Increased thoracic fluid content is associated with higher risk for pneumonia in patients undergoing maintenance hemodialysis.

BACKGROUND: Pneumonia is the most common infectious disease in patients undergoing maintenance hemodialysis (MHD). The aim of this study is to determine the possible predictive value of thoracic fluid content (TFC) for pneumonia in this population. METHOD: Clinical data were recorded for 1412 MHD patients who were hospitalized for certain comorbidities or complications. Each patient underwent an impedance cardiography (ICG) examination before next dialysis session after admission. Patients were divided into Having-, Will-have-, and Non-pneumonia groups based on whether they had pneumonia at the time of ICG examination after the admission and within five months after the examination. Hemodynamic parameters and other clinical data were compared and analyzed. RESULTS: Patients who were going to develop pneumonia were older, and had a higher proportion of diabetes, poorer nutritional status, a higher level of inflammatory, poorer cardiac function, and more fluid volume load than those who did not develop pneumonia. Multivariate binary logistic analysis revealed that for each 1/KΩ increase in TFC and 1 increase in neutrophil-to-lymphocyte ratio (NLR), the risk of the development of pneumonia increased by 3.1% (p ˂ 0.01) and 7.2% (p = 0.035), respectively, whereas for each 1 g/L increase in hemoglobin and 1 g/L increase in serum albumin, the risk of the development of pneumonia decreased by 1.3% (p = 0.034) and 5% (p = 0.048), respectively. CONCLUSIONS: TFC, NLR, hemoglobin, and serum albumin were independent risk factors for the development of pneumonia in MHD patients. Given the advantages of ICG, TFC can be used clinically as a helpful predictor of pneumonia in MHD patients.

Urinary mitochondrial DNA: A potential early biomarker of diabetic nephropathy.

BACKGROUND: Mitochondrial dysfunction and chronic sterile inflammation are common features of type 2 diabetes. Therefore, we aimed to investigate whether mitochondrial DNA (mtDNA) could be a biomarker implicated in the progression of type 2 diabetes and diabetic nephropathy and explore the underlying mechanism. MATERIAL AND METHODS: We developed a method for relative quantification of mtDNA content in clinical practice. qRT-PCR was used to measure the mtDNA content both in vivo in CD-1 mice with diabetes induction by streptozotocin and in vitro in murine endothelial cells and conditionally immortalized mouse podocytes. By pumping mtDNA into the mouse circulation, the effect of mtDNA on the kidney was assessed in mice. In patients with type 2 diabetes (n = 42; 24 males; mean age 57.9 ± 12.00 years), plasma mtDNA was evaluated. RESULTS: Plasma mtDNA content was significantly decreased in patients with type 2 diabetes, particularly those with significant proteinuria. In vitro, high glucose treatment suppressed intracellular mtDNA content and facilitated the extracellular release of mtDNA, so excessive circulatory mtDNA induced by high glucose might be filtered through the kidney and then into urine. Indeed, urinary mtDNA content was significantly increased in both diabetic patients and mice. Moreover, by pumping excess mtDNA into circulation in mice, filtered mtDNA could trigger inflammation and induce kidney injury. CONCLUSION: Excessive mtDNA filtered through the kidney under diabetic conditions may be involved in chronic renal inflammation. Reduced plasma mtDNA content and increased urinary mtDNA/creatinine ratio might play a potential role as an early biomarker of diabetic nephropathy.

Changes in bone mineral density after total parathyroidectomy without autotransplantation in the end-stage renal disease patients with secondary hyperparathyroidism.

BACKGROUND: The patients with secondary hyperparathyroidism (SHPT) usually had reduced bone mineral density, which might lead to a substantial increase in osteoporosis, fracture and mortality. Although surgical intervention is effective in reducing parathyroid hormone (PTH) levels in suitable candidates refractory to medical therapy, the effect of surgery on bone mass changes still requires further evaluation. Thus, the aim of this study was to evaluate the characteristics of BMD changes after total parathyroidectomy (PTX) without autotransplantation and its associated factors. METHODS: The records of 34 patients who underwent successful total PTX without autotransplantation with a preoperative and postoperative dual energy X-ray absorptiometry (DEXA) scan in our institution within 4 years of operative intervention were reviewed. Correlation and regression analysis were used to identify factors that independently predict BMD changes. RESULTS: At baseline, we found that the prevalence of osteoporosis seemed to be much higher in the load-bearing lumbar spine than in the hip, varying greatly even between different lumbar vertebrae. The bone loss in SHPT had its predilection site in the load-bearing cancellous bone. After curative total PTX without autotransplantation, BMD improved significantly in both lumbar spine and hip overall. The largest increase in BMD occurred at L4 vertebrae with the lowest pre-operative BMD. At the most affected site L4, BMD improved in up to 94.1% of patients: 86.2% had significant improvement, 5.9% moderate improvement, and 5.9% declining bone mineral density. Correlation and regression analysis suggested that percentage changes in BMD were predicted negatively by the preoperative BMD and positively by the preoperative parathyroid mass but not intact PTH levels. CONCLUSION: Total parathyroidectomy without autotransplantation could improve BMD of secondary hyperparathyroidism at L1-L4 and the hip. Furthermore, the large parathyroid glandular mass and the preoperative BMD predicted the BMD changes after surgery.

PDE/cAMP/Epac/C/EBP-ß Signaling Cascade Regulates Mitochondria Biogenesis of Tubular Epithelial Cells in Renal Fibrosis.

AIMS: Cyclic adenosine 3'5'-monophosphate (cAMP) is a universal second messenger that plays an important role in intracellular signal transduction. cAMP is synthesized by adenylate cyclases from adenosine triphosphate and terminated by the phosphodiesterases (PDEs). In the present study, we investigated the role of the cAMP pathway in tubular epithelial cell mitochondrial biogenesis in the pathogenesis of renal fibrosis. RESULTS: We found that the cAMP levels were decreased in fibrotic kidney tissues, and replenishing cAMP could ameliorate tubular atrophy and extracellular matrix deposition. The downregulation of cAMP was mainly attributed to the increased PDE4 expression in tubular epithelial cells. The inhibition of PDE4 by PDE4 siRNA or the specific inhibitor, rolipram, attenuated unilateral ureteral obstruction-induced renal interstitial fibrosis and transforming growth factor (TGF)-ß1-stimulated primary tubular epithelial cell (PTC) damage. The Epac1/Rap1 pathway contributed to the main effect of cAMP on renal fibrosis. Rolipram could restore C/EBP-ß and PGC-1α expression and protect the mitochondrial function and structure of PTCs under TGF-ß1 stimulation. The antifibrotic role of rolipram in renal fibrosis relies on C/EBP-ß and PGC-1α expression in tubular epithelial cells. Innovation and Conclusion: The results of the present study indicate that cAMP signaling regulates the mitochondrial biogenesis of tubular epithelial cells in renal fibrosis. Restoring cAMP by the PDE4 inhibitor rolipram may ameliorate renal fibrosis by targeting C/EBP-ß/PGC1-α and mitochondrial biogenesis. Antioxid. Redox Signal. 29, 637-652.

UCP2 attenuates apoptosis of tubular epithelial cells in renal ischemia-reperfusion injury.

Uncoupling protein-2 (UCP2) plays critical roles in energy metabolism and cell survival. Previous investigations showed that UCP2 regulated the production of extracellular matrix and renal fibrosis. However, little is known about UCP2 in acute kidney injury (AKI). Here, we used Ucp2 knockout mice to investigate the role of UCP2 in an AKI model generated by renal ischemia-reperfusion (I/R) injury. The Ucp2 global knockout mice were born and grew normally without kidney histological abnormality or renal dysfunction. Compared with littermates, deletion of Ucp2 exacerbated I/R-induced AKI whereas increase of UCP2 by conjugated linoleic acid (CLA) attenuated I/R injury. Tubular cell apoptosis and autophagy were induced by I/R. After injury, more tubular cell apoptosis and less autophagy were identified in the kidneys of knockout mice compared with their littermates, and less apoptosis and more autophagy were observed in mice fed with CLA. In vitro rotenone, an inhibitor of electron transport chain complex I, was applied to induce energy depletion in cultured tubular epithelial cells. As expected, rotenone-recovery (R/R) treatment induced tubular cell apoptosis and autophagy. UCP2 plasmid transfection reduced cell apoptosis and facilitated autophagy after R/R treatment, whereas UCP2 small interfering RNA (siRNA) transfection sensitized cell apoptosis but reduced autophagy induced by R/R treatment. Interference of autophagy by treatment with autophagy inhibitor 3-methyladenine or autophagy initiation protein Beclin-1 siRNA transfection resulted in tubular cell apoptosis. Thus UCP2 attenuates I/R-induced AKI, probably by reducing cell apoptosis through protection of autophagy.

Two-stage model of chemically induced hepatocellular carcinoma in mouse.

The aim of this study was to develop an efficient and reproducible mouse model for hepatocellular carcinoma (HCC) research and assess the expression of two proto-oncogenes (c-myc and N-ras) and tumor suppressor gene p53 in the carcinogenic process. In this study, we found that diethylnitrosamine initiation with CCl4 and ethanol promotion could induce a short-term, two-stage liver carcinogenesis model in male BALB/c mice, the process of hepatocarcinogenesis including liver damage, liver necrosis/cell death, liver inflammation, liver proliferation, liver hyperplasia, liver steatosis, and liver cirrhosis and hepatocellular nodules, which mimicked the usual sequence of events observed in human HCC. We also identified that the increase in expression of the p53 gene is related to the proliferation of hepatocytes, whereas overexpression of the c-myc and N-ras genes is associated with hepatocarcinogenesis. This animal model may serve as a basis for recapitulating the molecular pathogenesis of HCC seen in humans.

[Dendritic cell vaccine modified by murine mAFP gene enhances immunoprotective effect on liver carcinogenesis and tumor development in mice].

OBJECTIVE: To construct a dendritic cell vaccine transduced by murine alpha-fetoprotein (mAFP) gene, and evaluate its immunoprotective effect on C57BL/6J mice during the induction of hepatocellular carcinoma by diethylnitrosamines, carbon tetrachloride and ethanol. METHODS: Dendritic cells (DCs) were induced and augmented by murine IL-4 and GM-CSF, and transfected by recombinant adenovirus engineered with mAFP gene. Major MHC class I and II, B7.1 (CD80), B7.2 (CD86), CD18a, and CD54 molecules on DC were analyzed by FACS. 80 C57BL/6J male mice were randomly divided into 4 groups (20 mice per group): Simple DC inoculated group, pAdBM5-mAFP-DC inoculated group, pAdBM5-mAFP plasmid inoculated group, and PBS control group. They were immunized once with 5 x 10(5) DCs (0.1 ml)/mouse administered s. c. in the left flank or 100 mg pAdBMS-mAFP plasmid/mouse administered i. m. in the left tibialis anterior muscle. Inoculation was conducted once a week for 4 weeks after 3 times consecutive immunization initially. At the same time of immunization, DEN/CCl4/ethanol were given to induce hepatocellular carcinoma. Tumor incidence was assessed after 20 weeks. RESULTS: A transgenic DC vaccine was successfully constructed and the mAFP transgenic DCs expressed high level molecules of major MHC class I and II , B7.1, B7.2, CD18a, and CD54. After the 20-week induction, the incidence of primary hepatocellular carcinoma (PLC) was 70.0% in simple DC inoculated group, 25.0% in pAdBMS-mAFP-DC inoculated group, 65.0% in pAdBM5-mAFP plasmid inoculated group, and 75.0% in PBS control group. There was a significant difference between group B and other groups (P < 0.05). CONCLUSION: mAFP transgenic DC tumor vaccine inoculation may induce strong immunoprotection against liver carcinogenesis and tumor development and reduce PLC incidence induced by DEN/CCl4/ethanol.

[Effects of hMIP-1beta gene modification on in vivo tumorigenicity and vaccine efficacy of tumor cells].

UNLABELLED: OBJECTIVE To explore the effects of human macrophage inflammatory protein-1 beta (hMIP-1beta) modification on the in vivo tumorigenicity and vaccine efficacy of tumor cells. METHODS: Murine colorectal adenocarcinoma CT26 cells were transfected with a recombinant adenovirus carring the hMIP-1beta gene (AdhMIP-1beta). The efficacy of gene transfection was tested by X-gal staining. The hMIP-1beta level in the supernatant of hMIP-1beta gene-modified CT26 cells was assayed by ELISA, and the chemotactic activity for CD4+ T cells, CD8+ T cells, NK cells and immature dendritic cells (imDCs) were assayed by a transwell chamber. The changes of growth characteristics and in vivo tumorigenicity of hMIP-1beta gene-modified CT26 cells were also assessed. BALB/c mice were immunized with hMIP-1beta gene-modified CT26 tumor vaccine and the antitumor effect was evaluated. RESULTS: hMIP-1beta gene could be transfected into CT26 cells by AdhMIP-1beta with an efficiency over 95%. The level of hMIP-1beta in the culture supernatant of hMIP-1beta gene-modified CT26 cells was 980 pg/ml and the supernatant displayed ramarkable chemotactic activity to CD4+ T cells, CD8+ T cells, NK cells and imDCs compared with LacZ gene-modified CT26 cells and control. When the hMIP-1beta gene-modifited CT26 cells were subcutaneously inoculated in BALB/c mice, the tumorigencity was delayed and suppressed, and overt necrosis and lymphocyte infiltration were observed in the tumor tissue, but not in those inoculated with LacZ gene-modified CT26 cells or parental CT26 cells. The mice immunized with hMIP-1beta gene-modified CT26 tumor vaccine could induce tumor specific CTL activity and nonspecific NK activity, and exhibited resistance to later challenge with wild-type CT26 cells. CONCLUSION: hMIP-1beta gene-modified CT26 cells exhibit decreased tumorigenicity, and hMIP-1beta gene-modified tumor vaccine may induce a powerful specific and nonspecific antitumor response. The data suggested that hMIP-1beta gene-modified tumor vaccine may play a potent role in prevention of metastasis and recurrence of malignant tumors.

Influence of irbesartan on expression of ILK and its relationship with epithelial-mesenchymal transition in mice with unilateral ureteral obstruction.

AIM: Irbesartan, a new antagonist of the type 1 angiotensin II receptor, has been proven to be renal protective in both diabetic and non-diabetic nephropathy, but its exact mechanism is still uncertain. Here we investigated the influence of irbesartan on the expression of the integrin-linked kinase (ILK) and its relationship with epithelial-mesenchymal transition (EMT) in mice with unilateral ureteral obstruction (UUO). METHODS: The mice were randomly divided into 3 groups: sham operation (C, n=20), UUO (n=40), and UUO with irbesartan treatment (UUO+irbesartan, n=40). Irbesartan was given at a dose of 50 mg/kg body weight per day by gavage. The experimental animals in the control group received the same volume of vehicle (0.9% saline solution). The animals were sacrificed at d 1, 3, 7, and 14, respectively, after the surgery. RESULTS: The expression of the ILK at mRNA and protein levels were significantly increased in the UUO group 1 d after the surgery, which was significantly decreased by treatment with irbesartan (P<0.01, respectively). The expression of alpha-smooth muscle actin (alpha-SMA) was significantly increased, while E-cadherin was decreased in mice with UUO at d 3 after the surgery. Treatment with irbesartan significantly abrogated such effects (P<0.01). The immunohistochemistry analysis indicated that the protein expression of the ILK was positively correlated with alpha-SMA, but negatively with E-cadherin. CONCLUSION: These results suggested that irbesartan attenuated renal tubulointerstitial fibrosis in UUO mice, which may be related to the inhibition of ILK expression, subsequently preventing the tubular EMT.

[Role of integrin-linked kinase in renal tubular epithelial-mesenchymal transition of mice with obstructive nephropathy].

OBJECTIVE: To investigate the expression of integrin-linked kinase (ILK) in kidneys of mice with unilateral ureteral obstruction and its relevance with the epithelial-mesenchymal transition. METHODS: Mice were randomly divided into two groups, sham operation (C, n = 20) and unilateral ureteral obstruction (UUO, n = 40). The animals were sacrificed at day 1, 3, 7 and 14 respectively after the surgery. Tubulointerstitial fibrosis (TIF) was graded according to Masson staining. The protein level of ILK was examined by Western blot. Tissue/cytological expression for ILK, alpha-SMA and E-cadherin were investigated by immunohistochemistry. The mRNA levels of ILK, alpha-SMA and E-cadherin were analyzed by quantitative real-time PCR. RESULTS: In the control animals (group C), weak staining for ILK was detected mainly in the podocytes. Significant increase of staining for ILK in the experimental mice (UUO group) was detected from day 1 onward (t = 16.5, P < 0.01), reaching the peak at day 7. The protein expression of E-cadherin was continuously down-regulated from day 3 onward after surgery (t = 21.0, P < 0.01), while expression for alpha-SMA was up-regulated. From day 1 to day 7, the protein expression of ILK was positively correlated with alpha-SMA (R = 0.88, P < 0.01), but negatively correlated with E-cadherin (R = -0.87, P < 0.01). The mRNA expression of ILK and alpha-SMA analyzed by real-time PCR increased from postoperative day 1 and 3 respectively, but the mRNA expression of E-cadherin decreased from day 3 onward. CONCLUSION: Increasing expression of ILK occurs in the early phase of UUO mouse and may play an important role in the process of TIF through mediating the epithelial-mesenchymal transition.