In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
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Question: Context: Atopic dermatitis (AD) is a chronically relapsing, pruritic, eczematous skin disorder accompanying allergic inflammation. AD is triggered by oxidative stress and immune imbalance. The effect of oral arjunolic acid (AA) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in mice was investigated.', 'Repeated epicutaneous application of DNCB to the ear and shaved dorsal skin of mice was performed to induce AD-like symptoms and skin lesions: 250mg/kg AA was given orally for three weeks to assess its anti-pruritic effects. Serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-10, immunoglobulin (Ig)E and caspase-3 were assessed by ELISA.', 'We found that AA alleviated DNCB-induced AD-like symptoms as quantified by skin lesions, dermatitis score, ear thickness and scratching behavior. Levels of reactive oxygen species in the AA group were significantly inhibited compared with those in the DNCB group. In parallel, AA blocked a DNCB-induced reduction in serum levels of IL-4 and IL-10 associated with an attenuation of DNCB-induced increases in serum TNF-α, IL-6, IgE and caspase-3.\Question: Does arjunolic acid protect against DNCB-induced atopic dermatitis-like symptoms in mice by restoring a normal cytokine balance?

Answer: The results indicate that AA suppresses DNCB-induced AD in mice via redox balance and immune modulation, and could be a safe clinical treatment for AD.


Question: Context: Apicomplexan parasites actively release transmembrane (TM) adhesive proteins involved in host cell attachment and invasion. Rhomboids, a family of intramembrane serine proteases, cleave these secreted adhesive proteins within their TM domains as an essential step in completing the invasion process. In Cryptosporidium parvum, the activity of rhomboids in cleaving microneme proteins (MICs) has not been reported. In the present study, the interaction between C. parvum rhomboids (CpROM1 and CpROM4) and C. parvum microneme proteins (CpGP900 and CpTRAP-C1) was investigated using yeast two-hybrid assay and co-immunoprecipitation assays.', 'Our study demonstrated that CpROM1 protein could interact with CpGP900 protein in co-transformed AH109 yeasts. Analysis of these proteins in co-transfected mammalian cells showed that the cleavage product of the CpGP900 protein was detected in the co-transfected cells. As control, CpGP900 only was transfected into cells and no cleavage was observed. The results suggested that CpGP900 protein was the substrate of CpROM1. Moreover, CpROM1 and CpROM4 could not cleave CpTRAP-C1 protein, which is the substrate of T. gondii rhomboid 2.\Question: Does cryptosporidium parvum rhomboid1 have an activity in microneme protein CpGP900 cleavage?

Answer: Our results showed that CpROM1 is an active protease that is involved in microneme protein CpGP900 cleavage, which lay the foundation for further research on the mechanisms of C. parvum invasion.


Question: Context: Cilostazol, a selective inhibitor of PDE3, has a protective effect on endothelium after ischemic vascular damage, through production of nitric oxide (NO). The purpose of the present study was to clarify the molecular mechanisms underlying the preventive effect of treatment with cilostazol on oxidative stress-induced premature senescence in human endothelial cells.', 'Prematurely senescent human umbilical vein endothelial cells (HUVECs) were induced by treatment with hydrogen peroxide (H(2)O(2)) as judged by senescence-associated beta-galactosidase assay (SA-betagal), cell morphological appearance, and plasminogen activator inhibitor-1 (PAI-1) expression. Treatment with H(2)O(2) caused 93% of the cells to be SA-betagal positive, whereas 46% of cilostazol (100 micromol/L)-treated cells were positive. HUVECs treated with other cAMP-elevating agents and DETA-NO showed a reduction of SA-betagal-positive cells as well. Cilostazol increased phosphorylation of Akt at Ser(473) and of endothelial nitric oxide synthase (eNOS) at Ser(1177), with a dose-dependent increase in Sirt1 expression. Moreover, the effect of cilostazol on premature senescence was abrogated through inhibition of Sirt1.\Question: Does cilostazol inhibit oxidative stress-induced premature senescence via upregulation of Sirt1 in human endothelial cells?

Answer:
Our results indicated that cilostazol exerted protective effects against endothelial senescence and dysfunction, and enhancement of NO production is a key mediator in upregulation of Sirt1.