Inhibition of hexokinase 2 with 3-BrPA promotes MDSCs differentiation and immunosuppressive function.

The adoptive transfer of ex vivo generated myeloid-derived suppressor cells (MDSCs) may be a promising therapeutic strategy for preventing allograft rejection after solid organ transplantation. Currently, the precise role of immune-metabolic pathways in the differentiation and function of MDSCs is not fully understood. Hexokinase 2 (HK2) is an isoform of hexokinase and is a key enzyme involved in the increased aerobic glycolysis of different immune cells during their activation and function. Here, we demonstrate that the addition of HK2 inhibitor 3-Bromopyruvic acid (3-BrPA) into traditional MDSCs induction system in vitro significantly promoted MDSCs production and enhanced their immunosuppressive function. Treatment with 3-BrPA increased the expression of MDSC-related immunosuppressive molecules, such as iNOS, Arg1, and CXCR2. Moreover, the adoptive transfer of 3-BrPA-treated MDSCs significantly prolonged the survival time of mouse heart allografts. This study provides a novel strategy to solve the problems of harvesting enough autologous cells for MDSC production from sick patients, and producing functionally enhanced MDSCs for preventing graft rejection and inducing tolerance.

Personalized management of anastomotic leak after surgery for esophageal carcinoma.

OBJECTIVE: To summarize the management of anastomotic leak following surgery for esophageal carcinoma. METHODS: The medical records of the patients developing digestive tract leak after surgery for esophageal carcinoma in our hospital from January 2003 to March 2011 were retrospectively analyzed. RESULTS: A total of 36 patients were included, in whom 13 developed cervical anastomotic leak, 18 had intra-thoracic anastomotic leak, and 5 had intra-thoracic gastric necrosis. Of these patients, 7 were treated with resurgery, 6 with esophageal stent implantation, and 23 with conservative treatment. Treatment lasted for 5 to 181 days, averagely 47.0 +/- 31.9 days. After management, 9 patients died (25.0%). Among seven patients with resurgery, four had deceased, two were cured, and one developed leak again and was switched to conservative treatment until discharged. All the 6 patients treated with stent implantation were cured. Of the 24 patients receiving conservative treatment (including one switched from resurgery), 18 (75.0%) were cured and 1 was not cured but survived. CONCLUSIONS: Anastomotic leak following surgery for esophageal carcinoma should be treated individually based on the onset time, location, size, and extent of the leakage. Conservative treatment is still a safe and effective method. The efficacy of stent implantation needs further investigation to confirm.

Ketogenic Diet Suppressed T-Regulatory Cells and Promoted Cardiac Fibrosis via Reducing Mitochondria-Associated Membranes and Inhibiting Mitochondrial Function.

Ketogenic diet (KD) is popular in diabetic patients but its cardiac safety and efficiency on the heart are unknown. The aim of the present study is to determine the effects and the underlined mechanisms of KD on cardiac function in diabetic cardiomyopathy (DCM). We used db/db mice to model DCM, and different diets (regular or KD) were used. Cardiac function and interstitial fibrosis were determined. T-regulatory cell (Treg) number and functions were evaluated. The effects of ketone body (KB) on fatty acid (FA) and glucose metabolism, mitochondria-associated endoplasmic reticulum membranes (MAMs), and mitochondrial respiration were assessed. The mechanisms via which KB regulated MAMs and Tregs were addressed. KD improved metabolic indices in db/db mice. However, KD impaired cardiac diastolic function and exacerbated ventricular fibrosis. Proportions of circulatory CD4+CD25+Foxp3+ cells in whole blood cells and serum levels of IL-4 and IL-10 were reduced in mice fed with KD. KB suppressed the differentiation to Tregs from naive CD4+ T cells. Cultured medium from KB-treated Tregs synergically activated cardiac fibroblasts. Meanwhile, KB inhibited Treg proliferation and productions of IL-4 and IL-10. Treg MAMs, mitochondrial respiration and respiratory complexes, and FA synthesis and oxidation were all suppressed by KB while glycolytic levels were increased. L-carnitine reversed Treg proliferation and function inhibited by KB. Proportions of ST2L+ cells in Tregs were reduced by KB, as well as the production of ST2L ligand, IL-33. Reinforcement expressions of ST2L in Tregs counteracted the reductions in MAMs, mitochondrial respiration, and Treg proliferations and productions of Treg cytokines IL-4 and IL-10. Therefore, despite the improvement of metabolic indices, KD impaired Treg expansion and function and promoted cardiac fibroblast activation and interstitial fibrosis. This could be mainly mediated by the suppression of MAMs and fatty acid metabolism inhibition via blunting IL-33/ST2L signaling.

Metformin Attenuates Cyclosporine A-induced Renal Fibrosis in Rats.

BACKGROUND: The aim of the present study was to investigate the therapeutic potential of metformin in preventing cyclosporine A (CsA)-induced nephrotoxicity. METHODS: Three groups of adult male Sprague-Dawley rats were treated with vehicle, CsA, and CsA + metformin for 4 weeks following 1 week on low sodium diet, respectively. At the end of treatment, all animals were euthanized, and the samples of kidney, urine, and blood were collected for functional, morphological, and molecular biological evaluation. RESULTS: Metformin effectively prevented CsA-induced renal dysfunction with increased creatinine clearance rate and reduced blood urea nitrogen and serum creatinine, as well as less proteinuria in comparison to the CsA group. Morphologically, metformin ameliorated CsA-induced renal fibrosis and tissue collapse in the areas of arteries, glomeruli, and proximal tubules. We further demonstrated that the antifibrotic effects of metformin in kidneys treated with CsA were associated with decreased phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). CONCLUSIONS: In conclusion, our study revealed new therapeutic potential of metformin to attenuate calcineurin inhibitor-induced renal fibrosis, which was closely related to the suppression of MEK/ERK1/2 pathway.

[bcl-2 expression in small cell lung cancer: a mechanism for apoptosis antagonism and immune evasion].

OBJECTIVE: To observe bcl-2 expression and its correlation with apoptosis antagonism and immune evasion of small cell lung cancer cell line and explore the application of bcl-2 antisense thio-oligonucleotide (bcl-2 SON) in gene therapy for lung cancer. METHODS: Western blotting was performed to detect bcl-2 expression in NCI-H69 cell line expressing Bcl-2 protein treated with bcl-2 SON. The treated NCI-H69 cells, along with the cells without bcl-2 SON treatment and NCI-H82 cells that did not express Bcl-2 protein, were respectively co-cultured with tumor-infiltrating lymphocytes (TILs) isolated from fresh tumor samples, and the apoptosis of the lung cancer cells was assessed by JAM assay. RESULTS: Western blotting revealed obvious inhibition of bcl-2 expression in NCI-H69 cells in response to bcl-2 SON treatment. JAM assay showed that the apoptosis of bcl-2 SON-treated H69 cells and NCI-H82 cells increased with the elevation of TIL ratio in the co-culture, while such changes were not observed in NCI-H69 cells without bcl-2 SON treatment. CONCLUSION: Small cell lung cancer cells expressing bcl-2 may antagonize the antitumor immune attack in the host, and bcl-2 SON may provide an effective alternative in gene therapy for small cell lung cancer.