Minkyu Shin

CD4+CD25+ regulatory T cells attenuate cisplatin-induced nephrotoxicity in mice

Nephrotoxicity limits the use of cisplatin, a widely used chemotherapeutic agent for treatment of various malignancies. Overall, CD4+ T cells mediate cisplatin-induced renal injury; however, the CD4+CD25+ regulatory T-cell subset (CD4+CD25+ Treg) has broad suppressive effects on many different cell types. In this study, we determined whether CD4+CD25+ Treg cells had protective effects against cisplatin-induced acute renal injury in nu/nu mice that lack mature T cells. In these mice, there was marked attenuation of the decreased survival, renal dysfunction and tubular injury, renal tumor necrosis factor-α, and interleukin-1β cytokine levels. Furthermore, renal macrophage accumulation was reduced in CD4+CD25+ Treg cell-adoptive transferred nu/nu mice compared with control mice. Infusion of CD4+CD25+Treg cells into wild-type Balb/c mice reduced serum blood urea nitrogen and creatinine levels equivalent to those in nu/nu mice and extended their survival time after cisplatin injection. In contrast, depletion of CD4+CD25+ Treg cells in wild-type mice exacerbated kidney injury after cisplatin administration. Transcription factor Foxp3-positive cells (Treg cells) were detected in the kidneys of nu/nu mice after cisplatin injection. Our results suggest that CD4+CD25+ Treg cells directly affect cisplatin nephrotoxicity and their modulation represents an additional treatment strategy.

Original ArticleCD4+CD25+ regulatory T cells attenuate cisplatin-induced nephrotoxicity in mice

Nephrotoxicity limits the use of cisplatin, a widely used chemotherapeutic agent for treatment of various malignancies. Overall, CD4+ T cells mediate cisplatin-induced renal injury; however, the CD4+CD25+ regulatory T-cell subset (CD4+CD25+ Treg) has broad suppressive effects on many different cell types. In this study, we determined whether CD4+CD25+ Treg cells had protective effects against cisplatin-induced acute renal injury in nu/nu mice that lack mature T cells. In these mice, there was marked attenuation of the decreased survival, renal dysfunction and tubular injury, renal tumor necrosis factor-α, and interleukin-1β cytokine levels. Furthermore, renal macrophage accumulation was reduced in CD4+CD25+ Treg cell-adoptive transferred nu/nu mice compared with control mice. Infusion of CD4+CD25+Treg cells into wild-type Balb/c mice reduced serum blood urea nitrogen and creatinine levels equivalent to those in nu/nu mice and extended their survival time after cisplatin injection. In contrast, depletion of CD4+CD25+ Treg cells in wild-type mice exacerbated kidney injury after cisplatin administration. Transcription factor Foxp3-positive cells (Treg cells) were detected in the kidneys of nu/nu mice after cisplatin injection. Our results suggest that CD4+CD25+ Treg cells directly affect cisplatin nephrotoxicity and their modulation represents an additional treatment strategy.

The association of cholecystokinin-A receptor expression with the responsiveness of electroacupuncture analgesic effects in rat.

The purpose of this study is to determine whether the level of cholecystokinin (CCK) receptor expression causes the differences between the responder and non-responder to electroacupuncture mediated analgesic effects. Male Sprague-Dawley rats were stimulated at the Zusanli (ST36) acupoint in the absence of any anesthetics and holders. The tail flick latency test was performed to quantify analgesic effects and then the responder and non-responder groups were classified. The hypothalamus of each group was dissected and RNA was purified. The amount of mRNA expression of CCK-A and CCK-B receptors was determined by reverse transcription-polymerase chain reaction. The results show that CCK-A receptors are significantly more expressed in non-responders than responders, whereas CCK-B receptor expression is similar in both groups.

Constituents of Asarum sieboldii with Inhibitory Activity on Lipopolysaccharide (LPS)‐Induced NO Production in BV‐2 Microglial Cells

Bioassay‐guided fractionation of the root extract of Asarum sieboldii led to the isolation of the four active compounds (−)‐sesamin (1), (2E,4E,8Z,10E)‐N‐(2‐methylpropyl)dodeca‐2,4,8,10‐tetraenamide (2), kakuol (3), and ‘3,4,5‐trimethoxytoluene’ (=1,2,3‐trimethoxy‐5‐methylbenzene; 4), in terms of inhibition of lipopolysaccharide (LPS)‐induced nitric oxide (NO) production. Compounds 1–4 showed potent inhibition of NO production, with IC50 values in the low nanomolar‐to‐micromolar range. Also isolated were the known compounds methylkakuol (5), ‘3,5‐dimethoxytoluene’, safrole, asaricin, methyleugenol, and (−)‐asarinin, which were found to be inactive in the above assay. Among the ten known isolates, compounds 1, 2, and 5 were found for the first time in this plant.

CD4+CD25+ regulatory T cell depletion modulates anxiety and depression-like behaviors in mice.

Stress has been shown to suppress immune function and increase susceptibility to inflammatory disease and psychiatric disease. CD4+CD25+ regulatory T (Treg) cells are prominent in immune regulation. This study was conducted to determine if anti-CD25 antibody (Ab) mediated depletion of Treg cells in mice susceptibility to stress-induced development of depression-like behaviors, as well as immunological and neurochemical activity. To accomplish this, an elevated plus-maze test (EPM), tail suspension test (TST), and forced swim test (FST) were used to examine depression-like behaviors upon chronic immobilization stress. Immune imbalance status was observed based on analysis of serum cytokines using a mouse cytometric bead array in conjunction with flow cytometry and changes in the levels of serotonin (5-HT) and dopamine (DA) in the brain were measured by high performance liquid chromatography (HPLC). The time spent in the open arms of the EPM decreased significantly and the immobility time in the FST increased significantly in the anti-CD25 Ab-treated group when compared with the non stressed wild-type group. In addition, interlukin-6 (IL-6), tumor necrosis factor-á (TNF-á), interlukin-2 (IL-2), interferon-gamma (IFN-γ), interlukin-4 (IL-4) and interlukin-17A (IL-17A) concentrations were significantly upregulated in the stressed anti-CD25 Ab-treated group when compared with the non stressed wild-type group. Furthermore, the non stressed anti-CD25 Ab-treated group displayed decreased 5-HT levels within the hippocampus when compared with the non stressed wild-type group. These results suggest that CD4+CD25+ Treg cell depletion modulated alterations in depressive behavior, cytokine and monoaminergic activity. Therefore, controlling CD4+CD25+ Treg cell function during stress may be a potent therapeutic strategy for the treatment of depression-like symptoms.

Enhancement of electroacupuncture-induced analgesic effect in cholecystokinin-A receptor deficient rats

Previously, we have showed that the cholecystokinin (CCK)-A receptor expression in hypothalamus is closely related with the responsiveness of electroacupuncture (EA)-mediated analgesic effects in rats. In order to confirm this observation more directly in vivo, the EA-mediated analgesic effects are compared between Otsuka Long-Evans Tokushima Fatty (OLETF) rats, the natural knockout rats with the homozygously disrupted CCK-A receptor gene, with Long-Evans Tokushima Otsuka (LETO) rats. They were stimulated at the zusanli (ST36) acupoint without using anesthetics or holders. The tail flick latency (TFL) test was performed to quantify analgesic effects and then the mean TFL increase ratios were calculated. OLETF rats showed a mean increase of 53% and LETO rats showed a mean increase of 31% of TFL. Our results suggest that the analgesic effect of acupuncture is closely related with the amount of CCK-A receptor expression.

Inhibitory effects of casticin on migration of eosinophil and expression of chemokines and adhesion molecules in A549 lung epithelial cells via NF-κB inactivation

ETHNOPHARMACOLOGICAL RELEVANCE The fruits of Vitex rotundifolia L. have long been used for the treatment of inflammation of the respiratory tract in East Asia. AIM To determine if casticin, one of the constituents of Vitex rotundifolia L., has anti-allergic and anti-inflammatory effects in asthma. MATERIALS AND METHODS The in vitro anti-inflammatory activity of casticin was studied in A549 human type II-like epithelial lung cells using an eotaxin inhibition assay. Additionally, its effects on eotaxin, regulated on activation normal T cell expressed and secreted (RANTES), vascular cell adhesion molecule (VCAM)-1, and inter-cellular adhesion molecule (ICAM)-1 expression were investigated by real time-polymerase chain reaction (real time-PCR). The inhibition of nuclear factor κB (NF-κB) activity in the presence of casticin was determined by analyzing confocal microscopy images of fluorescence immunocytochemical analysis while the suppression of inhibitory κB (IκB)-α phosphorylation was studied using Western blot analysis. Finally, the inhibitory effect of casticin on eosinophil migration toward prestimulated A549 cell media was measured using the human eosinophilic leukemia cell line. RESULTS AND DISCUSSION Casticin significantly suppressed eotaxin production in cytokine activated A549 lung epithelial cells. Casticin also suppressed the mRNA expression levels of eotaxin, RANTES, VCAM-1, and ICAM-1, which subsequently contributed to the inhibition of eosinophil migration. Furthermore, casticin inhibited IκB-α phosphorylation and nuclear translocation of p65 in A549 cells. CONCLUSION Casiticin inhibited the eosinophil migration and activity of chemokines and adhesion molecules involved in the inflammatory process of asthma by suppressing the NF-κB pathway. These results suggest that casticin has the potential for use in the treatment of allergic asthma.

The Anti-Depressant Effect of Nelumbinis Semen on Rats under Chronic Mild Stress Induced Depression-Like Symptoms

Nelumbinis Semen is a well-known traditional herbal medicine frequently used in treatment of depression in many Asian countries. In this study, its anti-depression effects in rats were investigated by comparing the test results of those treated with Nelumbinis Semen to those treated with other herbal anti-depressants, including Rehmanniae Radix Preparat, Corni Fructus, Lycii Fructus, Pinelliae Rhizoma and Hypericum Perforatum. In order to induce depression-like symptoms, the animals were placed under chronic mild stress in the form of overnight illumination for 2 consecutive days. They were treated with the respective herbal extract and forced swimming tests were conducted afterwards. The anti-depression effects of each extract were then evaluated based on a measured index, which consisted of struggling time, first latency and first rest duration. These test results show that Nelumbinis Semen provides greater anti-depression effects than the other herbal extracts. Specifically, only the rats treated with Nelumbinis Semen showed significant increases in struggling time (43.9%, p < 0.005, p = 0.0037) and in first latency time (90.2%, p < 0.05, p = 0.0116). However, the first rest duration for Nelumbinis Semen treated rats was not significantly different from the other rats. It appears that Nelumbinis Semen provides even greater anti-depression effects than Hypericum Perforatum (commonly referred to as St. Johns Wort, perhaps the most widely used natural antidepressant today). The anti-depression effects of Nelumbinis Semen might be due to the modulation of the amount of neurotransmitters involved in depression.

Suppression of IgE production and modulation of Th1/Th2 cell response by electroacupuncture in DNP-KLH immunized mice

Effects of electroacupuncture (EA) on Th1/Th2 cell response were investigated in BALB/c mice immunized intraperitoneally with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH). Successive electroacupuncture stimulation on the ST36 acupoint was performed just after immunization. Serum levels of antigen-specific IgE and total IgE were significantly decreased compared with non-acupunctured controls. Production of the Th2-specific cytokines IL-4 and IL-13 in the anti-CD3 mAb-activated splenocytes was significantly suppressed in ST36 electroacupunctured mice compared with non-acupunctured mice. These results imply that successive electroacupuncture on ST36 can decrease the serum level of antigen-specific IgE and total IgE by suppression of the Th2 lineage development.

Methyl Gallate Exhibits Potent Antitumor Activities by Inhibiting Tumor Infiltration of CD4+CD25+ Regulatory T Cells

CD4+CD25+ regulatory T (Treg) cells play crucial roles in the host response to tumors. Increasing evidence supports the existence of elevated numbers of Treg cells in solid tumors and hematologic malignancies. In this study, the effects of methyl gallate on Treg cells were examined. Methyl gallate inhibited Treg cell-suppressive effects on effector CD4+ T cells and Treg migration toward tumor environment. The expression of Treg surface markers including CTLA-4, CCR4, CXCR4, and glucocorticoid-induced TNFR was significantly suppressed upon methyl gallate treatment. Furthermore, forkhead box P3 (Foxp3) expression was also significantly decreased by methyl gallate, suggesting that the suppressive effects of methyl gallate on Treg were medicated by decrease of Treg-specific transcription factor Foxp3. In tumor-bearing hosts, methyl gallate treatment substantially reduced tumor growth and prolonged the survival rate. In contrast, nu/nu mice did not show decreased tumor progression in response to methyl gallate. In addition, in tumor-bearing Treg-depleted mice, tumor growth and the survival rates were not changed by methyl gallate treatment, strongly suggesting that the main therapeutic target of methyl gallate in tumor suppression was related to modulation of the CD4+CD25+ Treg cell functions. In the spleen of tumor-bearing mice, methyl gallate treatment induced a significant decrease in the CD4+CD25+Foxp3high Treg cell population. Especially, the number of tumor-infiltrating CD25+Foxp3high Treg cells was significantly lower in methyl gallate-treated mice. These results suggest that methyl gallate can be used to reverse immune suppression and as a potentially useful adjunct for enhancing the efficacy of immune-based cancer therapy.