Intestinal Cckbr-specific knockout mouse as a novel model of salt-sensitive hypertension via sodium over-absorption.

OBJECTIVES: To investigate the value of CCKBRfl/fl villin-Cre mice as a mouse model of salt-sensitive hypertension (SSH). METHODS: In the first part, 2-month-old CCKBRfl/fl villin-Cre mice (CKO) and control CCKBRfl/fl mice (WT) were fed with normal diet (0.4% NaCl) or high salt diet (4% NaCl), separately for 6 weeks. In the rescue study, one week of hydrochlorothiazide or saline injection were treated with the CKO mice fed high salt diet. The blood pressure, biochemical indexes, and the expression of small intestinal sodium transporters (NHE3, NKCC1, eNaC) was detected. The organ injury markers (MMP2/MMP9) and the histopathological changes of kidneys were observed, whereas the changes of duodenal sodium absorption were detected by small intestinal perfusion in vivo. RESULTS: The CCKBRfl/fl villin-Cre mice with high salt intake exhibited high blood pressure, increased duodenal sodium absorption and urinary sodium excretion, and with renal injury. The protein expression of NHE3, NKCC1 and eNaC were also significant increase in the intestine of CKO-HS mice. Treatment with hydrochlorothiazide remarkably attenuated the elevated blood pressure by high salt absorption in the CCKBRfl/fl villin-Cre mice, but no significant histopathological changes were observed. CONCLUSIONS: These results support a crucial role of intestinal Cckbr deficiency on SSH development and the diuretic antihypertension effect in CCKBRfl/fl villin-Cre mice. The CCKBRfl/fl villin-Cre mice with the high salt intake may serve as a stable model of salt-sensitive hypertensive induced by sodium overloading.

P-selectin glycoprotein ligand 1 deficiency prevents development of acute pancreatitis by attenuating leukocyte infiltration.

BACKGROUND: Acute pancreatitis (AP) is rapid-onset pancreatic inflammation that causes local and systemic inflammatory response syndrome (SIRS) with high morbidity and mortality, but no approved therapies are currently available. P-selectin glycoprotein ligand 1 (PSGL-1) is a transmembrane glycoprotein to initiate inflammatory responses. We hypothesized that PSGL-1 may be involved in the development of AP and would be a new target for the treatment of AP. AIM: To investigate the role and mechanism of PSGL-1 in the development of AP. METHODS: The PSGL-1 expression on leukocytes was detected in peripheral blood of AP patients and volunteers. Pancreatic injury, inflammatory cytokines expression, and inflammatory cell infiltration was measured in AP mouse models induced with PSGL-1 knockout (PSGL-1 -/-) and wild-type (PSGL-1 +/+) mice. Leukocyte-endothelial cell adhesion was measured in a peripheral blood mononuclear cell (PBMC)-endothelial cell coculture system. RESULTS: The expression of PSGL-1 on monocytes and neutrophils was significantly increased in AP patients. Compared with PSGL-1 +/+ mice, PSGL-1 -/- AP mice induced by caerulein exhibited lower serum amylase, less Interleukin-1beta (IL-1beta) and Interleukin-6 (IL-6) expression, less neutrophil and macrophage infiltration, and reduced peripheral neutrophil and monocyte accounts. PSGL-1 deficiency alleviated leukocyte-endothelial cell adhesion via IL-6 but not IL-1beta. CONCLUSION: PSGL-1 deficiency effectively inhibits the development of AP by preventing leukocyte-endothelial cell adhesion via IL-6 stimulation and may become a potential therapeutic target for treating AP.

[Purification Efficiency and Microbial Characteristics of Four Biofilters Operated Under Different Conditions].

To explore the effects of aeration, microbial acclimation period, and pool shape or flow pattern change on the purification efficiency of biofilters at the microbiological level, four biofilters with different working conditions, that is, MAVF, NAVF, NVF, and BHF, were studied. The first three are vertical-flow biofilters and the last one is a baffled-flow biofilter. The four filters filled with the same ceramsite were made of organic glass. The MAVF filter was connected with the BHF filter in series and was operated for one year prior to the trial. The NAVF and NVF filters are newly activated filters. The four filters that were used to treat domestic sewage were synchronously operated in batch mode in this study. The MAVF and NAVF filters were intermittently aerated in contrast to the other two. During the period of microbial acclimation of the newly activated filters, the purification efficiency of the four filters was continuously monitored and the microbial community structure characteristics were analyzed at the end of microbial acclimation. The results show that the purification efficiency of the three vertical-flow filters is significantly higher than that of the horizontal-flow one and aeration significantly enhances the purification efficiency. However, aeration has a weaker effect on the efficiency than the microbial maturity of the filter. An apparent accumulation of nitrates or nitrites in the four filters was not observed, indicating that the denitrification was rather thorough. The 16S rDNA high-throughput sequencing analysis shows that the diversity index of the four filters is BHF > MAVF > NAVF > NVF, indicating that the more mature the filter is, the higher is the diversity index. Most of the packing microorganisms are facultative heterotrophic bacteria and the most abundant are heterotrophic denitrifying bacteria. Heterotrophic nitrification occurs in the NVF and BHF filters and aeration promotes the enrichment of aerobic ammonium-oxidizing bacteria. Aerobic phosphorus-accumulating organisms were not detected in the four filters. Therefore, phosphorus was mainly removed via denitrifying phosphorus accumulation. Under the test conditions, the removal rate of total nitrogen was not high, mainly because nitrifying bacteria were not enriched in the filter or their abundance was insufficient. The latter resulted in the limited ammonium-oxidizing ability of the filter, thus affecting the removal of total nitrogen. The above-mentioned results show that the adjustment of different working conditions will affect the redox status and associated enrichment of functional bacteria inside the biofilter, which will ultimately affect the purification efficiency.

Targeting renal cell carcinoma with gambogic acid in combination with sunitinib in vitro and in vivo.

PURPOSE: To evaluated the effect of the gambogic acid (GA), one of the effective components of Garcinia, in combination with a new multi-targeted oral medication, sunitinib (SU) on renal cancer cell proliferation in vitro and on tumor growth in vivo. METHODS: After treatment with GA or SU, either alone or in combination, MTT and FACS analysis were used to examine cell viability and cycle distribution of the renal carcinoma cell lines 786-0 and Caki-1. Western blotting was employed to examine the expression of proteins related to the cell cycle and vascular formation. Furthermore, a xenograft model was applied to study the antitumor efficacy of SU or GA alone or in combination, with immunohistochemistry to detect expression of proteins related to xenograft growth and angiogenesis. Western blotting was used to examine NF-?B signaling pathway elements in xenografts. RESULTS: Treatment of 786-0 and Caki-1 cells with GA or SU resulted in decreased tumor cell proliferation, especially with joint use. Cells accumulated more strongly in the sub-G1 phase after joint treatment with GA and SU than treatment of GA and SU alone. Western blotting arrays showed 1 protein significantly upregulated, 2 proteins downregulated, and 2 proteins unchanged. Moreover, combined use of GA and SU inhibited the growth and angiogenesis of xenografts generated from Caki-1 significantly. Immunohistochemistry arrays showed downregulation of the expression of proteins promoting xenograft growth and angiogenesis, and Western blotting showed inhibition of the NF-?B signaling pathway after treatment by GA alone and in combination with SU in xenografts. CONCLUSIONS: Our results show that the joint use of GA and SU can provide greater antitumor efficacy compared to either drug alone and thus may offer a new treatment strategy for renal cell carcinoma.