Metronomic capecitabine inhibits liver transplant rejection in rats by triggering recipients' T cell ferroptosis.

BACKGROUND: Capecitabine (CAP) is a classic antimetabolic drug and has shown potential antirejection effects after liver transplantation (LT) in clinical studies. Our previous study showed that metronomic CAP can cause the programmed death of T cells by inducing oxidative stress in healthy mice. Ferroptosis, a newly defined non-apoptotic cell death that occurs in response to iron overload and lethal levels of lipid peroxidation, is an important mechanism by which CAP induces cell death. Therefore, ferroptosis may also play an important role in CAP-induced T cell death and play an immunosuppressive role in acute rejection after trans-plantation. AIM: To investigate the functions and underlying mechanisms of antirejection effects of metronomic CAP. METHODS: A rat LT model of acute rejection was established, and the effect of metronomic CAP on splenic hematopoietic function and acute graft rejection was evaluated 7 d after LT. In vitro, primary CD3+ T cells were sorted from rat spleens and human peripheral blood, and co-cultured with or without 5-fluorouracil (5-FU) (active agent of CAP). The levels of ferroptosis-related proteins, ferrous ion concentration, and oxidative stress-related indicators were observed. The changes in mito-chondrial structure were observed using electron microscopy. RESULTS: With no significant myelotoxicity, metronomic CAP alleviated graft injury (Banff score 9 vs 7.333, P < 0.001), prolonged the survival time of the recipient rats (11.5 d vs 16 d, P < 0.01), and reduced the infiltration rate of CD3+ T cells in peripheral blood (6.859 vs 3.735, P < 0.001), liver graft (7.459 vs 3.432, P < 0.001), and spleen (26.92 vs 12.9, P < 0.001), thereby inhibiting acute rejection after LT. In vitro, 5-FU, an end product of CAP metabolism, induced the degradation of the ferritin heavy chain by upregulating nuclear receptor coactivator 4, which caused the accumulation of ferrous ions. It also inhibited nuclear erythroid 2 p45-related factor 2, heme oxygenase-1, and glutathione peroxidase 4, eventually leading to oxidative damage and ferroptosis of T cells. CONCLUSION: Metronomic CAP can suppress acute allograft rejection in rats by triggering CD3+ T cell ferroptosis, which makes it an effective immunosuppressive agent after LT.

Fungal polyketides from a rhizospheric soil-derived Penicillium sp. YUD17004 associated with Gastrodia elata.

Five unprecedented polyketide metabolites were isolated and characterized from a rhizospheric soil-derived Penicillium sp. YUD17004. Their diverse structures included two indanone-type polyketides penicillyketides A and B, a phthalide-like polyketides penicillyketide C, a symmetrical chromone dimer penicillyketide D, along with a pyrone derivative pyranlyketide, which were elucidated by spectroscopic data interpretation and quantum chemical electronic circular dichroism calculation. Notably, the structures of penicillyketides A and B feature a highly functionalized indanone ring nucleus, but differ from other indanone-containing polyketides by the alkyl substitution pattern. The structure of penicillyketide C comprises a furanone ring instead of the hydroxycyclopentenone ring characteristic for penicillyketides A and B, and represents an undescribed arrangement within C17 polyketides. Penicillyketide D represented the first example of a chromone homodimer with the bridge at C-2/2'. Penicillyketide B exhibited weak anti-inflammatory activity with an IC50 value of 32 ± 1.0 µM. Penicillyketide D displayed weak cytotoxicity against MCF-7 cell line with an IC50 value of 25 ± 0.9 µM.

Penctrimertone, a bioactive citrinin dimer from the endophytic fungus Penicillium sp. T2-11.

Penctrimertone (1), a novel citrinin dimer bearing a 6/6/6/6 tetracyclic ring scaffold, along with two known compounds xerucitrinic acid A (2) and citrinin (3) were isolated from the endophytic fungus Penicillium sp. T2-11. Their structures were unequivocally established by a comprehensive interpretation of the spectroscopic data, with the stereochemistry for 1 was defined by a combination of TDDFT-ECD calculations and the DP4+ probability analysis based on NMR chemical shift calculations. Bioassays revealed that compound 1 exhibited noticeable antimicrobial activities and moderate cytotoxicity. A plausible biosynthetic pathway of 1 was also proposed.

Peniterester, a carotane-type antibacterial sesquiterpene from an artificial mutant Penicillium sp. T2-M20.

Peniterester (1), a new tricyclic sesquiterpene, together with 6 known compounds (2-7) were isolated from the secondary metabolites of an artificial mutant Penicillium sp. T2-M20 which was obtained from the parental strain Penicillium sp. T2-8 via UV irradiation as well as nitrosoguanidine (NTG) induction. Peniterester was only produced by the mutant T2-M20 on the basis of LC-MS analysis. Meanwhile, the results of in vitro bioactivities screening indicated that peniterester owned obvious antibacterial activities against Bacillus subtilis, Escherichia coli and Staphylococcus aureus with MICs of 8.0, 8.0 and 4.0 µg/mL, respectively.

Protoilludane-type sesquiterpenoids from Armillaria sp. by co-culture with the endophytic fungus Epicoccumsp. associated with Gastrodia elata.

An investigation of a co-culture of the Armillaria sp. and endophytic fungus Epicoccum sp. YUD17002 associated with Gastrodia elata led to the isolation of eight new compounds, including five protoilludane-type sesquiterpenes (1-5) and three aryl esters (6-8), together with six known analogues (9-14). The assignments of their structures were conducted via extensive analyses of the spectroscopic data and comparison of experimental and calculatedelectronic circular dichroism(ECD)data. Notably, these new compounds were not present in the pure culture controls and were only detected in the co-cultures. Compound 4 is the first example of an ent-protoilludane sesquiterpenoid scaffold bearing a five-membered lactone. Compound 6 exhibited moderate in vitro cytotoxic activities against five human cancer cell lines (HL-60, A549, MCF-7, SMMC-7721, and SW480) with IC50 values ranging from 15.80 to 23.03 µM. Moreover, 6 showed weak acetylcholinesterase inhibitory activity (IC50 value of 23.85 µM).

Involvement of xanthine oxidase and paraoxonase 1 in the process of oxidative stress in nonalcoholic fatty liver disease.

Xanthine oxidase (XOD) and paraoxonase 1 (PON1) are important enzymes in redox reactions in vivo, and are predominantly synthesized by the liver. The aim of the present study was to investigate the redox state in nonalcoholic fatty liver disease, and determine the association between the activities of XOD and PON1 and the severity of NAFLD. Sprague­Dawley rats were randomly divided into control, model and α­lipoic acid (high and low dose) groups. The rats in the NAFLD model were induced by feeding a high fat diet for 12 weeks and the in vitro cell model of hepatocyte steatosis was induced by treating L­02 cells with oleic acid for 24 h. The body weight, liver function, lipid and oxidative stress indices, and histological features of the liver were examined in the rats. Compared with the control group, the rats in the NAFLD model group showed impaired liver function, lipid disorders and damage from oxidative stress. The serum activity of XOD increased significantly from the 4th week and was markedly higher, compared with that in the control group, reaching a peak in the 12th week. The activity of PON1 was negatively correlated with that of XOD. Compared with the control cells, the activity of XOD and levels of free­fatty acids were significantly higher, and the activity of PON1 was significantly lower in the NAFLD L­02 cell model. All the above indicators were significantly improved by treatment with the antioxidant, α­lipoic acid. The activities of XOD and PON1 may be promising as markers in a noninvasive approach for detecting the severity of NAFLD clinically. α­lipoic acid had protective effects on the NAFLD rats, and the potential mechanism may be associated with the inhibition of oxidative stress and lipid peroxidation.

Clinical utility of haptoglobin in combination with CEA, NSE and CYFRA21-1 for diagnosis of lung cancer.

PURPOSE: To investigate the clinical value in lung cancer of a combination of four serum tumor markers, haptoglobin (Hp), carcinoembryonic antigen (CEA), neuron specific enolase (NSE) as well as the cytokeratin 19 fragment (CYFRA21-1). MATERIALS AND METHODS: Serum Hp (with immune-turbidimetric method), CEA, NSE, CYFRA21-1 (with chemiluminescence method) level were assessed in 193 patients with lung cancer, 87 patients with benign lung disease and 150 healthy controls. Differences of expression were compared among groups, and joint effects of these tumor markers for the diagnosis of lung cancer were analyzed. RESULTS: Serum tumor marker levels in patients with lung cancer were obviously higher than those with benign lung disease and normal controls (p<0.01). The sensitivities of Hp, CEA, NSE and CYFRA21-1 were 43.5%, 40.9%, 23.3% and 41.5%, with specificities of 90.7%, 99.2%, 97.9% and 97.9%. Four tumor markers combined together could produce a positive detection rate of 85.0%, significantly higher than that of any single test. With squamous carcinomas, the positive detection rates with Hp and CYFRA21-1 were higher than that of other markers. In the adenocarcinoma case , the positive detection rate of CEA was higher than that of other markers. For small cell carcinomas, the positive detection rate of NSE was highest. The area under receiver operating characteristic curve (AUCROC) of Hp in squamous carcinoma (0.805) was higher than in adenocarcinoma (0.664) and small cell carcinoma (0.665). CONCLUSIONS: Hp can be used as a new serum tumor marker for lung cancer. Combination detection of Hp, CEA, NSE and CYFRA21-1 could significantly improve the sensitivity and specificity in diagnosis of lung cancer, and could be useful for pathological typing.

Overexpression of tumstatin in genetically modified megakaryocytes changes the proangiogenic effect of platelets.

BACKGROUND: Thrombocytopenia is a common side effect of tumor chemotherapy, the main management approach to which is based on platelet (PLT) transfusion. However, PLTs, containing angiogenesis regulators, play a major role in boosting tumor growth and metastasis. The purpose of the study was to determine whether PLTs have the capacity to overexpress tumstatin by modified megakaryocyte (MK) and PLT precursors using lentivirus-mediated gene transfer, which might lead to alteration in proangiogenic effect of PLTs. STUDY DESIGN AND METHODS: CD34+ hematopoietic stem cells (HSCs) were transduced with recombinant lentivirus carrying tumstatin and induced to produce MKs and PLTs in the culture medium containing a cytokine cocktail. Flow cytometry and aggregation test were used to detect the generation and function of MKs and PLTs. Western blot analysis and confocal microscopy were applied to examine the expression and distribution of tumstatin in transgenic MKs and PLTs. Capillary tube formation of human umbilical vein endothelial cells (HUVECs) was used to evaluate the inhibitory effect of transgenic PLTs. RESULTS: CD34+ HSCs can be efficiently transduced with lentivirus vectors and successfully differentiated into MKs and PLTs. Large amounts of functional MKs and PLTs could be generated and had correct biologic characteristics. The tests demonstrated the feasibility of tumstatin expression in MKs and PLTs under control of the cytomegalovirus promoter, that thus tumstatin was stored in the α-granules of PLTs, and that the releasate of thrombin or A543 cell-stimulated transgenic PLTs obviously inhibited the growth of capillary tube network structures of HUVECs. CONCLUSION: Gene-modified CD34+ HSCs not only successfully differentiated into MKs and PLTs but also expressed tumstatin protein. Release of tumstatin in transgenic PLT granules led to antiangiogenic effect of PLTs.