The H 2 O 2 -catabolizing peroxidase activity of human peroxiredoxin I (hPrxI) was previously shown to be regulated by phosphorylation of Thr 90 . Here, we show that hPrxI forms multiple oligomers with distinct secondary structures. HPrxI is a dual function protein, since it can behave either as a peroxidase or as a molecular chaperone. The effects of phosphorylation of hPrxI on its protein structure and dual functions were determined using site-directed mutagenesis, in which the phosphorylation site was substituted with aspartate to mimic the phosphorylated status of the protein (T90D-hPrxI). Phosphorylation of the protein induces significant changes in its protein structure from low molecular weight (MW) protein species to high MW protein complexes as well as its dual functions. In contrast to the wild type (WT)-and T90A-hPrxI, the T90D-hPrxI exhibited a markedly reduced peroxidase activity, but showed about sixfold higher chaperone activity than WT-hPrxI.

Most solid tumor tissues possess a significant population of macrophages, which are known to be closely linked with tumor progression and metastasis. Clusterin has been reported to be overexpressed in various tumors and to have a tumor-promoting role. As clusterin induction and macrophage infiltration occur concurrently at the tumor site, it raises a possibility that clusterin may regulate the function of macrophages via facilitating ECM remodeling. Here, we demonstrate for the first time the expression of MMP-9 by clusterin in human primary monocytes as well as human and murine macrophage cell lines, THP-1, and Raw264.7. MMP-9 expression was accompanied by increased enzymatic activity, as revealed by gelatin zymography. The MMP-9 activity promoted by clusterin was found to be dependent on the activation of ERK1/2 and PI3K/Akt but not p38 or JNK pathways. Inhibition of PI3K activity did not affect the activation of ERK1/2 and vice versa, indicating that the two pathways were independently operated to stimulate MMP-9 activity. Moreover, clusterin facilitated nuclear translocation of NF-κB p65 along with IκB-α degradation and phosphorylation, which was critical for MMP-9 expression. As NF-κB is a central regulator of inflammation, clusterin may provide a molecular link between inflammation and cancer via up-regulating NF-κB and MMP-9. Collectively, these data highlight a novel role of clusterin as a stimulator for MMP-9 expression in macrophages, which may contribute to the tissue reorganization by serving as a modulator for ECM degradation.

BackgroundBenign prostatic hyperplasia (BPH) is one of the common male diseases, which is provoked by dihydrotestosterone (DHT) and androgen signals. Several studies showed that curcumin has various effects of prevention and treatment to diseases. We investigated whether curcumin may repress the development of BPH in male Wistar rats.MethodsSeven weeks male Wistar rats were and divided into 4 groups (normal group, BPH group, finasteride group, curcumin group; n = 8 for each group). In order to induce BPH in rats, rats were castrated and testosterone was injected subcutaneously everyday (s.c., 20 mg/kg). Rats in the curcumin group were treated 50 mg/kg, administered orally for 4 weeks. After 4 weeks, all rats were sacrificed and their prostate and serum were analyzed.ResultsCompared to the finasteride group as positive group, the curcumin group showed similarly protective effect on BPH in histopathologic morphology, prostate volume. Results of immunohistochemistry and western-blot showed decreased expressions of VEGF, TGF-ß1, and IGF1 were also decreased in the curcumin group.ConclusionsThese results suggested that curcumin inhibited the development of BPH and might a useful herbal treatment or functional food for BPH.

Cytochrome P450 1B1 (CYP1B1) is recognized as a universal tumor biomarker and a feasible therapeutic target due to its specific overexpression in cancer tissues. Despite its up-regulation in prostate cancer (PCa), biological significance and clinicopathological features of CYP1B1 are still elusive. Here, we show that overexpression or hyperactivation of CYP1B1 stimulated proliferative, migratory and invasive potential of non-tumorigenic PCa cells. Attenuation of CYP1B1 with its specific small hairpin (sh) RNAs greatly reduced proliferation through apoptotic cell death and impaired migration and invasion in PCa cells. Intratumoral injection of CYP1B1 shRNA attenuated growth of pre-existing tumors. The antitumor effect of CYP1B1 shRNA was also observed in prostate tumor xenograft mouse models. Among the genes altered by CYP1B1 knockdown, reduction of caspase-1 (CASP1) activity attenuated the antitumor effect of CYP1B1 inhibition. Indeed, CYP1B1 regulates CASP1 expression or activity. Finally, CYP1B1 expression was increased in higher grades of PCa and overall survival was significantly reduced in patients with high levels of CYP1B1 protein. CYP1B1 expression was reversely associated with CASP1 expression in clinical tissue samples. Together, our results demonstrate that CYP1B1 regulates PCa tumorigenesis by inhibiting CASP1 activation. Thus, the CYP1B1-CASP1 axis may be useful as a potential biomarker and a therapeutic target for PCa.

The heat shock 70 kDa protein 1B (HSPA1B), which has been well-studied among the famous heat shock proteins HSPA1A/B/L, is related to autoimmune diseases, including Alopecia Areata (AA). In this study, the association of a 5'-untranslated region (5'UTR) SNP rs6457452 and a promoter SNP rs2763979 (-1140C > T) of HSPA1B with AA was investigated in 236 controls and 228 AA patients. Statistical analyses using the multiple logistic models were done, according to the onset and the clinical features of AA, including the age of onset, family history, type of AA lesion, nail involvement and body hair involvement. The results showed that rs6457452 was associated with the onset of AA (p < 0.002). In the analysis of clinical features of AA, rs6457452 was weakly related to the age of onset (p ≤ 0.04) and that rs2763979 was only weakly related to the type of AA lesion (p = 0.041). In conclusion, we suggest that the 5'UTR SNP rs6457452 of HSPA1B may be associated with the onset of AA and the T allele of rs6457452 may confer the reduced susceptibility to AA in the Korean population.