH promoter activity through the ARE. We conclude that androgens may directly affect CRH neurons in the human PVN via AR binding to the CRH-ARE, which may have consequences for sex-specific pathogenesis of mood disorders.

Glucose 6-phosphate dehydrogenase (G6PD) deficiency, known as favism, is classically manifested by hemolytic anemia in human. More recently, it has been shown that mild G6PD deficiency moderately affects cardiac function, whereas severe G6PD deficiency leads to embryonic lethality in mice. How G6PD deficiency affects organisms has not been fully elucidated due to the lack of a suitable animal model. In this study, G6PD-deficient Caenorhabditis elegans was established by RNA interference (RNAi) knockdown to delineate the role of G6PD in animal physiology. Upon G6PD RNAi knockdown, G6PD activity was significantly hampered in C. elegans in parallel with increased oxidative stress and DNA oxidative damage. Phenotypically, G6PD-knockdown enhanced germ cell apoptosis (2-fold increase), reduced egg production (65% of mock), and hatching (10% of mock). To determine whether oxidative stress is associated with G6PD knockdown-induced reproduction defects, C. elegans was challenged with a short-term hydrogen peroxide (H2O2). The early phase egg production of both mock and G6PD-knockdown C. elegans were significantly affected by H2O2. However, H2O2-induced germ cell apoptosis was more dramatic in mock than that in G6PD-deficient C. elegans. To investigate the signaling pathways involved in defective oogenesis and embryogenesis caused by G6PD knockdown, mutants of p53 and mitogen-activated protein kinase (MAPK) pathways were examined. Despite the upregulation of CEP-1 (p53), cep-1 mutation did not affect egg production and hatching in G6PD-deficient C. elegans. Neither pmk-1 nor mek-1 mutation significantly affected egg production, whereas sek-1 mutation further decreased egg production in G6PD-deficient C. elegans. Intriguingly, loss of function of sek-1 or mek-1 dramatically rescued defective hatching (8.3- and 9.6-fold increase, respectively) induced by G6PD knockdown. Taken together, these findings show that G6PD knockdown reduces egg production and hatching in C. elegans, which are possibly associated with enhanced oxidative stress and altered MAPK pathways, respectively.

Reduced DNA repair capability is associated with developing lung cancer, especially in nonsmokers. XPC participates in the initial recognition of DNA damage during the DNA nucleotide excision repair process. We hypothesize that inactivation of XPC by promoter hypermethylation may play an important role in the reduction of DNA repair capability to cause p53 mutation during lung carcinogenesis. In this report we demonstrate that hypermethylation of 17 CpG islands between À175 and À1 of the XPC promoter correlates very well with XPC expression levels in eight lung cancer cell lines. When cells with hypermethylated XPC promoters were treated with the demethylating agent 5-aza-2 0 -deoxycytidine, XPC expression was de-repressed. Interestingly, XPC hypermethylation was found in 4 of 5 (80%) lung cancer cell lines harbored p53 mutation, but not observed in two lung cancer cells which had a wild-type p53 gene. Among the analysis of the hypermethylation status of 158 lung tumors, XPC hypermethylation is more common in nonsmokers (39 of 94, 41%) than in smokers (14 of 64, 22%; P ¼ 0.010). Additionally, XPC hypermethylation is more often with G-T or G-C mutations in the p53 gene. To verify whether XPC inactivation is involved in the occurrence of p53 mutation, XPC gene of A549 cells was knockdown by a small interference RNA and then XPC-inactivated cells were treated with benzo[a]pynrene for different passages. Surprisingly, G-T mutation in p53 gene at codon 215 was indeed detected in XPCinactivated A549 cells of passages 15 and confirmed by loss of transcription activity of mdm2. These results show that hypermethylation of the XPC promoter may play a crucial role in XPC inactivation, which may partly contribute to the occurrence of p53 mutations during lung tumorigenesis, especially nonsmokers.

Pulsed electric fields with nanosecond duration and high amplitude have effects on biological subjects and bring new venue in disease diagnosis and therapy. To address this respect, we investigated the responses of paired tumor and normal human skin cells - a basal cell carcinoma (BCC) cell line, and its sister normal cell line (TE) - to nanosecond, megavolt-per-meter pulses. When BCC (TE 354.T) and TE (TE 353.SK) cells, cultured under standard conditions, were exposed to 30 ns, 3 MV/m, 50 Hz pulses and tested for membrane permeabilization, viability, morphology, and caspase activation, we found that nanoelectropulse exposure: 1) increased cell membrane permeability in both cell lines but to a greater extent in BCC cells than in normal cells; 2) decreased cell viabilities with BCC cells affected more than normal cells; 3) induced morphological changes in both cell lines including condensed and fragmented chromatin with enlarged nuclei; 4) induced about twice as much caspase activation in BCC cells compared to normal cells. We concluded that in paired tumor and normal skin cell lines, the response of the tumor cells to nanoelectropulse exposure is stronger than the response of normal cells, indicating the potential for selectivity in therapeutic applications.

Leukocyte adhesion to endothelium plays a critical initiating role in inflammation. Berberine, an antiinflammatory natural compound, is known to attenuate lipopolysaccharide (LPS)-induced lung injury and improve survival of endotoxemic animals with mechanism not fully clarified. This study investigated the effects of berberine on the LPS-induced leukocyte-endothelial cell adhesion both in vivo and in vitro. We first established an animal model to observe the in vivo LPS-induced adhesion of leukocytes to the endothelium of venules in the lung tissue dose-dependently. Pretreatment of LPS-stimulated rats with berberine for 1 h reduced the leukocyte-endothelium adhesion and vascular cell adhesion molecule-l (VCAM-l) expression in lung. Pretreatment of LPS-stimulated vascular endothelial cells with berberine also dose-dependently decreased the number of adhered THP-l cells and VCAM-l expression at both RNA and protein levels. Berberine was further confirmed to inhibit the nuclear translocation and DNA binding activity of LPS-activated nuclear factor-kappa B (NF-kappa B). These data demonstrated an additional molecular mechanism for the profound anti-inflammatory effect of berberine.