Photochemical Synthesis of Succinic Ester-Containing Phenanthridines from Diazo Compounds as 1,4-Dicarbonyl Precursors.

We disclosed herein a straightforward photochemical method for the construction of phenanthridines containing a synthetically useful succinate unit. The reaction occurred under visible-light irradiation with cheap eosin Y Na as photoredox catalyst and a diazo compound as the succinate precursor. Under the optimal reaction conditions, a wide range of phenanthridines were obtained in moderate to good yields. Note that the succinate units in the final heterocycles could be easily transformed into many valuable structures, such as γ-butyrolactone, dihydrofuran-2(3H)-one, and tetrahydrofuran. Mechanistic experiments were performed to support the proposed mechanism.

The role of laparoscopic surgery for ulcerative colitis: systematic review with meta-analysis.

PURPOSE: Crohn's disease is established in laparoscopic surgery due to partial bowel dissection and low postoperative complication rate. However, laparoscopic surgery for ulcerative colitis remains further discussed even if the trend of minimally invasive technique exists. This study is to figure out how laparoscopic surgery works for ulcerative colitis. METHODS: Sixteen controlled trials were identified through the search strategy mentioned below. There was only one prospective randomized study among the studies selected. A meta-analysis pooled the outcome effects of laparoscopic surgery and open surgery was performed. Fixed effect model or random effect model was respectively used depending on the heterogeneity test of trials. RESULTS: Postoperative fasting time and postoperative hospital stay were shorter in laparoscopic surgery for ulcerative colitis (-1.37 [-2.15, -0.58], -3.22 [-4.20, -2.24], respectively, P < 0.05). Overall complication rate was higher in open surgery, compared with laparoscopic surgery (54.8% versus 39.3%, P = 0.004). However, duration of laparoscopic surgery for ulcerative colitis was extended compared with open surgery (weighted mean difference 69.29 min, P = 0.04). As to recovery of bowel function, peritoneal abscess, anastomotic leakage, postoperative bowel obstruction, wound infection, blood loss, and mortality, laparoscopic surgery did not show any superiority over open surgery. Re-operation rate was almost even (5.2% versus 7.3%). The whole conversion to open surgery was 4.2%. CONCLUSIONS: Laparoscopic surgery for ulcerative colitis was at least as safe as open surgery, even better in postoperative fasting time, postoperative hospital stay, and overall complication rate. However, clinical value of laparoscopic surgery for ulcerative colitis needed further evaluation with more well-designed and long-term follow-up studies.

Induction of surface CCR4 and its functionality in mouse Th2 cells is regulated differently during Th2 development.

T helper cell type 1 (Th1) and Th2 cells express distinct sets of chemokine receptors. In contrast to Th1 chemokine receptors, it is largely unknown how Th2 chemokine receptors such as CC chemokine receptor 4 (CCR4) are induced during Th2 differentiation. Here, we investigated the induction of CCR4 surface expression and ligand responsiveness evaluated by functional assays such as chemokine binding and chemotaxis. This was done in comparison with those of a Th1 chemokine receptor, CXC chemokine receptor 3 (CXCR3). Resting T cells expressed neither CXCR3 nor CCR4. CXCR3 expression and ligand responsiveness were observed when resting T cells were stimulated with anti-CD3 plus anti-CD28 in the presence of [interleukin (IL)-12+anti-IL-4] and then recultured without T cell receptor (TCR) stimulation. Unlike CXCR3, CCR4 was induced immediately after anti-CD3/anti-CD28 stimulation in the presence of (IL-4+anti-interferon-gamma+anti-IL-12). However, these CCR4-positive cells failed to exhibit chemokine binding and chemotaxis. Although the levels of surface CCR4 expression were not increased after the subsequent reculture in the absence of TCR stimulation, CCR4 responsiveness was induced in this stage of Th2 cells. The induction of CCR4 expression and the acquisition of CCR4 responsiveness did not occur in IL-4-deficient (IL-4(-/-)) and signal transducer and activator of transcription (STAT)6(-/-) T cells. CCR4 expression and functionality were regained in IL-4(-/-) but not in STAT6(-/-) T cells by the addition of recombinant IL-4. Although surface expression and functionality of CCR4 are induced depending on the IL-4/STAT6 signaling pathway, the present results indicate that the functionality of CCR4 does not correlate with CCR4 expression but emerges at later stages of Th2 differentiation.

Anti-HER-2/neu immune responses are induced before the development of clinical tumors but declined following tumorigenesis in HER-2/neu transgenic mice.

HER-2/neu oncogene products have been implicated as a potential target of T cell-mediated immune responses to HER-2/neu-induced tumors. Using HER-2/neu transgenic mice (oncomice), we investigated whether, and if so how, anti-HER-2/neu immune responses are induced and modulated in these oncomice from birth to tumor initiation. Female oncomice carrying the activated HER-2/neu oncogene displayed apparent hyperplasia in mammary glands at 10 weeks of age and developed mammary carcinomas around an average age of 26 weeks. Unfractionated spleen cells from 10- to 15-week-old oncomice that were cultured without any exogenous stimuli exhibited cytotoxicity against the F31 tumor cell line established from an HER-2/neu-induced mammary carcinoma mass. The final antitumor effectors were a macrophage lineage of cells. However, this effector population was activated, depending on the stimulation of oncomouse CD4(+) T cells with oncomouse-derived antigen-presenting cell (APC) alone or with wild-type mouse APC in the presence of F31 membrane fractions, suggesting the presence of HER-2/neu-primed CD4(+) T cells and HER-2/neu-presenting APC in 10- to 15-week-old oncomice. These antitumor cytotoxic responses were detected at approximately 5 weeks of age and peaked at age 10 to 15 weeks. However, the responses then declined at tumor-bearing stages in which the expression of target proteins could progressively increase. This resulted from the dysfunction of CD4(+) T cells but not of APC or effector macrophages. These results indicate that an anti-HER-2/neu CD4(+) T cell-mediated immune response was generated at the pretumorigenic stage but did not prevent tumorigenesis and declined after the development of clinical tumors.

Risk factors for primary liver carcinoma in Chinese population.

AIM: To evaluate the risk factors for primary liver carcinoma (PLC) in Chinese population. METHODS: Chinese Biomedical Literature Database, China Hospital Knowledge Database and MEDLINE were searched. All the related literatures were screened, and the risk factors for PLC in Chinese population were studied. Heterogeneity was evaluated by odds ratio (OR) q test. Combined OR and its 95% confidence interval (95%CI) were calculated, the association between the investigated risk factors and PLC was determined. Validity and bias of the findings were evaluated by sensitivity analysis and funnel plot analysis respectively. RESULTS: Fifty-five of one hundred and ninety identified studies were accepted according to the inclusive criteria. Ten factors related to PLC were demonstrated by sensitive analysis and funnel plot analysis. They were cirrhosis (OR = 11.97, P = 0.000), HBV infection (OR = 11.34, P = 0.000), HCV infection (OR = 4.28, P = 0.000), family history of liver cancer (OR = 3.49, P = 0.000), unstable emotion (OR = 2.20, P = 0.000), depressed characters (OR = 3.07, P = 0.000), aflatoxin (OR = 1.80, P = 0.000), alcoholic (OR = 1.88, P = 0.000), intake of musty food (OR = 1.87, P = 0.000) and drinking contaminated water from pond (OR = 1.77, P = 0.003). CONCLUSION: The main risk factors for PLC in China are liver diseases, family history of liver carcinoma, poor psychic status, aflatoxin, and some unhealthy behaviors.

The unique target specificity of a nonpeptide chemokine receptor antagonist: selective blockade of two Th1 chemokine receptors CCR5 and CXCR3.

CC chemokine receptor (CCR) 5 and CXC chemokine receptor (CXCR)3 are expressed on T helper cell type 1 cells and have been implicated in their migration to sites of inflammation. Our preceding study demonstrated that a nonpeptide synthetic CCR5 antagonist, TAK-779 (N, N-dimethyl-N-[4-[[[2-(4-methylphenyl)-6, 7-dihydro-5H-benzocyclohepten-8-yl]carbon-yl]amino]benzyl]-tetrahydro-2H-pyran4-aminium chloride, inhibits the development of experimentally induced arthritis by modulating the migration of CCR5(+)/CXCR3(+) T cells to joints. The present study investigated the functional properties of TAK-779, including the effect of this antagonist on CXCR3 function. For this purpose, transfectants expressing mouse CCR5 (mCCR5) or mCXCR3 and expressing mCCR4 or mCXCR4 as controls were established by introducing each relevant gene into 2B4 T cells and were subjected to the following assays. First, the ligand binding to chemokine receptors was assayed by incubating transfectants with [(125)I]-labeled relevant ligand or with the unlabeled relevant ligand followed by staining with anti-ligand antibody. Second, chemokine-induced lymphocyte function-associated antigen-1 (LFA-1) activation was assayed by measuring the adhesion of cells to microculture plates coated with purified intercellular adhesion molecule-1. Third, chemokine-stimulated chemotaxis was assayed by observing the cell migration through transwells. In these assays, TAK-779 blocked the ligand binding as well as LFA-1 up-regulating and chemotactic function of mCXCR3 and mCCR5 but did not elicit a biologically significant inhibition of those functions of mCCR4 and mCXCR4. These observations indicate the unique target specificity of TAK-779 and explain why this antagonist efficiently blocks the migration of T cells expressing CCR5 and CXCR3 to sites of inflammation.

Tumor suppressor Menin acts as a corepressor of LXRα to inhibit hepatic lipogenesis.

Menin, encoded by the MEN1 gene, was initially identified as a tumor suppressor for endocrine neoplasia. Our previous report showed that Menin enhances PPARα transactivity preventing triglyceride accumulation in the liver. Here, we further explore the role of Menin in liver steatosis. Transient transfection assays demonstrate that Menin inhibits the transcriptional activity of nuclear receptor liver X receptor α (LXRα). Accordingly, Menin overexpression results in reduced expression of LXRα target genes, such as lipogenic enzymes including SREBP-1c, FASN and SCD-1. Co-immunoprecipitation assays revealed physical interaction between Menin and LXRα. Collectively, our data suggest that Menin acts as a novel corepressor of LXRα and functions as a negative regulator of hepatic lipogenesis.

Menin prevents liver steatosis through co-activation of peroxisome proliferator-activated receptor alpha.

Fatty liver is strongly associated with metabolic syndrome. Here, we show that the impaired hepatic expression of menin, the product of the MEN1 (multiple endocrine neoplasia type 1) tumor suppressor gene, represents a common feature of several fatty liver mouse models. The liver specific ablation of MEN1 gene expression in healthy mice induced hepatic steatosis under high-fat dietary conditions. Moreover, overexpression of menin in livers of steatotic db/db mice reduced liver triglyceride accumulation. At the molecular level, we found that menin acts synergistically with the nuclear receptor PPARα to control gene expression of fatty acid oxidation. Collectively, these data suggest a crucial role for menin as an integrator of the complex transcriptional network controlling hepatic steatosis.

[Systematic review on safety and efficacy of lateral node dissection in rectal cancer].

OBJECTIVE: To evaluate the safety and efficacy of lateral node dissection in rectal cancer. METHODS: Data of safety and efficacy in 27 case-controlled studies comparing lateral node dissection and non-lateral node dissection in rectal cancer were meta-analyzed using fixed effect model or random effect model. RESULTS: The increased operating time, blood loss and urinary dysfunction were more common in lateral node dissection group. The postoperative total complications, pelvic abscess, anastomotic leak, sexual dysfunction and defecation dysfunction were similar in both groups. There was no reasonably clear evidence in favor of lateral node dissection for recurrence, local recurrence, distal metastasis and 5-year survival. CONCLUSION: Lateral node dissection can neither reduce recurrence nor improve survival in the current study, which is not recommended to be a routine procedure in rectal cancer surgery.

[Safety and feasibility of laparoscopic surgery and open surgery in ulcerative colitis: a meta-analysis].

OBJECTIVE: To compare the safety and feasibility of laparoscopic surgery and open surgery in ulcerative colitis. METHODS: A search of published studies in English and Chinese between January 1992 and May 2008 was performed. Nine hundred and twenty-three patients from 16 studies were recruited which met the inclusion criteria. Meta-analysis was performed through fixed effect model or random effect model dependent on heterogeneity. RESULTS: Compared to open procedure, patients with ulcerative colitis undergone laparoscopic surgery were able to tolerate oral intake significantly earlier (P<0.01) with shorter hospital stay (P<0.01) and had lower total complication rate (P<0.01). But duration of laparoscopic surgery was significantly longer than that of open procedure(P=0.04). Laparoscopic procedure was no more superior to open procedure in recovery of bowel function, re-operation rate, intra-abdominal abscess, anastomotic leak, postoperative bowel obstruction, wound infection, blood loss and mortality. The conversion rate was 4.2% in this analysis. CONCLUSION: Laparoscopic surgery for ulcerative colitis is safe and feasible with better recovery in short-term as compared to the open procedure.

The capacity of the natural ligands for CD28 to drive IL-4 expression in naïve and antigen-primed CD4+ and CD8+ T cells.

The B7/CD28 costimulatory pathway plays a critical role in T cell activation including Th1/Th2 differentiation. However, little is known about whether CD28 costimulation favors polarization of either Th1 and Th2 or both. Here, we show a critical role of the natural ligands for CD28 molecules (B7.2-Ig or B7.1-Ig fusion proteins), particularly in the induction of type 2 T cell polarization. Upon TCR-triggering with suboptimal doses of anti-CD3, costimulation of naïve CD4+ T cells with anti-CD28 mAb or B7-Ig fusion proteins led to comparable levels of IFN-gamma production. Naïve T cells could produce IL-4 when CD28 costimulation was done with B7-Ig, but not with anti-CD28. IL-4-selective upregulation was also observed when T cells from anti-OVA TCR transgenic mice were stimulated with OVA in the presence of B7-Ig. Correlating with IL-4 expression, GATA-3 expression was induced much more potently by costimulation with B7-Ig than with anti-CD28 mAb, while T-bet induction by these two costimulatory reagents was comparable. This B7 effect was also applied for naïve and antigen-primed CD8+ T cells: IL-4-expressing CD8+ T cells were generated when naïve and alloantigen-primed T cells were stimulated with anti-CD3 and recall antigens, respectively, in the presence of B7-Ig costimulation. Importantly, such CD8+ T cell differentiation required the coexistence of CD4+ T cells during the initial TCR stimulation. These observations indicate that both type 2 CD4 and CD8 T cell polarizations are efficiently induced via costimulation of CD28 with its natural ligands, although the differentiation of CD8+ T cells is dependent on CD4+ cells.

Molecular mechanisms underlying differential contribution of CD28 versus non-CD28 costimulatory molecules to IL-2 promoter activation.

T cell costimulation via CD28 and other (non-CD28) costimulatory molecules induces comparable levels of [(3)H]TdR incorporation, but fundamentally differs in the contribution to IL-2 production. In this study, we investigated the molecular basis underlying the difference between CD28 and non-CD28 costimulation for IL-2 gene expression. Resting T cells from a mutant mouse strain generated by replacing the IL-2 gene with a cDNA encoding green fluorescent protein were stimulated with a low dose of anti-CD3 plus anti-CD28 or anti-non-CD28 (CD5 or CD9) mAbs. CD28 and non-CD28 costimulation capable of inducing potent [(3)H]TdR uptake resulted in high and marginal levels of green fluorescent protein expression, respectively, indicating their differential IL-2 promoter activation. CD28 costimulation exhibited a time-dependent increase in the binding of transcription factors to the NF-AT and NF-kappaB binding sites and the CD28-responsive element of the IL-2 promoter, whereas non-CD28 costimulation did not. Particularly, a striking difference was observed for the binding of NF-kappaB to CD28-responsive element and the NF-kappaB binding site. Decreased NF-kappaB activation in non-CD28 costimulation resulted from the failure to translocate a critical NF-kappaB member, c-Rel, to the nuclear compartment due to the lack of IkappaBbeta inactivation. These observations suggest that unlike CD28 costimulation, non-CD28 costimulation fails to sustain IL-2 promoter activation and that such a failure is ascribed largely to the defect in the activation of c-Rel/NF-kappaB.

A mechanism underlying STAT4-mediated up-regulation of IFN-gamma induction inTCR-triggered T cells.

IL-12 promotes T(h)1 development/IFN-gamma expression by activating STAT4. However, it is still unclear how STAT4 elicits IFN-gamma promoter activation. Here, we investigated the mechanism by which IL-12-activated STAT4 functions for IFN-gamma induction in TCR-triggered T cells. TCR stimulation induced high levels of IFN-gamma production depending on co-stimulation with IL-12. IL-12 stimulation greatly enhanced the promoter-binding activity of c-Jun/AP-1, a critical transcription factor for IFN-gamma gene expression in wild-type T cells, but not in STAT4-deficient (STAT4(-/-)) T cells. Comparable amounts of c-Jun were induced by TCR stimulation in both wild-type and STAT4(-/-) T cells irrespective of IL-12 co-stimulation. However, c-Jun bound to STAT4 in IL-12-co-stimulated wild-type T cells. c-Jun forming a complex with STAT4 efficiently interacted with the AP-1-related sequence of the IFN-gamma promoter. Such an enhanced c-Jun binding did not occur in STAT4(-/-) T cells. These results show that STAT4 contributes to enhancing IFN-gamma expression by up-regulating the binding of TCR signal-induced AP-1 to the relevant promoter sequence.

Induction of tumor regression by administration of B7-Ig fusion proteins: mediation by type 2 CD8+ T cells and dependence on IL-4 production.

CD28 signals contribute to either type 1 or type 2 T cell differentiation. Here, we show that administration of B7.2-Ig fusion proteins to tumor-bearing mice induces tumor regression by promoting the differentiation of antitumor type 2 CD8(+) effector T cells along with IL-4 production. B7.2-Ig-mediated regression was not induced in IL-4(-/-) and STAT6(-/-) mice. However, it was elicited in IFN-gamma(-/-) and STAT4(-/-) mice. By contrast, IL-12-induced tumor regression occurred in IL-4(-/-) and STAT6(-/-) mice, but not in IFN-gamma(-/-) and STAT4(-/-) mice. Moreover, B7.2-Ig treatment was effective in a tumor model not responsive to IL-12. B7.2-Ig administration elicited elevated levels of IL-4 production. Tumor regression was predominantly mediated by CD8(+) T cells, although the induction of these effector cells required CD4(+) T cells. Tumor regression induced by CD8(+) T cells alone was inhibited by neutralizing the IL-4 produced during B7.2-Ig treatment. Thus, these results indicate that stimulation in vivo of CD28 with B7.2-Ig in tumor-bearing mice results in enhanced induction of antitumor type 2 CD8(+) T cells (Tc2) leading to Tc2-mediated tumor regression.

Reversible CD8 expression induced by common cytokine receptor gamma chain-dependent cytokines in a cloned CD4(+) T(h)1 cell line.

T cells that are intrathymically lineage committed are believed to maintain their CD4 or CD8 co-receptor expression. Here, we investigated whether intrathymic lineage commitment involves irreversible genetic modification or whether co-receptor expression can be reprogrammed depending on external stimuli. The CD4(+) T(h)1 clone 2D6 established from splenic T cells as an IL-12-dependent line survived in culture with IL-2, IL-7 or IL-15 alone. Surprisingly, CD8 expression occurred in 2D6 cells upon replacement of IL-12 with any one of the three cytokines that stimulate the common cytokine receptor gamma chain, yielding CD4(+)CD8(+) 2D6 cells. CD8 expression declined when IL-2 was replaced with IL-12 and CD8 induction was inhibited when IL-12 was included in IL-2 or IL-7 culture. Our observations show that even a lineage-committed mature T cell can be reprogrammed for co-receptor expression in response to particular external stimuli.