[Equol and its enantiomers inhibited urethane-induced lung cancer in mice]

OBJECTIVE

To investigate the effects and mechanisms of equol and its enantiomers on urethane-induced lung cancer in mice.

METHODS

A total of 120 5-week-old male C57BL/6 mice were randomly divided into 8 groups: lung cancer tumor control group (CG), genistein control group (GCG), low dose racemic equol group (LEG), high dose racemic equol group (HEG), low dose R-equol group (LRE), high dose R-equol group (HRE), low dose S-equol group (LSE) and high dose S-equol group (HSE). Urethane was injected subcutaneously twice a week for 4 weeks to induce lung cancer and then the mice were fed for 4 months. The body weight and food intake of each group were measured and recorded weekly. After the mice were sacrificed, the blood, livers and lungs of the mice were collected. The incidence of lung cancer in each group was recorded. The concentration of serum superoxide dismutase (SOD), malondialdehyde (MDA) and 8-hydroxydeoxygunosine (8-OHdG) were detected by the corresponding kits. Western blotting was used to detect the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in the livers. Between-group differences in body weight and food intake of the mice were compared using repeated measures ANOVA, and ANOVA for the differences between non-repeated measurements, with post hoc analysis using Tukey's method if there were between-group differences. Comparisons of categorical data were performed by chi-square test, and if there were differences between the groups, the Bonferroni method was used for pairwise comparison.

RESULTS

A total of 49 in the 120 mice developed lung cancer. The overall incidence of lung cancer was 40.8%. Compared with the control group, the incidence of lung cancers in each experimental group was lower, and the difference was statistically significant. The incidence of lung cancer in the high-dose experimental group was significantly lower than that in the low-dose experimental group. However, the incidence of lung cancer was similar in the three equol groups and the genistein group at the same dose. Compared with the control group, the high-dose experimental group had higher serum SOD concentration, lower MDA and 8-OHdG concentrations, and the differences were statistically significant. Western blotting analysis showed that the expression levels of Nrf2 protein in the experimental groups were higher than those in the control group except the low-dose racemic equol group, and the Nrf2 protein expression level in the high-dose equol groups was higher than that in the low-dose equol groups.

CONCLUSION

Racemic equol and its enantiomers mayinhibit lung carcinogenesis through antioxidant effects.

[Levels of human milk oligosaccharides in breast milk of mothers delivering preterm infants of different gestational ages and their effects on early growth and development]

Objective: To investigate the human milk oligosaccharides (HMOs) levels in breast milk of mothers delivering preterm infants and their effects on the early growth and development of infants. Methods: In this prospective cohort study, full-term and preterm newborns whose parents decided to breastfeed were recruited from Peking University Third Hospital between December 1, 2017 and November 30, 2018. The preterm infants were divided based on their gestational ages into extremely preterm (<28 weeks), very preterm (28-31⁺⁶ weeks) and moderate to late preterm (32-36⁺⁶ weeks) groups. Breast milk was collected from mothers at 7, 14, 28 and 120d postpartum. 368 breast milk samples were collected from 125 mothers in this study, including 54 mothers of full-term infants, 23 mothers of moderate to late preterm infants, 39 mothers of very preterm infants, and 9 mothers of extremely preterm infants. Ultra-performance liquid chromatography-mass spectrometer (UPLC-MS/MS) was used to determine the concentration of 2'-fucosyllactose (2'FL), 3-fucosyllactose (3FL), 3'-sialyllactose (3'SL), A-tetrasaccharide (P1), lacto-N-tetraose (LNT), lacto-N-neotetraose (LNnT), lacto-N-fucopentaose Ⅱ (LNFP-Ⅱ) and lacto-N-fucopentaose Ⅴ (LNFP-Ⅴ). Secretor status of mothers was defined as 2'-fucosyllactose (2'FL) concentration in colostrum and transitional milk greater than 200 μg/mL. Weight gain and the occurrence of allergic diseases of infants were collected at 120 d(4 months) postpartum. The chi-square test or the Fisher's exact test was used for the comparison of categorical data between groups; Kruskal-Wallis test and Wilcoxon rank sum test were used for comparison of continuous data between groups. Nemenyi test was used for multiple comparison. Results: 79.2% (99/125) of the mothers were secretor. There were no statistical differences between groups in the secretor status of mothers (χ²=1.31,P>0.05). The total concentration of HMOs peaked at 1-2 weeks postpartum. Compared to the preterm milk, the HMOs from the term milk was trending downwards at an earlier time. In the breast milk of secretor mothers on 28 d, total concentration of HMOs significant differed among the three groups of preterm milk and the term milk, with the median value of 4 587.09,4 615.25,5 277.44,5 476.03 μg/mL, respectively (Kruskal-Wallis χ²=8.1234,P=0.044). When analyzed by the median weight gain of the infants (low vs high weight gain) at 4 months postpartum, 2'FL was significantly lower in the high weight gain group at 7 d (1 818.04 μg/mL vs 2 181.67 μg/mL, W=1 386,P=0.018), while LNT & LNnT were significantly higher (1 182.36 μg/mL vs 1 053.62 μg/mL, W=816,P=0.044). The level of 3FL at 120 d was significantly affected by presence of allergic disease in infants, breast milk from mothers of infants with allergic disease had lower 3FL than those from mothers of infants without allergic disease (256.17 μg/mL vs 286.18 μg/mL, W=564,P=0.026). Conclusions: The overall profiles of HMOs in breast milk of mothers delivering preterm infants was basically the same as that of mothers delivering term infants; individual HMOs play a role in weight gain and the development of allergic diseases in preterm infants, but the mechanism is unclear and needs further study.

Primary pulmonary artery sarcoma with intrapulmonary metastases based on PET/CT imaging: a case report and literature review

Primary pulmonary artery sarcoma is an extremely rare and highly aggressive malignant tumor of cardiovascular system. It is usually misdiagnosed as pulmonary thromboembolism due to its atypical clinical features and similar clinical symptoms. Different from published reports, our case received both enhanced CT and 18F-FDG PET/CT examination before the pathologic result, and lung metastases had already occurred at the time of diagnosis. We herein reported a case of 41-year-old female patient who suffered from cough and chest tightness for more than a month. Laboratory examination indicated that both blood routine and tumor markers were within the normal range, and only the D-dimer slightly elevated. Contrast-enhanced chest computed tomography showed right pulmonary artery lesion and multiple nodular located right upper lung, the lesion was mild heterogeneous enhancement. No obvious abnormalities were found in deep vein of bilateral lower extremities on ultrasonography. In order to confirm the nature of these lesions, PET/CT scan was performed, which revealed stripe hypermetabolism in right pulmonary artery and nodular hypermetabolism in right upper lung, and the rest of the whole-body PET imaging were negative, a diagnosis of primary pulmonary artery malignancy with pulmonary metastases was made, and pulmonary thromboembolism was ruled out. Biopsy of right pulmonary lesions was performed and histopathological examination indicated pulmonary artery sarcoma. She only received palliative conservative medical treatment because the disease was late stage according to the tumor-node-metastasis (TNM) staging system, and did not acceptable surgical treatment, and was in good health during recent follow-up. Our study suggested that 18F-FDG PET/CT image is a good approach for the diagnosis of pulmonary artery sarcoma and could provide adjunct value for further treatment.

An improved iterative wave function reconstruction algorithm in high-resolution transmission electron microscopy

Exit wavefunction reconstruction is a powerful image processing technique to enhance the resolution and the signal-to-noise ratio for atomic-resolution imaging in both aberration uncorrected and corrected transmission electron microscopes. The present study aims to improve the performance of the iterative wavefunction reconstruction algorithm in comparison not only with its conventional form but also with the popular commercial Trueimage software for exit wavefunction reconstruction. It is shown that by implementing a wave propagation procedure for refining its image alignment, the iterative wavefunction reconstruction algorithm can be greatly improved in accurately retrieving the wavefunctions while keeping its original advantages, which allow the reconstruction be performed with less images and a larger defocus step in the data set of through-focus image series. In addition, calculations of this algorithm can be accelerated drastically by the graphic processing unit (GPU) hardware programming using the popular computer unified device architecture language, whose computing speed can be 25-38 times as fast as a central processing unit (CPU) program.

Accumulation of High Levels of Monocytic Myeloid-Derived Suppressor Cells Enhances Graft Survival in Almost-Tolerant Kidney Transplant Recipients

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells that suppress immune responses during organ transplantation and participate in mediating long-term graft survival and immune tolerance in animal transplant models. However, their role in regulating transplant tolerance in human subjects is not well understood. In the present study, we investigated the role of MDSCs in mediating long-term graft survival in almost-tolerant kidney transplant recipients (ATKTRs) and the mechanism(s) responsible for increasing MDSC numbers in these recipients.

METHODS

Peripheral blood mononuclear cells (PBMCs) from whole blood samples were collected from 30 ATKTRs (graft survival, > 10 years after kidney transplant [KTx]) treated with low doses of immunosuppressive drugs and with stable kidney function, 10 short-term graft survival kidney transplant recipients (STKTRs; graft survival, ∼1-3 years post-KTx) with stable kidney function, and 10 healthy donors (HDs). MDSC and regulatory T cell (Tregs) levels were analyzed using multicolor flow cytometry in PBMCs.

RESULTS

ATKTRs had significantly higher levels of monocytic MDSCs (P < .001) and CD4⁺CD25⁺FoxP3⁺ Tregs than STKTRs and HDs. Furthermore, the M-MDSC levels correlated positively with the survival rates, estimated glomerular filtration rates (eGFRs) of grafts, and the levels of CD4⁺CD25⁺FoxP3⁺ Tregs in ATKTRs.

CONCLUSIONS

Accumulation of high levels of MDSCs was observed in ATKTRs. Changes in MDSC levels may play important roles in mediating transplant tolerance and regulating Tregs. Therefore, we propose that MDSCs may be potentially used for recognizing tolerant transplant recipients and guiding dosage reduction for immunosuppressive drugs for KTx.

Construction and characterization of recombinant adenovirus carrying a mouse TIGIT-GFP gene

Recombinant adenovirus vector systems have been used extensively in protein research and gene therapy. However, the construction and characterization of recombinant adenovirus is a tedious and time-consuming process. TIGIT is a recently discovered immunosuppressive molecule that plays an important role in maintaining immunological balance. The construction of recombinant adenovirus mediating TIGIT expression must be simplified to facilitate its use in the study of TIGIT. In this study, the TIGIT gene was combined with green fluorescent protein (GFP); the TIGIT-GFP gene was inserted into a gateway plasmid to construct a TIGIT-GFP adenovirus. HEK 293A cells were infected with the adenovirus, which was then purified and subjected to virus titering. TIGIT-GFP adenovirus was characterized by flow cytometry and immunofluorescence, and its expression in mouse liver was detected by infection through caudal vein injection. The results showed the successful construction of the TIGIT-GFP adenovirus (5 x 10(10) PFU/mL). Co-expression of TIGIT and GFP was identified in 293A and liver cells; synthesis and positioning of TIGIT-GFP was viewed under a fluorescence microscope. TIGIT-GFP was highly expressed on liver cells 1 day (25.53%) after infection and faded 3 days (11.36%) after injection. In conclusion, the fusion of TIGIT with GFP allows easy, rapid, and uncomplicated detection of TIGIT translation. The construction of a TIGIT-GFP adenovirus, mediating TIGIT expression in vitro and in vivo, lays the foundation for further research into TIGIT function and gene therapy. Moreover, the TIGIT-GFP adenovirus is a helpful tool for studying other proteins (which could replace the TIGIT gene).

Gas breakthrough and emission through unsaturated compacted clay in landfill final cover

Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas-water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different climate conditions. The results of experimental study and numerical simulation reveal that as the degree of saturation and thickness of clay increase, the gas breakthrough pressure increases but the gas emission rate decreases significantly. Under a gas pressure of 10 kPa (the upper bound limit of typical landfill gas pressure), a 0.6m or thicker compacted clay is able to prevent gas breakthrough at degree of saturation of 60% or above (in humid regions). Furthermore, to meet the limit of gas emission rate set by the Australian guideline, a 0.6m-thick clay layer may be sufficient even at low degree of saturation (i.e., 10% like in arid regions).

Generation and characterization of polyclonal antibodies against mouse T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory domain by DNA-based immunization

Mouse T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory domain (TIGIT) is a newly identified surface protein expressed in regulatory, memory, natural killer (NK), and activated T cells. Several studies indicate that mouse TIGIT is a vital immunomodulator that can control the activities of both NK and T cells and plays an important role in transplantation tolerance. In this study, we designed a vector, TIGIT-pcDNA3.1 (+), that encodes the complete coding sequence of mouse TIGIT. The vector was intramuscularly injected into rats, and then the specific antisera were harvested and purified using a protein A/G PLUS-agarose affinity column. Western blot and immunohistochemistry analyses revealed that the antibodies generated by DNA immunization can bind with the mouse TIGIT. Using these antibodies in immunoblots, TIGIT was detected in lysates of mouse organs, T cells from mouse lymph nodes, and recombinant mouse fusion protein of TIGIT and Fc fragment. Immunohistochemistry analysis of normal mouse kidney showed that immunoreactivity was located on endothelial cells of glomerular capillary loops and peritubular capillaries. Our results demonstrated that the DNA immunization of rats through intramuscular injection was a simple and easily available method of producing polyclonal antibodies that can be used to detect and analyze mouse TIGIT expression in mouse systems.

miR-499A>G rs3746444 and miR-146aG>C expression and hepatocellular carcinoma risk in the Chinese population

We conducted a case-control study of a possible association of miR-499A>G rs3746444 and miR-146aG>C rs2910164 with risk of hepatocellular carcinoma. Samples from 172 hepatocellular carcinoma patients and 185 cancer-free controls were collected from October 2008 to December 2011. PCR-RFLP analysis was performed to determine the polymorphisms in each individual. The MAFs of miR-146aG>C and miR-499A>G in controls were similar to that known from the SNP database, and frequencies of genotypes in controls were in line with Hardy-Weinberg equilibrium. We found that miR-499 AG was significantly associated with decreased risk for hepatocellular carcinoma when compared with miR-499 AA genotype (adjusted odds ration = 0.74, 95% confidence interval = 0.24-0.96). However, subjects carrying miR-146a GG had a non-significant 0.62-fold decreased risk of hepatocellular carcinoma. We did not find a significant association of miR-146aG>C rs2910164 and miR-499A>G rs3746444 polymorphisms with hepatocellular carcinoma risk in the Chinese population. Further investigations are warranted to clarify the relationship between miRNA polymorphisms and susceptibility to hepatocellular carcinoma risk in various ethnic populations.

Galectin-7 in cardiac allografts in mice: increased expression compared with isografts and localization in infiltrating lymphocytes and vascular endothelial cells

We sought to identify elevated expression of galectin-7, a T-cell-binding protein, in renal allograft recipients undergoing acute rejection episodes. Allografts and isografts were examined immunohistologically and using quantitative Western blot analysis for galectin-7 protein. The expression of galectin-7 in T lymphocytes from draining lymph nodes in the recipient mice was examined using flow cytometry. We observed galectin-7 to gradually increase with time in the allografts to be significantly higher than that in isografts at days 3, 5, and 7 postoperative: 0.85 ± 0.03 versus 0.69 ± 0.05; 1.15 ± 0.11 versus 0.81 ± 0.02; and 2.02 ± 0.12 versus 0.81 ± 0.05 (P < .05). The majority of galectin-7 was located in the infiltrating lymphocytes and vascular endothelial cells. Furthermore, the percentage of CD4+galectin-7+ and CD8+galectin-7+ T cells from draining lymph nodes in the allograft group was higher than that in the isograft group: 28.0 ± 1.0% versus 1.2 ± 0.2%; and 12.4 ± 0.8% versus 0.4 ± 0.1% (P < .01). In conclusion, galectin-7 relates to acute allograft rejection and T-cell responses possibly as an accelerant.

Transforming growth factor beta 1 plays an important role in inducing CD4(+)CD25(+)forhead box P3(+) regulatory T cells by mast cells

The role of mast cells (MCs) in the generation of adaptive immune responses especially in the transplant immune responses is far from being resolved. It is reported that mast cells are essential intermediaries in regulatory T cell (T(reg)) transplant tolerance, but the mechanism has not been clarified. To investigate whether bone marrow-derived mast cells (BMMCs) can induce T(regs) by expressing transforming growth factor beta 1 (TGF-β1) in vitro, bone marrow cells obtained from C57BL/6 (H-2(b) ) mice were cultured with interleukin (IL)-3 (10 ng/ml) and stem cell factor (SCF) (10 ng/ml) for 4 weeks. The purity of BMMCs was measured by flow cytometry. The BMMCs were then co-cultured with C57BL/6 T cells at ratios of 1:2, 1:1 and 2:1. Anti-CD3, anti-CD28 and IL-2 were administered into the co-culture system with (experiment groups) or without (control groups) TGF-β1 neutralizing antibody. The percentages of CD4(+)CD25(+)forkhead box P3 (FoxP3)(+) T(regs) in the co-cultured system were analysed by flow cytometry on day 5. The T(reg) percentages were significantly higher in all the experiment groups compared to the control groups. These changes were deduced by applying TGF-β1 neutralizing antibody into the co-culture system. Our results indicated that the CD4(+) T cells can be induced into CD4(+)CD25(+)FoxP3(+) T cells by BMMCs via TGF-β1.

Adenovirus-mediated heme oxygenase transfer inhibits graft arteriosclerosis in rat aortic transplants

PURPOSE

Heme oxygenase-1 (HO-1) has been implicated in graft protection because its induction is associated with long-surviving allografts. The aim of this study was to analyze the efficacy of adenovirus-mediated HO-1 overexpression to inhibit graft arteriosclerosis and estimate whether the protective role correlated with nuclear factor kappaB (NF=kappaB) expression and grafts apoptosis.

METHODS

Aortic transplantation was performed using inbred Brown-Norway (BN) rats (RT1n male) as donors and Lewis rats (RT1l male) as recipients. The experiments were divided into four groups: group A, Lewis-Lewis (n=6), no treatment; group B, BN-Lewis (n=6), no treatment; group C, BN-Lewis (n=6), donor aorta perfused with buffer containing 4x10(10) pfu Ad-Null (the noncoding adenoviral vector); and group D, BN-Lewis (n=6), donor aorta perfused with buffer containing 4x10(10) pfu Ad-HO-1 (adenoviral vector coding for HO-1). All grafts were harvested at 60 days after transplantation. Reverse transcriptase polymerase chain reaction was performed to detect the expression of HO-1 gene. Hematoxylin and eosin staining was used to detect the morphology and cytology of the transplanted vessels. Intimal thickening was detected by Masson staining. Immunohistochemistry was used to detect the localization and expression of HO-1 and NF-kappaB and TUNEL assays to detect the apoptosis of the grafts.

RESULTS

Gene transfer of HO-1 grafts using an adenoviral vector resulted in the expression of HO-1 protein in endothelium and adventitia. We observed that the intimal thickness in Ad-HO-1-treated aortas (11.11+/-0.92 microm) was significantly thinner compared with untreated (85.20+/-6.90 microm) or Ad-null treated (87.20+/-6.20 microm) aortas (P<.01). Immunohistology showed that treatment with Ad-HO-1 resulted in a significant reduction in leukocyte infiltration and a decreased number of vascular smooth muscle cells in the intima, compared with Ad-null-treated aortas. The levels of NF-kappaB and the number of apoptotic cells in Ad-HO-1-treated aortas showed significantly lower compared with Ad-null-treated arotas (P<.05).

CONCLUSION

HO-1 prevented the development of graft arteriosclerosis in the rat aortic transplant model. The protective role of HO-1 in chronic rejection lesions seemed to correlate with downregulation of the expression of NF-kappaB and inhibition of apoptosis in the grafts.

Heme oxygenase-1 protects INF-gamma primed endothelial cells from Jurkat T-cell adhesion

PURPOSE

The heme oxygenase-1 (HO-1) system is associated with the rate-limiting step of conversion of heme, one of the most critical roles in cytoprotective mechanisms. Our study investigated its potential role in protection of endothelial cells from T cells.

METHODS

The recombinant plasmid pcDNA3-HO-1 was transfected into endothelial cells. Indirect fluorescent staining was used to examine the expression of HO-1 protein. Then endothelial cells primed by INF-gamma were mixed in culture with Jurkat T cells labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE). The number of adhesive Jurkat T cells was determined using FACS to evaluate the adhesion effect. After being cultured with endothelial cells, the cell cycle of Jurkat T cells was detected using FACS.

RESULTS

Expression of HO-1 on endothelial cells conferred significant protection against Jurkat T-cell-mediated adhesion. The rate of Jurkat T-cell adhesions was reduced to 19.06%, in contrast with 31.42% in the control group (P<.05). After using ZnPP, an inhibitor of HO-1, the rate of Jurkat T-cell adhesion recovered to 29.08%. The binding activities between endothelial cells and Jurkat T cells was blocked by HO-1 expression. The proliferation of Jurkat T cells was inhibited after culture with endothelial cells, which had been transfected with HO-1, which blocked cell cycle entry of T cells. More than 60% of Jurkat T cells remained in G0/G1 compared with 40% among the control group.

CONCLUSION

HO-1 directly protected endothelial cells primed by INF-gamma from Jurkat T cells and down-regulated the expression of HLA-DR on the surface of endothelial cells. These results indicated that transgenic expression of HO-1 may be useful to prevent lymphocytes from responding to endothelial cells.

Antisense ERK1/2 oligodeoxynucleotide gene therapy attenuates graft arteriosclerosis of aortic transplant in a rat model

Chronic rejection is a major cause of transplant loss that is effected by the extracellular signal-regulated kinases (ERK) pathway. This study investigated the effects of antisense ERK1/2 oligodeoxynucleotide(ODN) gene therapy on chronic rejection.

METHODS

Lewis (RT1(1)) rats served as recipients of Brown-Norway (BN, RT1n) grafts. The BN rat abdominal aortas were harvested and orthotopically grafted into Lewis rats. The recipients were divided into three groups: (1) control group (n = 9), (2) random ODN transfer group (n = 10), and (3) antisense ODN transfer group (n = 10). At day 60 after transplantation, the recipients were sacrificed; the grafted aortas were evaluated histologically and immunohistochemically. ERK1/2 protein expression in the grafts was determined using Western Blot assays. Serum levels of slCAM-1 were detected by ELISA.

RESULTS

In the control group and random ODN transfer group, we observed a remarkable degree of intimal hyperplasia and inflammatory cell infiltration, including macrophages and T cells. Compared with the control group, antisense ERK1/2 ODN gene therapy resulted in a significant reduction in neointimal proliferation (P < .01), inhibition of ERK1/2 protein expression (P < .01), decreased graft infiltration with CD4+ T lymphocytes (P < .01), CD8+ T lymphocytes(P < .05), and ED-1 macrophages (P < .01) with decreased serum levels of sICAM-1 (P < .05). We obtained a negative correlation between ERK1/2 expression and immune cell infiltration or ICAM-1 level.

CONCLUSIONS

Antisense ERK1/2 gene therapy can attenuate graft arteriosclerosis so as to protect aortic allografts. The protection seemed to correlate with inhibition of inflammatory infiltration, implying that the ERK1/2 signal transduction pathway plays an important role in the process of chronic vascular rejection.

Expression of Neuropilin-1 In Kidney Graft Biopsies: What Is the Significance?

OBJECTIVE

Recent work has suggested that neuropilin-1 (NRP-1) is a surface marker of regulatory T cells (Treg). However, no further relative evidence has been provided to confirm this finding. Since Treg should decline during rejection, the expression of NRP-1 on lymphocytes should decline in a rejected graft. To test this proposal, we examined NRP-1 expression in kidney graft biopsies.

MATERIALS AND METHODS

Tissue samples were obtained from 20 kidney graft biopsies with pathologically confirmed acute rejection and from 10 without rejections. We performed immunohistochemistry assays using an anti-NRP-1 monoclonal antibody. The positive cells were counted and the ratios among lymphocytes analyzed.

RESULTS

Compared with samples from nonrejected graft biopsies (18.71 +/- 20.60), the number of positive cells among lymphocytes in the rejected samples showed a lower percentage (3.16 +/- 1.72; P < .05).

CONCLUSIONS

NRP-1 has an important role in directing the growth of nervous synapses and immune synapses. We found in rejected grafts that the percentage of NRP-1 positive cells among lymphocytes decreased significantly. Therefore, NRP-1 may have a previously unrecognized role to predict the immune state of the graft as a potential marker for Treg.

Induction of Accommodation Model by Combined RNA Interference Targeting 1,3-Galactosyltransferase Gene and Low-Dose GS-IB4 Lectin In Vitro

OBJECTIVE

This study sought to mimic the interaction of xenograft endothelial cells and human serum in vitro after successfully silencing the expression of porcine alpha1,3-galactosyltransferase (alpha1,3GT) gene by RNA interference (RNAi), and to investigate the possibility of inducing accommodation in vitro by stimulation of alpha-Gal-specific binding lectin, Griffonia simplicifolia isolectin B4 (GS-IB4) and RNAi.

MATERIALS AND METHODS

Various alpha-Gal expression patterns on a pig endothelial cell immortalized line (PED) was achieved by serial doses of small interfering RNA (siRNA) targeting porcinc alpha1,3GT gene. alpha1,3GT-siRNA transfected PEDs were exposed to increasing doses of GS-IB4 lectin (0.5, 2, and 8 microg/mL) for 4 hours before incubation with normal human serum (NHS). Accommodation phenomenon of PEDs in NHS was observed by 51Cr release and antibody/complement binding assays.

RESULTS

With combined RNAi and low-dose GS-IB4 stimulation, PEDs remarkably inhibited complement-mediated cytotoxicity, which showed a better protective effect than using RNAi alone. At a concentration of 2 mug/mL, GS-IB4 exhibited the maximum protective effect. The expression of E-selectin on alpha1,3GT-siRNA transfected PEDs did not differ from that on parental PEDs with heat-inactivated NHS (HINHS) stimulation. Combined with GS-IB4 stimulation, however, it inhibited expression of E-selectin, which was GS-IB4 dose dependent, resulting in mean fluorescence intensity values of 98.5, 42.0, and 36.3 at 0.5, 2, and 8 microg/mL. The mRNA expression of the protective gene HO-1 was significantly up-regulated after treatment with RNAi and low-dose of GS-IB4.

CONCLUSIONS

Combined RNAi and low-dose GS-IB4 induced pig endothelial cell accommodation in vitro. The level of alpha-Gal expression played an important role in the induction of accommodation.

Magnesium supplementation prevents chronic cyclosporine nephrotoxicity via adjusting nitric oxide synthase activity

INTRODUCTION

Nitric oxide synthase (NOS) is a protective factor for chronic cyclosporine nephrotoxicity by virtue of adjusting the production of nitric oxide (NO). The aim of this study was to explore the role of NOS in the effect of magnesium supplementation to prevent chronic cyclosporine nephrotoxicity.

METHODS

Rats maintained on a low-salt diet were divided into three groups: normal controls, cyclosporine group (CsA 15 mg x kg(-1) x d(-1) subcutaneously) and CsA + Mg2+ group (CsA subcutaneously and dietary supplementation with 0.6% Mg enriched by MgCl2). On day 28, plasma Mg2+, plasma creatinine, NOS activity, and NO content in renal tissue were examined. The renal expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in kidneys was determined by an immunohistochemistry technique. The lesions of chronic cyclosporine nephrotoxicity were identified by HE and PAS stains as well as electron microscope.

RESULTS

After 28 days of CsA administration, characteristic histological lesions of chronic cyclosporine nephotoxicity were observed, including arteriolopathy, tubular atrophy and interstitial fibrosis. Giant mitochondria and microcalcifications were observed by electron microscopy. Simultaneously, constitutive nitric oxide synthase (cNOS) activity in kidneys was increased, but NO content did not increase correspondingly (P < .05) compared with normal controls. Dietary supplementation with Mg2+ ameliorated the CsA-induced histological lesions. cNOS activity was decreased to normal levels and NOS was increased (P < .05) compared with animals that only received CsA. CsA and magnesium supplementation did not change iNOS activity.

CONCLUSIONS

Dietary supplementation with Mg2+ seems to improve renal function and almost abolish CsA-induced histological lesions via altering the abnormal activation of cNOS in this model.

Inhibition of MD-1 expression by immunosuppressants or antisense oligodeoxynucleotides on skin allograft survival in mice

AIM

The aim of this study was to investigate the effects of inhibition of MD-1 expression using nonspecific immunosuppressants and specific antisense oligodeoxynucleotides (AS-ODNs) treatment on skin allograft survival in mice.

METHODS

C57BL/6 to Balb/c skin allograft model was used in all groups, followed by Cyclosporine (CsA), Tacrolimus (FK506), Mycophenolate Mofetil (MMF), and Sirolimus (SRL) intraperitaneally, as well as AS-ODNs intravenously. Recipients were humanely killed at 11 days after transplantation. MD-1 expression was determined using flow cytometric analysis (FACS). AlamarBlue was used to evaluate proliferation. And serum levels of interleukin (IL)-2 and IL-10 were detected using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with saline controls, the mean survival times (MST) of skin allografts in all of the immunosuppressants and AS-ODNs treated groups were significantly prolonged (P < .05). CsA, MMF, and AS-ODNs inhibited MD-1 expression and lymphocyte proliferation, as well as decreased serum level of IL-2 and increased that of IL-10; FK506, treatment showed all the effects mentioned above but up-regulated the IL-10 level; SRL had no significant influence on either MD-1 expression or IL-2 and IL-10 level, although it equally suppressed the proliferation (P < .05 vs controls). The negative correlation between MD-1 expression and lymphocyte proliferation or IL-2 level was significant, as was the positive correlation between it and IL-10 level (P < .01).

CONCLUSIONS

CsA, FK506, MMF, and AS-ODNs can efficiently inhibit MD-1 expression. The effects of the immunosuppressants are seemingly associated with the down-regulation of the IL-2 serum level. MD-1 was theorized to play an important role in rejection promotion, although the precise relationship between it and allograft survival still remains ambiguous.

The survival and value of liver transplantation for liver carcinoma: a single-center experience

Liver transplantation for liver carcinoma with cirrhosis is a treatment still in dispute. The objectives were to summarize the survival and cost of 50 liver transplant cases performed for liver carcinoma over nearly 3 years.

METHODS

We performed 138 liver transplants from January 1999 to February 2002. There were 50 cases (36.2%) of liver carcinoma with HBV cirrhosis, which were divided into three stages based on the tumor pathology: Stage 1 cases showed a single mass (< or = 5 cm), 4 cases; Stage 2, a single mass > 5 cm or intrahepatic multiple masses without PV cancer embolus, 32 cases; and Stage 3: tumor invasion of the PV or perihepatic lymph nodes or organs, 14 cases. All patients received three to six courses of chemotherapy postoperatively.

RESULTS

All four cases of stage 1 survived > 1 year; one of them is at 3 years with good liver function and tumor free. The mean half-year medical cost was $27.100 +/- 108 in stage 1. The half-year survival and medical costs were 62.5% and $31,500 +/- 260 in stage 2 and 15.0% and $35,500 +/- 134 in stage 3.

CONCLUSION

Liver transplantation is an effective treatment for early-stage liver carcinoma, that achieves good medical and economic results, but should be limited to advanced liver cancer.

Prolonged heart allograft survival resulted from donor-specific T-cell sequestering and removal by selective splenectomy in mice

INTRODUCTION

Selective splenectomy when donor antigen-specific activated T cells are sequestered in the recipient spleen may prolong allograft survival because of removal of all of these T cells.

OBJECTIVES

We investigated the effect on cardiac allograft survival in mice by means of removal of activated specific T cells by splenectomy.

METHODS

Donor (Balb/c) spleen cells were injected into primed allogeneic recipients (C57BL/6). Selective recipient splenectomy and donor-type cervical heart grafting in Balb/c to C57BL/6 from mice were examined at 0, 24, 48, and 72 hours after donor spleen cell infusion.

RESULTS

Control C57BL/6 mice rejected Balb/c heart grafts at 6.86 +/- 0.19 days. Delayed heart grafting plus splenectomy at 24 or 48 hours after donor-type spleen cell infusion significantly prolonged heart allograft survival (24 hours: 15.86 +/- 3.44 days, P < .001; 48 hours: 21.71 +/- 5.22 days, P < .001, respectively). However, 72-hour delayed heart grafting plus splenectomy failed to prevent acute rejection (72 hours: 9.57 +/- 2.51 days, P > .01). Immunohistochemistry showed, at 24 to 48 hours after donor antigen infusion, the recipient spleens characterized by an obvious increase in CD4+ CD8+ T cells in periateriolar lymphoid sheaths, marginal zones, and red pulp compared with the 72-hour group.

CONCLUSIONS

Transient accumulation of donor-specific activated T cells in the spleen of recipients provide an opportunity to remove all of these T cells by a surgical procedure. As the largest immune organ the spleen is the main place where T cells are activated and regenerated. At 24 or 48 hours when donor-specific T cells were sequestered in the spleen after donor antigen stimulation, selective recipient splenectomy was able to remove the T cells and prolong was allograft survival. Refinement of this protocol may eventually warrant clinical application.

Hand-assisted transperitoneal laparoscopic living donor nephrectomy

OBJECTIVE

We introduced and evaluated the advantages and disadvantages of the hand-assisted transperitoneal laparoscopic technique for living donor nephrectomy.

MATERIALS AND METHODS

In December 2001, we started using the technique of hand-assisted transperitoneal laparoscopic living donor nephrectomy (HLDN) in 10 cases. The procedure utilizes a hand-assisted device to increase safety and control of the laparoscopic technique.

RESULTS

Only left nephrectomy was performed. The mean total operating and the warm ischemia times were 130 minutes and 3.0 minutes, respectively. Average lengths of renal artery and vein were 1.95 cm and 2.8 cm, respectively. There were no intraoperative or postoperative complications.

CONCLUSIONS

HLDN is an easier procedure than the traditional laparoscopic living donor nephrectomy and can greatly mitigate the learning curve. HLDN has shortened warm ischemia time and operating time. It is also good for trocar placement, prevention of torsion of the kidney, control of potential bleeding at the final stage of vascular stapling, and kidney removal. Therefore, HLDN is a promising method for living donor nephrectomy.

Effect of sodium dimercaptopropanesulfonate on antagonism of tetramethylenedisulphotetramine to GABA receptor

AIM

To study effects of sodium dimercaptopropanesulfonate (DMPS) on the antagonism of tetramethylenedisulphotetramine (TETS) to gamma-aminobutyric acid (GABA) receptor.

METHODS

Acute toxicity experiments were conducted to observe the effects of DMPS and TETS on mice. Contents of free amino acids in mouse brain were determined with automatic analyzer for amino acids. Autoradiography was used to observe the [3H]GABA bindings in the rat brain slices under different conditions.

RESULTS

After icv and ip DMPS, the number of mice experiencing convulsions reduced from 20 in control group to 4 and 2 respectively in TETS poisoned mice. The content of GABA was altered in DMPS control group and TETS control group compared with DMPS protection group and NS control group [micromol/g: (2.09 +/- 0.05) and (2.67 +/- 0.15) vs (2.40 +/- 0.10 (micromol/g)) and (2.41 +/- 0.21)]; the content of glutamic acid was (12.3 +/- 1.2), (12.0 +/- 0.8), (10.2 +/- 0.6), and (11.8 +/- 1.0) micromol/g in NS control group, DMPS control group, TETS control group, and DMPS protection group, respectively. The OD value of autoradiograms decreased in TETS group compared with buffer control group in cortex, hippocampus, diencephalon, and brainstem [(0.084 +/- 0.008), (0.081 +/- 0.009), (0.094 +/- 0.006) and (0.081 +/- 0.006), vs (0.102 +/- 0.003), (0.109 +/- 0.005), (0.128 +/- 0.007), and (0.125 +/- 0.008), respectively]. OD value was maintained or higher than the normal level in DMPS+TETS group in the four brain areas [(0.116 +/- 0.008), (0.125 +/- 0.011), (0.129 +/- 0.005), and (0.128 +/- 0.010) vs (0.102 +/- 0.003), (0.109 +/- 0.005), (0.128 +/- 0.007), and (0.125 +/- 0.008), respectively].

CONCLUSION

The inhibitory effects of DMPS on the antagonism of TETS to GABA receptor are due to the increase in the GABA binding to its receptors in brain caused by DMPS

Isolation and characterization of a group of oligopeptides related to oxidized glutathione from the root of Panax ginseng

Six gamma-glutamyl oligopeptides were isolated for the first time from aqueous methanol extracts of Panax ginseng root by using column chromatography on ion-exchange resin, gel filtration and reverse-phase high-performance liquid chromatography. Their structures had been established with the methods of amino acid analysis, N-terminal, C-terminal determination and double-coupling sequence analysis. They were: P-I (N-gamma-glutamylcystinyl-bis-glycine), P-ll (gamma-glutamylcysteinylglycine disulfide, oxidized glutathione), P-III (N,N'-bis-gamma-glutamylcystinylglycine), P-IV (gamma-glutamylcysteinylglycinamide disulfide), P-V (N-gamma-glutamylglycylcysteine disulfide), P-VI(gammaglutamylarginine); five of them are related to oxidized glutathione. The structures were further confirmed by the chemical synthesis. As far as we know, P-V (N-gamma-glutamylglycylcysteine disulfide) is a new biologically active peptide which exhibits somnogenic effect and is more potent than that of P-II.

Prolongation of murine vascularized heart allograft survival by recipient-specific anti-major histocompatibility complex class II antibody

BACKGROUND

Antibodies targeting recipient major histocompatibility complex (MHC) class II molecules have been demonstrated to be effective at prolonging allograft survival. However, antigen-presenting cell depletion would explain this effect and has not been definitively excluded as the mechanism of action of such antibodies. We have studied an anti-MHC class II antibody (OX6) proven to be noncytotoxic in the recipient strain used.

METHODS

Antibody was administered the day before, 2 hr before, and the day after grafting.

RESULTS

Antibody administration on the day before, 2 hr before, and the day after grafting significantly prolonged vascularized cardiac allograft survival. Importantly, treatment recognizing recipient MHC was effective, whereas a similar regimen recognizing donor MHC was not.

CONCLUSIONS

Noncytotoxic recipient MHC class II-specific antibodies modify allograft rejection. Possible mechanisms for this therapeutic effect are discussed.

[Tissue concentration and secretion of renin in human placental villi during early pregnancy]

In this study, tissue concentrations of renin and angiotensins in human placental villi during early pregnancy and contents of renin and angiotensin I (A I) secreted by cultured chorion were measured by radioimmunal assay (RIA). The results are as follows. During early pregnancy, the human chorion contains renin and A II. The activity of renin is much higher at 6th week of gestation, but as gestation proceeds, it decreases gradually, while A II shows somewhat increased change. The activity of renin secreted by cultured chorion can also be measured. A I in human placental villi can not be detected by RIA in chorion leaves or their culturing fluid. These results indicate that renin-angiotensin system may exist independently in human placental villi during early pregnancy.

Amplification of natural regulatory immune mechanisms for transplantation tolerance

There is a need to derive donor-specific tolerance in clinical organ transplantation, where potential benefits remain overshadowed by chronic rejection and side effects of continual immunosuppressive therapy. It is known that the mature immune system in mice can be reprogrammed to accept a foreign graft as if it were "self." Here we show that, once generated, this state of operational tolerance becomes self-sustaining, imposing itself on new cohorts of lymphocytes as they arise. These new cohorts retain specificity for the tolerizing antigen and can be selectively amplified to tolerate new antigens that have linked expression with the original tolerogen. Regulation is critically dependent upon the continuous presence of tolerizing antigen and is mediated by the CD4+ lymphocyte population. We propose that such natural mechanisms of immune regulation may eventually be exploited for transplantation tolerance, even in fully immune-competent recipients.

[Effects of stimulating rabbit's cerebral cortex on respiratory frequency and amplitude]

The effects on respiration upon stimulation of different areas of cerebral cortex were studied in 38 urethance anesthetized rabbits after both vagotomy and section of the maxillary division of trigeminal nerves. The results showed that: (1) Light continuous stimulations of the limb motor area (L) enforced inspiration by increasing respiratory frequency (RF) and tidal volume (TV). Stimulation of the facial motor area (F) increased RF notably, but depth of expiration and inspiration were notably decreased. Upon stimulation of the masticatory motor area (M), expiration or inspiration was accentuated, RF and TV were obviously increased. Upon stimulation of the posterior orbital area RF and TV were decreased markably. No obvious effects on respiration were observed on stimulation of the other areas of the cortex. (2) With shortened total period of stimulation, a stimulating L, F or M area would cause a longer period of apnoea after expiration and resumption of inspiration insured an increased TV.

[Antidotal effects of 2,3-dimercaptopropane-1-sulfonate sodium (DMPS) and combined with diazepam on acute poisoning caused by sodium ammonium dimethyl-2-propano-1,3-dithiosulfate monohydrate (SCD)]

In mice, DMPS (250 mg/kg, i.v.) combined with diazepam (1.25 mg/kg, i.p.) could increase LD50 of p. o. SCD 5.3 times. DMPS (62.5 mg/kg, i.v.) antagonized completely the respiratory depression and neuromuscular blockade caused by SCD(7.5 mg/kg, i.v.) in rabbits. SCD (15 mg/kg, i.v.) caused tremor, tonic convulsion and the abnormal paroxysmal discharges in EEG in rabbits. DMPS (0.5 mg/kg, i.c.v) could not eliminate the abnormal paroxysmal discharges in EEG of rabbits. DMPS (62.5 mg/kg, i.v.) combined with diazepam (5 mg/kg, i.v.) completely and rapidly antagonize these toxic symptoms and the abnormal changes in EEG.

[Neuromuscular blocking and respiratory depressing actions of sodium ammonium dimethyl-2-(propano-1,3-dithiosulfate) monohydrate]

The neuromuscular blocking and respiratory depressing actions of the new insecticide sodium ammonium dimethyl-2-(propano-1,3-dithiosulfate) monohydrate (SCD) were investigated. In peroneal-tibialis anterior nerve-muscle preparations of urethane anesthetized rabbit, SCD 6.5 mg/kg iv completely depressed the indirectly elicited twitch tension but not the directly elicited one. This compound also caused initial potentiation of the indirectly elicited twitch tension. In the partially paralyzed preparations, potentiation of contractions occurred following a brief period of indirectly tetanic stimulation. Nereistoxin but not SCD blocked the indirectly elicited twitch tension of isolated rat diaphragm. The neuromuscular blockade induced by SCD and nereistoxin was antagonized by neostigmine and 4-aminopyridine. SCD and nereistoxin had little or no effect on arterial blood pressure and phrenic nerve discharge of rabbits. The results indicated that SCD-poisoned rabbits died of respiratory paralysis following the neuromuscular blockade.

[Antidotal effects of sulfhydryl compounds on acute poisonings by sodium ammonium dimethyl-2-(propane-1,3-dithiosulfate) monohydrate, nereistoxin and cartap]

Sodium dimercaptopropanesulphonate (DMPS) and sodium dimercaptosuccinate (DMS) were discovered to be effective antidotes for acute poisoning of insecticides SCD [sodium ammonium dimethyl-2-(propane-1,3-dithiosulfate) monohydrate], nereistoxin (4-N,N-dimethylamino-1,2-dithiolane) and cartap (dihydronereistoxin dicarbamate). In mice, DMPS (250 mg/kg) or DMS (1000 mg/kg) ip 20 min before SCD increased LD50 of ig SCD from 97 to 374 or 251 mg/kg, respectively. The prophylactic effect of DMPS was better than that of DMS. Administration of DMPS prior to cartap increased LD50 of ig cartap from 130 to 375 mg/kg. The therapeutic effect of DMPS was also demonstrated in SCD-poisoned conscious rabbits. DMPS 62.5 mg/kg or DMS 500 mg/kg iv completely antagonized the neuromuscular blockade and respiratory depression caused by SCD, nereistoxin and cartap in anesthetized rabbits. The antagonism of SCD-induced neuromuscular blockade by cysteine (400 mg/kg, iv) was less effective and of shorter duration than that by DMPS and DMS. Dimercaprol 50 mg/kg im showed little effect on SCD-induced paralysis. The antagonistic actions of sulfhydryl compounds on neuromuscular blockade induced by these insecticides probably belong to chemical antagonism.