High-Level Secretion of Pregnancy Zone Protein Is a Novel Biomarker of DNA Damage-Induced Senescence and Promotes Spontaneous Senescence.

Identification of unique and specific biomarkers to better detect and quantify senescent cells remains challenging. By a global proteomic profiling of senescent human skin BJ fibroblasts induced by ionizing radiation (IR), the cellular level of pregnancy zone protein (PZP), a presumable pan-protease inhibitor never been linked to cellular senescence before, was found to be decreased by more than 10-fold, while the level of PZP in the conditioned medium was increased concomitantly. This observation was confirmed in a variety of senescent cells induced by IR or DNA-damaging drugs, indicating that high-level secretion of PZP is a novel senescence-associated secretory phenotype. RT-PCR examination verified that the transcription of the PZP gene is enhanced in various cells at senescence or upregulated following DNA damage treatment in a p53-independent manner. Moreover, pretreatment with late pregnancy serum containing a high level of PZP led to inhibition of doxorubicin-induced senescence in A549 cells, and depletion of PZP in the pregnancy serum could enhance such inhibition. Finally, the addition of immuno-precipitated PZP complexes into tissue culture attenuated the growth of A549 cells and promoted the spontaneous senescence. Therefore, we revealed that high-level secretion of PZP is a novel and unique feature associated with DNA damage-induced senescence, and secreted PZP is a positive regulator of cellular senescence, particularly during the late stage of gestation.

Norisoboldine, an alkaloid from Radix linderae, inhibits NFAT activation and attenuates 2,4-dinitrofluorobenzene-induced dermatitis in mice.

CONTEXT: The nuclear factor of activated T-cells (NFAT) is a family of transcription factors, essential for T-cell activation. Norisoboldine (NOR), an isoquinoline alkaloid from Radix linderae, has been demonstrated to possess anti-inflammatory activity. OBJECTIVE: This study examines NOR's effect on NFAT activation and its therapeutic potential for atopic dermatitis (AD). MATERIALS AND METHODS: The transcriptional activity of NFAT was examined with luciferase reporter assay, using K562-luc cells, stimulated with 20 ng/mL PMA plus 1 µM ionomycin. NFAT dephosphorylation was examined by immuno-blotting in K562-luc cells and Jurkat cells. Interleukin-2 (IL-2) expression in Jurkat cells was examined by real-time PCR. A mouse model of dermatitis, induced by 2,4-dinitrochlorobenzene (DNCB), was used to test NOR's therapeutic potential for AD. RESULTS: NOR, dose-dependently, inhibited PMA and ionomycin-induced NFAT reporter gene expression in K562-luc cells in the range of 2-50 µM. NOR also inhibited PMA and ionomycin-induced NFAT dephosphorylation in K562-luc cells and Jurkat cells. Consequently, NOR suppressed PMA plus ionomycin-induced IL-2 expression in Jurkat cells. The administration of NOR (10 mg/kg, i.p.), alleviated DNCB-induced dermatitis in mice, by the reduction of ear swelling and attenuation of inflammatory infiltration into ear tissue. Moreover, mRNA levels of INF-γ, TNF-α, IL-4 and IL-6 in ears of NOR-treated mice were reduced by 78.4, 77.8, 72.3 and 73.9%, respectively, compared with untreated controls. DISCUSSION AND CONCLUSION: This study demonstrates that NOR inhibits NFAT activation in T-cells and alleviates AD-like inflammatory reaction in a DNCB-induced dermatitis model, highlighting NOR as a potential therapeutic agent for AD.

1ß-Hydroxyalantolactone, a sesquiterpene lactone from Inula japonica, attenuates atopic dermatitis-like skin lesions induced by 2,4-dinitrochlorobenzene in the mouse.

CONTEXT: 1ß-Hydroxyalantolactone (IJ-5) is a sesquiterpene lactone compound isolated from Inula japonica Thunb (Asteraceae). Sesquiterpene lactones have been shown to modulate many processes that influence inflammatory reactions. OBJECTIVE: The present study examines the protective effect of IJ-5 on atopic dermatitis (AD) in a mouse model induced by 2,4-dinitrochlorobenzene (DNCB). MATERIALS AND METHODS: AD-like skin lesions were induced in Balb/c mice by sensitizing once with painting 100 µL of 5% DNCB on their shaved back skin and then challenging with 20 µL of 0.2% DNCB five times on their right ears at 3 d interval starting on day 5 post-sensitization. IJ-5 was administrated intraperitoneally at 10 mg/kg 1 h before each DNCB challenge. RESULTS: IJ-5 treatment attenuated DNCB-induced dermatitis severity and right ear swelling. The serum levels of IgE, IL-4, and IL-6 in IJ-5-treated mice were reduced by 54.7, 56.5, and 53.0%, respectively, while the mRNA levels of TNFα, IL-1, IL-4, and IL-6 in back skin lesions of IJ-5-treated mice were reduced by 47.7, 61.5, 57.5, and 58.5%, respectively, compared with untreated controls. Histopathological examination showed that IJ-5 treatment decreased DNCB-induced hypertrophy, hyperkeratosis, and infiltration of inflammatory cells in both ear and back skins. Moreover, IJ-5 suppressed the expression of TNFα, IL-1, and IL-6 with IC50 values of 6.58, 9.48, and 7.01 µM, respectively, and inhibited the activation of NF-κB pathway in TNFα-stimulated HaCat cells. DISCUSSION AND CONCLUSION: The present study demonstrates the protective effects of IJ-5 against AD-like skin inflammation and highlights IJ-5 as a potential therapeutic agent for AD.

Mechanistic Characterization of De Novo Generation of Variable Number Tandem Repeats in Circular Plasmids during Site-Directed Mutagenesis and Optimization for Coding Gene Application.

Site-directed mutagenesis for creating point mutations, sometimes, gives rise to plasmids carrying variable number tandem repeats (VNTRs) locally, which are arbitrarily regarded as polymerase chain reaction (PCR) related artifacts. Here, the alternative end-joining mechanism is reported rather than PCR artifacts accounts largely for that VNTRs formation and expansion. During generating a point mutation on GPLD1 gene, an unexpected formation of VNTRs employing the 31 bp mutagenesis primers is observed as the repeat unit in the pcDNA3.1-GPLD1 plasmid. The 31 bp VNTRs are formed in 24.75% of the resulting clones with copy number varied from 2 to 13. All repeat units are aligned with the same orientation as GPLD1 gene. 43.54% of the repeat junctions harbor nucleotide mutations while the rest don't. Their demonstrated short primers spanning the 3' part of the mutagenesis primers are essential for initial creation of the 2-copy tandem repeats (TRs) in circular plasmids. The dimerization of mutagenesis primers by the alternative end-joining in a correct orientation is required for further expansion of the 2-copy TRs. Lastly, a half-double priming strategy is established, verified the findings and offered a simple method for VNTRs creation on coding genes in circular plasmids without junction mutations.